Crop Updates 2002 - Oilseeds

Research Library Crop Updates Grain and other field crop research 20-2-2002 Crop Updates 2002 - Oilseeds David Eksteen Department of Agriculture K. Neil Harker Agriculture and Agri-Food Canada George W. Clayton Agriculture and Agri-Food Canada Keith Downey Agriculture and Agri-Food Canada Keith Alcock Department of Agriculture Follow this and additional works at: https://researchlibrary.agric.wa.gov.au/crop_up the for Agribusiness Agronomy and Crop Sciences Commons, Aquaculture and SeePart nextof page additional Commons, authors Fisheries Commons, Botany Commons, Entomology Commons, Plant Breeding and Genetics Commons, and the Plant Pathology Commons Recommended Citation Eksteen, D, Harker, K N, Clayton, G W, Downey, K, Alcock, K, Walden, K, Addison, B, Carlton, P, Morthorpe, K, Addenbrooke, S, Ford, A, Zaheer, S H, Walton, G, Farré, I, Carmody, P, Fortescue, J A, Turner, D W, Tan, B, Campbell, M C, Pritchard, I, Bell, R W, Frost, K, Wong, M, Brennan, R, Jones, R, Hawkes, J, Thackray, D, Salam, M U, Khangura, R K, Diggle, A J, Barbetti, M, Michael, P, Berlandier, F, Valentine, C, Shea, G, Riethmuller, G, Alam, R, Hamilton, G, Hawksely, J, Smith, P, Neve, P, Flugge, F, Abadi, A, Powles, S, Glencross, B, Curnow, J, and Hawkins, W. (2002), Crop Updates 2002 - Oilseeds. Department of Agriculture, Perth. Conference Proceeding. This conference proceeding is brought to you for free and open access by the Grain and other field crop research at Research Library. It has been accepted for inclusion in Crop Updates by an authorized administrator of Research Library. For more information, please contact [email protected], [email protected], [email protected]. Authors David Eksteen, K. Neil Harker, George W. Clayton, Keith Downey, Keith Alcock, Kevin Walden, Beven Addison, Peter Carlton, Kevin Morthorpe, Stephen Addenbrooke, Alex Ford, S. Hasan Zaheer, G. Walton, Imma Farré, Paul Carmody, J. A. Fortescue, D. W. Turner, B. Tan, Margaret C. Campbell, Ian Pritchard, Richard W. Bell, K. Frost, Mike Wong, Ross Brennan, Roger Jones, Jenny Hawkes, Debbie Thackray, Moin U. Salam, Ravjit K. Khangura, Art J. Diggle, Martin Barbetti, Phil Michael, Françoise Berlandier, Chriatiaan Valentine, Greg Shea, Glen Riethmuller, Rafiul Alam, Greg Hamilton, Jo Hawksely, Patrick Smith, Paul Neve, Felicity Flugge, Amir Abadi, Stephen Powles, Brett Glencross, John Curnow, and Wayne Hawkins This conference proceeding is available at Research Library: https://researchlibrary.agric.wa.gov.au/crop_up/17 ISSN 1445-0592 2002 OILSEED UPDATES WESTERN AUSTRALIA PRESENTED AT THE SHERATON HOTEL, PERTH WESTERN AUSTRALIA, 20-21 FEBRUARY 2002 Compiled and edited by David Eksteen © Chief Executive Office Department of Agriculture, Western Australia 2002 Permission of the publisher is required for articles being reproduced or presented. Unregistered pesticides and uses: This document reports the results of some research where the product, or the use reported for that product, is not currently registered. Any discussion of these uses does not constitute a recommendation for that use. All pesticide use must be in accord with the registered uses for that product. OILSEED UPDATES, 2002 Table of Contents Page FOREWORD AND ACKNOWLEDGMENTS iii Dave Eksteen PLENARY SESSION 1. GMO canola - Track record in Canada Neil Harker, George W. Clayton and R. Keith Downey 1 2. GM canola - Prospects in Western Australia farming systems Keith Alcock 5 3. Diamondback moth (DBM) in canola Kevin Walden 11 CANOLA AGRONOMY 1. Getting the best out of canola in the low rainfall central wheatbelt Bevan Addison and Peter Carlton 14 2. Canola variety performance in Western Australia Kevin Morthorpe, Stephen Addenbrooke and Alex Ford 17 3. Relative performance of new canola varieties in Department of Agriculture variety trials in 2000 and 2001 S. Hasan Zaheer and Graham Walton 19 4. Which canola cultivar should I sow? Imma Farré and Bill Bowden 26 5. The effect of seed generation and seed source on yield and quality of canola Paul Carmody 28 6. The accumulation of oil in Brassica species J.A. Fortescue, D.W. Turner and B. Tan 30 7. Potential and performance of alternative oilseeds in WA Margaret C. Campbell 32 8. Comparison of oilseed crops in WA Ian Pritchard, Paul Carmody and Margaret C. Campbell 35 9. Identifying constraints to canola production Dave Eksteen 37 Boron - Should we be worried about it? Richard W. Bell, K. Frost, Mike Wong and Ross Brennan 40 10. PEST AND DISEASE 1. Yield losses caused when Beet Western Yellows Virus infects canola Roger Jones and Jenny Hawkes 42 2. Influence of climate on aphid outbreaks and virus epidemics in canola Debbie Thackray, Jenny Hawkes and Roger Jones 44 3. The annual shower of blackleg ascospores in canola: Can we predict and avoid it? Moin U. Salam, Ravjit K. Khangura, Art J. Diggle and Martin J. Barbetti 47 i Page 4. Environmental influences on production and release of ascospores of blackleg and their implications in blackleg management in canola Ravjit K. Khangura, Martin J. Barbetti , Moin U. Salam and Art J. Diggle 50 5. WA blackleg resistance ratings on canola varieties for 2002 Ravjit Khangura, Martin J. Barbetti and Graham Walton 55 6. Bronzed field beetle management in canola Phil Michael 57 7. DBM control in canola: Aerial versus boom application Paul Carmody 59 8. Effect of single or multiple spray treatments on the control of Diamondback moth (Plutella xylostella) and yield of canola at Wongan Hills Françoise Berlandier, Paul Carmody and Christiaan Valentine 62 9. GrainGuard - A biosecurity plan for the canola industry Greg Shea 64 ESTABLISHMENT 1. Large canola seed is best, particularly for deep sowing Glen Riethmuller, Rafiul Alam, Greg Hamilton and Jo Hawksley 66 2. Canola establishment with seed size, tines and discs, with and without stubble Glen Riethmuller, Rafiul Alam, Greg Hamilton and Jo Hawksley 68 WEEDS 1. Role for Roundup Ready® canola in the farming system Art Diggle, Patrick Smith, Paul Neve, Felicity Flugge, Amir Abadi and Stephen Powles 70 FEED 1. Getting value from canola meals in the animal feed industries: Aquaculture Brett Glencross, John Curnow and Wayne Hawkins ii 73 Foreword The 1999 season produced a record canola crop of 960,000 tonnes. The crop decreased in 2000 to 550,000 tonnes with the price of canola falling to around $300 per tonne. The price started rising markedly at the start of the 2001 season. The weather was not kind with large areas having late opening rains. Those that got off to an early start experienced a dry spell just after emergence. Diamondback moths became a problem for the early sown Northern Region growers with canola having to be sprayed up to three times. By mid-season the yield estimate had dropped to 300,000 tonnes as dry conditions continued in the northern and western areas. Finally the rains came. The Southern region had a mild winter followed by a mild spring. The rain continued into summer, with some coastal farmers experiencing large losses due to waterlogging. The canola matured very slowly in the Southern area with cool moist conditions providing an extended growing season. The canola Department of Agriculture trials at Esperance required chemical desiccation, as they would not dry off sufficiently to allow direct harvest. Although most of the farming community experienced great difficulty in harvesting their crops, the canola proved to be a relatively easy crop to harvest with no down grading occurring. Record yields were experienced in the medium to high rainfall regions with record oils. The summary of deliveries tells the story: Geraldton Port Zone: 32,000 tonnes, 42% oil, 3% admixture. Fremantle Port Zone: 90,000 tonnes, 42% oil, 1.3% admixture. Albany Port Zone: 150,000 tonnes, 43% oil, 1.3% admixture. Esperance Port Zone: 110,000 tonnes, 45% oil, 0.9% admixture. The development of more highly resistant varieties to Blackleg with high oil contents has placed canola on a firm footing in the medium to high rainfall regions. The challenge still lies in getting suitable varieties for the low rainfall regions and in developing a management strategy for diamondback moth in the central and northern region. Canola remains a vital rotational crop in the farming system and as the constraints to production are identified and solutions sought, canola will remain an important component of the landscape. The 2002 Crop Updates again leads the way in ensuring that producers receive the latest R&D results and can confidently plan their 2002 sowing program. ACKNOWLEDGMENTS My sincere thanks to all the contributors for their fantastic effort to meet the deadlines, especially with the delayed harvest in the southern region. Special thanks to Pam Burgess for her huge effort to compile all these papers by the deadline, and to Chiquita Butler for typesetting it. Dave Eksteen ACTING MANAGER OILSEEDS PRODUCTIVITY AND INDUSTRY DEVELOPMENT iii GMO canola - Track record in Canada K. Neil Harker and George W. Clayton, Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta R. Keith Downey, Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan INTRODUCTION Genetically modified organisms (GMOs) have received extraordinary attention over the last few years. Some fear that the introduction of GMOs have brought considerable, negative short- and long-term environmental and health consequences. Others feel that GMOs have resulted in production efficiencies and increased environmental sustainability, i.e. less tillage, less pesticide use, and continued increases in crop productivity. In Canada GMO canola has been on the market since 1995 and has increased to more than 50% of the entire canola market. Canadian canola producers have four different herbicide tolerant (HT) systems to choose from. About 40% of the canola acreage is sown to transgenic Roundup (glyphosate) HT varieties, while the transgenic Liberty (glufosinate) and the mutant Pursuit or Clearfield (imidazolinone) systems each make up about 15-16% of the crop. Thus far, the more recently introduced transgenic bromoxynil-tolerance system has occupied only a relatively small area. GMO canola technology (transgenic) has been rapidly adopted in Canada because it is considered effective and economical. Given the alternative herbicide modes of action available with HT systems, some growers have utilised GMO canola to delay the development of herbicide resistance in weed populations. Gene stacking, resulting from pollen flow, has occurred in commercial fields where different systems have been grown side by side or in close proximity. However, all volunteer canola plants (transgenic, mutated and conventional), are readily controlled with standard phenoxy herbicides in pre-seed burn-off treatments, in cereal crops and in chemical fallow land. Some researchers and producers have been slow to accept that glyphosate must now be viewed as a selective rather than a non-selective herbicide. In this paper we report on experiences with, and short-term consequences of, GMO canola in western Canadian cropping systems. We also attempt to suggest how our experiences with GMO canola may impact GMO canola adoption decisions in Australia. HERBICIDE TOLERANCE The first marketed GMO trait in Canadian canola was herbicide tolerance (HT). The weed management benefits in GMO canola have been considerable in areas where ‘difficult’ weeds such as false cleavers (Galium spurium) or stork’s bill (Erodium cicutarium) are present. Canola relatives such as wild mustard (Brassica kaber) and stinkweed (Thlaspi arvense) can also be difficult problems in conventional canola, although the use of ethametuslfuron has provided some relief in that regard. Some GMO canolas also provide weed management advantages for control of perennial species such as quackgrass (Elytrigia repens) and Canada thistle (Cirsium arvense). Where relatively ‘easy-to-control’ weed populations predominate [e.g. wild oat (Avena fatua) or wild buckwheat (Polygonum convolvulus)], there appears to be no advantage in using HT canolas. Plot research indicates that canola yields are higher with HT canola treatments at some locations and similar to standard treatments such as sethoxydim plus ethametuslfuron at other locations (Derksen et al. 1999, Harker et al. 2000). Therefore, GMO herbicide tolerant canolas are more useful in some areas than others. Since the introduction of HT canolas, farmers have been able to grow canola in fields with weed infestations that previously would have been prohibitive to canola production. The question remains, “Do we really need GMO herbicide-tolerant canola?” What is the potential adoption level of GMO canola in Australia? In the western Australia wheatbelt, the almost complete dominance of triazine-tolerant canola varieties (Hashem et al. 2001) suggests that weed management requirements are much different in Australia than in Canada. In Canadian spring-planted canola, it is often sufficient to apply a single non-residual herbicide relatively early in the canola growth cycle (Clayton et al. 2002) and then depend on rapid canola growth and canopy closure to augment herbicide performance and prevent further significant weed interference. Fall-planted canola in Australia grows much slower and competes much less vigorously with weeds; thus the need for strong residual herbicide activity. Therefore, the economics of several applications of glyphosate to Roundup Ready canola or of glufosinate to Liberty Link canola require careful comparison with the current standard triazine treatments. WEED RESISTANCE In western Canada, there are two monocot [wild oat (Avena fatua) and green foxtail (Setaria viridis)] and nine dicot weed species that are resistant to herbicides. The probability of finding ACCase resistant wild oat in random samples of any treated annual crop field in western Canada is approximately 50% (personal correspondence: Hugh Beckie). However, the high level of adoption of GMO canola in western Canada may have led to somewhat of a reprieve in terms of selection intensity for further weed resistance build-up. Of the three herbicide-tolerant canolas, glufosinate-tolerant canola seems to provide the best management option to avoid development of herbicide resistant weeds. In western Canada, glufosinate is employed almost exclusively in glufosinate-tolerant canola, therefore selection intensity for resistance is minimal. The same cannot be said for glyphosate- and imidazolinone-tolerant canolas. Glyphosate and imidazolinones are used in many cropping situations other than HT canola. Weed resistance to imidazolinone and sulfonylurea herbicides is already considerable. Weed resistance to glyphosate has not been reported in Canada thus far, but resistance to glyphosate is probably inevitable in Canada. Therefore, increased usages of glyphosate and imidazolinones in tolerant canolas will increase the risk of selecting tolerant weed biotypes. In Australia, rigid ryegrass (Lolium rigidum) resistance to glyphosate has been confirmed (Powles et al. 1998). The considerable benefits from the potential adoption of glyphosate-tolerant canola in Australia should be weighed carefully with the consequences of increased selection intensity for further weed resistance to glyphosate. POLLEN FLOW Canola pollen is relatively ‘sticky’ and heavy but because of its minute size a small portion can become airborne and float on the wind. In addition, bees and other insects can effect considerable pollen transfer to other canola plants and plants of other species. Small amounts of pollen may also be transferred via fur and clothing. Careful management of breeders plots and the prevention of admixtures is important to contain GMO canola traits. Because there are so many agents and opportunities for pollen flow, outcrossing, although erratic and limited, is inevitable. The important question is “How much outcrossing will be acceptable?” The following factors can all influence outcrossing: distance between donor and recipient fields, relative size of donor and recipient fields, synchrony of flowering, rainfall, wind direction, temperature, and pollinators. Optimal outcrossing occurs when small (low pollen supply) recipient fields are beginning or ending flowering (low pollen supply) and adjacent large donor fields (high pollen supply) are in full flower. Therefore, flowering synchrony is not necessarily optimal for outcrossing. Two adjacent, large fields in synchronous flower would have limited outcrossing except at field margins. Careful management and crop rotation choices are required to manage pollen-flow risks. Canola seed companies and breeders must be extra vigilant to ensure their varieties are pure and as free as possible of HT genes from foreign sources. Breeder seed production is best done in a confined area where immuno test sticks or PCR are used to ensure each plant is the correct HT or susceptible genotype. In western Canada the risk of outcrossing and gene transfer to related weedy relatives of B. napus is very low (Bing et al. 1991, Lefol et al. 1997). Although interspecific crossing among B. napus, B. rapa and B. juncea has long been known to occur in nature, all three species are grown in western Canada as commercial crops and therefore are not present in the weedy form. On the other hand, wild mustard (Sinapis arvensis) is a widespread and persistent weed. Studies have shown that the cross B. napus by S. arvensis is a difficult cross to make and where hybrids have been obtained they were weak and largely sterile. Given the data to date there appears to be little or no natural gene flow occurring between these two species. A hybrid plant has also been obtained from the interspecific cross B. napus x dog mustard (Erucastrum gallicum), a minor weed in western Canada (Lefol et al. 1997). Although the hybrid was weak and would not likely survive in the wild it did set seed when pollinated by E. gallicum. Visual and cytological examination of the backcross progeny indicated they were poor competitors and apparently had reverted to the E. gallicum genotype. Fortunately other weedy relatives are not present (hoary -2- mustard, Hirschfelfdia incana) or are rare (wild radish, Raphanus raphanistrum and black mustard, Brassica nigra) in western Canada. What are the pollen flow risks in Australia? Wild radish is a major weed in Australian canola. However, even though Lefol et al. (1997) reported that B. napus and wild radish hybrids were vigorous, they were also mostly sterile. Also, French scientists (Chèvre et al. 1997 and Chèvre, personal communication) have found significant barriers to the introgression of B. napus marker genes as well as a herbicide tolerant gene into the genome of wild radish. Weed experts in Australia are best to comment on additional B. napus outcrossing risks with Australian weeds. Although pollen-flow was not implicated, the discovery of a triazine-resistant wild radish biotype from the northern zone of the western Australia wheatbelt (Hashem et al. 2001) will surely influence the GMO canola risk/benefit equation. If weed resistance eventually limits triazine use in significant canola areas, there will be a greater incentive to employ other herbicide mode of action groups including those that are utilised for transgenic canolas. As discussed above, some pollen flow between adjacent canola crops is inevitable. Multiple resistant canola volunteers (Hall et al. 2000) or the movement of transgenes into neighbouring production areas are also inevitable once GMO canola is introduced. The former phenomena has not proven too difficult to manage in Canada, whereas the latter phenomena may or may not be as manageable depending on tolerance levels set for non GMO crops. SURVEY In 2000, the Canola Council of Canada commissioned a survey to answer some questions regarding GMO canola (Canola Council of Canada 2001). The survey included 650 canola growers, half of which grew transgenics and half of which grew standard varieties. The main reason growers chose the transgenic route was superior weed control. The main reason growers chose the standard route over transgenics was the cost of the technology use agreement (TUA - only applicable for Roundup Ready canola). The cost of seed ($11.16/ha more expensive) and fertiliser ($4.25/ha more) were slightly higher for transgenic growers. On the other hand, the use of herbicides, tillage, and fuel were all reduced for transgenic growers. There was a 40% reduction in herbicide costs for transgenic growers, 15% more transgenic growers employed direct seeding (direct drilling), and the lower tillage required substantially reduced fuel costs for transgenic growers. Transgenic growers also had 10% higher yields and lower dockage (3.8% versus 5.1%). Returns for transgenic growers were $14.33/ha higher. Overall, the survey indicates that GMO canola provides opportunities for enhanced production and profits as well as environmental benefits (soil conservation and reduced fuel and pesticide use). GMOs AND DIVERSITY There are questions related to the adoption of GMO canola that cannot be answered in the short-term; indeed the same is true with regard to the consequences of adopting any new technology. Should we learn that GMO canola does not cause unmanageable outcrossing problems, or that GMO transgenes are not incorporated into unrelated organisms, or that there are no significant health or environmental risks to GMO canola, what are the consequences of unprecedented levels of weed control? If repeated applications of herbicides such as glyphosate allow the removal of almost every weed in a canola field, and canola represents 99.9% of the plant species in a given field, will other organisms in the ecosystem be affected? What about interdependent bird, insect, soil macro fauna, and soil microbe food chains (Taylor and Maxwell 2001)? Are there weeds that some of these organisms require as a food substrate? How many of these organisms will remain when the only plant food substrate in large fields is canola? Are there microbial populations involved in nutrient cycling that will be adversely affected by lower ecosystem diversity? Is ecosystem diversity as important in space as it is over time? These questions are interesting, important, and, as yet, unanswered. It is important to note that cropping practices in western Canada are constantly changing. Canola has never been the only crop grown. In addition to the dominant cereal production, pulse crops such as peas, lentils and chickpeas have been introduced and widely adopted in the rotation. These legumes have provided a new and valuable food source for birds, insects and wild life. In addition, these extensive legume plantings have resulted in desirable modifications to the soil micro flora (Lupwayi et al. 1998). Recent shifts to more livestock-pasture, minimum or zero till cultivation and continuous cropping have -3- provided greater refuge and diversity in ground cover for insects and wild life. Thus, although relatively weed-free canola may reduce the spectrum of plant species in a GMO canola field, the adjoining field may be an even more desirable and sustaining source of food and shelter than in recent years. There may be questions as to the ecological impact of GMO canola; these must be answered in the context of entire landscapes and cropping systems. To date the ecosystem has proved to be very resilient. LITERATURE CITED Bing, D.J., R. Downey and G.F.W. Rakow (1991). Potential of gene transfer among oilseed Brassica and their weedy relatives. Proc. 8th Interm. Rapeseed Cong. Saskatoon pp. 1022-1027. Canola Council of Canada (2001). An agronomic and economic assessment of transgenic canola. [Online] Available: http://www.canola-council.org/production/gmo_toc.html [14 January 2002]. Chèvre, A-M., F. Eber, A. Baranger, and M. Renard (1997). Gene flow from transgenic crops. Nature 389: 924. Clayton, G.W., K.N. Harker, J.T. O’Donovan, M.N. Baig and M.J. Kidnie (2002). Glyphosate timing and tillage system effects on glyphosate-tolerant canola (Brassica napus). Weed Technol. (In Press). Derksen, D.A., K.N. Harker and R.E. Blackshaw (1999). Herbicide tolerant crops and weed population dynamics in western Canada. Proc. of 1999 Brighton Conference on Weeds. Brighton, UK. Vol. 2: 417-424. Harker, K.N., R.E. Blackshaw, K.J. Kirkland, D.A. Derksen and D. Wall (2000). Herbicide-tolerant canola: Weed control and yield comparisons in western Canada. Can. J. Plant Sci. 80: 647-654. Hall, L., K. Topinka, J. Huffman, L. Davis and A. Good (2001). Pollen flow between herbicide-resistant Brassica napus is the cause of multiple-resistant B. napus volunteers. Weed Sci. 48: 688-694. Hashem, A., H.S. Dhammu, S.B. Powles, D.G. Bowran, T.J. Piper and A.H. Cheam (2001). Triazine resistance in a biotype of wild radish (Raphanus raphanistrum) in Australia. Weed Technol. 15: 636-641. Lefol, E., G. Seguin-Swartz and R.K. Downey (1997). Sexual hybridisation in crosses of cultivated Brassica species with Erucastrum gallicum and Raphanus raphanistrum: Potential for gene introgression. Euphytica 95: 127-139. Lupwayi, N.Z., W.A. Rice and G.W. Clayton (1998). Soil microbial diversity and community structure under wheat as influenced by tillage and crop rotation. Soil Biol. Biochem. 30: 1733-1741. Powles, S.B., D.F. Lorraine-Colwill, J.J. Dellow and C. Preston (1998). Evolved resistance to glyphosate in rigid ryegrass (Lolium rigidum) in Australia. Weed Sci. 46: 604-607. Taylor, R.L. and B.D. Maxwell (2001). Indirect effect of herbicides on avian food resources and beneficial arthropods. Proc. West. Soc. of Weed Sci. Paper #71, Coeur d= Alene, Idaho, 13-15 March. -4- GM canola - Prospects in Western Australia farming systems Keith Alcock, Crop Improvement Institute, Department of Agriculture, South Perth SUMMARY The canola industry in Western Australia is highly aware of the multiplicity of issues both positive and negative associated with GM canola. Many of these have become clearer as a result of Canadian experiences and the industry is grateful to have the benefit of the Canadian ‘trial marketing’. This experience and the comprehensive regulatory scrutiny that will be applied before GM canola will be licensed for commercial release in Australia provides the assurance that GM canola is safe to human health and to the environment. Analyses of world markets have consistently indicated that GM canola can be successfully sold on export markets and that there are no significant price discounts over non-GM canola. There are market access issues in some markets, notably in Europe where only non-GM is permitted. The Australian domestic market currently holds the same position as in Europe. Accordingly, there is an incentive for the Australian canola industry to develop separate paths-to-market for GM and non-GM canola. The industry has established a committee structure with Western Australia and Eastern States ‘nodes’ to develop a ‘Code of Practice’ governing the introduction of GM canola to ensure that effective segregation and ‘identity preservation’ is achieved to market standards of purity. On available evidence, the requisite degree of protection of the integrity of GM and non-GM production will be achievable without the need to separate GM and non-GM into different regions or even between farms or on the same farm. The industry is currently working cooperatively to further test and develop the Code of Practice ahead of the anticipated first release of GM canola in Australia in 2003. INTRODUCTION Current expectations are that Monsanto and Aventis will be submitting clearance applications by the middle of this year for the commercial release of GM canola varieties in all canola-growing States. On the basis of processing schedules proposed by the Office of the Gene Technology Regulator (OGTR) in Canberra, the companies are hopeful of seed sales and commercial production in the 2003 season. In anticipation of OGTR approval, current planning indicates that initial availability of seed is certain to be limited and the focus will be more on seed multiplication and demonstration sites in 2003. This is especially the case in Western Australia as the canola cultivars under development in the company programs tend more towards mid- to long-season types and there have been limited opportunities for varietal development trials under Western Australia conditions. Accordingly, the earliest that commercial production of GM canola in Western Australia could be anticipated is 2004, two seasons away. This allows the canola industry, the broader population and rural and urban communities time for further consideration of the issues surrounding the technology. Paramount in this area is the current community consultation process initiated by the Minister for Agriculture, Forestry and Fisheries, the Hon. Kim Chance MLC into ‘Genetic Modification-Free Zones’ as a means of protecting the integrity of both GM and non-GM production. This paper reviews the canola industry views on the production and marketing issues as developed through the GM Canola Technical Working Group, which consists of the Canola Association of Western Australia, the Western Australian Farmers Federation, the Pastoralists and Graziers Association of WA, The Grain Pool of WA, Cooperative Bulk Handling Ltd, the Biotechnology Committee of Avcare. The Australian Quarantine and Inspection Service and the Department of Agriculture. The focus of the paper is on two questions, is the technology safe and does it make economic sense in Western Australia? SAFETY Issues of occupational health, consumer safety and environmental impact are key objectives of the Gene Technology Act 2000. The Act describes the framework for the Australian system of regulation for GMOs and is administered by the Office of the Gene Technology Regulator (OGTR) which is headed by the Gene Technology Regulator (GTR). The GTR will decide upon submissions for -5- licensing laboratory, glass house and field trial testing through to general release of GM crops and commercial cultivation. The GTR is required to prepare a risk assessment and risk management plan for all licence applications in addition to determining measures necessary to manage any such risks. Where labelling of GM foods is at issue, the Australia and New Zealand Food Authority (ANZFA) will develop and enforce appropriate food standards though Food Standard A18 which requires both pre-market assessment and labelling of GM food. In the case of herbicide-tolerant crops, the National Registration Authority (NRA) will continue its role in regulating chemical usage. The Gene Technology Act 2000 provides that a Ministerial Council on Gene Technology, (Commonwealth and State body) may issue policy principles in relation to particular issues such as recognising areas, if any, designated under State laws for the purpose of preserving the identity of GM crops, non-GM crops or both for marketing purposes. Such policy principles underpin the activities of the GTR and the operation of the regulatory framework. The Ministerial Council will also consider and agree changes, as required, to the national legislative framework, undertake discussions and coordination with other Ministerial Councils on matters related to gene technology regulation, advise the Commonwealth on the appointment and dismissal of the GTR, and oversee periodic reviews of the legislative framework. Three key advisory groups have been established to assist the GTR and the Ministerial Council on Gene Technology: Gene Technology Technical Advisory Committee (GTTAC) GTTAC provides scientific and technical advice to the GTR or the Ministerial Council on matters including gene technology, GMOs and GM products and on applications made under the legislation. Gene Technology Community Consultative Group (GTCCG) GTCCG is a broadly based consultative committee established to provide views to the Ministerial Council and the GTR. This group will cover areas including community concerns regarding gene technology and the need for, and content of, policy guidelines and codes of practice to the development of the procedural and policy documents that will guide the GTR’s decision-making. Gene Ethics Committee (GTEC) GTEC will provide advice to the GTR and the Ministerial Council on the ethics of gene technology, appropriate ethics guidelines and any necessary prohibitive directives. The Legislation provides that licenses can only be issued by the GTR following rigorous scientific risk assessment and extensive consultation with the expert advisory committees, Government agencies, Shire Councils and the public. RISK MANAGEMENT IN FARMING SYSTEMS In considering health and safety issues, the GTR will examine the broader farming systems risks that have been widely studied for GM canola. The risks that have been identified relate to the weediness potential of volunteer canola, the risk of herbicide-tolerance genes outcrossing into weedy cruciferous species and the risk of over-use of the herbicides leading to selection of herbicide-resistant weeds. These are discussed in turn below. Volunteer canola Volunteer canola can occur as a weed in high numbers in subsequent rotational cropping as a result of canola seed shedding prior to and during harvest. Volunteer canola is readily controlled in following cereal crops with knockdown herbicides, and then in-crop by sulfonyl urea or phenoxy herbicides. In a lupin crop, volunteer canola weeds can be selectively controlled by the use of the herbicide simazine (if not triazine tolerant varieties), followed by metribuzin, Brodal® and/or Eclipse®. Other options are available for field pea, chickpea or other pulse crops following canola. In this respect it is easier to control GM canola volunteers than TT canola volunteers. Under current circumstances, wheat is probably the preferred crop to grow as the first rotational crop after canola, whether GM or non-GM. -6- Based on Canadian experience, multiple herbicide-tolerant (HT) canola is no more weedy or invasive than single HT or non-HT canola types. The range of herbicides available for control of multiple HT canola is reduced. However, the choice of an appropriate herbicide for volunteer control will still readily eliminate these types. Canola seed can also become a roadside and fenceline weed as a result of seed production by volunteer plants in paddocks or spillage during loading and transport. It is a plant of ‘disturbed land’ habitats which results in it being easily dominated by other more competitive species when it is present in areas such as roadsides and fence lines where the soil does not tend to be disturbed. In this and fallow situations where glyphosate is such a widely-used herbicide, the knockdown can be ‘spiked’ with a Group I herbicide such as 2,4-D or MCPA to control the volunteer canola. Gene transfer to weedy cruciferous relatives of canola The possibility of herbicide-tolerance genes spreading from cultivated canola into other cultivated Brassica species or weedy relatives from the Brassicaceae family creating so-called ‘superweeds’ is an issue that needs to be considered with the release of GM canola. This area has been extensively researched, including Australian studies and reviews (Rieger et al. 1999; Salisbury, 2000). Researchers have demonstrated the capacity of canola to outcross in nature to closely related cruciferous weeds. In terms of Western Australia farming systems, only wild radish (Raphanus raphanistrum) is in this category. Other cruciferous weeds that do cross with canola in nature, Buchan weed, Hirschfeldia incana and charlock, Sinapis arvensis, are not weed problems in Western Australian broadacre systems. Other less closely related weeds such as wild turnip (Brassica tournefortii) and mustards (Sisymbrium spp.) do not cross with canola in the wild. The key conclusion from the range of studies carried out is that while isolated instances of hybrids are recorded, such hybrids are sterile and there is as yet no evidence of canola x wild radish hybrids surviving as weed species. Nevertheless, the introduction of GM canola to Australia should acknowledge that hybrids can occur, that gene flow from canola to weedy species is at least theoretically possible and have in place appropriate monitoring systems to identify any change in cruciferous weed status. Selection of herbicide-resistant weeds through over-use of herbicides There has been keen discussion on the potential for increased use of the herbicide glyphosate, as the herbicide component of Roundup Ready® canola to pose additional selection pressure for glyphosate resistance in key weeds. The risk must be acknowledged, especially in annual ryegrass (Lolium rigidum) as a result of the discovery of a number of populations of glyphosate-resistant ryegrass (Powles et al. 1998). It is essential the potential impacts of this are understood and guidelines developed to conserve the use of such a valuable product for as long as possible. A number of options are already widely practised as part of ryegrass resistance management. These would particularly include the use of the alternative knockdown herbicide SpraySeed® as a double knock or as an alternative to glyphosate pre-seeding or in spraytopping. Alternatives options for ryegrass resistance management, based on the application of glyphosate as a pre-seeding operation with or without the application in Roundup Ready® canola, are currently being intensively studied at Charles Sturt University, together with supporting trials being undertaken in Western Australia. The strategy outcomes from this research will be included as an integral part of the Crop Management Plan for Roundup Ready® canola. The resistance management case for glufosinate-ammonium, or Liberty®, is clearer. It represents a novel mode-of-action in Western Australian broadacre cropping systems and its use in Liberty Link® canola will broaden the herbicide resistance management options available to graingrowers. The major use of Liberty® in Australia is as an effective broad spectrum herbicide in horticulture. Overseas, including in Canadian and US, Liberty Link herbicide-tolerant crops, it has proven a safe and effective product that has demonstrated a low risk of weeds developing herbicide-resistance. -7- ECONOMIC BENEFITS Canadian experience (Canola Council of Canada, 2001) indicates 10% higher yields on average for GM varieties over non-GM, and higher quality as expressed by lower dockages. In Western Australia, where triazine tolerant (TT) varieties dominate, the inherent ‘yield drag’ of 10-20% and downward pressure on oil content provides further scope for GM varieties to deliver increased yield and quality benefits than in Canada. However, in the absence of any published data on the potential yield and quality benefits from the GM canola varieties under development in Australia it is difficult to do more than speculate on the likely increases in returns. The same applies for costs. The same Canadian studies point to substantial (40%) reduction in herbicide costs but seed costs were generally higher and for Roundup Ready® canola there was an additional technology license fee to be paid. Clearly, there is substantial potential for increased returns to farmers. It is to be hoped that the companies settle on terms that provide for an equitable sharing of the benefits. The potential for recombinant DNA technologies to introduce new traits unavailable to conventional plant breeders is seen as providing options for GM canolas with modified oil content to produce ‘healthier’ cooking or salad oils and ‘designer oils’ for non-food uses, such as industrial and pharmaceutical active ingredients or feedstocks (Green and Salisbury, 2001). The development of high erucic acid canola varieties for biodiesel production is a current example and offers expanded markets and potential price premiums. The increased medium to long-term potential for GM crops to capture productivity and price premiums in the marketplace is in accord with the conclusions of the 2001 ABARE study into market implications (Foster, 2001). FARMING SYSTEMS BENEFITS There can be greater immediate certainty on the farming systems benefits of GM canola technology both from the traits under development now and the potential into the future. Effective weed management is a prerequisite to the continuing success of Western Australian minimum tillage systems, as the intensity of the battle with herbicide resistant weeds attests. The key to managing herbicide resistance is integration of a variety of control measures, chemical and non-chemical, across the rotation. Each rotation phase needs effective tools and in canola in Western Australia at present, the Group H herbicide atrazine effectively is that tool. Triazine tolerant (TT) canola, currently accounts for over 90% of the Western Australian crop The sustainability of atrazine as the herbicide in this system is under threat from the development of resistance in the key weeds annual ryegrass and wild radish. While such populations are as yet isolated, the rapidity with which herbicide-resistant weeds can escalate is only too familiar to Western Australian growers who use Group A and Group B products. The central role of the related Group H product simazine in lupins increases the triazine resistance selection potential. The introduction of imidazolinone-resistant Clearfield® canola provides some relief, but as a Group B product, to which resistant ryegrass and radish are widespread, the benefits are greatly lessened in managing these two weeds. For canola to continue in Western Australian crop rotations, farmers need another superior herbicide option. The availability of Liberty® and especially glyphosate as in-crop alternatives in canola is the scale of impact required to reverse the current increase and spread of triazine-resistant weeds and to sustain the crop in the rotation. DELIVERING THE BENEFITS, MINIMISING THE RISKS - IDENTITY PRESERVATION The Canadian experience with GM canola demonstrates that there can be multiple benefits from the introduction of GM varieties. The canola industry in Western Australia has clearly recognised the potential, but has also identified a preferred option, at least in the short to medium term, of retaining the ability to supply both GM and non-GM canola according to market demands. In research carried out by the Grain Pool with their customers (Peter Portmann, pers. com.) and published data, there is limited evidence of market premiums for non-GM canola. Premiums that may occasionally be available are likely to be outdone by production benefits (Foster, ibid). However, for the foreseeable future there are market access (as against price) issues in Europe that support a segregated supply -8- chain approach. This strategy is fully in accord with Minister Chance’s intention to protect the integrity of GM and non-GM crop production in the State. The Australian canola industry through the Western Australian GM Canola Technical Working Group and the Eastern States counterpart, the Eastern Zone Gene Technology Grains Committee, has focused on phasing in GM canola through separate production and marketing streams. The two committees are currently developing a Code of Practice for supply chain management of GM and non-GM canola. The target of this segregation and ‘identity preservation’ (IdP) system is in meeting market specifications for non-GM canola of no more than 1% ‘adventitious presence’ of GM material (AFFA, 2001). Calculations of the cost of IdP systems currently in use in grain-based production have been estimated at from 0.6-5% of the commodity price (Fernandez and Smith, 2002). Within this range of costs were examples of differentiation between GM and non-GM product. The canola industry is anxious to aim for the lower end of this scale, consistent with meeting market demands. The industry acknowledges that in instances where IdP costs are associated solely to facilitate GM canola introduction then the costs should be met by the GM growers as much as possible. At the same time, it is acknowledged that QA and IdP systems are increasingly important as a means of maintaining access to highest-paying markets and capturing price premiums for quality, irrespective of the introduction of GM crops. Accordingly, non-GM growers wishing to maximise their returns will not be isolated from this general trend. The Code of Practice is supported at all levels in the canola supply chain and will be audited by an approved third party. It is being developed in conjunction with the Joint Accreditation System for Australia and New Zealand (JASANZ) and with AQIS to provide the backing of key organisations that the market is looking for in certifying compliance with their requirements. The national industry welcomes the fact that there will be at least one and, in Western Australia, probably two more seasons to develop, test and validate the proposed IdP system since this will allow time for responsibilities to be met by all stages of the canola supply chain. Looking at the stages as ‘pre-farm’, ‘on-farm’ and ‘post-farm’, some of the issues that have been identified are described below. Seed production and distribution There are well-established codes of practice in the seeds industry that govern seed production and distribution. The Seeds Industry Association of Australia is affiliated with the international standards and compliance organisations (OECD/AOSCA) and would administer standards as agreed by the GM regulatory authorities (OGTR). Crop production, on farm storage delivery to receival It is intended that the basis for on-farm IdP will be ‘Crop Management Plans’ set in place by the biotechnology companies supplying the technology. The plans will set out ‘good agricultural practice’ in paddock preparation, seeding, crop agronomy and will cover herbicide resistance management, crop volunteer management, crop rotational strategies, machinery hygiene and maintenance, farm record management, on farm storage and transport principles. On-farm planning, hygiene and record-keeping will be the key to keeping GM and non-GM canola production apart, as there are so many operational steps in crop production where inadvertent admixture can occur. Cross-pollination potential in the field Part of the challenge of minimising opportunities for admixture of GM with non-GM will be management of cross-pollination potential from neighbouring crops. The GM Canola Technical Working Group information paper (GMCTWG, 2001) reviewed cross-pollination studies in canola carried out in four Australian States in the 2001 season by the CRC for Australian Weed Management (Rieger, 2001). The Working Group observed that no single data point from the Australian trials exceeded the most stringent world standards of 1% unintended presence, even where the paddocks were side-by-side and sampling took place along the immediate boundary. It was concluded that this was consistent with world literature on the subject (including Salisbury ibid), and that the likely level of cross-pollination is estimated to be of the order of 0.1% in adjacent paddocks, well within market standards. The most advanced systems of DNA based GM testing has a limit of detection of GM presence in a non-GM sample of 0.1% (and a cost of $200-600 per test). In the majority of cases, cross pollination even across a fenceline would be below the limits of detection. -9- From receival to market The current view of Cooperative Bulk Handling Ltd (David Fienberg, pers. com.) is that in the first 2-3 years, when GM canola hectarages were low, CBH would set up dedicated bins at specified receival sites. The CBH Q-Track system could ‘flag’ growers with GM crop and put in place the most cost-effective monitoring and testing of deliveries. The approach is in accord with the Grain Pool’s drive to capture market premiums through QA and IdP. Working with the Grain Pool, CBH have initiated a pilot study this season (using a new variety of non-GM canola) to test their model of a least cost but fully effective segregation and IdP system though all stages from ‘gate to plate’, which is seen as a necessity in the short term. In the longer term, the Canadian model of not segregating GM from non-GM for the main crop may well emerge, with IdP systems only used to capture price premiums. Such is certainly the case now with ‘specialty oil’ canolas such as the high oleic acid Monola varieties, and is likely to increase as further diversification options identified in ‘healthier’ canolas and industrial oils, both GM and non-GM based, will become the key to industry growth and prosperity. LITERATURE CITED Agriculture Fisheries Forestry Australia (2001). Segregating Gene Technology Products Requirements, Costs and Benefits of Identity Preservation, Segregation and Certification. [Online]: http://www.affa.gov.au/corporate_docs/publications/pdf/innovation/Scoping_ study_report.pdf. Canola Council of Canada (2001). An agronomic and economic assessment of transgenic canola. [Online]: http://www.canolacouncil.org/production/gmo_toc.html. Foster, M. (2001). Genetically Modified Grains: Market Implications for Australian Grain growers. ABARE Research Report 01.10, Canberra. Fernandez, M. and Smith, K. (2002). Knowing where it’s going. Proceedings from a Workshop sponsored by Pew Initiative on Food and Biotechnology and Economic Research Service of the US Department of Agriculture. [Online]: http://pewagbiotech.org/events/0911/marketingsummary.pdf GM Canola Technical Working Group (2001). Genetically Modified Canola in Western Australia: Industry Issues and Information. [Online]: http://www.agric.wa.gov.au/biotechnology/ gmcanola/index.htm. Green, A. and Salisbury, P. (2001). Novel plant products from gene technology. 10th Australian Agronomy Conference, Hobart, Australia, 2001. Powles, S.B., Lorraine-Colwill, D.F., Dellow, J.J. and Preston, C. (1998). Evolved resistance to glyphosate in rigid ryegrass (Lolium rigidum) in Australia. Weed Science 46: 604-607. Rieger, M.A., Preston, C. and Powles, S.B. (1999). Risks of gene flow from transgenic herbicideresistant canola (Brassica napus) to weedy relatives in southern Australian cropping systems. Australian Journal of Agricultural Research 50: 115-28. Rieger, M.A. (2001). Pollen movement over distance with Brassica napus. Unpublished Report submitted to CRC for Australian Weed Management, Monsanto Australia and Aventis Crop Sciences. Salisbury, P.A. (2000). The myths of gene transfer - a canola case study. Plant Protection Quarterly 15(2): 71-76. -10- Diamondback moth (DBM) in canola Kevin Walden, Department of Agriculture, Geraldton INTRODUCTION In the last two seasons the diamondback moth (DBM) (Plutella xylostella) has caused considerable damage to canola in WA. In 2000 the most severe damage occurred in crops east of Geraldton while last year damage was reported from locations throughout the Northern Agricultural Region and from some locations in Central and Southern Regions. On the world scene, DBM is ranked as the major insect pest of a large number of commercially grown cruciferous plants, including canola. The annual bill for managing the pest is estimated to be well in excess of $2 billion. Will DBM become the major pest of canola in WA? And if so, how will it be managed? POTENTIAL PEST STATUS Trials conducted last year demonstrated that during winter the number of DBM larvae in a canola crop can dramatically increase over a short period of time. A low-density population of less than 10 larvae in 10 sweeps of an insect net in July can develop into over 1000 larvae in 10 sweeps by September. The trials also indicated that large numbers of DBM cause both significant yield reductions (in one trial over 60% of the yield was lost) and affect grain quality (grain weight decreased by up to 30%). If the large populations of the last two years become the norm then DBM has the potential of becoming the major pest of canola. Winter temperatures of the last two years have been well above average enabling DBM to develop quickly and winter rainfall has been below average, which may have enhanced survival. Whether these are key factors that enable DBM to build up to such large numbers will be investigated over the coming seasons and will further define its pest status. While we await a more definitive definition of DBM’s pest status, for the present we will assume that DBM is a major pest and the Department of Agriculture will develop management strategies accordingly in consultation with Agribusiness and canola growers. ASPECTS OF DBM BIOLOGY THAT NEED TO BE CONSIDERED IN THE DEVELOPMENT OF A MANAGEMENT STRATEGY Origins Knowing the origin of DBM outbreaks is fundamental to predicting future outbreaks and developing resistance strategies if necessary. The key issue is whether DBM can survive in cropping regions over summer. If they do not survive the key issue becomes from where outside the cropping region do they originate. It has been stated that in WA outbreaks originate as a consequence of cyclones forming a ‘green bridge’ of host plants that enables DBM to continue breeding over summer, however, this was never proved. Extensive surveys last summer and autumn using a grid of pheromone traps and regular sampling of potential DBM habitats demonstrated that host plants, including wild radish, that germinated in response to summer rain did not produce any detectable DBM populations. Investigations aimed at identifying the origins of DBM outbreaks will continue. Movement Studies in other countries have indicated that DBM can migrate and disperse over long distances. Moths can remain in flight for several days and cover hundreds even thousands of kilometres. Major insect pests in WA, such as the Australian plague locust (Chortoicetes terminifera) and the native budworm (Helicoverpa punctigera), use migration as a survival strategy to escape from cropping regions when they become inhospitable then return when conditions improve. It is possible that DBM moves some distance to establish populations in canola crops. Once breeding begins, the extent of moth movements and the likelihood of populations being established in other canola crops is not known. -11- Development and survival The eventual size of a DBM infestation depends on the size of the initial population, the amount of time available for it to develop, the rate of development and the proportion of insects that survive to complete each generation. The initial size of a population depends on the number of moths invading the canola crop and their fecundity. The time available is determined by when the first eggs are laid in the crop. The rate of development is related to temperature with more generations being completed during warmer periods. The proportion surviving will depend on the intensity of key mortality factors such as heavy rainfall and natural enemies. In 2000, large populations of DBM were established in canola crops soon after germination. In 2001, populations were not noticeable until mid-July yet there was sufficient time for large populations to develop. In the Northern Agricultural region DBM can complete more than six generations over winter, and with female moths able to lay almost 200 eggs, it is possible for large infestations to develop from a single, low density moth invasion. There does not appear to be the diversity or abundance of predators and parasites associated with both DBM and aphids in canola as there is with the native budworm and aphids in lupins. Consequently it is unlikely that natural enemies will regulate DBM numbers to levels where the use of insecticides is not required. However, in 2000 a fungal disease (Zoophthora radicans) killed large numbers of DBM larvae in many canola crops in the Northern Agricultural Region. Although it was stated that the fungus caused DBM populations to crash in the middle of winter, this was never proved. Further studies are required to get more definitive information on the potential impact of the fungus on DBM populations. Resistance Throughout the world DBM has developed resistance to insecticides. The situations where this has readily happened is where the moths have a high fecundity and reproductive potential, where there is a rapid turnover of generations, a long growing season, extensive areas of crucifers, and frequent insecticide applications. There is the potential for DBM to develop resistance to insecticides in WA. Insecticides are used to control DBM not only in canola but also in cruciferous horticultural crops (e.g. cabbage, cauliflower, broccoli, radish, turnip, Brussels sprouts). The significance of insecticide treatments in canola and horticultural crops in exacerbating levels of insecticide resistance and how the potential problem is managed will to a large extent depend on the origins of DBM that invade both canola and horticultural crops. Tests on the levels of insecticide resistance of DBM populations from WA canola crops at Burabadji and Wongan Hills during 1999 indicate very low levels of resistance (resistance ratios* of 5.1 to 6.7). In 2001, resistance levels of populations tested from canola crops at Tenindewa and Wongan Hills were much higher (11.5 to 17.2) but not at a level that would result in significant control failures. However, the levels recorded may have contributed to the lack of acceptable levels of control from a single insecticide application. Also, the trend of increasing levels of resistance is cause for concern and given the history of the rapid development of insecticide resistance in DBM, regular monitoring will be undertaken and a resistance management plan devised.  Resistance ratios are the levels of resistance in the field population being tested compared to a laboratory population that has not previously been exposed to insecticides. ASPECTS OF DBM MANAGEMENT PRACTICES THAT NEED TO BE CONSIDERED Insecticides The effectiveness of synthetic pyrethroid insecticides needs to be evaluated again. Trials conducted at Yuna in 2000 demonstrated that most single spray applications controlled 80 to 90% of the larvae depending on the product and the rate of application. Last year canola growers reported that single insecticide applications at high rates were far less effective. New insecticides will need to be evaluated and their cost effectiveness compared to current treatments. -12- Insecticide application The effectiveness and costs of aerial versus ground application were investigated in 2000 and 2001. Marginally better levels of control were obtained by ground application in 2000 and significantly better levels in 2001. There is no obvious explanation for the difference. The levels of control attained by each method have to be balanced against the cost of application, which in the case of ground application includes yield loss from driving over the crop. TIMING AND NUMBER OF INSECTICIDE APPLICATIONS Trials conducted last year demonstrated that multiple insecticide applications were more effective at controlling DBM than a single application. Trials need to be conducted to determine whether the interval between sprays affects the level of control and whether controlling populations early in their development is more cost effective than delaying control to later in the season. MANAGEMENT STRATEGY FOR THIS SEASON This strategy may be amended during the season as more information is collected. The outlines of the strategy include: • Monitoring alternative host plants during autumn and winter to determine the location and size of any early DBM infestations in the cropping region. Regular monitoring of canola crops should begin soon after they emerge. • Estimating the number of DBM larvae in canola crops regularly using a sweepnet. • Applying an insecticide if the number of grubs is steadily increasing and they pass the economic threshold level. • Estimating the number of DBM larvae at least three days after spraying. • Applying a second spray if more than 20% of the initial population remains. • Monitoring the crop regularly after insecticide treatments. • Continuing to control the DBM if their number increase beyond the threshold and if the crop is potentially high yielding and another spray can be economically justified. -13- Getting the best out of canola in the low rainfall central wheatbelt Bevan Addison and Peter Carlton, Elders Ltd KEY MESSAGE Final grain yield and oil content were low across all sites. The 2001 season demonstrated an over-riding effect of unpredictable seasonal conditions, rather than farmer decisions, on yield and profit. Agronomic treatments did not improve yield above the basal treatments, however the newer canola varieties performed best in the yield trials and their oil contents were higher than Karoo. BACKGROUND Canola has become an important part of the overall strategy for farm rotations in WA. It is profitable for farmers in the medium to high rainfall areas where agronomic packages have been developed and the environmental conditions support good canola growth. However, for the majority of growers in the lower rainfall zones, it remains an opportunistic crop, demonstrated by the move away from canola in these areas in 2000. Disappointing yield and oil content, possibilities of low prices and late breaks to the season mean that canola is a high-risk investment. Better variety information and more detailed and specific agronomic packages need to be developed for growers in these lower rainfall zones of the WA wheatbelt if the benefits of canola are to be realised and on-farm productivity increased. This series of trials, funded by GRDC, is targeting the lower rainfall zones of the central wheatbelt. METHODS A series of variety by agronomy trials were conducted at five locations in the low rainfall (< 375 mm) central wheatbelt, covering the L2, L3, L4, M3 and M4 zones. Plots were 10 m or 20 m in length * 1.4 m wide and sown by plot air seeder using inverted T points and presswheels. Varieties were evaluated in yield trials with 2 or 3 sowing times at each site. Experimental design was split/split plot with sowing time as main effect, herbicide tolerance of varieties as sub plot and variety as sub/sub plot. There were 3 replications. Agronomic trials investigated response to seeding rate (3, 4, 5, 7 kg/ha-1), crop nutrition (N, P, K, S, trace element), fungicide treatments for blackleg (varietal resistance * Impact Infurrow) and bare earth treatments for insect control, especially RLEM (with and without Talstar). Agronomy trials were randomised complete block design and had 3 replicates. AGRONOMY TRIAL RESULTS Canola established well in each trial, however final grain yield and oil content were very disappointing across the four sites harvested. The Varley site was lost due to a severe hailstorm. The long dry spell during the growing season limited yield potential and negated most treatments, demonstrating the over-riding effect of unpredictable seasonal conditions on yield and profit in 2001, rather than factors such as variety choice. In general there was no response to any treatment in each agronomy trial at each site and little useful information can be inferred from the 2001 season. However, this project will continue for another 2 growing seasons. Some observations from the agronomy trials are: • Grain yield and oil were not affected by lowering seeding rate to 3 kg/ha -1. • Blackleg infection was low at all sites. Treatment with Impact In Furrow showed no response. • RLEM numbers were low at each site. Bare earth treatments did not improve plant number. Additional N, P, K or S nutrition treatments did not improve yield or oil content above a basal treatment of 60 kg/ha-1 Agstar or 50 kg DAP. Yield varied 0.12 (Kellerberrin) to 0.98 t/ha-1 (Jitarning). -14- VARIETY TRIAL RESULTS The first time of sowing at each site was put in within two days of the opening rains. Even so, yields were very low, with site means ranging 0.28 to 0.77 t ha-1 for the first sowing time (Table 1). Two sowing times again demonstrated the importance of early sowing. A two week delay in seeding reduced grain yield by an average 30% amongst varieties that flowered at a similar time or earlier than Karoo (flowering times not shown). Oil content was not affected. Grain yield differed among varieties at all sites (P < 0.05) and G*E interaction was also significant. In general, variety response was similar across sowing times and sites. Oil content was generally about 40%, except Kalannie, where the site mean dropped to 36%. Varieties showed a degree of yield stability with the same varieties performing best at each site. Beacon, Karoo, and Surpass 501TT were the best performers of the TT varieties, whilst 44C73 and Surpass 402CL were the best of the IT varieties. Karoo still performed relatively well in these trials, however the newer varieties had much better oil content with at least 2.5% higher oil over all sites. Surpass 300TT looks to have a reasonable fit, flowering 12 days earlier than Karoo. The short maturity may limit upper yield potential in longer/higher rainfall seasons. Variety performance was not dependent on herbicide resistance with the best IT and TT varieties showing similar yield and oil content at each site. Grain yield (GY) (t ha-1), oil content (%), and dollar return ($ ha-1) of 18 canola varieties grown at four sites, sown at the break at each site, 2001 Table 1. Kalannie (seeded 9 May) Kellerberrin (seeded 10 May) Jitarning (seeded 22 May) Wyalkatchem (seeded 9 May) GY oil $ GY oil GY oil $ GY oil $ Mean $ return IT 44C71 0.25 35.8 90 0.21 42.3 90 0.77 40.5 315 0.30 42.8 127 156 IT 44C73 0.43 34.8 153 0.30 40.5 123 1.06 42.2 447 0.59 41 245 242 IT 45C75 0.23 34.6 83 0.18 42.1 74 0.44 38.1 170 0.40 41.7 168 124 IT 46C74 0.17 33.2 58 0.20 40.7 83 0.56 40 226 0.28 40.4 114 120 IT Surpass 402CL 0.37 38.3 146 0.37 43.7 158 0.84 40.6 343 0.41 42.7 174 205 IT Surpass 603CL 0.40 39.7 161 0.24 44.4 105 0.57 43.5 244 0.56 43.7 241 188 Herb type Variety Mean of IT varieties $ 0.31 36.1 115 0.25 42.3 105 0.71 40.8 291 0.42 42.1 178 172 TT AGT 105 - - - - - - 0.89 40.5 364 - - - - TT AGT 108 - - - - - - 1.15 41.6 479 - - - - TT Beacon 0.50 36.7 187 0.30 41.5 125 0.96 41.3 399 0.59 40.1 241 238 TT Clancy 0.28 32.9 94 0.23 39.9 94 0.60 38.6 238 0.44 37.4 168 149 TT 1 Eyre 0.26 37.3 99 0.33 42.3 138 0.88 43.9 381 0.42 40.7 172 198 TT Grace 0.31 37.6 121 0.26 41.2 109 0.67 38.9 264 0.52 39.7 208 175 TT Hyden 0.34 34.7 120 0.31 40.4 126 0.79 39.9 319 0.57 37.8 222 197 TT Karoo 0.39 33.9 134 0.36 40.8 148 0.95 38.3 370 0.61 36.3 227 220 TT Pinnacle 0.26 34.8 91 0.23 40.8 94 0.66 38.5 258 0.46 38.2 180 156 TT Surpass 300TT 0.46 37 174 0.35 43.5 149 0.97 41.4 403 0.34 40.8 141 217 TT Surpass 501TT 0.53 40.6 218 0.42 44.8 183 0.59 44.2 256 0.52 42.6 220 219 TT Surpass 600TT 0.27 35.3 99 0.25 42.7 107 0.51 41.1 212 0.40 36.3 147 141 Mean of TT varieties 0.36 36.1 134 0.30 41.8 127 0.80 40.7 329 0.49 39.0 193 191 Site mean 0.34 36.1 127 0.28 42.0 119 0.77 40.7 316 0.46 40.1 187 184 2 LSD (P < 0.05) 0.11 0.12 0.13 0.17 3 LSD (P < 0.05) ns ns ns ns 1 2 3 Tested as T03. LSD for differences between varieties. LSD for differences between IT and TT mean values. -15- CONCLUSIONS • Early flowering varieties with high and stable yield potential and high oil content are now becoming available from canola breeding programs, increasing the probability of identifying well adapted varieties for the lower rainfall areas of WA. • Beacon, Surpass 300TT and Surpass 501TT (TT varieties) and 44C73 and Surpass 402CL (IT varieties) appear to be the most promising varieties for this region. • Seeding as close as possible to the break in 2001 was essential to set high yield potential. Yield was reduced by about 30% by delaying sowing 2 weeks after the first seeding opportunity. • Variety performance is not dependent on herbicide resistance. The best IT and TT varieties showed similar yield and oil content at each site. • In 2001 grass weed control was a problem in IT plots and farmers crops in the dry environments. Use of a knockdown for effective weed management is already recommended but more consideration is warranted for dry environments. The inherent yield penalty of TT varieties may be balanced against IT varieties by better weed control and the ability to seed earlier. • Diamond Back Moth did not affect these trials in 2001, however, turnip and cabbage aphids were detected at Kalannie and Kellerberrin. Insect control will be included in the agronomy trials for 2002. GRDC Project No.: - Paper reviewed by: Paul Carmody, Brent Pritchard -16- Canola variety performance in Western Australia Kevin Morthorpe, Stephen Addenbrooke and Alex Ford, Pioneer Hi-Bred Australia P/L KEY MESSAGE Genetic improvement is likely to lead productivity gains in agriculture in future. A new canola variety with the CLEARFIELD* trait has shown great promise as an alternative option to TT canola in herbicide tolerant [HT] cropping systems. Pioneer® 44C73 delivers a complete package of proven consistent performance, high yield, canola quality, improved agronomic traits and weed control. INTRODUCTION AND AIMS TT varieties, Karoo and Pinnacle have dominated the total area planted to canola in Western Australia. This dependence on TT canola is being challenged by new variety options that will help to ensure Australian farmers maintain market access and are very competitive in world oilseed markets. The resistance mechanism in TT varieties is associated with photosynthesis in the plant and this reduces seedling vigour and vegetative growth resulting in lower oil and yield potential. Canola breeders have developed varieties without this yield or oil penalty and which offer growers increased herbicide options across the rotation to control a broad spectrum of weeds. Previous comparisons of canola variety performance have concentrated on replicated small plots only. There is an increasing trend across all States towards larger scale side-by-side tests on-farm. This update will summarise the yield performance of new varieties compared to the benchmark varieties in Western Australia using the combined results from a range of trials. METHOD In 2001 trials were conducted over many locations in the State by various organisations. A new canola variety, 44C73, was used as an example, to present data from the complete range of individual locations and commercial varieties using different trial formats. Locations covered most rainfall zones and trial formats included replicated small plots to larger scale strips (limited or no replication) cultivated with grower equipment and commercial management systems. All trials published were audited for uniformity visually and using the accepted industry standard for experiment analysis of variance, i.e. CV < 15.0. Average data for individual pair-wise variety comparisons are unadjusted and were not weighted using across site analysis. RESULTS The new variety, 44C73 with the CLEARFIELD trait for herbicide tolerance, has shown consistently higher yield across a wide range of locations, management systems and trial formats than the benchmark varieties and other varieties grown in the State (Table 1). Testing of 44C73 in the State has been conducted over three (3) seasons with similar promising results. Across all trials conducted throughout the State last season, 44C73 yields show an average advantage of 43 per cent than Pinnacle; 30 per cent than Surpass 300 TT; 20 per cent than Hyden; 18 per cent than Karoo; 11 per cent than Surpass 402CL and 603CL; and 4 per cent than Surpass 501TT. It has also demonstrated better seedling vigour, canola quality, higher oil and protein contents than Karoo and Pinnacle in addition to good blackleg resistance and excellent standability for ease of harvest. CONCLUSION Canola varieties should be evaluated over many locations and across years for greater accuracy in predicting in-field performance. There are advantages in using replicated small plots in conjunction with larger scale side-by-side trials to ensure consistency in variety performance and determine the benefits of new alternative technologies. 44C73 sets the new benchmark in early maturity herbicide tolerant varieties for canola growers in the State. The CLEARFIELD trait will help growers increase their yields, provide extra herbicide options to control many troublesome weeds in-crop (particularly wild radish), and meet international standards for canola quality. There may also be a fit for new varieties such as 44C73 as a canola option to other -17- varieties where there are residual levels of SU and Group F herbicides in rotation, and is ideal for environmentally sensitive situations limiting future use of triazine herbicides. KEY WORDS canola varieties, herbicide options Table 1. Performance of canola varieties in WA 2001 402CL 44C73 Location 501TT 44C73 Arthur River (BASF) Location 1.744 1.871 Cunderdin (AgriTech) 2.000 2.200 Cunderdin (AgriTech) 2.000 2.200 Geraldton (Elders) 1.917 1.990 Cunderdin (BASF) 1.227 1.140 Hyden (Elders) 1.540 1.860 Hyden (Dept. of Agric.) 1.421 1.577 Mingenew East (MIG) 0.940 0.830 Geraldton (CAWA/WFL) 1.020 1.220 Mingenew Sth (C/M) 1.990 2.060 Geraldton (Elders) 1.933 1.990 Scadden (WFL) 1.830 1.929 Lake O'Connor (Dept. of Agric.) 1.132 1.286 Average 1.277 1.359 603CL 44C73 Mingenew East (MIG) 0.940 0.830 Mingenew Sth (C/M) 2.000 2.060 Newdegate (Dept. of Agric.) 0.762 1.388 Arthur River (BASF) 1.421 1.871 Scadden (WFL) 1.604 1.929 Cunderdin (AgriTech) 2.300 2.200 Williams (PHA) 1.640 1.930 Cunderdin (BASF) 1.435 1.140 Williams (PHA) 2.150 2.720 Geraldton (C/M) 0.940 1.220 Wubin (BASF) 0.498 0.572 Geraldton (Elders) 2.034 1.990 Wubin (PHA-381) 1.600 1.600 Scadden (WFL) 1.912 1.929 Wubin (PHA-282) 1.570 1.730 Wickepin (CAWA) 0.276 0.278 Average 1.367 1.532 Williams (PHA) 2.080 1.930 Williams (PHA) 1.560 2.720 Location Karoo 44C73 Wubin (BASF) 0.584 0.572 Arthur River (BASF) 1.328 1.871 Wubin (PHA-381) 1.500 1.600 Cunderdin (AgriTech) 1.700 2.200 Wubin (PHA-282) 1.800 1.730 Cunderdin (BASF) 0.995 1.140 Average 1.487 1.598 Geraldton (Elders) 1.523 1.990 Hyden (Dept. of Agric.) 1.238 1.577 Pinnacle 44C73 Lake O'Connor (Dept. of Agric.) 0.983 1.286 Arthur River (BASF) 1.172 1.871 Mingenew East (MIG) 0.870 0.830 Cunderdin (AgriTech) 1.400 2.200 Mingenew South (C/M) 1.820 2.060 Cunderdin (BASF) 0.810 1.140 Newdegate (Dept. of Agric.) 1.010 1.388 Scadden (WFL) 1.407 1.929 Scadden (WFL) 1.407 1.929 Wickepin (CAWA) 0.231 0.278 Wubin (BASF) 0.394 0.575 Williams (PHA) 2.590 2.720 Average 1.021 1.296 Wubin (BASF) 0.214 0.572 Average 1.118 1.530 Location Location Hyden 44C73 Cunderdin (AgriTech) 1.600 2.200 Mingenew East (MIG) 0.900 0.830 Mingenew South (C/M) 1.780 2.060 Scadden (WFL) 1.648 1.929 Average 0.988 1.170 ® * Location C/M - (CAWA/MIG) Registered trademark of Pioneer Hi-Bred International Inc. Registered trademark of BASF. -18- Relative performance of new canola varieties in Department of Agriculture variety trials in 2000 and 2001 S. Hasan Zaheer, GSARI, Department of Agriculture, Katanning G. Walton, Crop Improvement Institute, Department of Agriculture, South Perth KEY MESSAGE • The main features to consider when selecting suitable variety for your paddock are early vigour, maturity, level of blackleg resistance, potential yield and oil content in that specific environment. • If possible, include two varieties of different maturity in your cropping program to reduce risk of unpredictable growing season. INTRODUCTION Recently a number of new canola varieties have been released. Information on responses of these new varieties in different agricultural regions and/or annual rainfall zones is important to enable growers to make decisions about variety selection. Two opportunities to compare these new varieties in Department of Agriculture variety trials occurred in 2000 and 2001. The seasons were challenging for crop performance, with, in most regions in 2000, a late start to seeding and low rainfall during the season, and in 2001, a prolonged dry period after seeding, plus the damage to crops by insects, particularly by DBM in the northern region. This summary records the relative performances of the new varieties in the season 2000 and 2001, as influenced by variety maturity, rainfall of different climatic zones and the seasonal variations. DESCRIPTION OF SOME CHARACTERISTICS OF THE VARIETIES Triazine tolerant varieties in comparison with Karoo Variety Height Maturity Oil concentration1 Dept. of Agric. blackleg rating2 Karoo Medium Early 38.8 4 ATR-Beacon Medium Early - mid 39.8 5 ATR-Grace Medium Late 39.6 7P ATR-Hyden Medium Early - mid 39.2 6 TI1 Pinnacle Medium Mid - late 39.3 6 Surpass 300TT Medium - short Early 40.9 4P Surpass 501TT Medium Early - mid 42.7 8+P Surpass 600TT Tall Mid - late 40.5 6 ATR-Eyre Tall Early 41.8 N/A 1 Oil % (at 8.5% seed moisture). Limited number of trials in 1999 and 2000. The Department of Agriculture ratings for resistance to blackleg combines both the plant survival and stem canker scores. 1 = highly susceptible, 8+ = highly resistant. N/A Rating not available because of insufficient data. P Rating is Provisional, based on a minimum of data. 2 -19- Clearfield System varieties in comparison with Karoo Oil concentration1 Dept. of Agric. blackleg rating2 Early 43.4 8+ Medium Mid 42.4 8+P Medium Mid 42.1 5 44C73 Medium Early 41.6 5P 46C74 Medium Mid - late 41.8 4P 45C75 Medium Mid 42.0 N/A Karoo Medium Early 40.0 4 Variety Height Maturity Surpass 402CL Medium Surpass 603CL 44C71  Trade Mark of BASF. Non-herbicide tolerant varieties in comparison with Oscar Variety Height Maturity Oil concentration1 Dept. of Agric. blackleg rating2 Surpass 400 Medium Early 44.6 8+ Hyola 60 Tall Mid 45.6 8+ Purler Tall Mid - late 47.0 6 Ripper Medium Late 45.4 5 Mystic Medium Early 44.2 4 Surpass 600 Medium-tall Mid 45.2 5 Oscar Medium Mid 41.8 5 Ag-Emblem Medium Mid 42.1 6 Monty Medium Early 43.4 4 Georgie Medium Early - mid 43.6 4 Ag-Outback Medium Early 43.0 4 46CO3 Tall Late 41.8 4P Dunkeld Medium - tall Late 43.4 6 Lantern Tall Early - mid 46.0 N/A Rivette Medium Early 44.9 N/A Rainbow Medium Early - mid 41.9 5 AC-Castle Medium Early - mid 46.6 N/A AV-Fortress Medium Mid 45.3 N/A Karoo Medium Early 40.0 4 FLOWERING RELATIVE TO CONTROL VARIETY Flowering dates of the varieties were recorded on many trials, histograms showing the differences in days after sowing that 50% of plants had first flowers are presented for the different types of herbicide tolerance. The flowering differences are recorded for the north, central and south agricultural regions in WA: North region includes the Geraldton district out to Yuna, Mullewa and Coorow. Central region includes Badgingarra, Wongan Hills, Cadoux, Merredin, Hyden and Williams. South region includes Katanning, Mount Barker, Newdegate and Esperance. -20- Days after sowing Average flowering time of TT canola varieties in 2000 and 2001 North Central South 100 80 60 40 20 0 roo Ka n e on de rac y ac e G H B RTR RT T A A A le T T re TT ac 1T 0T Ey 0 n 0 0 0 n 5 6 Pi s3 TR ss ss ss a a A a p p r r rp Su Su Su TT canola variety Days after sowing Average flowering time of Clearfield canola varieties in 2000 and 2001 South North 100 80 60 40 20 0 1 C7 4 4 2 C7 6 4 3 C7 4 4 4 C7 6 4 5 C7 5 4 L L 3C 2C 0 0 s4 s6 as as p p r r Su Su Clearfield canola variety Days after sowing Average flowering time of non-herbecide tolerant canola varieties in 2000 and 2001 South North 120 100 80 60 40 20 0 r k m e w w r 0 c e n ty d ca bo on bac orgi ble ysti 400 astle kel la 6 urler ippe 600 ter ignia tress ivett nbo n s s i o n s Os ain M ut m r s s e C a M P R R Ra a a E G L In - Fo R Du Hy -O rp AC rp V Su Su AG A Non-herbecide tolerant canola variety All herbicide and non-herbicide tolerant varieties flowered earlier in Northern agricultural regions compared to the Southern agricultural regions, while most of the TT varieties delayed flowering in the Central agricultural region compared to both Northern and Southern agricultural regions. This is an adoptive response of varieties to cope with unpredictable seasonal influences, which were more severe in the Central region in 2001. -21- GRAIN YIELD A summary of the yield of varieties is presented as relative (percentage of) to Karoo for the herbicide resistant varieties and to Oscar for the non-herbicide resistant varieties. The yields are grouped into geographic/agricultural regions and average annual rainfall zones. Triazine tolerant varieties in the northern region Relative seed yield of Triazine tolerant (TT) canola varieties (% of Karoo) in the Northern Region High rainfall (HRF*) 2000 2000 2001 Mean 2000 2001 Mean Karoo 100 100 100 100 100 100 100 ATR-Beacon 100 100 94 97 79 90 85 84 84 95 95 107 104 79 100 90 81 31 85 38 Variety Medium rainfall (MRF)** ATR-Grace ATR-Hyden 121 101 Bugle 87 81 Pinnacle 86 72 Surpass300TT 83 83 83 83 Surps501TT 91 106 125 116 Surps600TT 92 82 98 90 111 111 98 ATR-Eyre No. of trials LSD 5% 1 3 1 15 16 24 Low rainfall (LRF)*** 31 74 56 128 78 103 119 100 109 40 85 67 103 103 20 1 1 28 18 23 Trials were located at Geraldton, Mingenew, Coorow, Watheroo, Yuna (sown between 10 and 29 May) and at Mullewa (sown 15 June) in 2000 and 2001. * High rainfall (HRF) = 450-750 mm ** Medium rainfall (MRF) = 325-450 mm *** Low rainfall (LRF) = < 325 mm Triazine tolerant varieties in the central region Relative seed yield of Triazine Tolerant (TT) canola varieties (% of Karoo) in the Central Region Variety High rainfall Medium rainfall Low rainfall 2000 2001 Mean 2000 2001 Mean 2000 2001 Mean Karoo 100 100 100 100 100 100 100 100 100 ATR-Beacon 118 102 98 100 101 106 103 86 86 87 87 90 85 103 99 101 59 74 94 106 118 118 108 117 112 80 Bugle 90 82 90 59 Pinnacle 97 128 112 54 84 69 70 86 78 Surpass300TT 85 66 76 90 75 82 106 90 98 Surpass501TT 110 96 103 101 103 102 78 99 88 Surpass600TT 100 147 123 65 79 72 71 127 127 85 85 ATR-Grace ATR-Hyden ATR-Eyre No. of trials LSD 5% 2 1 14 33 24 3 2 25 14 20 74 76 73 102 102 2 3 20 13 17 Trials were located at Badgingarra, York, Wongan Hills, Cadoux, Meckering, Kunjin, Newdegate, Williams, Merredin and Hyden, sown between 8 May and 15 June in 2000 and 2001. -22- Triazine tolerant varieties in the southern region Relative seed yield of Triazine tolerant (TT) canola varieties (% of Karoo) in the Southern Region High rainfall Variety Medium rainfall 2000 2001 Mean 2000 2001 Mean Karoo 100 100 100 100 100 100 ATR-Beacon 121 132 126 119 113 116 130 130 98 98 135 125 114 99 107 96 88 124 100 83 ATR-Grace ATR-Hyden 115 Bugle 96 Pinnacle 107 141 88 92 Surpass300TT 90 82 86 99 99 99 Surps501TT 95 128 111 114 97 105 Surps600TT 99 119 109 87 86 86 97 97 103 103 ATR-Eyre No. of trials LSD 5% 2 2 13 26 20 4 1 15 15 15 Trials were located at Newdegate, Katanning, Mount Barker, Esperance, Wittenoom Hills and Ravensthorpe, sown between 10 May and 14 June in 2000 and 2001. Clearfield System  varieties in the north, central and south regions Relative seed yield of Clearfield Production System  varieties (% of Karoo) in the Northern, Central and Southern Regions Central Region Variety North* 2000** Med. RF 2000** Southern Region Low rainfall High RF Medium rainfall 2000** 2001 Mean 2001 2000** 2001 Mean 100 Karoo 100 100 100 100 100 100 100 100 44C71 58 93 135 135 110 125 97 111 46C72 40 54 122 122 75 75 44C73 164 131 131 99 168 103 136 46C74 115 103 103 105 120 78 99 100 100 108 85 85 115 104 92 126 81 104 115 115 45C75 Surps402CL 162 Surps603CL 115 No. of trials LSD p = 0.05 2 113 92 115 6 30 1 95 138 92 1 2 3 2 25 26 25 14 * Northern Region. ** The comparison of varieties in these trials were conducted without the use of herbicides in 2000. In 2001, three trials were conducted comparing the varieties using the Clearfield System. Trials were located at Coorow, Mullewa, Meckering, Kunjin, Beverley, Wongan Hills, Newdegate, Katanning, Wittenoom Hills, Mount Barker and Esperance, sown between 10 May and 15 June in 2000 and 2001. -23- Non-herbicide tolerant varieties in the north, central and south regions Relative seed yield of non-herbicide tolerant varieties (% of Karoo) in the Northern, Central and Southern regions, with medium to low annual rainfall Central Region Southern Region North* med. RF 2000 Med.-Low RF Low RF 2000 2001 2000 2001 Karoo 100 100 100 100 100 Oscar 100 95 Monty 137 149 109 119 129 124 AG-Outback 133 160 103 151 128 140 119 119 Georgie 112 119 94 122 107 114 Emblem 87 117 115 120 122 121 144 118 118 120 124 122 96 99 108 114 114 114 136 103 144 140 106 123 86 74 Variety 125 Rivette Mystic Rainbow Surpass400 46CO3 No. trials LSD p = 0.05 Medium RF 127 Mean 100 125 100 100 1 3 1 2 1 27 28 25 27 12 20 * Northern Region. Trials were located at Coorow, Meckering, Kunjin, Hyden. Newdegate, Katanning, Wittenoom Hills and Esperance, sown between 10 May and 14 June in 2000 and 2001. Relative seed yield of non-herbicide tolerant varieties (% of Oscar) in the Southern and Central Regions, with high annual rainfall Variety Southern Region Central Region 2000 2001 Mean 2000 100 100 100 100 102 102 93 85 89 95 Hyola 60 97 109 103 111 Rainbow 106 103 105 99 Purler 88 97 92 91 Ripper 92 118 105 98 Surpass600 86 96 91 93 103 103 87 87 Oscar AC-Castle Dunkeld Lantern AV-Fortress No. trials LSD p = 0.05 4 2 30 14 1 22 12 Trials were located at York, Newdegate, Bridgetown, Katanning, Mount Barker, Boxwood Hills and Esperance Downs, sown between 4 May and 14 June in 2000 and 2001. NEW VARIETIES SHOWING GOOD YIELD AND BLACKLEG CHARACTERISTICS IN 2000 AND 2001 Triazine tolerant varieties Northern region: High annual rainfall: Medium annual rainfall: Low annual rainfall: ATR-Hyden, ATR-Beacon Surpass 501TT, ATR-Hyden (ATR-Eyre, a promising variety) ATR-Beacon and ATR-Hyden (ATR-Eyre, a promising variety) -24- Central region: High annual rainfall: Medium annual rainfall: Low annual rainfall: Surpass 600TT, ATR-Grace, ATR-Hyden, Pinnacle, (ATR-Eyre, a promising variety, but has lower blackleg tolerance than the other varieties) Surpass 501TT, ATR-Beacon ATR-Beacon, ATR-Hyden (ATR-Eyre, a promising variety) Southern region: High annual rainfall: Medium annual rainfall: ATR-Grace, ATR-Beacon, ATR-Hyden, Pinnacle ATR-Beacon, ATR-Hyden, Surpass 501TT Clearfield System varieties Northern region*: Surpass 402CL and Surpass 603CL Central region*: Medium annual rainfall: Low annual rainfall: 44C73, 44C74, Surpass 402CL 44C71, 44C73, Surpass 603CL Southern region: High annual rainfall: Medium annual rainfall: 44C71, 46C74, 45C75 44C71, 44C73, Surpass 603CL * Performance was evaluated in the absence of in-crop herbicide. Non-herbicide tolerant varieties Northern region: Medium annual rainfall: Mystic, Surpass 400, Monty, AG-Outback Central region: High annual rainfall: Medium annual rainfall: Low annual rainfall: Hyola 60 AG-Outback, Monty Surpass 400, Monty, Emblem, Mystic (Rivette, a promising variety) Southern region: High annual rainfall: Medium annual rainfall: Rainbow, Ripper, Lantern, Hyola 60, AGC-10/AGC0Castle AG-Outback, Monty, Rivette, Georgie, Emblem, Mystic, Rainbow, Surpass 400 GRDC Project No.: DAW 714 Paper reviewed by: Graham Walton, Dave Eksteen -25- Which canola cultivar should I sow? Imma Farré, CSIRO Plant Industry, Floreat ([email protected]) and Bill Bowden, Western Australia Department of Agriculture, Northam KEY MESSAGE The choice of canola cultivar to maximise yield and oil content depends on factors such as location, soil type and sowing date. Simulation modelling can provide expected yields for combinations of these factors. Knowledge of the expected yield can help in crop management options such as choice of cultivar for each location. It can also help to optimise fertiliser inputs. INTRODUCTION Which cultivar to sow to match the break of the season and soil type in any region is a perennial question for cropping in Western Australia. For traditional crops such as wheat, there is a large trial database, which can be referred to. Given the variability from site to site and season to season in the relative performance of cultivars, even this data base has been found to be too small, particularly when used to determine the appropriate sowing time of new cultivars. For newer crops such as canola, local information based on field trials is limited to a few seasons. A validated simulation model offers an ideal way of addressing the problem of site and season variability in agronomic data. The aim of this paper is to demonstrate the strength of the simulation approach in providing information that can improve crop management decisions, such as the choice of cultivar for different times of sowing, canola cultivars, soil types and locations in the variable environment of Western Australia. METHODS The APSIM-Canola model has been tested against data from Eastern Australia (Robertson et al. 1999) and Western Australia (Farre et al. 2001). The model was used in simulation experiments with 100 years of climatic data, for 6 locations in Western Australia, 5 times of sowing (from 5 April to 24 June), 2 soil types (duplex/heavy and sand) and 2 cultivars (short and long season). The cultivars Monty and Oscar (both non TT) were used in the simulations as representative of a short and a long season cultivar, respectively. Current management practices were selected for the simulations (sowing depth 2 cm, plant density 80 pl/m2). In the simulations nitrogen supply was high and assumed to be not limiting. The model simulates yields free of pests or diseases. RESULTS AND DISCUSSION When sowing on the 5 April, the long season cultivar out yielded the short season cultivar in most of the locations and soil types (Table 1). When sowing on the 25 April, the long season cultivar had a yield advantage only in the higher rainfall locations, such as Geraldton, Kojonup and Esperance. For sowing dates later than the end of April, the short season cultivar had higher yields in most of the years in all locations. These results highlighted that in the event of an early sowing opportunity (April), the choice of cultivar is an important issue, and that the choice will depend on the location. The median yields of cultivar Monty sown on 5 April ranged from 1.6 to 3.7 t/ha for the different locations (Table 1). Combining crop modelling with additional information can improve the choice of cultivar. Information such as summer rainfall, or residual water in the soil from previous year, can improve the choice of cultivar. For example, in Mullewa, on a duplex soil, sown on the 5 April, a long season cultivar would out yield a short season cultivar on average in 53% of the years (Table 1). Using rainfall information to divide the 100 years into wet and dry summer years, we can see that the probabilities of a higher yield with a long season cultivar would be 65% in the wet summer years but only 40% in the dry summer years. Simulation yields can be presented in different ways. Figure 1 shows the median yields for 100 years of simulations for Monty and Oscar in two of the locations on a duplex soil. Simulated yields for combinations of location, soil type, cultivar and sowing date can be used to improve crop management. Based on the yield expectation and its probability, growers can establish whether or not to include canola in the rotation in a given year. Knowledge of expected yields can also improve the choice of cultivar and the optimisation of fertiliser inputs. A modelling approach allows us to obtain this information for each location. -26- Table 1. Ag zone 1 2 Percentage of years that the long season cultivar out yields the short season cultivar, for 6 locations in different Agricultural Zones, 2 soil types and 5 sowing dates. Also included are the median yield of the short season cultivar (Monty) sown at 5 April and the yield difference of the long season cultivar (Oscar) sown at the same date. Shaded cells show percentages greater than 50 Geraldton Wongan Hills 3 Kojonup 4 Mullewa 5 Salmon Gums 6 Esperance 5 April 25 April 4 June Duplex 92 Sand 91 64 8 1 3 3.2 0.5 67 22 9 20 2.2 0.3 Duplex Sand 66 13 0 1 2 3.4 0.2 76 22 6 8 14 2.5 0.2 Duplex 70 57 26 4 8 3.7 0.1 Sand 67 36 18 10 21 2.9 0.1 Duplex 53 11 4 2 2 2.5 -0.1 Sand 73 23 8 14 15 1.6 0.2 Duplex 38 21 29 21 25 2.1 -0.2 Sand 62 31 40 42 54 1.7 0.0 Duplex 87 31 13 17 11 3.7 0.3 Sand 90 61 48 41 42 3.0 0.5 Mullewa Esperance 5.0 4.0 4.0 Yield (t/ha) Yield (t/ha) (t/ha) Oscar difference 15 May 5.0 3.0 2.0 3.0 2.0 1.0 1.0 0.0 30-Mar 29-Apr 29-May 0.0 30-Mar 28-Jun 29-Apr 29-May 28-Jun Sowing date Sowing date Figure 1. 24 June (t/ha) Monty yield Sowing date Soil type Location Median yields for a 100-year simulation for Esperance and Mullewa for a long season cultivar (Oscar) (-•-) and a short season cultivar (Monty) (--) on a duplex soil. CONCLUSIONS Given canola is a relatively new crop in Western Australia, information derived from field experiments is currently limited to a few seasons and sites. The APSIM-Canola model, together with historical weather data, can be used to simulate canola yields and its probability distributions. Expected canola yields can be obtained for different soil types, cultivars, locations and sowing dates across the cropping area of Western Australia. This information can help growers make crop management decisions, such as the choice of cultivar and the amount of fertiliser input. ACKNOWLEDGMENTS This research has been funded by the Grains Research and Development Corporation REFERENCES Farre, I., Robertson, M.J., Walton, G.H. and Asseng, S. (2001). Simulating response of canola to sowing date in Western Australia. Proceedings 10th Australian Agronomy Conference. Hobart. Robertson, M.J., Holland, J.F., Bambach, R. and Cawthray, S. (1999). Response of canola and Indian mustard to sowing date in risky Australian environments. Proceedings 10 th International Rapeseed Congress. Canberra. CD-ROM. GRDC Project No.: Paper reviewed by: CSP293 Paul Carmody -27- The effect of seed generation and seed source on yield and quality of canola Paul Carmody, Department of Agriculture, Northam, Western Australia KEY MESSAGE In this trial yield and quality did not decline for Karoo and Pinnacle grown from seed retained for up to three generations. AIM To determine the effect on yield (performance) and oil quality of different generations of canola seed compared to ‘new’ or quality assured seed. BACKGROUND The effect of retaining successive generations of canola seed on yield and quality of canola has long been a concern amongst canola breeders, agronomist and growers. In theory a decline in quality and yield would be expected due to contamination, cross pollination and increase variability in maturity with successive generations of retained canola seed. Canola varieties are not genetically homogenous and continue to segregate for plant characters with each successive generation. Canola is approximately 30% outcrossing which also contributes to genetic impurity with each generation. Seed source has been shown to effect the performance of other crops (e.g. lupins) but very limited work has been done with canola in this regard. In 1994 a trial was set up in Katanning (95GS108) where grower seed and company seed of various generations were tested over two years. Unfortunately the results of this trial were inconclusive due to poor establishment but it did show some trend for declining yield with each subsequent generation of retained canola seed. This needs to be investigated further. METHOD During the harvest of 1999, seed was collected from a range of canola growers across the State who were retaining seed for sowing in 2000 (Treatments 2, 4, 6 and 9). Dovuro also supplied QA seed released in 1999 (Treatments 1 and 8), and 2000 (Treatments 3 and 5) for both Karoo and Pinnacle. This seed was then grown out at two locations; Beverley (00AD73) and Katanning (00GS80) in 2000 on high (120 Agras plus 100 Urea topdress) and low (60 Agras plus 70 Urea topdress) fertiliser inputs. The seed yields were obtained and the harvested seed from Beverley was retained for re-planting in 2001. The seed retained in 2000, along with fresh 2001 QA seed of Pinnacle and Karoo (Treatments 10 and 11) were sown at Beverley on 30 May. All sown seed was graded off the top of a 1.7 mm sieve to remove any potential seed size effects. The trial (01AD09) was direct harvested and analysed for yield and oil quality, including erucic acid contents using NIR and gas chromatography techniques. RESULTS There was no differences between the high and low fertiliser level s indicating that fertility had no effect on retained seed at these sites. Karoo yielded slightly better than Pinnacle but there was no difference in retained seed compared to new certified seed. -28- Table 1. Treatment Summary of mean grain yields from different sources/generations sown at Avondale in 2001 (01AD09) Seed source Generation Variety Hi fert. Lo fert. 1 QA 1999 3 Karoo 1526 1478 1502 6 8 QA 1999 3 Pinnacle 1456 1196 1326 6 3 Pedigree 2000 2 TM8 1489 1444 1467 6 5 QA 2000 2 Karoo 1381 1522 1452 6 1267 1393 7 QA 2000 2 Pinnacle 1330 6 10 QA 2001 1 Karoo* 1300 3 11 QA 2001 1 Pinnacle 1296 3 4 Grower South 1 4 Karoo 1448 1474 1461 6 6 Grower Central 3 4 Karoo 1463 1426 1444 6 9 Grower East 3 4 Karoo 1393 1256 1324 6 2 Grower North 2 4 Karoo 1493 1445 1469 6 Mean 1435 1404 LSD 5% for comparing within treatment 10 and 11 LSD 5% for comparing treatment 10 and 11 with the rest LSD 5% for comparing within treatment s 1 to 9 * Average No. plots 1397 162.1 140.4 3 vs 3 3 vs 6 114.6 6 vs 6 Two plots harvested only. The quality data for the trial was assessed on composite samples of each replicate, therefore no statistical analysis was possible. There was no apparent trend of deterioration of seed quality over successive generations of canola from this trial. CONCLUSION In this trial there were no significant difference of yield found in comparing QA seed with retained seed for 2 consecutive years whether it was Karoo or Pinnacle. The level of nutrition (high or low fertiliser input), had little effect on the performance of retained canola. ACKNOWLEDGMENTS Emmon Rath, Dovuro who supplied the QA seed each year and assisted in the analysis of the seed quality for the seed grown out in 2000 trial. Ms Jane Speijers, Biometrics Section, Department of Agriculture for statistical analysis of data. GRDC Project No.: GOP -29- The accumulation of oil in Brassica species J.A. Fortescue and D.W. Turner, Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009 and B. Tan, PO Box 1249, South Perth WA 6951 KEY MESSAGE Increasing the rate of growth of the cotyledons in developing canola seed delayed the beginning of oil accumulation, but increased its rate when it did begin. This combination of features would increase oil concentration at maturity if the time available for oil accumulation was not limited by environmental or genetic constraints. INTRODUCTION The accumulation of oil in canola seed has a space and time dimension. The space dimension describes the location of the oil in the tissues of the seed. The oil concentration will be low if the tissue that contains it occupies only a small proportion of the seed. The time dimension describes when the oil accumulates during the growth of the seed. The oil concentration will be low if the time over which the oil accumulates is short, or the rate at which it accumulates is low. Hocking and Mason (1993) provide a good description of the time component of oil accumulation for canola grown in southern NSW. In their study, oil did not accumulate at all in the first 30 days after flowering and then the rate increased to about 1.7%/day in the oil accumulation phase, which lasted about 25 days (each of these phases was about 400 growing degree days, Turner and Farre 2000). After this, the oil concentration stabilised. Among the tissues of the canola seed, oil accumulates in the cotyledons of the embryo. Thus, the oil concentration in the seed will be influenced by the size of the cotyledons, relative to the remainder of the seed, and the concentration of oil in the cotyledon tissue. We may expect that seeds with large cotyledons will have high oil concentrations. However, conditions that occur early in the development of the seed and might increase cotyledon size, for example improved supply of water or nitrogen, do not necessarily increase oil concentrations in mature canola seed. If we increase the rate at which the cotyledons grow, does it affect the concentration of oil in the seed, either by increasing the time over which oil accumulates or the rate at which it occurs? This knowledge will contribute to understanding the impact of management, environment and genetics on oil concentrations in canola seed. AIM To determine the impact of changing the rate of development of canola embryos on the growth of the cotyledons and oil accumulation in them. METHOD In 1999, (project GRS6) plants of canola cv. Monty were grown in 30 cm plastic containers in a glasshouse and thinned to a single plant per container. We changed the ratio of leaf surface area to the number of siliqua (pods) developing on the inflorescence. There were two treatments - unpruned (control) and pruned, with 42 plants per treatment in 3 replications. To prune, we removed the lateral inflorescences as soon as they appeared. Each flower was labelled at anthesis giving us a population of siliqua of known ages. Siliqua, and their growing seeds, were sampled at 25, 30, 50 and 56 days after flowering. Samples of seed were fixed, examined under a light microscope and the sectional areas of the different organs in the seeds, including cotyledons, was measured using ‘video trade version 3.45 colour video measurement system’, © 1997 Leading Edge Pty Ltd, Adelaide, Australia (Project 292). We repeated this experiment in 2001 (project UWA 368) in a sunlit phytotron at 20/13C, day/night temperature. We examined cvs Monty, Mystic and Karoo and changed our sampling procedure so that we measured a daily increment in growth and oil accumulation from fertilisation to maturity. A photographic record of the growing embryos was made. -30- RESULTS Pruning the lateral inflorescences increased the length of the mature siliqua on the main stem by 10%, the number of seeds within by 6% and, in the first 50 days after flowering, delayed the accumulation of oil by about a week. Then, the oil accumulated at twice the rate and by 56 days after flowering, the seed on the pruned plants contained 7% more oil than seed on the unpruned plants. Pruning increased the cross-sectional area of the cotyledons by 3 to 7%. The organs of the pruned plants tended to delay the onset of rapid expansion by up to 5 days, but they grew more rapidly when begun, to arrive at the same or slightly larger size. Pruning appeared to have the most effect on the outer cotyledon and radicle. During the oil filling phase, the seeds from the pruned plants were slightly larger, had slightly larger embryos and more importantly, slightly larger cotyledons. Pruning did not affect the amount of protein bodies in the cotyledons. At maturity, after desiccation, the proportion of the seed occupied by the cotyledons did not differ between the treatments. In both experiments, pruning caused the mainstem inflorescence to continue to elongate, thus increasing the height of these plants compared with controls. On the control plants, the leaves began to yellow 23 days after flowering when the siliqua had reached 85% of their final size. On the pruned plants leaves were still green and intact at 50 days after flowering, when the siliqua had reached their final length. About 6 weeks after flowering, the seeds separated from the siliqua walls and changed colour, beginning at the chalazal end, i.e. the end not attached to the siliqua, changing from green to black over 2 to 3 days while the embryo within changed from green to yellow. The embryo changed from green to yellow over 3 to 5 days. It was not unusual to see half-green embryos inside newly blackened seeds. The timing of the final phase of maturation - the blackening of seeds, occurred 41 to 45 days after anthesis and did not vary between cultivars or treatments, despite the amount of green foliage still remaining on the pruned plants. We have yet to discover whether this difference is associated with a change in oil concentration. CONCLUSION Increasing the early rate of development of the cotyledons, the oil bearing tissues (e.g. by increasing the supply of nitrogen), does not automatically increase oil concentration in the mature seed. Increased early growth of cotyledons delays the beginning of oil accumulation slightly, but when it starts it goes at a faster rate. If this combines with a long period of accumulation (associated with cool growing conditions and early sowing), final oil concentration will be high. On the other hand, a 'good start' to oil accumulation may be limited later by warmer weather that reduces the time over which oil accumulates, or dry conditions that may reduce the rate of oil accumulation, thus producing seed with low oil concentrations. KEY WORDS canola, embyro growth, oil concentration, cotyledon ACKNOWLEDGMENTS Dr N. Galwey and Doug Hall contributed to the design of the first experiment and Dr D. Harris, Chemistry Centre of Western Australia, advised B. Tan about the analysis of oil concentrations. Prof J. Kuo and H. Ngo provided advice on microscopy. REFERENCES Hocking, P.J. and Mason, L. (1993). Accumulation, distribution and redistribution of dry matter and mineral nutrients in fruits of canola (oilseed rape) and the effects of nitrogen fertiliser and windrowing. Australian Journal of Agricultural Research 44: 1377-1388. Turner, D.W. and Farre, I. (2001). Simulating oil concentrations in canola - virtually just the beginning. Crop Updates 2001, 21-22 February 2001, Burswood, WA 2 pages. GRDC Project Nos: GRS 6, UWA 292, UWA 368 Paper reviewed by: Dr Bill Bowden -31- Potential and performance of alternative oilseeds in WA Margaret C. Campbell, Centre for Legumes in Mediterranean Agriculture KEY MESSAGE The agronomic performance of a number of different oilseed species to WA growing conditions is currently being measured. These alternative oilseeds have a range of qualities and characteristics that make them suitable for different markets not accessed by canola. Some have potential as specialty oils with health benefits and others are highly desirable as industrial oils. Trials conducted at a range of sites in the wheatbelt of WA have shown that some of the species are well adapted to WA and often produced higher yields than canola. BACKGROUND The major focus of this research is to evaluate a range of edible, industrial and pharmaceutical oilseed species for their suitability to Australian growing conditions. The oilseed industry has expanded rapidly over the past five years in Australia. It is currently dominated by canola, however, as disease, insect and economic pressures change, canola may not continue to provide agronomic/economic benefits. There are other potentially valuable oilseed species that have been neglected in Australia, which have the potential to be grown for the production of oils to fit different niches in the markets. Some of the species are already being cropped in other countries. Increasing the diversity of crops that may be profitably grown may also have additional benefits in rotations, as disease breaks and in the reduced use of chemicals. METHODS In May 2000 and 2001, two trial sites were established on farmers paddocks; one at Miling, 200 km north-east of Perth, the other near Wagin, 220 km south-east of Perth. Plots were seeded using a cone seeder at varying seed rates depending on the species. In 2000, plots were 8 m long at Miling and 6 m long at Wagin and comprised 6 rows 20 cm apart. Plots were sown dry on 2 May at Miling and on 17 May at Wagin. In 2001, plots were 10 m long and comprised 8 rows 20 cm apart. Plots were again seeded dry on 3 May at Miling and on 20 May at Wagin. Karoo canola (Brassica napus) was used as a control in the trials. Brassica campestris and Sinapis alba (White mustard) were included for the first time in 2001. Plots were harvested at maturity using a conventional plot harvester. Seed for each species was collected, cleaned by sieving, weighed to determine yield and then analysed using soxhlets and gas chromatography for oil content and quality. The seed yields for both years are given, plus the oil content and quality for the 2000 harvest. RESULTS AND DISCUSSION The average harvest yields species and lines grown are shown in Table 1. The sowing rates are quoted in kg/ha and the cleaned seed yield in tonnes/ha. Table 1. Comparison of seed yield for a range of oilseed species Sowing rate Miling 2000 Miling 2001 Wagin 2000 Wagin 2001 Mean yield Canola (Karoo) 6 1.88 2.4 0.75 shattered 1.68 Brassica campestris 6 0.78 0.77 Brassica carinata 6 2.5 1.9 1.65 1.27 1.83 Brassica juncea 6 2.75 2.3 1.9 2.53 2.37 Camelina sativa 6 1.94 1.0 1.13 1.23 1.32 Crambe abyssinica* 15 2.54 1.9 1.3 1.11 1.71 Linum usitatissimum (Linseed) 30 1.8 1.75 1.0 1.0 1.39 Linum usitatissimum (Linola) 30 1.5 1.5 0.95 0.4 1.09 0.83 0.59 Species Sinapis alba * 0.75 6 0.35 The seed of Crambe abyssinica retains its fruit coat intact during and after harvesting, i.e. seed is unhulled. -32- The results quoted represent 4 of a total of 9 regional trials conducted by CLIMA/Paramount Seeds and the West Australian Department of Agriculture (2001 only). The new species had a similar maturity to the canola used as a standard, but had the advantage of not requiring swathing in these trials. In general, seed yield was comparable with Karoo canola; a promising result given that there has been little opportunity for selection of improved genotypes. Species such as Brassica juncea (Indian mustard) and B. carinata (Ethiopian mustard) performed much better than Karoo at both sites in each year. Camelina sativa and Crambe abyssinica also yielded well. In 2001, after an uncooperative end to the season, 95% of the canola was lost due to shattering at the Wagin site. The other species suffered losses of up to 25% due to high winds and the untimely rains that delayed harvesting. However, despite the adverse conditions, Brassica juncea and B. carinata produced consistently good yields. Yields of Sinapis alba were inferior to Karoo and the other mustards. The mediocre yields of Karoo may have been influenced by its susceptibility to blackleg disease (not measured). The mustards generally, Crambe abyssinica (Crambe), Camelina sativa (Camelina or False flax) and Linum usitatissimum (Linseed and Linola) have better resistance than Karoo. The Brassica campestris line on the other hand was very susceptible to blackleg. The species generally would have a place in the rotations with canola due to better resistance to root diseases. They also provide the opportunity for oilseed production in environments in which Canola often performs poorly, e.g. Linum usitatissimum is adapted to wet soils and Camelina sativa to sandy soils and could significantly out yield canola in such situations. Table 2. Comparison of oil content and fatty acid profiles for a range of oilseeds Species % Oil Palmiti Stearic Oleic Linolei Linoleni Canola (Karoo) 40 5 2 59 21 10 2 B. campestris X 35 2 1 10 12 8 56 B. carinata 39 3 1 9 15 11 47 B. juncea 36 4 2 31 25 11 13 Camelina sativa 38 5 3 17 16 36 15 3 Crambe abyssinica* 32 2 1 15 8 7 2 60 Linseed 37 6 5 18 18 52 Linola 35 7 4 15 70 3 Sinapis alba 26 6 3 18 12 12 10 34 * Eicosenoi Erucic Unhulled seed. Although the oil content of Karoo was highest, other species were comparable and there are breeding lines that are reportedly equal. Crambe abyssinica had typically high erucic acid, which makes it very valuable as an industrial oil. A very early maturing Brassica campestris line proved to have an unusually high erucic acid content for that species. This line, with its earliness, large fruit size and vigor, is worth further development. The mustards; Brassica juncea, B. carinata and Sinapis alba, all made good vegetative growth and higher yielding lines are likely to be available. Linseed and Camelina sativa are high in the Essential Fatty Acids, e.g. Omega 3 (Alpha linolenic acid). However, their high content of unsaturated fatty acid may influence their keeping qualities. Camelina oil is currently being marketed in Europe as a food, cosmetic and health food supplement. CONCLUSIONS Although niche market opportunities exist in all cases with the new oilseeds, market development is the main problem if they are to become viable crops in WA. Indian mustard has a market in India in excess of 160,000 tonnes, which is currently dominated by the Canadian producers. With an existing specialty local market this is one species worthy of serious marketing research. Camelina is included in food and cosmetic preparations and given its high Omega 3 content is an oilseed of considerable real potential. A market development and survey will be commenced this year with contact made with UK, French and Finnish companies currently marketing the oil. Linseed may represent an opportunity for local producers to revive the crop, which has fallen from favour. The European subsidy system provides little incentive for local linseed production or alternative oilseeds generally and export market opportunities are likely to arise. -33- ACKNOWLEDGMENTS This project is funded by Rural Industries Research and Development Corporation (RIRDC) and supported by Paramount Seeds. RIRDC Project No.: UWA 47a Paper reviewed by: Peter Carlton -34- Comparison of oilseed crops in WA Ian Pritchard and Paul Carmody, Department of Agriculture, Centre for Cropping Systems Northam. Margaret Campbell, Centre for Legumes in Mediterranean Agriculture BACKGROUND AND AIM In Africa and Europe a wide range of fully domesticated oilseed crops and semi-domesticated species are being grown commercially for edible, industrial and pharmaceutical oils. At present within WA only Canola is grown widely. With the diverse range of environments and soil types within the WA grainbelt there may be many opportunities/specialised niches for each oilseed. The aim of the two trials described here was to compare the growth and yield of oilseeds in WA. METHOD Two trials were conducted at Merredin and Muresk each species being sown at the known optimum seeding rate for the species. Plots were 8 rows (1.44 m) x 20 m sown on 2.5 m centres by 4 replications, a total of 40 plots. Seed and fertiliser were sown separately. Table 1. Trial site details for 01ME87 and 01AD68 Site Merredin Research Station-01ME87 Layer depth 0-10 cm Texture 10-20 cm Sandy-Loam Loamy-Sand Phosphorus mg/kg Muresk-01AD68 20-30 cm 0-10 cm 10-20 cm 20-30 cm Loam Loam Loam Loam 20 14 14 19 22 15 113 108 106 43 49 43 12 17 24 4 3 4 Nitrogen nitrate mg/kg 7 9 12 10 6 4 Nitrogen ammonium mg/kg 4 3 3 1 1 1 Organic carbon % 0.86 1.08 0.72 0.48 0.68 0.52 Potassium mg/kg Sulfur mg/kg Reactive iron mg/kg 535 818 1063 1234 1188 1176 EC dS/m 0.04 0.04 0.06 0.03 0.02 0.02 pH 1:5CaCl2 5.3 4.9 5.0 5.0 4.9 5.0 Table 2. Monthly rainfall for 01ME87 and 01AD68 Site J F M A M J J A S O N D Total M-O Merredin-01ME87 122 34 0 3 40 9 73 30 27 10 11 5 364 189 Muresk-01AD68 12.5 62 9.5 87 42.5 26.5 23.5 15.0 0 RESULTS AND DISCUSSION Thanks to the 2001 season both trials were sown into a drying seedbed with very dry conditions following sowing. Establishment at Merredin was relatively poor with the exception of the false flax which seemed to thrive under the adverse conditions which may be related to it’s very small seed size (1000 seed wt 0.9-1.5 g). At the Muresk site Lucerne Flea resulted in considerable damage with the false flax being the most affected again due it’s very small seed size and subsequent cotyledon size and crambe the least affected with its almost plastic/rubber leaf texture (Table 3). Growth and development at both sites was similar. Both trial sites had similar growing season rainfall and variable soil properties (Tables 1 and 2). The Avon Valley site 01AD68 showing its historical age with low pH, potassium and organic carbon per cent. It will also be interesting to see if the low soil sulfur levels at this site will have any affect on the oil properties of the different species compared to the Merredin Site. Initial observations at Merredin indicate that Diamond Back Moth did not appear to infect false flax. Crop yields at Muresk were generally disappointing when compared to the yields achieved at -35- Merredin. Both the false flax and crambe lines at Merredin yielded significantly better than the standard karoo plots with only the crambe line 33710 yielding significantly better than karoo at Muresk. The implications of these results and work carried out by M. Campbell CLIMA (see paper) are that it appears there are at least two species which may have potential in the WA grainbelt as oilseed alternatives to canola. Both species are grown and utilised overseas for various purposes ranging from pharmaceutical to an industrial slip agent. The inclusion of these species by growers into their rotations will be determined by market demand and the subsequent price received. Table 3. Establishment counts and harvested yield (t/ha) for 01ME87 and 01AD68 Site Merredin-01ME87 Muresk-01AD68 May 23 May 18 Sowing date Oilseed species Plant counts plants/m2 Yield t/ha Plant counts plants/m2 Yield t/ha Canola Brassica napus - Karoo 76.9 1.54 96.0 0.83 Crambe Crambe abyssinica - 337110 62.2 1.94 60.8 1.34 Crambe Crambe abyssinica - 94053 52.2 1.72 55.8 1.09 Ethiopian Mustard Brassica carinata - 193467 56.1 1.13 77.7 0.80 Ethiopian Mustard Brassica carinata - 195923 54.1 1.28 89.4 0.94 False flax Camelina sativa - 4164 146.8 1.76 114.3 0.94 False flax Camelina sativa - R339 199.5 2.05 125.4 0.70 Indian Mustard Brassica juncea 100.2 1.34 133.8 1.11 Linseed (Flax) Linum usitatissum - Glenelg 107.7 0.44 204.8 0.77 211.7 0.80 Linseed (Flax) Linum usitatissum - Walaga LSD p = 0.05 0.219 0.236 ACKNOWLEDGMENTS Margaret Campbell, CLIMA Research Officer for seed and advice and Avondale and Merredin Research Station RSU’s for their on the job learning curve on the agronomy and harvesting of the oilseed species. GRDC Project No.: GOP Paper reviewed by: Paul Carmody -36- Identifying constraints to canola production Dave Eksteen, Canola Development Officer, Esperance KEY MESSAGE • Potash and calcium appeared to be possible limiting factors on the sandplain. AIMS OF PROJECT DAW 709 • Undertake research to overcome the primary agronomic constraints to profitable canola production. • Develop both variety specific, integrated and fine tuned new generation production packages for canola based on this research which integrates yield, costs and value. • Demonstrate (large scale basis) these packages to growers with emphasis on crop management and yield and to ensure the adoption of the management practices required to produce profitable canola. INTRODUCTION Growers often have sections within a paddock that appears to be less vigorous in growth and often yield lower than the rest of the paddock. As one of the aims of the GRDC sponsored project (DAW 709) to identify the constraints to production, good and poor patches within a paddock were analysed nutritionally to try and identify if poiuytrewl;’was a limiting factor. CASE STUDY A Location: Gibson Soil type: Sand (60 to 80 cm) over gravel. A canola trial looking at possible constraints to production was sown on the 1 June 2001. A blanket application of 100 kg Muriate of potash per ha and 190 kg gypsum per ha was topdressed on the 7 May 2001. The trial was sown to Pinnacle and Surpass 501TT with 80 kg summit pasture. The trial lacked vigor and showed severe calcium deficiency during flowering. Approximately half way down the trial block two strips of very healthy and vigorous growing canola appeared across the plots. Soil and leaf samples were taken of both good and poor sites. RESULTS Soil analysis (CSBP) mg/kg Sample ID % Nitrate N Amm N* P K S OC* Fe mg/kg Exchangeable meq/100 g pH** Ca Mg Na K Al mg/kg GOOD 0-10 cm 5 2 10 37 3.1 1.37 120 4.4 1.20 0.21 0.07 0.05 19.5 10-20 cm 4 5 14 38 4.1 1.03 157 4.6 1.30 0.21 0.09 0.08 18.6 60 cm 3 2 5 124 12.6 0.50 603 6.4 3.31 0.54 0.17 0.31 0 0-10 cm 4 2 23 73 5.6 0.99 223 4.5 1.28 0.47 0.10 0.04 13.3 10-20 cm 2 2 11 12 1.9 0.47 65 4.6 0.42 0.04 0.06 0.00 7.2 60 cm 2 2 41 19 5.7 0.29 162 6.6 3.19 0.19 0.07 0.03 0 POOR Amm N* = Ammonium Nitrate, 0C** = Organic Carbon, pH*** in CaCl. -37- Leaf sample (CSBP) Sample ID N % P % K % S % Na % Ca % Mg % Cu mg/kg Zn mg/kg Mn mg/kg Fe mg/kg Nitrate mg/kg B mg/kg GOOD 2.85 0.27 2.52 0.81 0.16 1.36 0.44 3.46 POOR 1.81 0.38 1.67 0.49 0.22 0.56 0.33 3.64 25.38 68.6 68.8 955.8 31.32 24.46 100.8 47.5 56.2 29.05 DISCUSSION From the soil analysis of both good and poor areas, the soil nitrogen seems to be similar for both, but the good growth took up more nitrogen. Phosphorus actually increases in the poor indicating that phosphorus is not likely to be the limiting factor. One of the likely limiting factors appears to be potassium. The good production showed low potassium in the top 20 cm but had good levels in the 60 cm sample. Potassium decreased markedly from below 10 cm in the poor section. The tissue test showed low potash in the poor growth section (1.6%), supporting that potassium was probably deficient (the adequate range is 2.9-5.1%). The soil test shows similar reasonable levels of Calcium in both good and poor growth plots. Both plots, however, showed severe calcium deficiency in the earlier growth stage. The tissue test shows less than half the amount of calcium in the poor growth plants compared to the good growth. This would indicate that calcium was probably also another factor limiting production. CONCLUSION It would seem that the low potassium combined with low calcium and low pH could have contributed to the low production in the poor site. The low pH and high levels of Al could indicate that there were Al toxicity problems, reducing root growth and thus Ca and K uptake. CASE STUDY B A grower in Gibson found that on one corner of his canola paddock the canola was twice the size of the rest of the paddock. Soil samples were taken of the good growing area and compared to the poor growing area. Soil analysis (CSBP) mg/kg Sample ID Exchangeable meq/100 g % Nitrate N Amm N* P K S OC** Fe mg/kg pH*** Ca Mg Na K Al mg/kg 0-10 cm 5 1 9 43 2.9 1.84 159 4.4 2.29 0.43 0.07 0.10 0.20 10-20 cm 3 1 12 99 6.4 0.80 258 5.5 1.67 0.35 0.06 0.21 20-30 cm 4 1 5 206 6.8 1.07 411 6.2 2.51 0.58 0.12 0.49 60 cm 6 1 6 100 7.5 0.85 305 7.0 4.74 1.18 0.18 0.27 0-10 cm 7 1 13 27 3.5 1.14 91 5.2 1.66 0.32 0.03 0.05 0.03 10-20 cm 3 1 14 16 1.7 0.25 77 5.1 0.31 0.07 0.03 0.04 0.03 20-30 cm 4 1 14 17 2.7 0.31 90 5.4 0.40 0.07 0.03 0.04 0.03 60 cm 17 1 34 42 ? 0.19 120 6.7 1.40 0.11 0.05 0.12 GOOD POOR Amm N* = Ammonium Nitrate, 0C** = Organic Carbon, pH*** in CaCl. DISCUSSION The soil sample shows good nitrate nitrogen levels in the poor patch, again indicating that nitrogen was probably not the limiting factor. The phosphorus is also higher in the poor section. The nutrients that are significantly different in the poor section are potash, calcium and magnesium. -38- These results would indicate that the limiting factor in this paddock was low potash and possibly low calcium and magnesium. The exchangeable aluminium was low indicating that this should not have been a limiting factor. The low organic carbon level could have resulted in greater leaching of the elements such as potash and calcium. Growers need to look at the availability of these elements to ensure they are not limiting production on these deep sands. RIRDC Project No.: DAW 709 Paper reviewed by: Mohammad Amjad -39- Boron – Should we be worried about it? Richard W. BellA, K. FrostA, Mike WongB, and Ross BrennanC ASchool of Environmental Science, Murdoch University, Murdoch WA 6150 BCSIRO Land and Water, PO Box 5, Wembley WA 6913 CDepartment of Agriculture Western Australia, Albany WA 6330 KEY MESSAGE Soil B levels are marginal in sandy, acid soils in West Australia, especially those developed on sandstones of the Dandaragan plateau. In pots, B deficiency decreased seed yield of canola and lupin in sandy acid soils from the west Moora-Dandaragan area. Low B levels in seeds of lupin and canola harvested from low B soils decreased seed viability and vigour. Foliar B increased canola seed yields in simple on-farm trials in 1998 in the Great Southern Region, but in 14 field trials carried out in 2000 and 2001, no positive responses to soil or foliar B application were found. No general recommendations for B fertiliser application seem warranted at this stage but soil and plant analysis should guide its use on a case-by-case basis for the time being. Care needs to be taken not to overuse B as toxicity was induced in lupin and canola on sandy soils on the Yuna sandplains with only 5-10 kg borax/ha. METHOD Young leaves of canola and lupin crops and soil (0-10;10-30 cm) were sampled for B analysis at over 150 sites in the wheatbelt, predominantly on sandy soils in 1998. Surface horizons of 73 Reference Soils of SW Australia were analysed for hot CaCl 2 extractable B, and these values were correlated with soil properties (pH, clay, sand) reported by McArthur (1991). From the above Reference Soils, 14 (including sub-soils of 4 soils) were selected for a pot experiment with canola and lupins (8 soils only) as test crops. Plants were grown in pots with and without added B, and harvested at maturity for seed yield. On farm trials were carried out in 1998 using foliar B applications. In 2000 and 2001 cropping seasons, 14 field trials tested soil and foliar B fertiliser applications. RESULTS Levels of B in young leaves of canola and lupin crops in 1998 and in soil samples suggested that 1020% of sites were potentially B deficient. Although predominantly sandy soils were selected, these sites were widely distributed throughout the wheatbelt. In Reference Soils of southwest Australia, extractable soil B was positively correlated with clay content and pH, negatively with sand content but not with organic matter levels. This suggests that low clay content (< 10%) and low pH (< 5 in CaCl2) are useful predictors of low soil B status. Boron fertiliser increased growth and seed set in canola on four low B soils from the northern sandplains (Table 1). These soils are acid sandy soils and were formed on sandstone rather than granitic parent rocks. In lupins, B increased pod set only on the MRA 5 soil from east of Dandaragan. In lupin, seed viability was about as sensitive to low soil B as seed yield. Decreases in seed viability can be expected when seed B is < 12 mg/kg, and especially at < 6 mg/kg. The symptoms of B deficiency observed on pods may be a useful field guide to the probability of harvesting lupin seed which is low enough in B to impair seed viability. In canola, seed yield was more sensitive to low soil B than in lupin. However, at marginal B levels in the soil, seed harvested may have decreased germination and vigour. The critical seed B levels for viability and vigour of canola could not be defined with the data available. In the 2000 field experiments, no seed yield increases from B fertiliser application were recorded in either lupin or canola. However, canola yields were very low at Corrigin and Yuna due to low growing season rainfall. Yields of lupin were reasonable at Yuna due to early sowing and Moora, but there was no positive effect of adding B fertiliser. In 2001, canola yields were higher but still no positive responses to foliar or soil applied B fertiliser were found. Indeed at 3 sites, adding 5 or 10 kg borax/ha at sowing depressed seed yield, mostly by decreasing plant density. -40- Table 1. Properties of soils on which B application increased growth or seed set in canola in pots Soil type pH (CaCl2) Sand (%) Clay (%) Soil B (mg/kg) Parent material GTN 05 Siliceous sand Uc 5.11 5.1 90 7 0.5 sandstone MRA 05 Siliceous sand Uc 4.21 4.5 99 1 0.1 sandstone MRA 08 Yellow duplex Dy 4.51 4.6 98 1 0.1 sandstone MRA 09 Siliceous sand Uc 5.11 5.2 92 6 0.2 sandstone Soil code Table 2. Yield, soil B (0-10 cm) and leaf B concentrations (at budding) in canola and lupin crops with B fertiliser (B 0) and significant B responses to B fertiliser in field experiments in 2000 and 2001. *B tox indicates that yield was depressed by B toxicity at 5-10 kg borax/ha B0 yield (t/ha) B response Soil B (mg/kg) B0 yield (t/ha) Leaf B (mg/kg) Canola 2000 B response Soil B (mg/kg) Leaf B (mg/kg) Lupin 2000 *B Yuna 0.77 ns 0.5 25 Yuna 2.15 0.2 25 Corrigin 0.38 ns 0.7 27 Dandaragan 1.89 ns 0.4 23 Dandaragan 1.50 ns 0.3 21 0.3 24 0.3 19 Canola 2001 Lupin 2001 Moora 1.07 ns 0.3 - Yuna 0.98 Narrogin 0.81 ns 0.5 - Watheroo 0.64 Katanning 0.88 ns 0.6 - Munglinup 1.45 ns 0.5 - Esperance 2.00 ns 0.6 - Corrigin 0.69 ns 0.5 - 0.5 - Yuna 1.36 *B tox tox *B tox ns CONCLUSION Our results confirm that the risk of B deficiency cannot be discounted but field evidence suggests it is not severe in any of the areas studied. The areas most at risk have sandy, acid soils and occur on the sandplains of the Dandaragan Plateau, stretching from West Midlands to the Eradu sandplains. No general recommendations for the use of B fertiliser on lupin and canola are warranted at this stage. However, farmers should remain vigilant for B deficiency symptoms especially on sensitive crops (canola, lucerne, chickpea); request soil and plant tests for B if concerned about B deficiency risk; and act on this information plus the advice of their local agronomist. Soil or foliar B applications can be used to treat B deficiency. Foliar application is rapid acting but the correct timing of the application is important. Solutions of 1% (w/v) solubor (containing 21% B) are commonly used. Soil applications generally last longer although B may be leached from acid sandy soils and this may reduce the effectiveness of B fertiliser. Rates of B application should be < 5 kg of borax/ha on sandy soils to prevent the risk of B toxicity. KEY WORDS boron, deficiency, sandy acid soils, seed set, seed viability, soil analysis, toxicity REFERENCES McArthur, W.M. (1991). Reference Soils of South-Western Australia. WA Dept. of Agriculture/Aust. Soc. Soil Science Inc. (WA Branch), Perth. GRDC Project No.: UMU69 Paper reviewed by: Dave Eksteen -41- Yield losses caused when Beet Western Yellows Virus infects canola Roger Jones and Jenny Hawkes, Department of Agriculture, and Centre for Legumes in Mediterranean Agriculture KEY MESSAGE In two field experiments in 2001, infection with BWYV that started early and reached 98% and 93% of plants decreased seed yield of canola by 37% and 46% respectively. BACKGROUND Beet western yellows luteovirus (BWYV) is transmitted by aphid vectors. In the grainbelt of south-west Australia, aphids spread BWYV to canola and pulse crops from infected weeds, especially wild radish. In surveys in 1998 and 1999, BWYV was found in 59% and 66% of canola crops sampled respectively. In Europe, infection with BWYV is reported to decrease seed yields of canola by 10-35%, and also to diminish oil and increase glucosinolate contents. No yield loss data has been collected for viruses infecting canola in Australia. METHODS In the 2001 growing season, at two Department of Agriculture Research Station sites (Badgingarra and Medina), field experiments with BWYV and canola were done to provide yield loss information. To obtain early BWYV spread and high incidences of infection, small numbers of canola plants infected with BWYV and infested with green peach aphids (Myzus persicae) were introduced into plots of some treatments in each experiment. Foliar pyrethroid + imidacloprid insecticide applications were used to suppress BWYV spread differentially within the treatments. Colonising aphids were counted before and after spray applications. Each plot was sampled fortnightly to determine BWYV incidence and the samples tested by TBIA using BWYV specific antiserum. Harvest and threshing was by machine following swathing at Badgingarra and by a mixture of machine and hand at Medina. RESULTS In both experiments, BWYV spread very quickly in young plants causing symptoms of leaf reddening and plant stunting that were absent in healthy plants. These symptoms persisted and growth of heavily infected plots was noticeably stunted compared with the lush growth of sprayed plots without infector plants. Spraying at emergence was ineffective in suppressing early virus spread at Badgingarra. Blanket insecticide sprays were eventually needed at both sites to prevent substantial BWYV infection of control plots. At Badgingarra, BWYV infection in plots with infector plants but without insecticide spray treatments (up until 12 weeks from emergence) reached 98% of plants compared with 8% in plots with no infector plants and regular spray treatments starting at emergence, giving yield losses of 37% (Figure 1). At Medina, BWYV infection in plots with infector plants but without insecticide spray treatments (up until 3 months from sowing) reached 93% compared with 10% in plots with no infector plants and regular spray treatments, giving yield losses of 46% (Figure 2). Early aphid numbers before plots were sprayed were insufficient to have contributed directly to the yield losses. CONCLUSIONS This work shows that, when aphids spread it to canola crops early, BWYV has substantial yield limiting potential in the WA grainbelt. Although the results represent a ‘worse case scenario’, the losses were greater than those reported in Europe and are cause for concern. KEY WORDS canola, oilseed, virus, disease, yield loss, risks We thank Brenda Coutts, Lisa Smith, Rohan Prince, Gavin D’adhemar and Stewart Smith for technical support, and the Grains Research and Development Corporation for funding. GRDC Project No.: UWA 313 Paper reviewed by: Martin Barbetti -42- Badgingarra (01BA6), machine harvested plots % BWYV 1.8 100 1.6 90 1.4 80 70 1.2 60 1.0 50 0.8 40 0.6 30 0.4 20 0.2 10 0.0 0 A B C D E % BWYV infection Yield t/ha Yield F Treatment Figure 1. Effect of BWYV on yield of canola cv. Pinnacle, Badgingarra. A = sprayed at emergence, 4, 8 and 12 weeks + infector plants; B = sprayed at 8 and 12 weeks + infector plants; C = no spray + infector plants; D = no spray - infector plants; E = sprayed at emergence, 4, 8 and 12 weeks - infector plants; F = sprayed at 8 and 12 weeks - infector plants. Starting at 12 weeks, all plots sprayed fortnightly. Bar = LSD. Medina (01MD27), hand harvested plots Yield t/ha % BWYV 100 3.0 90 2.5 70 Yield t/ha 2.0 60 50 1.5 40 1.0 30 % BWYV infection 80 20 0.5 10 0.0 0 A B C D Treatment Figure 2. Effect of BWYV on yield of canola cv. Pinnacle, Medina. A = sprayed at emergence and then every 2 weeks + infector plants; B = no spray + infector plants; C = no spray - infector plants; D = sprayed at emergence, then every 2 weeks infector plants. Starting at 3 months from sowing, treatments B and C also sprayed fortnightly. Bar = LSD. -43- Influence of climate on aphid outbreaks and virus epidemics in canola Debbie Thackray, Jenny Hawkes and Roger Jones, Centre for Legumes in Mediterranean Agriculture and Department of Agriculture KEY MESSAGES • A predictive model and decision support system (DSS) are being developed for use by advisers and growers in canola crops. The DSS will forecast the risk of aphid outbreaks and of beet western yellows virus (BWYV) epidemics and the need for insecticides to control both spread of the virus by its aphid vectors and direct aphid feeding damage. • Once completed, the DSS will allow efficient targeting of insecticides, so as to avoid unnecessary and costly prophylactic use, reduce the likelihood of insecticide-resistant aphid populations building up and provide an environmentally responsible approach to control. • To validate the forecasting model, aphid population and virus epidemic development was recorded each year over 3 years in canola blocks at four sites in different rainfall zones in the WA grainbelt. • Early aphid arrival followed substantial rainfall in the two months preceding the growing season. • When the key BWYV vector, the green peach aphid, predominated, early aphid arrival led to substantial BWYV spread. This did not occur when turnip aphid predominated. BACKGROUND The primary inoculum source of beet western yellows virus (BWYV) in the WA grainbelt is infected plants surviving over summer. Aphids moving into canola crops after feeding on these virus sources, especially wild radish, spread BWYV to healthy plants during feeding. A forecasting model is being developed to forecast aphid build-up and BWYV transmission in canola crops. To validate the model and ensure that it accurately forecasts aphid arrival and numbers and virus spread at different locations over a range of seasons, data on aphid and virus incidence in canola have been collected from sites representing the different rainfall zones in the WA grainbelt. Large, square blocks of canola were established in 1999, 2000 and 2001 at Agricultural Research Stations at Merredin (average annual rainfall 330 mm), Avondale (Av. 420 mm), Badgingarra (Av. 600 mm) and Mount Barker (Av. 750 mm). The blocks were always sown by 2 June. The blocks were sown adjacent to wild radish weeds, potential sources of BWYV. Sites were visited every 2-3 weeks during the growing season. On each visit, numbers of aphids of different species were counted on one shoot tip (top 10 cm) and two lower leaves of each of 50 plants. Also, 200 canola shoot samples collected at random were tested for BWYV in the laboratory by tissue blot immuno-assay (TBIA). RESULTS In 1999 and 2000, aphids arrived earliest and virus spread was greatest at those sites with highest pre-growing season rainfall (Table 1). Conversely, aphids arrived latest and virus spread was least at those with lowest pre-growing season rainfall. In all three years, across all sites the magnitude of BWYV spread that occurred was not correlated with numbers of aphids colonising canola plants. In 2001, in contrast to previous years, except at Mount Barker where green peach aphid dominated, the predominant aphid species present was turnip aphid. Aphids were most numerous at Merredin with an average of 36 per shoot tip (all species) in mid-August (Figure 1). BWYV incidence at Mount Barker, Avondale and Merredin only reached 2%, 0.5% and 0.5% respectively, with no BWYV recorded at Badgingarra. At all sites, final virus incidence was much lower than in 1999, and the same as or lower than in 2000. However, peak aphid numbers were generally higher than in previous years. Time of arrival of green peach aphid but not turnip aphid was correlated with rainfall in March-April. In 2001, there was very little summer rainfall except at Merredin, where rainfall was substantial in January-February (165 mm) but low in March-April (3.4 mm). Early expectations were that aphid -44- arrival would be late at all sites, and this occurred except at Merredin where turnip aphids were first recorded early (19 June). However, green peach aphids were not recorded at Merredin until 14 August where their numbers remained low. Consequently BWYV spread was very low at all four sites. Table 1. Canola validation blocks 1999-2001 at four sites: date green peach aphids first recorded, final BWYV incidence and March-April rainfall (mm) March + April rainfall (mm)* Site Avondale % Final BWYV infection Date aphids first recorded 1999 2000 2001 1999 2000 2001 1999 2000 2001 38 33 1.5 29 June no aphids 14 August 44 0.5 0.5 170 60 4.9 9 June 13 June 7 August 81 6 0 Merredin** 93 68 3.4 11 June 19 July 14 August 48 0.5 0.5 Mount Barker 52 162 37.2 5 August 1 June 26 July 17 Badgingarra 2 Rainfall data from SILO Data Drill (Queensland Department of Natural Resources). 8 Highest aphid numbers/shoot % plants with BWYV Date aphids first recorded 6 23-Jul 2-Aug 4 12-Aug 2 0 Date aphids first recorded Highest aphid Nos/shoot % BWYV infected plants * 51 22-Aug 1.5 3.4 4.9 37.2 Avondale Merredin Badgingarra Mount Barker Site and total Mar/Apr rainfall (mm) Figure 1. Date green peach aphids first seen, highest average green peach aphid numbers/shoot and final % BWYV incidences in canola blocks in different rainfall zones in 2001. CONCLUSIONS When the key BWYV vector, the green peach aphid, predominated, early aphid arrival in canola led to substantial BWYV spread. However, when the predominant species was turnip aphid, early aphid arrival did not. Late aphid arrival always resulted in low BWYV incidence. Rainfall promotes growth of weed and pasture plants which aphids can build up on before flying to crops. When there is little pre-growing season rainfall over summer, aphids and BWYV can persist only in isolated pockets of surviving vegetation, so aphid build-up and migration to crops is delayed. Early aphid arrival always followed substantial rainfall in the two months preceding the growing season. When little rain fell in March-April, aphids arrived late. The only exception was Merredin in 2001 when turnip aphids arrived in mid-June but green peach aphids were not seen until mid-August. Presumably, the difference in arrival dates of the two aphid species at Merredin was influenced by differences in their tolerance of dry conditions and in the survival of their preferred host plants during the dry months of March and April, which followed substantial rainfall in January and February in 2001. The information gathered from these blocks is being used to validate the model forecasting aphid outbreaks and BWYV epidemics in canola. Subsequently, the model will be adapted to provide a decision support system (DSS) for use in targeting insecticides to control BWYV spread by aphid vectors. Information on summer host plants of BWYV is being collected throughout the grainbelt and on yield losses from BWYV infection (GRDC project UWA 313) and will be used to refine model predictions. Data on aphid feeding damage from GRDC project DAW 489 (see Berlandier in 2000 and 2001 Updates) will also be incorporated. Forecasts will be made available through the Internet, PestFax, TopLine, rural radio, etc. -45- ACKNOWLEDGMENTS This work was supported by the Grains Research and Development Corporation. We thank Brenda Coutts, Lisa Smith, Donna Atkins, Rohan Prince and Christine Woods for technical assistance. KEY WORDS BWYV, aphids, model, decision support system GRDC Project No.: UWA 290 Paper reviewed by: Roger Jones and Martin Barbetti -46- The annual shower of blackleg ascospores in canola: Can we predict and avoid it? Moin U. Salam, Ravjit K. Khangura, Art J. Diggle and Martin J. Barbetti, Department of Agriculture, Western Australia. KEY MESSAGE A simple computer model has been developed to simulate temporal discharge of blackleg ascospores from canola stubble left in the paddock from previous season’s crop. The model was tested and verified with the blackleg spores trap data. Using historical weather data, the model was employed to predict annual ascospore showers in three locations: East Chapman, Wongan Hills and Mt Barker. The model predicts that canola seedlings can avoid major ascospore showers in East Chapman area by sowing early in the season. This is possible given that the break is early or even average, but not when it is late. Early sowing in Wongan Hills area can also avoid major ascospore showers coinciding with the susceptible seedling stage of canola to a considerable extent, but here this is only limited to an early break. On the contrary, late sowing, irrespective of time of break, could help seedlings escape the largest of the major ascospore showers in Mt Barker area. This will, however, encounter yield penalty due to delayed sowing and it is still possible that the remaining smaller ascospore showers falling on seedlings could potentially cause serious blackleg disease in spite of delayed sowing. BACKGROUND Blackleg, caused by Leptosphaeria maculans (Desm.) Ces. and de Not., is a serious disease of canola, Brassica napus L., and is of world-wide importance (West et al. 2000). The overwhelming source of blackleg inoculum is infected canola stubble from previous years’ cropping. In autumn and winter, depending on rainfall and temperature, the fruiting bodies (pseudothecia) mature on the stubble. Release of ascospores is then triggered by rainfall events. As most of the canola cultivars, irrespective of the level of their adult plant resistance, are highly prone to infection by the fungus at the seedling stage, the pattern of ascospore release (i.e. the events of ascospore shower) could provide a valuable information to manage the disease at the early growth stage of the crop. Canola pathologists in the last few years have been studying the maturation of pseudothecia and ascospore discharge by blackleg fungus on canola residues in Western Australia (Khangura et al. 2002, this book). Analysing and synthesising this information, we have developed a computer model to address two key questions: (i) Can we predict the temporal discharge of ascospores from canola stubble? If so, (ii) can we use the model to investigate if the major ascospore showers at seedling stage be avoided by manipulating sowing time? METHOD A computer model has been developed using seven parameters related to temperature and rainfall requirements for pseudothecia maturity, maturity duration of pseudothetia during a season, rainfall requirement for ascospore release from the matured pseudothecia, and fraction of ascospores released from the matured pseudothecia during each rainfall event. The model runs on a daily scale for a whole year using daily maximum and minimum temperatures and rainfall as weather inputs. The model was tested with the blackleg spores trap data collected daily from Mt Barker during 1999 and 2000 seasons and from East Chapman during 2000 season (Khangura et al. 2002). Using historical weather data, the model was employed to predict annual ascospore showers in three locations: East Chapman (1998-2000), Wongan Hills (1998-2001) and Mt Barker (1991, 1993-2001). RESULTS The model satisfactorily predicted the events of ascospore showers as observed in two locations (not shown) indicating its potential value to use as a tool for such predictions in an area where such information is required especially in relation to management of the disease through sowing time manipulation. For example, in the East Chapman area, major ascospore showers can be avoided by sowing early in the season in some years. This is possible given the break is early (1999) or average (1998), but not when it is late (2000). Early sowing in Wongan Hills area can also avoid major -47- ascospore showers to a considerable extent, but this is only limited to an early break (such as occurred in 1998). On the contrary, late sowing, irrespective of time of break, could help seedlings escape the largest of the major ascospore showers in Mt Barker area. However, in this area late sowing is associated with potential yield penalty (Figure 1) and it is still possible that the remaining smaller ascospore showers falling on seedlings could potentially cause serious blackleg disease in spite of delayed sowing. East Chapman Wongan Hills Simulated spores First sowing opportunity Mt. Barker Late sowing opportunity Delayed sowing yield penalty 1.0 Relative fraction of discharged spores 0.8 0.6 Early break 14 April ’99 0.4 Early break 15 April ’98 Early break 8 May ’01 0.2 0.0 Delayed sowing yield penalty 1.0 0.8 0.6 Normal break 10 May ‘98 0.4 Normal break 18 May ‘99 Normal break 24 May ‘97 0.2 0.0 Delayed sowing yield penalty 1.0 0.8 0.6 Late break 19 June ‘00 0.4 Late break 15 June ‘00 Late break 18 June ‘97 0.2 0.0 Apr Jun Aug Oct Dec Apr Jun Aug Oct Dec Apr Jun Aug Oct Dec Time (month) of the year Figure 1. Prediction of ascospore discharge from one-year-old canola stubbles in East Chapman, Wongan Hills and Mt Barker areas. Three scenarios of seasonal break (arrows), early, mid and late within the best-bet sowing window of an area (CVSG, 2002) have been highlighted. CONCLUSION In addition to forecasting the ascospore showers, the model can track down the stages of development of pseudothecia maturity. Pseudothecia maturity is a good indicator of whether an early shower is possible or likely. Such information a month ahead of the sowing time, especially in Wongan Hills and Mt Barker areas, could help growers in deciding blackleg management strategies, including the use of sowing time. ACKNOWLEDGMENTS The Grains Research and Development Corporation (GRDC) provide funds for this research. GRDC Project DAW 591, Agriculture Victoria and the University of Melbourne are collaborating with this modelling. -48- REFERENCES CVSG (2002). Crop Variety Sowing Guide for Western Australia. Bulletin 4529. Department of Agriculture, Western Australia. Khangura, R.K., Barbetti, M.J., Salam, M.U. and Diggle, A.J. (2002). Environmental influences on production and release of ascospores of blackleg and their implications in blackleg management in canola Crop Updates 2002, 2002 Oilseeds Update-Western Australia. West, J.S., Kharbanda, P.D., Barbetti, M.J., and Fitt, B.D.L. (2000). Epidemiology and management of Leptosphaeria maculans (phoma stem canker) on oilseed rape in Australia, Canada and Europe. Plant Pathology 50: 10-27. KEY WORDS canola stubble, quantitative epidemiology, modelling GRDC Project No.: DAW 621 Paper reviewed by: Dr Martin Barbetti -49- Environmental influences on production and release of ascospores of blackleg and their implications in blackleg management in canola Ravjit K. Khangura, Martin J. Barbetti , Moin U. Salam and Art J. Diggle, Department of Agriculture, Western Australia KEY MESSAGE Blackleg survives on canola residues after harvest in the form of fruiting bodies. Release of ascospores from the fungal fruiting bodies usually synchronises with the crop emergence. However, the exact timing of production of fruiting bodies on the residues and subsequent initiation of ascospore discharge in different environments of WA is not known. A study was undertaken to investigate the timings of maturation of fruiting bodies in 4 different environments of WA. The results indicated that the fruiting bodies matured earlier in high rainfall than in medium and low rainfall areas. Likewise, ascospore discharge commenced early in high rainfall areas and late in northern low rainfall areas. The ascospore release was at its peak during May and June in high rainfall areas and during July-August in low rainfall areas. Environmental influences were also observed on the total number of ascospores discharged in different rainfall areas. This information could be used in modelling towards developing a decision support system for a regional scale management of blackleg in WA. AIMS Blackleg is a major disease of canola and is known to cause substantial yield losses in canola in Western Australia (Khangura et al. 2001; Salam et al. 2001). In WA, blackleg is generally managed through use of resistant cultivars and cultural practices and by using fungicides such as Impact®. An understanding of the environmental effects on the development of the blackleg is important to further improve blackleg management strategies in the State. Ascospores released from fruiting bodies (pseudothecia) of infected residues serve as a source of primary inoculum. However, no information is available on the maturation of fruiting bodies in the Mediterranean climate of WA. There is very little information available on the discharge of ascospores from residues in WA. The information gained on effect of various environmental factors on the release of blackleg spores will help in refining the blackleg management packages. This is particularly important in decision making with regards to the judicious use of fungicides in order to maximise grower’s returns. METHODS Monitoring maturation of fruiting bodies on residues Canola stems from previous year’s crop were collected during 1998, 1999, and 2000 from Mt Barker, Wongan Hills, Merredin and East Chapman to represent high, medium and low rainfall and northern areas, respectively, of WA. Approximately 20-40 stems were collected weekly, each year from each of the above locations. Each stem was observed for the maturation of fruiting bodies of blackleg under the microscope. A total of about 10,000 stems were observed for these studies during 1998-2000. Spore trapping At Mt Barker the ascospore release was studied from residues of the previous year’s crop (1-year old) during 1999 and 2000 and 2 year old residues during 2000. Likewise, at East Chapman the ascospore release was studied from 1 and 2 year old residues during 2000. A 7-day recording volumetric spore trap (Burkard Scientific, Rickmansworth, Hertfordshire, England) was set up in each paddock containing either 1 or 2-year old residues. -50- RESULTS Monitoring maturation of fruiting bodies on residues Fruiting bodies matured earlier at Mt Barker compared with the other locations during all three years of study (Table 1). However, at Wongan Hills and Merredin that represent medium and low rainfall areas, respectively, the fruiting bodies matured almost at the same time during 1999 and 2000. There was a variation in the timings of fruiting bodies maturation between years within the same location. At East Chapman, the fruiting bodies matured about 3 and 5 weeks earlier in 1999 than in 1998 and 2000, respectively. Table 1. Dates of first detection of ascospores in the fruiting bodies at different locations during 1998-2000 Location Year 1998 1999 2000 Mt Barker 12 May 14 April 13 March Wongan Hills 21 June 26 May 22 June 6 July 24 May 25 June Merredin E. Chapman 19 June 1 June 4 July Spore trapping There was a daily variation in the discharge of ascospores. At Mt Barker, the release of ascospores from residues of the previous year’s crop started on 17 March (Figure 1a) and at E. Chapman on 18 July (Figure 1b). No apparent diurnal pattern of ascospore discharge was observed. At Mt Barker, the maximum numbers of ascospores were released in the month of June during 1999 and in May during 2000 (Figure 2a). At East Chapman, the ascospore discharge from residues of previous year’s crop started in July, reached a peak in August and then declined in September. No ascospores were discharged in October (Figure 2b). At both the locations, the discharges of ascospores from 2-year old residues followed a similar pattern except that the number of ascospores discharged from 2-year old residues was reduced by about 90%. This lower number of ascospores could be attributed to the reduced amount of residues due to raking and burning. The amount of residues left after raking and burning in another location was observed to be about 20-30% of the total amount (R.K. Khangura and M.J. Barbetti, unpublished data). At Mt Barker the number of ascospores discharged from residues of previous year’s crop was higher in 1999 compared with during 2000. This could possibly be ascribed to relatively drier conditions in April and May in 2000. This dry spell appeared to have retarded the development of fruiting bodies. CONCLUSIONS The fruiting bodies of the blackleg fungus matured at different times in different rainfall areas of WA and appeared to be possibly influenced by temperature and rainfall. The spore trapping studies indicated that there was a seasonal pattern of ascospore discharge. This information on fruiting body maturation coupled with initiation of ascospore discharge could possibly be exploited to develop disease management strategies by avoiding major ascospore showers at the seedling stage of maximum susceptibility. This study could also help to make decisions about the use of fungicides for better blackleg management in different environments. The results from these studies will form the basis of developing models for predicting ‘ascospore showers’ by blackleg in different canola growing regions of WA. ACKNOWLEDGMENTS The Grains Research and Development Corporation (GRDC) provided funds for this research. We also thank Mr M. Aberra and Mr Tim Trent for providing excellent technical assistance. -51- REFERENCES Khangura, R., Barbetti, M.J., Salam, M.U. and Diggle, A.J. (2001). Maturation of pseudothecia and ascospore discharge by blackleg fungus on canola residues in western Australia: Preliminary results from field observations. In proceedings ‘12th Australian Research Assembly on Brassicas, ed. S.J. Marcroft’, Geelong, Victoria, pp. 87-91. Salam, M.U., Galloway, J., Khangura, R., Diggle, A.J., Macleod, W.J. and Barbetti, M.J. (2001). Spread of blackleg in canola: A regional scale simulation model. . In proceedings ‘12 th Australian Research Assembly on Brassicas, ed. S.J. Marcroft’, Geelong, Victoria, pp. 101-105. GRDC Project No.: DAW 591 Paper reviewed by: Dr M.J. Barbetti and Dr M. Sweetingham -52- -53- 31/10/2000 24/10/2000 17/10/2000 10/10/2000 03/10/2000 26/09/2000 19/09/2000 12/09/2000 05/09/2000 29/08/2000 22/08/2000 15/08/2000 08/08/2000 01/08/2000 25/07/2000 18/07/2000 11/07/2000 04/07/2000 100 27/06/2000 20/06/2000 13/06/2000 06/06/2000 30/05/2000 23/05/2000 16/05/2000 09/05/2000 02/05/2000 25/04/2000 Figure 1a. Daily ascospore discharge pattern of ascospores of blackleg from 1 year old residues at Mt Barker during 2000. The arrow indicates timing of fruiting bodies maturation. 350 300 250 200 150 FB Mature 50 0 Figure 1b. Daily ascospore discharge pattern of ascospores of blackleg from 1 year old residues at E. Chapman during 2000. The arrow indicates timing of fruiting bodies maturation. 27/10/2000 13/10/2000 29/09/2000 15/09/2000 01/09/2000 18/08/2000 04/08/2000 21/07/2000 07/07/2000 23/06/2000 09/06/2000 26/05/2000 12/05/2000 28/04/2000 14/04/2000 31/03/2000 17/03/2000 500 18/04/2000 03/03/2000 0 11/04/2000 04/04/2000 28/03/2000 Daily spores Daily spores 2500 2000 1500 1000 FB mature 20000 spores in 99 on 1-year residues at MB Total number of ascospores/m3 18000 spores in 00 on 1-year old residues at MB spores in 00 on 2-year old residues at MB 16000 14000 12000 10000 8000 6000 4000 2000 0 March April May June July Aug Sept Oct Figure 2a. Total number of ascospores discharged/m3 on monthly basis from residues of previous crop trapped during 1999 and 2000 and from 2 year old residues that were raked and burnt in the previous year trapped during 2000 at Mt Barker 1600 spores in 00 on 1-year old residues at EC Total number of ascospores/m3 1400 spores in 00 on 2-year old residues at EC 1200 1000 800 600 400 200 0 March April May June July Aug Sept Oct Figure 2b. Total number of ascospores discharged/m3 on monthly basis from residues of previous crop and from 2 year old residues that were raked and burnt in the previous year trapped during 2000 at East Chapman -54- WA blackleg resistance ratings on canola varieties for 2002 Ravjit Khangura, Martin J. Barbetti and Graham Walton, Department of Agriculture, Western Australia Blackleg is one of the most important diseases of canola and has the potential to cause major yield losses. Growing resistant varieties is the most economic method of managing blackleg in canola, and breeding for blackleg resistance is one of the key objectives of canola breeders in Australia and overseas. Commercial varieties bred in Australia are screened around the country at their advanced stages of development in the blackleg disease nurseries under extreme blackleg pressure. There are two separate rating systems available for assessing the level of blackleg resistance in canola varieties namely Blackleg Survival Ratings and Blackleg Canker Ratings. BLACKLEG SURVIVAL RATINGS Various commercial varieties and high performance crossbred selections are grown under severe disease pressure and establishment and maturity plant counts are made. The percentage of surviving plants is calculated for each line and then a survival score is assigned to each line/variety accordingly. Each variety must have been in trials at least for two years and at six sites, until then only a provisional ranking is assigned. These ratings are published annually by the Canola Association of Australia as the ‘National Australian Canola Variety List’ for ‘Blackleg Survival Ratings’. The advantage of this system is that it records plants lost during the season, but, it assumes that all plants lost are from blackleg, when on some occasions other causes (e.g. Rhizoctonia damping-off or insect damage and or environmental factors) may also result in plants being lost. Blackleg canker ratings Various varieties and advanced selections are grown in disease nurseries as above. When flowering is finished the plants are rated for the severity of blackleg crown cankers. A per cent disease index on each line is calculated and a Blackleg Canker Rating score is assigned to each line or variety accordingly. Each variety must have been in trials at least for two years and at four sites, and until then only a provisional ranking is assigned. The advantage of this system is that it gives a reliable assessment of the impact of blackleg on surviving plants and can be related to yield losses occurring in WA. On the other hand, this system does not account for plants lost to blackleg during the season. Since neither of the above systems demonstrates a complete picture of blackleg resistance, ‘WA Blackleg Resistance Ratings’ have been derived to combine the benefits of both systems. The blackleg survival rating provides the level of survival among different varieties and the blackleg canker rating provides severity of crown cankers on the surviving plants. Combining both systems provides a complete picture of the level of resistance of a variety based upon its performance in relation to plant survival and the severity of crown cankers. In assigning WA Blackleg Resistance Rating scores to canola varieties for 2002, the blackleg canker rating scores from 1996 to 2001 along with the blackleg survival scores for 2000 and 2001 have been used. The WA Blackleg Resistance Ratings varietal scores for 2002 are given in Table 1. These ratings should be used as a guide in determining the yield losses in WA from blackleg for varieties with different Blackleg Resistance Rating scores under various disease pressure situations as outlined in Bulletin No. 4480 ‘Managing Blackleg’. -55- Table 1. WA Blackleg Resistance Rating for canola varieties for 2002. (The higher the number the greater the level of resistance to blackleg.) Variety Triazine tolerant Rating Variety Clearfield # system Rating Karoo 4 46C74 4P Surpass300TT 4P* 44C71 5 Beacon 5 44C73 5P* Drum 5 Surpass 402CL 8+ Clancy 5 Surpass 603 CL 8+P* Hyden 6 Pinnacle 6 Surpass 600 TT 6 Grace 7P* Surpass501TT 8+P* Conventional * Georgie 4 Outback 4 Monty 4 Mystic 4 46CO3 4P* 47CO2 5 Oscar 5 Rainbow 5 Ripper 5 Surpass 600 5 Charlton 6 Dunkeld 6 Emblem 6 Purler 6 Hyola 60 8+ Surpass 400 8+ The varieties with less than two years or four sites data have been given a provisional rating and a letter P follows the scores for these. This means their rating could change based upon their performance for blackleg resistance in trials in 2002. 0-2 = Highly susceptible. 3-4 = Moderately susceptible. 5-6 = Moderately resistant. 7-8 = Resistant. 8+ = Highly resistant. # Trademark of BASF. -56- Bronzed field beetle management in canola Phil Michael, Department of Agriculture, Albany KEY MESSAGES Bronzed field beetle larvae can destroy canola stands and they thrive where surface plant material is abundant. The adult stage can be counted more easily, and less than 13 beetles/m 2 may lead to economic damage. Chemicals are not highly effective against this pest. BACKGROUND The bronzed field beetle, Adelium brevicorne, is abundant in southern high and medium rainfall zones. Little was known of the biology of this pest prior to this project, set up to investigate false wireworms and other new seedling pests of canola. METHODS Adults and larvae of bronzed field beetle were observed in and around paddocks over three years. The density of adults was estimated with quadrat counts in the field, whereas larvae were estimated by taking soil cores (usually 12 cores 10 cm in diameter) and searching for larvae. In experiment A, lupin and previous cereal crop residue of almost 5 t/ha was removed off one treatment with a light lawn rake (in February before eggs were laid) and placed on the other treatment. For experiments B and C, chemicals were applied with a boom spray onto crops seeded into crop residues with minimal disturbance. It had been observed on commercial crops that a single spray, applied on heavy stubble, was not very effective against larvae. Therefore in experiment C, three sprays were applied after dark, as larvae became active, with the first spray being applied before crop emergence. FINDINGS Observations have shown that adults shelter by day under crop residues, stumps or tufts of grass. In early autumn, a large proportion of a female's body may be occupied with eggs before these are laid. In one m2 of heavy plant residues (especially lupins) approximately 13 adults gave rise to over 1,500 larvae, which was sufficient to kill most of the seedlings. Half this number may be worth treating. Although larvae may be seen under trash, it is difficult to estimate population densities this way. Adults are more easily counted on small areas of ground. Four times the number of adults may be found under squares of carpet anchored to the ground and left for a few days. If moisture is sufficient, these larvae may reach a damaging length of five mm before the crop is seeded. Larvae (false wireworm) chew canola stems at ground level, causing thinning of the crop or destruction of large areas. They begin changing to the pupal stage in August and new adults appear soon after. Adults may be harvested with swathed crops and have led to problems with export grain. In experiment A with raked and stubble treatments, it was clearly shown that the bronzed field beetle requires surface residues for shelter and breeding. Counts by day showed that adults were only in stubble plots, but sampling with pitfall traps and carpet squares revealed that adults actually moved freely at night between stubble and raked plots. No breeding occurred in raked plots, which had 43 plants/m2, but large numbers of larvae bred in stubble plots (Figure 1) which had three plants/m 2. In experiment B, very high rates of chemical were applied to kill most of the larvae. In the sprayed treatment in July there were 44 plants/m2 and the yield was 2.83 t/ha. The unsprayed treatment was significantly different with eight plants/m2 (P < 0.001) and a yield of 0.64 t/ha (P < 0.01). -57- Figure 1. Number of bronzed field beetle larvae in stubble and raked treatments, Kendenup. 1600 Larvae (stubble) Larvae (raked) No. larvae/m 2 1200 800 400 0 21-Mar 10-May 29-Jun 18-Aug 7-Oct The level of control was not high in the third experiment despite the three night sprays (Figure 2). Figure 2. Number of bronzed field beetle larvae following sprays at South Stirling. Night Sprays Unsprayed 600 200 mL/ha Fastac 400 mL/ha Fastac 500 No. larvae/m 2 100 mL/ha Regent 400 300 200 100 0 19-May 18-Jun 18-Jul 17-Aug Seed dressings are used against other false wireworms and showed promise against this pest when used in pot trials but provided very poor control in the field. The larvae live under trash but above the soil and do not require living plant material. The chemical on the seed is therefore insufficient to gain control of this species. Control of adults with baits or sprays prior to seeding have been unsuccessful. CONCLUSIONS High-risk situations for this pest include abundant surface plant material, minimal disturbance and some early moisture, which allows larvae to grow to damaging sizes before seeding. Fewer than 13 adults/m2 may lead to economic damage in these situations, but chemicals are not highly effective. ACKNOWLEDGMENTS Much thanks to Tony Dore for his invaluable help. This project was partly funded by GRDC. GRDC Project No.: DAW612 Paper reviewed by: Dr S. Peltzer -58- DBM control in canola: Aerial versus boom application Paul Carmody, Department of Agriculture, Northam KEY MESSAGE • Boom spray achieves the best initial knockdown of DBM numbers compared to either EC or ULV aerial application; there is no advantage in doubling insecticide rates in the boom • Both ULV and EC aerial formulations gave a similar initial reduction in DBM numbers but EC had more impact on large and medium size grubs. INTRODUCTION Diamondback Moth (DBM), Plutella xylostella (DBM), is a major pest of brassica crops throughout the world, including Australia. In 2001 DBM were found in damaging numbers throughout canola crops in much of the Northern and Central Agricultural Region of Western Australia. Spray application technology is an issue as DBM over large areas of canola required treatment. An evaluation of the different types of aerial application (ULV and EC formulations of insecticide) was needed to improve recommendations to Industry. Experiments conducted by Agriculture Western Australia found differences in the effectiveness of different application techniques of insecticides to control DBM. Ground spray rigs gave up to 50% better knockdown that EC aerial applications at water volumes of 35 L/hectare in preliminary trials in the Geraldton area in 2000. AIM To compare the efficacy aerial applications of EC and ULV formulations of insecticide (alphacypermethrin 100 g/L) with EC boom spray applications to control DBM in canola during the podding stage. METHOD An opportunistic field trial was conducted on a very uniform commercial crop of Karoo infested with DBM and located four km north of Meckering. The trial was set up on 12 October 2001 and tested alpha-cypermethrin applied as: a) aerial spray @ 400 mL/ha (ULV formulation); b) aerial spray @ 400 mL/ha with 35 L water/ha (EC formulation); c) boomspray @ 400 mL/ha in 100 L/ha water; or d) boomspray @ 800 mL/ha in 100 L/ha water. Each treatment was replicated three times. An initial population count was made the day before spraying and on two occasions thereafter on 15 and 22 October 2001. Control (nil spray) plots were in strips with 50 m borders for ULV and 100 m for EC, between treatments. Sampling for DBM was done using standard sweep nets, five sweeps every two metres, five times per plot. All counts reported are for 5 sweeps. RESULTS There were 180-200 grubs/10 sweeps on the day prior to spray application. One day after spray application there were fewer grubs in all treatments compared to the Nil spray (Table 1). -59- Table 1. Effect of alpha-cypermethrin applied by aerial and boomspray on numbers of DBM (mean/5 sweeps) 5 times per plot (n = 3) Total grub numbers Treatments * Day 1 % Reduction to control (Nil Boom)* Day 4 Day 11 Day 1 Day 4 Day 11 Aerial ULV 400 mL 45 23 41 38% 57% 21% Aerial EC 400 mL 48 27 28 34% 50% 46% Nil Aerial 73 54 52 Boom 400 mL/ha 26 33 21 80% 62% 52% Boom 800 mL/ha 13 33 18 89% 62% 59% Nil Boom 125 87 43 Expressed against the mean counts for the Nil Boom (Nil B) plots. The percentage reduction in DBM numbers the day after application, when compared to the Nil Boom, shows that the efficiency of the knockdown of the boom treatments was more than double compared to both aerial treatments. However by Day 11 the difference between the two treatments narrowed, although the boom treatments still remained significantly ahead of both aerial treatments. On day 1 there were significantly fewer grubs of all sizes in all treatments (p < 0.001) compared to Nil Boom. Although there was no significant difference between the rates of chemical in the boom treatments, insecticide applied by boomspray killed more grubs that the aerial treatments. By Day 4 there was no significant difference between all treatments (p = 0.144 for the log value) but there were less large grubs in the boom treatment compared to the aerial treatments (p = 0.033). However, by Day 11, with the exception of large grubs, there were significantly more grubs in the aerial treatments than the boom treatments (p < 0.001), but no difference within the aerial treatments. Table 2. Results of statistical analysis on the log counts of DBM numbers for Day 1 only Boom 800 mL Boom 400 mL Large (> 8 mm) 5.4 9.9 43.8 9.0 18.1 22.8 Medium (5-8 mm) 4.1 8.1 36.9 8.0 12.4 15.6 Small (2-5 mm) 2.5 4.3 33.1 9.8 6.8 11.4 Tiny (< 2 mm) 1.2 1.9 30.6 6.6 5.4 10.2 1.374 1.834 3.604 2.225 2.363 2.728 0.182 0.182 0.200 0.182 0.173 0.158 8.3 9.6 Treatment Size Nil B EC ULV Nil A DAY 1 Retr. count Average log (count) Standard error Average Retr. count 3.0 (Significance < 0.001) A 5.3 Ab -60- 35.7 E Bc c 14.3 d Large grubs Medium grubs 50.0 Boom 800 mL 40.0 Boom 400 mL Co unt 30.0 NilB EC 20.0 ULV 10.0 NilA 0.0 0 5 10 40.0 35.0 30.0 Co 25.0 unt 20.0 15.0 10.0 5.0 0.0 15 Boom 800 mL Boom 400 mL NilB EC ULV NilA 0 5 Day 10 15 Day Tiny grubs Small grubs 35.0 35.0 30.0 Boom 800 mL 30.0 Boom 800 mL 25.0 Co unt 20.0 15.0 Boom 400 mL 25.0 Boom 400 mL 10.0 ULV Co 20.0 un t 15.0 10.0 5.0 NilA 5.0 NilB EC 0.0 NilB NilA EC ULV 0.0 0 5 10 15 0 Figure 1. 5 10 15 Day Day Effect of alpha-cypermethrin applied by aerial and boomspray on different DBM grub stages (re-transformed means, log of counts) over time. CONCLUSION The boom spray applications gave the most effective instant knockdown of grub numbers compared to aerial application (both ULV and EC formulations). The age structure of the control population (Nil B) appeared to be relatively stable in terms of structure over the duration of the trial, which would indicate ongoing favourable feeding conditions in the canola crop. Nil B has a higher grub count than Nil A on Day 1 but the reverse was the case on Day 11. There is the possibly of some spray drift affecting grub populations within the nil aerial plots over time and this highlights the difficulty of doing aerial trials. There was no difference between treatments on Day 4, possibly a result of rainfall on Day 3 which may have forced grubs into the crop canopy where they could not be accessed by sweep net. By Day 11 all treatments had less large grubsthan Nil B. Furthermore, there was no difference in grub numbers between aerial and boom treatments, but age structure had altered, with fewer tiny and small grubs in the boom treatments. The EC and ULV aerial applications could not be statistically compared but ULV appeared to have less initial impact on large and medium size grubs than the EC application. Special thanks to: Powell Aviation, Northam and Greg Morrell, Meckering for their patience and time in conducting this trial, and to Christiaan Valentine for technical support, and to Françoise Berlandier. GRDC Project No.: GOP Paper reviewed by: Dave Eksteen and Françoise Berlandier -61- Effect of single or multiple spray treatments on the control of Diamondback moth (Plutella xylostella) and yield of canola at Wongan Hills Françoise Berlandier, Paul Carmody and Christiaan Valentine, Department of Agriculture, Western Australia KEY MESSAGE Applying sprays to control high levels of Diamondback moth increased canola yields by 0.35 t/ha. The yield response to a single spray was the same as for two and three spray treatments. BACKGROUND Diamondback Moth (DBM), Plutella xylostella, is a pest of brassica crops. Immature DBM (grubs) consume leaves, buds and flowers and in large numbers they can strip entire plants. In 2000 and 2001, large infestations of DBM caused severe damage to canola crops in the Northern Agricultural Region of the Western Australian wheatbelt which resulted in significant yield losses. To determine whether insecticidal sprays used to control DBM increase yield, a field trial was carried out at Wongan Hills Research Station in 2001. AIMS 1. To determine the effect of single and multiple sprays on control of DBM on flowering and podding canola at Wongan Hills. 2. To determine effect of DBM control on oilseed production. METHODS Experiments were carried out in an existing canola (cv. Karoo) paddock at Wongan Hills Research Station. The paddock was divided into plots measuring 20 m x 20 m and randomly assigned to one of four spray treatments (Table 1) arranged in a completely randomised block design. There was a 20 m wide buffer between blocks but no buffers within blocks. Treatments consisted of one-three applications (Trts 2-4) of the synthetic pyrethroid alpha-cypermethrin (Dominex) at the registered rate of 400 mL/ha (40 g active/ha), or were left unsprayed (Trt 1). Each treatment was replicated four times. The first spray was applied on 21 September 2001 when plants were at the late flowering stage. By 27 September 2001, 100% of plants had started to form pods and flowering was almost complete. Plots were first sampled for DBM grubs on 21 September 2001 and then at three-six day intervals thereafter (24, 27 September 2001; 3, 5 October 2001). Samples were taken by sweeping plants in each plot using a sweep net. When grub sampling and spraying fell on the same date, sampling was done prior to spraying. Oilseed was machine harvested on 7 November 2001 after swathing. Oil content was measured by infratec analysis. Data was analysed by analysis of variance (ANOVA) using Genstat 5. RESULTS Insects There was an average of 225 DBM grubs/10 sweeps when the first count was done (Figure 1), and over 70% of grubs were 1st-2nd instar. Three days after the first spray was applied, numbers of DBM grubs in all spray treatments had diminished, but there was little change in numbers in the nil spray treatment. On 27 September 2001, six days after the first count, DBM numbers had escalated sharply to a mean of 1,000 grubs/10 sweeps in the nil spray (Trt 1) and to a mean of 360 grubs/10 sweeps in the single spray treatment (Trt 2). By the final count (5 October 2001), only 11% of the grubs were 1st-2nd instars. -62- Effect of alpha-cypermethrin on DBM in canola at Wongan Hills 2001 1200 Mean No. grubs/10 sweeps 1000 800 3rd of 3 sprays 28/9 2nd of 2 sprays 24/9 1st spray 21/9 600 400 200 5-Oct 3-Oct 1-Oct 29-Sep 27-Sep 25-Sep 23-Sep 21-Sep 19-Sep 17-Sep 0 Date nil spr Figure 1. One-spr Tw o-spr Three-spr Effect of nil, one, two or three spray treatments of alpha-cypermethrin on numbers of DBM grubs/10 sweeps from canola at Wongan Hills in 2001. Yields Damage by DBM grubs significantly decreased oilseed yields (P = 0.049) (Table 1). Unsprayed canola (Trt 1) produced a significantly lower yield (1.13 t/ha) than any of the sprayed treatments (range of 1.38-1.48 t/ha; Table 1). Unsprayed canola lost 0.35 t/ha of oilseed, equivalent to $140/ha (calculated at $400/t, average price for the 2001 harvest). Although spraying did increase overall yield, there was no clear relationship between the number of spray treatments and yield (Table 1). Spraying appeared to affect increase oil content, with a trend of higher oil content in the sprayed treatments than in the nil spray treatment. However, this difference was not statistically significant at 5% when tested by ANOVA (P = 0.229). Table 1. Effect of different spray treatments on oilseed yields (t/ha) and oil content of canola cv. Karoo Yield (t/ha) Treatment Oil content % as is 1. Nil spray (Control) 1.13 36.20 2. One spray applied on 21 September 2001 1.48 36.95 3. Two sprays applied on 21 and 24 September 2001 1.40 38.13 4. Three sprays applied on 21, 24 and 28 September 2001 1.38 37.58 F pr. LSD (5%) 0.049 0.229 0.2523 1.983 CONCLUSIONS Spraying to control DBM grubs with 400 mL/ha of alpha-cypermethrin (Dominex) in an advanced canola crop (late flowering) was effective at reducing insect numbers and improved yields. Applying one, two or three sprays all increased oilseed production over nil spray, but there was no significant difference at 5% in oilseed yield between single and multiple spray treatments. Note that the label for the product Fastac Duo (alpha-cypermethrin), under canola, states ‘Do not apply more than 400 mL/ha per season to any one crop’. GRDC Project No.: GOP Paper reviewed by: Sonya Broughton -63- GrainGuard - A biosecurity plan for the canola industry Greg Shea, Department of Agriculture BACKGROUND The West Australian grains industry is highly exposed to a number of biological threats including incursions of exotic pests, the spread of endemic pests, the development of pesticide resistance and problems associated with grain contamination. The foundation of GrainGuard is the maintenance of a high level of bio-security beginning at the farm level. Growers, agribusiness and others throughout the grain handling chain are encouraged to be vigilant and report any unusual pest observations and seek identification of these pests or disorders by Department of Agriculture specialists. This Canola Industry Protection Plan developed under GrainGuard sets out how the Western Australian Canola Industry, Agriculture Western Australia and the Agriculture Protection Board will cooperate to assess and respond to new threats by appropriate prevention of entry, early detection and prompt incident response actions. The first step in developing the plan was to carry out threat identification and risk assessment. THREAT IDENTIFICATION AND RISK ASSESSMENT There are five categories of threats to the canola industry in Western Australia. These include insects, diseases, weeds, animal pests, and chemical (residue) threats. Within each group there are many potential threats. The serious threats have been identified through risk assessment and others may be added as a continual watch is kept for development of canola industry threats throughout the world. Key considerations A threat’s entry, establishment and spread potential in Western Australia and its impact on costs of production, productivity and market access? What are the consequences? How fast does the threat spread, what is its impact on productivity and market access and how difficult is it to control? By analysing this information, potential threats to canola industry businesses are allocated to one of four Categories ranging from high probability of occurrence and high impact (Category A) to minor impact (Category D). The following two tables summarise these Categories and the most serious threats identified in Category A. Table 1. Category A Threat category of canola insects, diseases, weeds and animal pests exotic to Western Australia B • • • C • • Characteristics High probability of establishing in Western Australia. Could spread throughout the State’s canola growing areas. Has major trade implications and/or substantial long-term effects on productivity or the cost of production. Low probability of establishing in Western Australia. Could spread throughout the State’s canola growing areas. Has major trade implications and/or substantial long-term effects on productivity or the cost of production. Biological restrictions to spread within Western Australia. Only moderate impact on long term productivity or the cost of production. D N • • Minor impact on productivity or the cost of production. Not yet assessed • • • -64- Table 2. Category ‘A’ exotic threats to WA’s canola industry Common name (Scientific name) Threat type Present in Australia (outside WA) Primary host crop or weed of Alternate host crop or weed of Previously eradicated from WA Verticillium wilt (Verticillium dahliae var. longisporum) Fungal pathogen No Canola Cruciferous plants No Seed pod weevil (Ceutorhynchus assimilis) Insect No Canola Cruciferous plants No Branched broomrape (Orobanche ramosa) Weed Yes, South Australia Non cereal crops Oilseeds, pulses and horticultural crops No Additional to these diseases, weeds and pests, the Working Group has identified the contamination of canola by rapeseed varieties which have high erucic acid and other undesirable characteristics as another Category A threat. A draft plan has been completed by the Working Group and has identified Quarantine, surveillance, research/development management and communication activities that can be carried out by government and industry. -65- Large canola seed is best, particularly for deep sowing Glen Riethmuller, Rafiul Alam, Greg Hamilton* and Jo Hawksley, Department of Agriculture, Merredin, *Department of Agriculture, South Perth KEY MESSAGE Large canola seed (> 1.7 mm diameter) produced more plants, matured earlier and produced a higher yield than small seed, particularly at deeper sowing depths. BACKGROUND Deeper than optimum seeding is often recommended as an option to provide soil moisture to the germinating seed, particularly in moisture limited seeding situations. In the season 2000, large seed (> 1.7 mm) improved canola establishment in four of five trials conducted in the sandplain farming systems in Northern Agricultural Region. In the UK, large seed (> 2.0 mm) improved canola establishment from seeding depth deeper than 3 cm. In Canada, seed larger than 2 mm is used to reduce the effects of beetle damage. Hence, effect of seeding depth and seed size on canola establishment needs to be investigated in different field planting situations. AIMS To measure the variation in seedling establishment, yield and seed quality at three sowing depths with three seed sizes. METHODS New quality assured Karoo seed was obtained from Dovuro and graded on mesh sieves into sizes greater than 1.7 mm, 1.4 to 1.7 mm and less than 1.4 mm of which the proportion was 82.2% (in 2000 this was 70.7%), 15.8% and 2.0% respectively and the seed weight was 3.67, 2.46 and 2.12 g/1000 respectively. Only 6.7% (5.46 g/1000) of this seed was above 2 mm in diameter. Location: Design: Seeding date: Seed rate: Seeder: Fertiliser: Sprays: Harvest date: Merredin Research Station, paddock T1, yellow sandy loam Randomised block with 4 replications 14 May 2001 160 seeds per square metre 5.87 kg/ha > 1.7 mm in diameter 3.94 kg/ha 1.4 to 1.7 mm in diameter 3.39 kg/ha < 1.4 mm in diameter Air cone seeder, 6 rows at 250 mm spacing Harrington knife 13 mm wide points ARP 80 mm wide banked press wheels set at 2 kg/cm None with the seed to avoid seed damage due to toxicity 29 May topdressed 88 kg/ha double super plus 33 kg/ha urea 19 July topdressed 99 kg/ha urea 9 February 01, 0.40 L/ha 2,4-D ester 800 9 February 01, 0.75 L/ha Roundup CT 24 April 01, 2.0 L/ha SpraySeed 250 24 July 01, 0.25 L/ha Select + 300 mL/ha Lontrel plus 0.10 L/ha Dominex 100 (for locusts) + 2% oil plus 0.2% wetter 3 and 12 October 2001 misted with 400 mL/ha Fastac 100 for DBM 13 November 2001 RESULTS The larger seed produced more plants than the smaller seed at the deeper sowing depths but was similar at the shallow 1.5 cm sowing depth (Table 1). As expected, the plant number decreased with increased sowing depth. -66- Table 1. Plants/m2 with seed size and sowing depth measured on 11 June 2001 Sowing depth\ Seed size 4.5 cm 3.0 cm 1.5 cm Average > 1.7 mm 41.7 64.2 77.0 61.0 1.4-1.7 mm 26.6 43.2 73.3 47.7 < 1.4 mm 23.0 33.0 78.5 44.8 Average 30.5 46.8 76.3 51.2 F pr LSD Size 0.01 10.5 Depth < 0.001 10.5 Size.Depth 0.17 ns Coeff. of variation 24.3% There were some locusts in the paddock but there was no evidence that any treatment had more damage than any others. Also since the plant number was similar at the 1.5 cm depth, this suggests the locusts did not target the smaller seed size treatments. At the Merredin Research Station Field Day on 27 September it was clear that the small seed treatments were less advanced since they were still flowering where the largest seed treatments had finished flowering. The yield increased with increasing seed size and the 4.5 cm sowing depth was lower yielding than the 1.5 or 3.0 cm sowing depth (Table 2). Table 2. Karoo yield (kg/ha) with seed size and sowing depth Sowing depth \Seed size 4.5 cm 3.0 cm 1.5 cm Average > 1.7 mm 983 1172 1093 1083 1.4-1.7 mm 727 973 852 851 < 1.4 mm 532 777 818 709 Average 747 974 921 881 F pr LSD Size < 0.001 103.5 103.5 Depth < 0.001 Size.Depth 0.54 Coeff. of variation 13.9% ns The oil content increased with increasing sowing depth (37.7-38.5%). The lower oil content of the 1.5 cm depth treatments may be due to their later maturity. There was no effect of seed size or sowing depth on seed protein (average 25.2%). The smallest seed (< 1.4 mm) had a higher admixture (1.63%) than the other seed sizes (average 1.15%) and there was no effect of sowing depth. The larger seed matured earlier than the smaller seed, which was reflected in the larger seed having lower seed moisture (5.2% vs 6.0%). CONCLUSIONS The larger seed produced more plants, matured earlier and produced a higher yield than small seed, particularly at the deeper sowing depth of 4.5 cm. This work needs to be repeated on lighter soils and possibly with seed larger than say, 1.8 mm in diameter. The implication for farmers is that if they are going to keep seed, it should be graded heavily. Importantly, the seed should be germination tested to be sure the seed is worth sowing. GRDC Project No.: DAW 625 Paper reviewed by: Paul Carmody -67- Canola establishment with seed size, tines and discs, with and without stubble Glen Riethmuller*, Rafiul Alam**, Greg Hamilton*** and Jo Hawksley*, Department of Agriculture, *Merredin, **formally Merredin, ***South Perth KEY MESSAGES Large Karoo canola seed (greater than 1.7 mm in diameter) increased establishment by 9.7% and yield by 6.9% (0.07 t/ha) at Mingenew but there was no significant effect on establishment or yield at Coorow. Seeding systems had an effect on establishment and yield but no clear trend was identified, which may have been due to the relatively good soil moisture conditions at sowing. Stubble burning improved the canola yield at Mingenew with no effect on establishment (burning reduced self-sown wheat) but there was no effect of stubble on yield at Coorow. BACKGROUND Low plant density and/or uneven plant density and size, have been recorded in 98% of the canola paddocks in crop establishment surveys during 2000 in the Northern and Central Agricultural Regions. At seeding, some seeds may fall in too deep and some may be trapped at shallower depths or on the soil surface depending on previous crop residues, furrow opener, seed covering device, seed-bed conditions, sowing methods and seed size used. AIMS To investigate the effect of seeding technique and seed size on canola establishment and yield with and without the previous wheat crop stubble at two locations in the Northern Agricultural Region. METHODS Experiment details 01GE84 01GE85 Property Gary Cosgrove, Mingenew Mike Bothe, Coorow Plot size and replication 20 m x 2.0 m 4 replicates 20 m x 2.0 m 4 replicates Soil type Pale yellow loamy sand Yellow loamy sand Sowing date 8 May 2001 10 May 2001 seeds/m2 Seeding rate Ungraded 4.6 kg/ha, 160 Graded 5.9 kg/ha, 160 seeds/m2 Ungraded 4.6 kg/ha, 160 seeds/m2 Graded 5.9 kg/ha, 160 seeds/m2 Fertiliser Agrich 50 kg/ha banded below seed Urea 60 kg/ha topdressed after seeding 15 June 2001, 120 kg/ha Sulphate of Ammonia topdressed 19 July 85 kg/ha Urea topdressed Agrich 50 kg/ha banded below seed Urea 60 kg/ha topdressed after seeding 15 June 2001, 120 kg/ha Sulphate of Ammonia topdressed 19 July 85 kg/ha Urea topdressed Paddock history 2000 - Wheat 2000 - Wheat Herbicides 7 June 2001, 2 L/ha Atrazine 15 June 2001, 250 mL/ha Select + Hasten 7 June 2001, 2 L/ha Atrazine 15 June 2001, 250 mL/ha Select + Hasten New quality assured Karoo seed was obtained from Dovuro and graded on a 1.7 mm mesh sieve into two sizes, greater than 1.7 mm (82.2% of the seed, in 2000 this was 70.7%) and ungraded and the seed weight was 3.67 and 2.88 g/1000 respectively. The air cone seeder sowed 6 rows at 250 mm using: Harrington 13 mm wide knife points, 50 mm wide SuperSeeder points, 180 mm wide full cut points with Loxton rotary harrows or Walker triple discs. ARP 80 mm wide banked and 50 mm wide flat press wheels were set at 2 kg/cm width. Seed pressing was done with the 80 mm wide press wheel and a following Janke finger tine attached to the press wheel frame covered the seed with loose soil. -68- RESULTS Both experiments established well with most treatments in the range of 60 to 90 plants/m 2. Burning stubble improved the canola yield by 19.6% at Mingenew with no effect on establishment (Table 1). Part of this yield response may have been due to less self sown wheat from the burning process. Also soil moisture at seeding (0-5 cm) averaged 5.8% on the burnt treatments and 3.6% on the retained stubble treatments. This may have been due to light falls of rain being held up in the stubble and dried out before reaching the soil. There were 11% more plants established in the stubble than the burnt treatments at Coorow but there was no effect of stubble on yield. At Coorow, treatment 2 and 4 had a higher establishment than the other treatments. The triple disc was lower establishing than all but the full cut at Mingenew. Table 1. Canola yield (kg/ha) with stubble, seed size and seeding technique Seed size Mingenew Seeding technique Coorow Graded Ungraded Graded Ungraded 1. Full Cut, Loxton rotary harrow 1251 1062 1049 1072 2. Knife, 50 mm press wheels (pw) 1176 1043 965 1058 3. Knife, 80 mm press wheels 1162 878 983 960 4. Knife, seed press, finger harrow 1166 997 993 1106 5. SuperSeeder, 80 mm pw 1032 956 976 1029 6. Walker triple disc 1244 1153 1097 1179 1172 1015 1010 1051 1. Full Cut, Loxton rotary harrow 995 989 983 993 2. Knife, 50 mm press wheels 955 1004 1010 1131 3. Knife, 80 mm press wheels 877 843 1057 1030 4. Knife, seed press, finger harrow 898 966 1094 1039 5. SuperSeeder, 80 mm pw 854 854 1049 916 6. Walker triple disc 835 892 1163 1080 Stubble burnt Average Stubble retained 903 925 1059 1032 Overall Average Average 1037 970 1035 1041 LSD stubble (p < 0.05) 87.9% ns LSD seeding technique (p < 0.05) 77.3% 62.6% LSD seed size (p < 0.05) 55.8% ns Coefficient of Variation 13.4% 10.5% At Mingenew there was no significant yield difference (p < 0.05) between the triple disc, full cut plus rotary harrow, knife points and 50 mm press wheels or the seed pressing technique. Knife points plus 80 mm press wheels and the SuperSeeder points plus 80 mm press wheels gave lower yields. At Coorow, the only significant yield result was the triple disc yielded higher than all the other seeding techniques except for the seed pressing technique with finger tines. The larger graded seed averaged 6.9% (0.07 t/ha) higher yielding at Mingenew compared to the ungraded seed but there was no significant effect on establishment or yield at Coorow. CONCLUSIONS The large seed was again important in 2001, which was also found in 2000. Sowing canola into stubble in the Northern Agricultural Region may not be a great problem provided many weed or wheat seeds are not present. Seeding machinery was not particularly important this season which might have been due to the relatively good soil moisture conditions at sowing. It was interesting that the triple disc had the lowest establishment at Mingenew but had the highest yield at Coorow. GRDC Project No.: DAW 625 Paper reviewed by: David Eksteen -69- Role for Roundup Ready® canola in the farming system Art Diggle1, Patrick Smith2, Paul Neve3, Felicity Flugge4, Amir Abadi5, Stephen Powles3 1Western Australian Department of Agriculture, 3 Baron-Hay Court, South Perth WA 6151 2CSIRO, Sustainable Ecosystems, Floreat WA 6014 3Western Australian Herbicide Resistance Initiative, University of Western Australia, Crawley WA 6009 4Centre for Legumes in Mediterranean Agriculture, University of Western Australia, Crawley WA 6009 5Touchstone Consulting, PO Box 375, Mt Hawthorn WA 6016 KEY MESSAGE • Use of Roundup Ready (RR) canola in crop rotations in conditions similar to Wongan Hills WA would be likely to produce similar or slightly higher returns in early years but would be likely to produce somewhat lower returns in later years • Control of established wild radish by glyphosate in crop is expected to be incomplete. This factor has an impact on the estimated value of RR canola in this case but would not be a factor where wild radish is not present BACKGROUND Roundup Ready canola is a genetically modified crop. For this reason there are several considerations in relation to its desirability that are peculiar to genetically modified organisms. However the analysis reported here concentrates only on agronomic considerations that are common to all herbicide resistant crops. This analysis is part of a more comprehensive risk assessment and optimal management plan for genetically modified herbicide resistant crops. A report on the complete analysis will be produced and widely circulated later this year and will include an assessment of factors peculiar to GM crops. The assumptions used in this analysis are still under review and may change before the final report is complete. Some of the GM specific factors are listed below but are not quantified. Factors considered here In this analysis the net returns from a Roundup Ready canola rotation are compared to the returns from a triazine tolerant (TT) canola rotation. In both cases the rotation is wheat, lupin, wheat, canola. Genes for triazine resistance carry a yield penalty, so RR canola is presumed to have a yield advantage in the order of 6%. All herbicide resistant crops will change the rate that herbicide resistance develops in weeds. Use of glyphosate on RR canola will increase the rate of development of glyphosate resistance in the weed populations. Similarly use of triazines on TT canola will increase the rate of development of triazine resistance in the weeds. Herbicide resistance reduces returns to the farmer through both reduced yields and increased costs of weed control by alternative methods. The weeds being considered in this analysis are ryegrass and wild radish, and development of glyphosate resistance and triazine resistance has been calculated for both species. Different farmers will get different results from RR canola, and different paddocks on the same farm will behave differently. In this analysis we have attempted to account for the range of diversity that exists. Some factors that have been considered are: • Different seasons - seasonal variability in crop yield and competitiveness has been represented here using output from the APSIM crop growth model run for 40 historical seasons at Wongan Hills WA for all crops grown both in monoculture and in competition with weeds. -70- • Different starting weed populations - initial ryegrass populations have been assumed to vary between 0 and 3000 seeds/m2 with 1000 seeds/m2 being most likely. For wild radish minimum, most likely and maximum populations are 0, 50 and 500 plants/m 2 respectively. • Different sowing rates - minimum, most likely, and maximum crop densities have been presumed to be 100, 175, and 300 plants/m2 for wheat; 40, 60 and 90 for lupin; and 40, 50 and 70 for canola. • Different initial frequency of resistance genes - initial frequencies of Roundup resistance genes have been presumed to vary between 10-9 and 10-5 for both ryegrass and wild radish, and between 10-7 and 10-3 for triazine resistance genes both ryegrass and wild radish. • For both rotations additional weed control in the form of higher seeding rates, use of 2,4-D in wheat, crop topping with paraquat in lupins, and seed catching is employed where weed populations exceed nominated thresholds. Factors that are not considered here • Genes from genetically modified canola crops can be transferred to non-GM canola crops through movement of pollen between crops and through survival of GM volunteers in later crops. Contamination of non-GM canola with GM genes may have economic significance. • Canola with several stacked resistance types may be produced and may be difficult to control. • Canola and wild radish have been shown to produce small numbers of hybrids in the field. These hybrids will have any herbicide resistance genes that are present in the canola parent and may become weeds in their own right. • There may be a price premium in some markets for canola that can be certified to be non-GM. Australian canola currently has this status. If GM canola is released there will be an increased cost of identity preservation for non-GM canola. RESULTS AND DISCUSSION The herbicides used in TT canola are considerably more expensive than those that would be used on RR canola (Table 1). However there is expected to be an as yet undisclosed technology cost for use of RR canola. Table 1. Comparison of herbicide costs for TT canola and RR canola Cost ($/ha) * Rate (L/ha) TT canola RR canola Glyphosate (knockdown) 1.0 11.00 11.00 Simazine (pre-emergent) 2.0 14.50 Simazine (post-emergent) 1.0 8.50 Select (Clethodim) (post-emergent) 0.15 25.50 Glyphosate (post-emergent) 1.0 Herbicide 11.00 TOTAL 59.50 22.00 Cost of herbicide includes a $2.50/ha cost of application (excluding Select, which is assumed to be applied with the simazine post-emergent application). Net returns decline somewhat through time for both rotations. This decline occurs primarily because of increasing herbicide resistance, requiring the use of additional weed control techniques and hence leading to additional costs. The RR canola has similar or slightly higher returns in the early years of the rotation but declines more rapidly. A technology cost for RR canola is not included. If, for example, this cost was to be $20/ha, the average net returns for RR canola would be reduced by $5.00 each year as canola is only planted one year in 4. A factor that is not apparent from this figure is that ryegrass is problematic in the TT rotation, while wild radish is more of a problem in the RR rotation. This result stems from the assumption made here that control of established wild radish is less complete for glyphosate than for triazine. This assumption -71- has yet to be comprehensively tested in crop as the test can only be done in RR crops. It is likely that the returns from RR canola would be higher where wild radish was not present. Figure 1. Average net return discounted (5% pa) and not discounted over 30 years for the 4 phases of a WLWC rotation (mean of 2048 simulation runs). GRDC Project No.: UWA 355 Paper reviewed by: P. Smith -72- Getting value from canola meals in the animal feed industries: Aquaculture Brett Glencross and John Curnow, Department of Fisheries - Government of Western Australia and Wayne Hawkins, Department of Agriculture INTRODUCTION Fishmeal replacement in fish diets Of all animal production industries, none has equalled the growth rate experienced by that of aquaculture over the past ten years. While this boom in fish production bodes well for those who want to keep eating fish, it has begun to present problems in that we are now asking, what do we feed the fish to keep this industry growth going? World supplies of fishmeals and oils are already static in supply, so any increase in feed production for the aquaculture industry must necessarily come from elsewhere to provide the necessary protein for these animals. Canola meals were first identified in the 1980s as having some potential as a useful feed ingredient in the diets of fish. More recently it was identified that protein concentrates made from these meals had more value to fish than the meals. Despite this progression, surprisingly little is known about the differences in nutritional value of the raw meals produced from different oil extraction methods, such as expeller and solvent extraction. ASSESSING NUTRITIONAL VALUE Protein content and composition As nutritionists, we tend not to look for the ‘perfect’ single ingredient from which to make diets, but rather a suite of high quality, complimentary ingredients of consistent composition from which formulations can be tailored to suit the varying dietary requirements of specific species. In this sense, canola meal has the potential to be a good ingredient for use in aquaculture diets. Critical to their value is the overall protein and energy content of the meal. More specifically though, the amount of digestible protein and energy in the meal. Notably, the composition of canola meals produced by different methods has different amounts of protein and energy (Table 1). This is likely to influence the nutritional value of these meals to animals. Table 1. Composition of fishmeal, canola meals and the protein concentrate used in the study Fishmeal Expeller canola meal Solventextracted canola meal Dry matter content (g/kg) 925 898 962 483 Crude protein (g/kg DM) 703 381 431 483 73 136 22 33 Nutrient Crude fat (g/kg DM) Ash (g/kg DM) Canola protein concentrate 216 66 86 59 8 418 461 425 Phosphorus (g/kg DM) 40 24 23 36 Gross energy (MJ/kg DM) 19.6 23.1 19.6 22.1 36.6 n/a Carbohydrates (g/kg DM) Phytate (g/kg DM) 0 Glucosinolates (mol/kg DM) 0 25.6 3620 1100 n/a n/a Not assessed. DM Dry matter. Nutritional utilisation of canola meals by fish Typically the digestible or useable protein and energy is determined by including the canola meal in a diet, usually at 30% of the total diet content, which also includes an indigestible marker. The concentration of this marker is then compared between the feed and the faeces, along with any -73- changes in protein and energy content, thereby allowing the calculation of the relative degree of loss of protein and energy and as such the level of protein and energy digestion and absorption. Recent work at Fremantle has evaluated the nutritional value of solvent-extracted and expeller extracted canola meals when fed to red seabream/pink snapper (Pagrus auratus). Also evaluated were the effects of heat damage on the value of expeller extracted canola meal, the potential for supplementary enzymes to improve the value of canola meals and also the value of a protein concentrate made from canola meal. The nutritional value of these canola meals was also compared against that of a high protein (48%) solvent extracted soyabean meal, the key competitor for all Australian plant protein meals in the worldwide feeds market. Table 2. Digestibility of protein and energy from each of the test treatment ingredients Solvent extract Expeller extract Expeller 120ºC Expeller 150ºC Phytase Soybean CPC Energy 46.1b 62.1 a 34.3 c 27.4 d 61.1 a 59.2 a 64.9 a Protein 82.1b 89.2 ab 61.4 c 37.4 d 97.3 a 79.4 b 74.4 b Different superscripts, within the same row, denote a significant difference. CPC: Canola Protein Concentrate Assessment of the apparent nutrient digestibilities of each of the canola meals clearly supported that they have excellent protein qualities, highly suitable for use in aquaculture diets. Protein digestibilities of both expeller and solvent-extracted meals were at least equal to that of solvent extracted soyabean meal. The highest protein digestibility was that of the expeller-extracted meal supplemented with the enzyme Phytase, though this was not a significant improvement (Table 2). Energy digestibilities of the canola meals differed, with the solvent-extracted canola meal having less digestible energy than the expeller-extracted meal. This is primarily a result of the difference in amount of fat in the two meals (Table 1). Increasing heat damage of canola protein has very significant negative effects. Declines in both protein and energy digestibility of the expeller-extracted meal was observed with an increase in heat exposure (30 minutes) temperature. The other treatments were prepared with temperatures of 90ºC and less. Qualities of the CPC are also very encouraging. A second important finding of this study was the lack of significant aberrations in the levels of blood thyroid hormones and also that no reductions in feed intake were observed with the inclusion of canola meals in the fish diets (Table 3). This finding is different from that reported by the Canadians and Europeans when they feed canola/rapeseed meals to fish. It is not yet known whether this difference is a function of different fish species, or that Australian canola meals don’t have the same level of problems with glucosinolate breakdown products in the meal as the Canadian and European varieties. Table 3. Feed intake of the treatment diets and blood thyroid hormone levels at the end of the study Feed intake (g/fish/d) Tri-iodothyronine (T3) Thyroxine (T4) Reference diet 1.05 b 12.2 ± 1.8 a 36.1 ± 10.6 a Solvent extracted 1.11 ab 12.0 ± 1.4 a 21.4 ± 1.7 a Expeller extracted 1.20 ab 13.1 ± 1.3 a 27.2 ± 1.5 a 120ºC Heated 1.20 ab 12.1 ± 1.2 a 28.8 ± 3.3 a 150ºC Heated 1.16 ab 10.9 ± 1.7 a 25.3 ± 4.5 a Phytase 1.24 a 10.5 ± 1.4 a 23.0 ± 5.2 a Soybean reference 1.15 ab 13.2 ± 1.4 a 42.8 ± 10.7 a Protein Concentrate 1.22 a 0.6 a 23.9 ± 5.4 a Treatment GRDC Project No.: FWA001 Paper reviewed by: Sofie Sipsas 12.0 ± -74-