Weed Control

Different weeding frequencies (WFs)―0WF, 2WF, 4WF, 6WF, and 8WF―were adopted in an organic rice field to investigate their influence on weed types, rice and weed biomass, rice tiller and weed number, N concentration, and N uptake. The study field was located in Tsuruoka, Yamagata, Japan. Rice (cv. Sasanishiki) was planted from May to September 2019, and all weeding events were carried out until 49 days after transplantation (DAT) using a rotary weeder. Rice and weed samples were collected at 60, 88, and 110 DAT. Echinochloa crus-galli (E. crus-galli), Schoenoplectus juncoides, and Monochoria vaginalis (Burm. f.) were the most commonly found weeds. High weed diversity was observed at both 6WF and 8WF, E. crus-galli was the dominant weed at 0WF. Compared to 0WF, 2WF displayed a significantly decreased weed biomass. However, at 8WF, the weed biomass was reduced by 79.0%, the rice biomass was increased by 277%, and the rice tiller number was almost three times higher than that at 0WF an...

The experiment was conducted at the Research Farm of the Punjab Agricultural University, Ludhiana in rabi seasons of 2005-06 and 2006-07 to study the efficacy of tank mix application of 2, 4-D, carfentrazone and metsulfuron with isoproturon in managing weeds of irrigated barley. Minimum weed dry weight was recorded in isoproturon 1000 g+metsulfuron 4 g/ha which was statistically on par with isoproturon 1000 g/ha, isoproturon 1000 g+carfentrazone 20 g/ha and isoproturon 1000 g+2, 4-D 500 g/ha during 2005-06. In 2006-07, minimum weed dry weight was recorded in two hand weedings which was statistically on par with isoproturon 1000 g+metsulfuron 4 g/ha, isoproturon 1000 g/ha, isoproturon 1000 g+carfentrazone 20 g/ha, and isoproturon 1000 g+2,4-D 500 g/ha. Highest test weight and barley grain yield were recorded in isoproturon 1000 g+metsulfuron 4 g/ha which were statistically on par with isoproturon 750 g+metsulfuron 4 g/ha, isoproturon 750 g+2,4-D 500 g/ha, isoproturon 1000 g+2, 4-D 500 g/ha and two hand weedings. The highest net returns of Rs. 29063 with isoproturon 1000 g+metsulfuron 4 g/ha and Rs. 39581 were recorded in isoproturon 1000 g+2, 4-D 500 g/ha as tank mix in 2005-06 and 2006-07, respectively.

The spectacular performance of Indian agriculture witnessed during the second half of the 20th century against the onslaught of rising demographic pressure is a vivid demonstration of the growing effectiveness of our agricultural research and development system. However, the issue of sustainability in agriculture still remains a question. Management of natural resources, especially soil and its fertility status and vegetation following suitable agronomic management practices for sustainable agricultural production, represents a most daunting task and is certainly going to receive much attention in the years to come. Many workers established functional relationships between nutrients and other agronomic factors at different locations in India but systematic compilation of those relationships is a rare effort. The present paper reviews the latest information on inter-relationships between nutrients and other agronomic factors (seed rate, planting density, age of the seedling, planting method, irrigation, weed control, tillage, bacterial inoculation and cultivar etc.) on field crops. Major findings of first and second order interactions are highlighted. None of the second order interaction was found signifi-P. K. Ghosh is Senior Scientist

A four-year study of site-specific weed control is presented in this paper. Weed seedling distribution was sampled and mapped prior to and after post-emergence herbicide application in four fields planted with maize, sugar beets, winter wheat and winter barley, rotating on one site. Herbicides and other weed control strategies were applied site-specifically according to the spatial variation of weed populations.

San Clemente Island has been subjected to largescale disturbance from grazing and subsequent weed infestation, particularly by two wild oat species, Avena fatua and A. barbata. An endemic disease, crown rust (caused by Puccinia coronata f.sp. avenae), was selected as a potential control agent. A strain with a short latent period was selected from a common island isolate. Three replicate sets of plots were established on the island, each set containing a plot treated with crown rust, a control plot, and a plot treated with a fungicide. Disease was assessed in these plots and outside of the inoculated plots to a distance of 100 m. Reproductive output of wild oats from these plots was measured and compared for differences among treatments. Results indicated that disease was established from artificial inoculations in both years, 2 weeks earlier than the onset of disease from natural infections in 1997, but not in 1998. This result may have been due to unusual weather patterns in 1998 that caused an earlier onset of natural infections and precluded higher success of artificial inoculations early in the season. Analysis of reproductive output of wild oats from these plots showed that biomass and seed number were significantly lower (P < 0.05) in inoculated plots than in control and fungicide-treated plots. These results indicated that, with augmentation over several years, crown rust may be effective in reducing populations of wild oats on San Clemente Island.

Weed infestation and inherent low soil fertility are among the major factors attributed to the low yield of rice in Nigeria. Field trials were therefore conducted to evaluate the effect of nitrogen application levels and weed control methods on growth and yield of upland rice (var. NERICA 2) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07o 15?N, 03o 25?E) during 2015 and 2016 cropping seasons. Three nitrogen (N) levels (0, 60 and 90 kg/ha) were evaluated and they constituted the main plot treatments, while three weed control treatments, viz: pre-emergence application of Orizo Plus? (propanil plus 2, 4-D) at 2.0 kg a.i ha-1, Orizo Plus? at 2.0 kg a.i ha-1 followed by supplementary hoe weeding (SHW) at 6 weeks after sowing (WAS) and three hoe-weeding regimes at 3, 6 and 9 WAS, and a weedy check constituted the sub-plot treatments. All the treatments in different combinations were laid out in a randomized complete block design with a split-plot ...

We test for a relation between football match results and the specific national stock index returns during the period 1990–2006 by means of an event study approach. We employ two different econometric frameworks to cross-check our results and prevent them from being solely model driven: the constant mean model and a two-state Markov-switching market model. Both approaches find no significant

While job search theory predicts that active labour market policies (ALMPs) can affect post-unemployment outcomes, empirical evaluations have mostly focused on the impact of ALMPs on exit rates from the current unemployment spell. We use a social experiment, which was conducted in Denmark in 2005-6, to investigate the potential long-term effects of a dramatic intensification of ALMPs. We evaluate the impact of treatment on post-unemployment employment stability, exits from the labor market and more generally on the transitions on the labour market up to 4 years after randomization. We estimate a multistate and multispell duration model with lagged duration dependence to separately identify "indirect" (through previous shorter unemployment duration) and "direct" (through a more efficient matching process) longer term effects of ALMPs. We adopt time-varying treatment and allow for ex ante effects of ALMPs. We find that intensive activation significantly reduces unemployment recurrence for men, but not for women. When we control for dynamic selection and lagged duration dependence, the positive impact of the treatment becomes smaller or insignificant, meaning that most of the impact acts through the indirect channel and the threat effect.

This study contributes to the stock returns-inflation relation literature in developing countries by revisiting the issue with reference to the emerging economy, India. More specifically, it tests whether the Indian stock market provides an effective hedge against inflation using monthly data on real stock return, inflation and real activity from April 1980 to March 2004 and a two-step estimation procedure. Results of the study indicate that (i) the Indian stock market reflects future real activity; (ii) the negative stock returns-inflation relation emerges from the unexpected component of the inflation and (iii) this negative relation vanishes when we control for the inflation-real activity relation, thereby providing a strong support for Fama’s proxy effect hypothesis. The split sample analyses indicate that the Fama hypothesis is valid only in pre reform period. In the post reform period, real stock returns have been independent of inflation, i.e., the Fisher Hypothesis is valid.

Saunders (1993) and Hirshleifer and Shumway (2001) document the effect of weather on stock returns. The proposed explanation in both papers is that investor mood affects cognitive processes and trading decisions. In this paper, we use a database of individual investor accounts to examine the weather effects on traders. Our analysis of the trading activity in five major U.S. cities over a six-year period finds vistually no difference in individuals propensity to buy or sell equities on cloudy days as opposed to sunny days. If the association between cloud cover and stock returns documented for New York and other world cities is indeed caused by investor mood swings, our findings suggest that researchers should focus on the attitudes of market-makers, news providers or other agents physically located in the city hosting the exchange. NYSE spreads widen on cloudy days. When we control for this, the significance of the weather effect is dramatically reduced. We interpret this as evidence that the behavior of market-makers, rather than individual investors, may be responsible for the relation between returns and weather.

Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower (Helianthus annuus L.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59 Fe), Mn (54 Mn), and Zn (65 Zn), root uptake of 59 Fe and 54 Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59 Fe within 12 h and 54 Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions.

In organic farming, weeds are one of the threats that limit crop yield. An early prediction of weed effect on yield loss and the size of late weed populations could help farmers and advisors to improve weed management. Numerous studies predicting the effect of weeds on yield have already been conducted, but the level of uncertainty about weed effect is expected to be very high in organic crops. It is thus more appropriate to provide farmers and advisors with distributions of possible production levels, rather than with point values. The purpose of this study was to estimate the effect of early weed density at the end of the tillering stage of organic winter wheat on subsequent yield and on late weed density at flowering, by using quantile regression. Results showed that this method can be applied to a hyperbolic model and to an allometric density-dependent model, to describe the distribution of yield values and of late weed density respectively, as functions of early weed density measurements. Mechanical weed control showed no significant effect on the relationship between early weed density and grain yield, but it decreased late weed density. Yield and late weed density distributions derived by quantile regression provided sound information on the possible effect of weeds on organic winter wheat production.

Bayesian Belief Network (BBN) modelling may be applied in rural extension in situations where program outputs are influenced by variables which are sequentially influenced by other variables. For a recently completed agroforestry extension program in Leyte the Philippines, BBN modelling of site factors, establishment practices and risk, predicted widely different program outputs for different levels of extension assistance and farmer inputs. In a situation where very little was known about how farmers would respond to offers of extension assistance, monitoring of the program over a period of three years revealed that extended extension assistance was crucial in determining the likely survival and growth of trees. Extended extension assistance was also important for the elimination of unsuitable sites and the use of appropriate establishment procedures. Where extension support was not available, farmers displayed a poor knowledge of the principles of tree growth, planting trees under...

Although weed research in maize has broadened from an emphasis on herbicide technology to include studies of weed± maize competition, many studies only consider competition descriptively (e.g. de®ning the critical period for weed control). Furthermore, studies of the mechanisms of weed competition in maize have considered only competition for resources such as soil moisture, nutrients and light. Physiological ecologists have recently recognized the signi®cance of early detection of neighbouring plants through the far-red/red (FR/R) signal as an important mechanism affecting plant±plant interactions. In this review, we have indicated the importance of integrating the concept of the mechanism of early detection of neighbours with the resource-limiting approach in reassessing weed competition in maize during the critical time for weed control. Hypothetical integration of early detection of neighbours into the existing concepts of critical time for weed control and weed thresholds led us to view maize±weed competition as a series of complex processes, which is triggered by the FR/R signal and followed by the development of shade avoidance characteristics accompanied by a reduction in the plant's ability to absorb nutrients and water, and to photosynthesize. However, due to lack of research on effects of weeds on light quality impinging corn plants as well as corn response to an increase in FR light during critical time for weed control, our conclusions remain to be speculative. We believe that incorporation of early detection of neighbours through the FR/R ratio as a primary signal during the critical period for weed control would open a new approach for future studies on weed competition in maize. We recognize that resource limitation occurs in a maize±weed association, however, this may be more of an effect rather than a cause of competition.

The production of potatoes has become important in Europe, especially since the 19th century. Since 1850 the yield of ware potatoes increased in The Netherlands from approximately 10 t ha-1 to the present level of 45 t ha-1. This was achieved by various improvements in production techniques. Several breakthroughs were accomplished in breeding for host resistance against pathogens. The current use of pesticides (nematicides, herbicides, fungicides, etc.) is high in potato production, at least in The Netherlands, particularly due to the use of fumigants to control nematodes in the starch potato growing areas. The Dutch government adopted objectives with respect to general reductions in the use of pesticides and the leaching of nutrients (nitrate). Adaptations in cultural measures are required to meet these objectives and to arrive at more sustainable systems of production in the future. In this paper special attention is given to past and present problems and possibilities with respect to cyst nematodes, late blight, wart, Colorado potato beetle, nitrogen nutrition, weed control, haulm destruction and sprout suppression.

Studies on planting crops no-till have been carried out extensively in many countries. So far, studies have not been conducted in the cultivation of flax. The purpose of this study was to compare no-till and conventional cultivation of flax on weed control, yield of fiber flax and seed, and the physical and biological properties of the soil. Precipitation in the years of study was significantly different and modified the effect of the treatments. Yields of whole flax plants with seeds and yields of straw in the dry year were higher, and in the year with optimal rainfall lower with no-tillage than conventional cultivation. Flax seed yield, regardless of the year, was higher in the no-till system. No-tillage, regardless of weed control, reduced the number and weight of weeds, compared to conventional cultivation with plowing. No-tillage resulted in a higher moisture content and lower soil capillary capacity than with conventional tillage. Cultivation systems did not affect the bulk density of topsoil but no-tillage contributed to an increase of humic substances content in the soil environment.

The hypothesis that grey mould incidence would be positively correlated to grapevine canopy development was confirmed over a period of 3 years (2004)(2005)(2006) on Aranel cultivar in an experimental vineyard near Montpellier, south France. Different levels of vine growth were generated by implementing three management schemes: (i) perennial cover crop, (ii) chemical weed control and (iii) irrigation and fertilisation. Grey mould incidence was assessed at harvest, together with various sets of variables linked with canopy microclimate, shoot vigour, vine capacity, cluster architecture, yield components and fruit composition. Significant positive correlations were observed between disease incidence and key variables of shoot vigour and vine capacity: total leaf number, leaf dry matter, leaf layer number, leaf area per metre of row, pruning mass and nitrogen accumulation. In 2004, Botrytis cinerea developed in all experimental plots because climatic and microclimatic conditions were conducive to grey mould. The climatic and microclimatic variables that significantly favoured grey mould development were: precipitation, duration of relative humidity 490% in the canopy and low potential evapotranspiration. However, in 2005 and 2006, under dry summer conditions, disease developed only in the most vigorous vines, which were both irrigated and fertilised. These vines showed a very high canopy growth, very compact clusters and a delayed fruit maturity. This evidenced that unfavourable climatic conditions for the disease development can be counterbalanced by conditions of high vine growth and associated canopy and cluster features. r

On wheat-sheep farms in the south-west of Western Australia, pasture production in winter is a major limiting factor for the sheep enterprise. This paper describes an economic evaluation of reducing herbicide usage in crops below recommended levels to increase subsequent pasture production in pasture-crop rotations. The analysis was of ryegrass (Lolium rigidum) control by diclofop-methyl in the Merredin region and conducted using MIDAS, a whole-farm linear programming model. Inputs to MIDAS were provided by a simulation model of the weed population and regression models of weed kill from herbicide application and yield response to weed removal. Results indicated that the gains from increased sheep and wool production and reduced herbicide cost are likely to exceed the losses from reduced grain yield. This conclusion appears to be insensitive to major biological and economic assumptions of the analysis, although the issue of year-to-year seasonal variation has not been addressed.

Ageratum conyzoides L. (billy goat weed), showed strong inhibition on Raphanus sativus L. (radish) germination and growth in a bioassay. The leaves exhibited a greater suppression than the stem and root. The leaves of A. conyzoides applied at 2 t ha À1 reduced about 70% of the growth of Echinochloa crus-galli var. formosensis Ohwi. and completely inhibited emergence of Monochoria vaginalis (Burm.f. Persil var. plantaginea Solms.) and Aeschynomene indica L. in calcareous soil condition. Application of A. conyzoides leaves at 2 t ha À1 in a paddy field 2 d after transplanting caused about 75% paddy weed reduction and increased yield by 14% compared with a herbicide treatment. Three phenolic compounds were identified in the leaves, stem and root including gallic acid, coumalic acid, and protocatechuic acid, and catechin was found only in the stem. p-hydroxybenzoic acid was detected in both A. conyzoides leaves and stem. Three additional putative allelochemicals were found in the leaves consisting of p-coumaric acid, sinapic acid, and benzoic acid. The greater number of growth inhibitors found in the leaves might result in the stronger inhibitory activity than the stem and root. A. conyzoides might be a natural herbicide for weed control in paddy fields to reduce the dependence on synthetic herbicides. r

The second edition of Miguel Altieri's 'Agroecology' is a very useful guide to some of the more recent developments in sustainable or ecologically oriented agriculture. The book is in five parts: Part One, The Theoretical Basis of Agricultural Ecology consists of three chapters: The Evolution of Agroecological Thought by Susanna B. Hecht, The Methodology and Practice of Agroecology by Richard P. Norgaard and Thomas O.

The competitiveness of sprawling (30e50 leaf angle), intermediate (50e70 leaf angle) and erect (70 e90 leaf angle) sugarcane cultivars ('B41227', 'B52298' and 'NCo334') was studied for two cropping seasons under 0, 3, 6, 9, 12, 15 weed-free weeks after planting (WAP) of sugarcane and weed-free conditions at three sugarcane plantations in Ethiopia. The study showed highly significant (P < 0.01) effects of cropping season, cultivar, duration of competition as well as the interaction effects of cultivar by durations on weed dry weight, milleable cane yield and sugar yield. Among the cultivars, 'B41227' suppressed weed population the most and gave the highest tiller number, cane yield and sugar yield. The highest rates of cane and sugar yield increase were recorded for weed free periods of 3 WAP to 12 WAP, while weeds emerging before 3 WAP and beyond 12 WAP had less effect. The extent of cane and sugar yield loss varied with season, plantation and cultivar. Sugar yield loss of the unweeded treatment (0 WAP) compared with weed-free (WF) treatment ranged from 74.1% for cultivar 'B41227' at Metahara to 90.5% for cultivar 'NCo334' at Wonji-Shoa plantations. Thus, the sprawling sugarcane cultivar 'B41227' appeared to be most competitive and the critical period for weed control should be between 3 and 12 WAP to prevent substantial cane and sugar yield loss due to weed competition.

This chapter mainly informed about the management of the weeds of different grain crops, vegetables, flower crops, oil crops, and others. The weeds were very damaging to main product the quality crops/fruits and this paper study on the inform about weed and how to management the weeds in field. Here is also focus on the common crops and their weeds and common name, scientific name and also added the herbicide name to manage weeds in different plants. The farmers used balance fertilizer and also used chemical insecticides to minimize crop damage. It has been estimated that of the average at 36.5% of total losses where 6.2% by weeds. This chapter has efforted the prescription to the weed management in farmer fields. Hence, I think if this book is available for all agriculturists and farmers then they will benefit.

In this paper, we examine the effect of implicit seller reserves on the estimation of value-at-risk based on historical asset sales data. We direct our examination toward how and whether fine art might prove an appropriate form of loan collateral for banks and other financial institutions. Using a data set of French Impressionist paintings brought to auction from 1985 to 2001, we control for the effect of works that are bought in-house to construct a distribution of potential sale values that corrects for sample selection bias. It turns out that the downside risk surrounding deviations of auction prices from expert presale estimates depends critically on how buy-ins are incorporated. If downside risk is assessed solely on historical experience with successful auction sales, the data appear to support loan-to-value ratios between 50% and a 100% larger than loan-to-value ratios that countenance the existence of seller reserves. The auction process, however, is quantifiable and can reveal the necessary risk information required for loan consideration.

... Weed control provided by the three types of rotary wick wiper applicator machines using glyphosate was com-plete for at least 60 DAT ... Chris Nazer1, Zel Bodulovic2 and Andrew Somervaille2 1 Canberra Urban Parks and Places, PO Box 352 Civic Square ACT 2608 2 Agtech ...

We present a novel dynamic analysis technique that finds real deadlocks in multi-threaded programs. Our technique runs in two stages. In the first stage, we use an imprecise dynamic analysis technique to find potential deadlocks in a multi-threaded program by observing an execution of the program. In the second stage, we control a random thread scheduler to create the potential deadlocks with high probability. Unlike other dynamic analysis techniques, our approach has the advantage that it does not give any false warnings. We have implemented the technique in a prototype tool for Java, and have experimented on a number of large multi-threaded Java programs. We report a number of previously known and unknown real deadlocks that were found in these benchmarks.

A seller of a real estate generally has three alternative ways of marketing his property. He can search for the buyer on his own efforts (FSBO -For Sale By Owners), list the house with an MLS (Multiple Listing Service) broker, or list it with a non-MLS broker. The choice of the marketing system may have broad implications for the seller. It may affect the time on the market, the seller's marketing costs, characteristics of the buyers contacted through that maketing system, buyers' search efforts, and the selling price. The focus of this paper will be on the relationship between the marketing system choice and the selling price.

Plant competition is thought to be driven by limiting resources. We propose that plant competition is triggered initially by the red to far-red light ratio (R:FR) originating from neighbouring plants, followed by a series of complex physiological processes, which exclude direct resource competition. Field experiments were conducted in 2005 and 2006 in which maize (Zea mays) was grown hydroponically. The effect of R:FR signal being reflected from the leaf surface of Amaranthus retroflexus was isolated by avoiding direct competition for light, water and nutrients. Results showed that the low R:FR reflected from the leaf surface of A. retroflexus did alter the carbon allocation pattern of maize when compared with maize growing free of weeds. Prior to silking, maize grown under low R:FR experienced temporal changes in plant height, persistent changes throughout the sampling period in root and shoot dry weights and rate of leaf appearance, but no changes in leaf area. At silking, low R:FR reduced ear and total plant dry weight. These results support the hypothesis that changes in R:FR acts as an early signal of pending competition by initiating a shade avoidance response. Data from this experiment suggest that once a plant is physiologically triggered into a shade avoidance response, these plants do so at a physiological cost, which may constrain plant development and possibly reduce reproductive fitness.

Abstract:  We examine the valuation role of customer acquisition cost, retention and usage in the wireless industry during the period 1997–2004. We develop and test a model that links customer acquisition cost, customer retention and call usage to future financial performance and valuation. In doing so, we control for the role of traditional accounting measures as predictors of firm performance. Although the wireless industry maintains a rapid pace of technological and commercial changes, fundamental accounting numbers are found to be value relevant. We provide new evidence that customer acquisition cost is likely a firm value driver. Specifically, we show that this cost is positively associated with customer retention, future profits and current market values. However, customer acquisition cost is not associated with future revenues, suggesting that successful investment in customer acquisition is capable of saving future expenses and hence of improving profitability. There does not seem to be a direct association between customer retention and usage. Nevertheless, we document a positive relation between retention and future revenues, as well as a positive association between usage and future profits. Collectively, these results suggest that retention and usage play an important mediating role linking customer acquisition with benefit generation. Consistent with this, we find some evidence that customer retention and usage enhance market values.

We estimate a production function model of aggregate economic growth including two variables that microeconomists have identified as fundamental components of human capital: work experience and health. Our main result is that good health has a positive, sizable, and statistically significant effect on aggregate output even when we control for experience of the workforce. We argue that the life expectancy effect in growth regressions appears to be a real labor productivity effect, and is not the result of life expectancy acting as a proxy for worker experience.

Generalist arthropod predators act as natural enemies of insect pests in agroecosystems. Crop management activities may cause a reduction in arthropod densities, either directly through mortality and emigration, or indirectly through habitat disruption. Our aim was to quantify direct mortality caused by mechanical crop treatments. For some treatments, we also quantified emigration and other indirect effects, such as population declines caused by the impact of habitat deterioration on reproduction and survival. 2. Direct mortality was determined by measuring predator densities simultaneously in control and treatment plots using closed emergence traps immediately following a mechanical treatment. Treatments consisted of the following crop management activities: ploughing, non-inversion tillage, superficial soil loosening, mechanical weed control and grass cutting. Predator densities were measured a second time 5-26 days after treatment to quantify emigration and indirect effects. 3. All treatments had a negative influence on one or more arthropod taxa. Direct mortality caused a 25-60% reduction in arthropod densities. Overall, spiders were more vulnerable to mechanical crop treatment than carabid and staphylinid beetles. Intensive soil cultivation, such as ploughing and soil loosening, did not kill more arthropods than weed harrowing and grass cutting. 4. We estimated the cumulative effects of mortality, emigration and indirect effects 3 weeks following treatment. The cumulative effect was greater than direct arthropod mortality, suggesting delayed effects of habitat disruption. 5. Grass cutting caused spiders and staphylinid beetles to move out of the crop, except in one case when the grass was left to dry, suggesting an important role of organic material or structural elements for arthropod persistence. Our results also suggest that arthropod predators aggregate in undisturbed or less disrupted habitats. 6. Synthesis and applications . Mechanical operations in arable crops and grass cutting cause mortality and emigration of generalist arthropod predators, especially spiders. Effects can be species-specific and are likely to be affected by the timing of management. In grassland, cutting and removal have greater adverse impacts than leaving cuttings that contribute to habitat structure. Adjacent, less-disturbed refuge areas are colonized by predators following husbandry events, demonstrating significant spatial dynamics among farmland arthropods. The negative effects of crop husbandry operations might be mitigated by the provision of refuge areas within and adjacent to fields and by maintaining crop and landscape diversity.

Raised beds are widely used in agriculture in developed countries and have proven to be an excellent option for wheat. Permanent raised beds may also offer benefits for rice-wheat (RW) systems in South Asia, in terms of both production and the possibility that furrow-irrigation may be more efficient than flood irrigation. The performance of a RW system on permanent raised beds (37 cm wide, 15 cm high, furrow width 30 cm) was compared with conventional cultivation on the flat on sandy loam and loam soils in replicated experiments in central Punjab, India. The experiments commenced with wheat sown in November 2002, and were continued for 8 crops.

An experiment was conducted to quantify the effect of different weed control intensities (WCI) during the first three growing seasons in a Pinus radiata plantation. At the end of the third growing season, results showed that stem volume index of check plants was similar to that of plants that received spot applications in the first and second year. On the other hand, when plots were treated with herbicide spot application (first year) plus band or total area application (second year), the stem volume index was two and three times larger, respectively. However, if the first year WCI consisted of total area application, the second and third year treatment had less effect on yield. The largest biomass yield was obtained when plots were submitted to total area WCI during the first and second year. r

Current Status Current Products and Adoption Rates. As of 2009, after 13 years of growing GR crops, there are five different GR crops grown in the United States (Table 1). Of these, GR cotton (Gossypium hirsutum L.), maize (Zea mays L.), canola (Brassica napus L. and B. rapa L.), and soybeans [Glycine max (L.) Merr.] are grown in other countries. GR soybean adoption was rapid in the United States (Figure 1), currently representing more than 90% of the area planted to soybean. The adoption rate of GR soybean in Argentina was even more rapid, reaching almost

Little seed canary grass (Phalaris minor L. Retz.) and normal wild oats (Avena ludoviciana Dur.) are dominating weed for wheat (Triticum aestivum L. emend Fiori & Paol) crop in rice (Oryza sativa L.) -wheat cropping system due to favourable ecological conditions created by this system. Isoproturon, clodinafop and fenoxaprop are being used successfully for control of these grassy weeds. However, continuous use of these herbicides may result in development of resistant biotypes . This calls for use of other competitive herbicides for the management of P. minor to avoid perceptible change in the weed flora. Pinoxaden is a novel grass active post-emergence from the chemical class phenylpyrazolin and effective against resistant biotypes of P. minor ). The impact of herbicide residues on succeeding crops is of great concern as very low concentrations can cause crop damage and increase the chance of leaching in soil profile (Sondhia 2008). Therefore, the present investigation was undertaken to find out the bioefficacy of pinoxaden in wheat, its residual effect on succeeding rice crop and persistence of pinoxaden and its metabolites in soil, wheat grains and straw.

Electronic devices are some of the most reliable consumer products. It is taken for granted that they will "work" but a consideration of the number of millions of interconnects and the complexity of the manufacturing processing makes this remarkable. The semiconductor industry has embraced the use of "Burn-in" to force the failure of marginal devices before they reach final assembly into end products. The burn-in process uses a combination of temperature and voltage to stress the device. For economies of scale this is usually accomplished by placing devices in a burn-in oven. The time to ensure the early failure of marginal devices is dependent on the junction temperature and this is a specified by the reliability engineer. However, do we really know the junction temperature? Is it estimated or controlled or how is it measured? This paper will review some of the aspects of burn-in and the way the junction temperature can be measured or inferred. The impact of on junction temperature for devices which have a wide power range will be evaluated and discussed. Methods to understand and control the junction temperature, during burn-in will be reviewed and the impact on burn-in time discussed. The ability to accurately control the process is dependent on an understanding of junction temperature. Accurately controlling the junction temperature, not the oven ambient temperature offers the opportunity to reducing burn-in time by raising the temperature. The potential for higher burn-in temperatures and the impact on burn-in time will be discussed.