Amaranths (Amaranthus sp.) are a popular leafy vegetable grown and consumed by resource-poor peop... more Amaranths (Amaranthus sp.) are a popular leafy vegetable grown and consumed by resource-poor people in many African countries. Greater awareness of the importance of nutritious foods has increased demand by African consumers for amaranth. Presently, most African farmers grow low-yielding local varieties of variable seed quality. High-yielding amaranth varieties that are adapted to the major agro-ecologies of eastern and southern Africa possess key traits needed by male and female farmers and meet diverse market preferences are required. The objective of this study was to identify amaranth lines adapted to major amaranth production environments in Kenya and Tanzania using a gender-disaggregated farmers participatory approach to explore possible gender differences in trait and variety preferences. Twenty amaranth entries were evaluated for vegetable yield, agronomic traits, and organoleptic taste tests in replicated, farmer-participatory variety selection trials at one location in Kenya and at four locations in Tanzania. Differences among entries (G), locations (E), and G × E interaction were significant or highly significant for marketable vegetable yield. Location followed by entry was the most important factor that explained differences in yield. G and G × E interaction biplot analysis classified the five locations into two different mega-environments, mainly based on altitude, temperatures, and soil characteristics. Marketable vegetable yield was positively correlated with leaf length, plant height, and the selection scores of female and male farmers at almost all locations. Selection scores of female and male farmers were positively correlated, indicating that male and female farmers shared similar amaranth variety preferences. Farmers identified and ranked important traits that can be used by breeders to design amaranth product profiles and develop amaranth breeding objectives. Lines combining high yield with high farmer and consumer preference scores have been retained for distinctiveness, uniformity, and stability tests for possible release as commercial varieties.
African spider plant, Cleome gynandra, is an economically important source of highly nutritious l... more African spider plant, Cleome gynandra, is an economically important source of highly nutritious leafy greens and traditional phytopharmaceuticals in sub-Saharan Africa. In this study, five genetic accessions of African spider plant were field grown in New Jersey, USA (2015) and Arusha, Tanzania (2016 and 2017). When the spider plant was at full flower and ready for the market, the leaves were manually sampled for nutritional and phytochemical investigation. Elemental analysis was conducted via inductively coupled plasma mass spectrometry to characterize the mineral nutrients of spider plant samples. Spectrophotometric determination of total polyphenol content, ferric reducing antioxidant power, and total flavonoid content provided additional characterization of the phytochemistry. Results showed that spider plant has high antioxidant activity and results from elemental analysis indicate the spider plant is a "source" of iron and a "high source" vegetable for calcium, manganese, and magnesium.
Selection for delayed flowering time in response to long Selection for delayed flowering time in ... more Selection for delayed flowering time in response to long Selection for delayed flowering time in response to long photoperiod to increase vegetative growth and multiple harvests photoperiod to increase vegetative growth and multiple harvests in spider plant (in spider plant (Cleome gynandra)) Follow this and additional works at: https://scholarworks.umass.edu/jmap Part of the Plant Sciences Commons Recommended Citation Recommended Citation Zorde, Martin; David R. Byrnes; Fekadu F. Dinssa; Steve Weller; and James E. Simon. 2020. "Selection for delayed flowering time in response to long photoperiod to increase vegetative growth and multiple harvests in spider plant (Cleome gynandra)."
Amaranthus species are used as grain and vegetable crops. As a C4 plant, amaranth is more toleran... more Amaranthus species are used as grain and vegetable crops. As a C4 plant, amaranth is more tolerant to heat and drought than many other vegetables. The extraordinary nutritional properties of the plant – the seed and leaf protein of amaranth has a composition comparable to milk protein – make it a valuable addition to human diets, particularly in countries where the population has limited access to animal protein sources. Production of this high-value crop can increase the income and improve the livelihoods of resource-poor smallholder farmers. The broader use of amaranth is constrained by the lack of improved cultivars combining disease resistance with high market and eating quality. Little is known about the breeding potential and sustainable use of different Amaranthus species. AVRDC–The World Vegetable Center holds a diverse collection of 800 amaranth accessions and has started to mine this collection for genotypes with farmerand consumer-desired traits for breeding. The most imp...
The importance and increasing awareness of African Leafy Vegetables (ALVs) as a rich source of hi... more The importance and increasing awareness of African Leafy Vegetables (ALVs) as a rich source of high-quality nutritional food as well as medicinal properties has continued to drive demand by families and consumers. Local ALV land races are low yielding prompting efforts to breed improved high yielding varieties. To enhance the adoption of new ALV varieties, farmers need to be involved in the process. In this study, improved varieties of African nightshade (Solanum spp.), amaranth (Amaranth spp.) and spider plant (Cleome gynandra) were sourced from WorldVeg in Arusha, Tanzania and planted at the Kenya Agricultural and Livestock Research Organization in Alupe agricultural experiment station in a randomized complete block trial and replicated three times. The objectives were to (1) determine farmer criteria for selecting ALVs, and (2) to evaluate and select farmers preferred improved varieties of African nightshade, amaranth and spider plant for possible release and commercial seed production. Thirty-two farmers, 28 women and 4 men from ALV producing farmer groups in Busia, Kisumu and Nandi Counties participated in ALV variety selection at Alupe Research Centre. These farmer groups were contributors to the implementation of the HORT Innovation project sponsored by USAID. The appointed farmers completed the preference questionnaires as guided by researchers during the in-person field evaluations. The results of the study indicated that seed viability and germination, yield, leaf color, resistance to pest and diseases were the most important criteria concern by the farmers while selecting the varieties of ALVs. The top three varieties selected by the farmers from each of the three vegetables species were African nightshade (BG-29, SS-52, commercial), amaranth (commercial, AC-45, Ex-Zim) and spider plant (UG-15, commercial, UG-23). Three selected varieties from WorldVeg Ex-Zim, Nduruma, SF-29, and AC 38 were given to farmers for community seed production and were also tested for distinctiveness, uniformity and stability by the national seed regulator and released for commercial seed production by the Kenyan Ministry of Agriculture in 2018.
African nightshade is an indigenous leafy vegetable in Eastern and Western Africa that is valued ... more African nightshade is an indigenous leafy vegetable in Eastern and Western Africa that is valued for its high nutrient content and potential to generate income. Efforts to improve this crop have been hampered by limited information available on intra-and interspecific genetic diversity. Here, we present data on the development and application of polymorphic simple sequence repeat (SSR) markers in a broad collection of entries (gene bank accessions, landraces from farmers, breeding lines and commercial cultivars) from two species of African nightshades, Solanum scabrum (Mill.) and S. villosum (Mill.). Next generation sequencing information was used to develop 16 polymorphic SSR markers that revealed genetic diversity within and between the 54 entries collected from various geographic locations in Sub-Saharan Africa. High levels of polymorphism were detected within entries, indicating gene flow between entries and/or a low intensity of selection during development of breeding lines and improved cultivars. As a consequence, they have retained sufficient variation for further selection within the improved germplasm. The two species were clearly distinct, and S. scabrum was found to be less diverse compared to S. villosum. Furthermore, some entries were identified as probably misclassified based on morphological markers as they can clearly be placed within the gene pool of either S. scabrum or S. villosum using the SSR data. In addition to the diversity studies, we determined the genome size and ploidy of a selection of 29 entries helpful for the design of future NGS-based marker projects. All entries of S. scabrum were found to be hexaploid, whereas entries of S. villosum were tetraploid with a haploid genome size of all samples slightly varying by approximately 1 pg. Finally, we also determined pollen viability parameters, which differed significantly between the two species but did not correlate to any of the other parameters measured.
Amaranth (Amaranthus sp.) is an important leafy vegetable in Africa where most farmers grow unimp... more Amaranth (Amaranthus sp.) is an important leafy vegetable in Africa where most farmers grow unimproved landraces. Information about amaranth genetic diversity and its adaptation to different environments will help breeders develop improved commercial varieties that meet market requirements. The objectives of this study were to investigate the performances of amaranth entries for vegetable yield across locations and seasons, assess the relative contributions of genetic vs. environmental sources of variation to yield, and cluster locations into mega-environments (MEs) to suggest future test sites. Twenty-six diverse entries were evaluated for vegetable yields in replicated trials at five locations in wet-cool and hot-dry seasons in Tanzania. Season explained the highest proportion (52.1%) of the total sum of squares followed by entries (24.9%) and locations (23.0%). Mean yield across the hot-dry season trials (27.7 t·ha−1) was 47.3% greater than the mean yield across wet-cool season t...
International Journal of Tropical Insect Science, 2018
Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and ... more Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and Africa. However, various foliar lepidopteran pests and stem-mining weevils hinder amaranth production. Insect-resistant cultivars can enhance the productivity of this crop. Here, we report on the performances of amaranth varieties screened for their resistance to insect pests under the field conditions at The World Vegetable Center stations in Asia and sub-Saharan Africa. We conducted two preliminary screening trials with a total of 263 entries from around the world in Taiwan and a third preliminary screening trial with 49 African-indigenous entries in Tanzania. Promising entries from these preliminary trials were collectively evaluated in an advanced screening trial in Tanzania, to identify lines resistant to foliar and stem-boring pests in East Africa. Four entries exhibited moderate resistance to foliar pests: TZ51 and TZ53 (Amaranthus cruentus), TZ34 (A. dubius) and TZ39 (Amaranthus ...
The importance of traditional African vegetables is increasing with the rising awareness of their... more The importance of traditional African vegetables is increasing with the rising awareness of their contribution to food security, human nutrition and income diversification, particularly in economically and environmentally marginal areas. Under the impetus of renewed donor interest, more research and development organizations are engaging in activities along the African traditional vegetable value chain, and these crops are receiving greater improvement research. From its regional office for Eastern and Southern Africa in Arusha, Tanzania, AVRDC-The World Vegetable Center commenced vegetable research and development in sub-Saharan Africa in 1992. We highlight significant achievements in germplasm collection, conservation, improvement and development activities regionally, and outline future breeding strategies for priority traditional African vegetables. The breeding strategy starts with selection within landraces or germplasm accessions and creation of genetic variability, and continues through to gender-disaggregated participatory plant breeding, in which selections are made within the target environment with the participation of local users, ensuring that the target production environment and the needs of the end users are fully taken into account. This paper defines the roles of partners at various stages of the breeding program (germplasm development, evaluation and cultivar release) and in subsequent development activities (cultivar deployment and seed systems) for more effective and sustainable research and development in traditional vegetables.
Amaranth (Amaranthus spp.) is a popular crop grown throughout sub-Saharan Africa, where both the ... more Amaranth (Amaranthus spp.) is a popular crop grown throughout sub-Saharan Africa, where both the grain and leaves are consumed. Amaranth cultivars that offer multiple options to small-scale farmers to produce high foliage yields, high grain yields, or both high foliage and grain yields would be desirable. The objective of this study was to determine the effects of multiple leaf harvests on grain yield and grain nutrient content of diverse amaranth entries (breeding lines and cultivars). Trials were conducted at the World Vegetable Center in Arusha, Tanzania in 2013 and 2014. Seventeen amaranth entries were evaluated for grain yield without defoliation, or after four leaf harvests. Grain samples of 10 entries were evaluated for calcium, iron, zinc, protein, sugar, and fiber content. Highly significant entry and leaf harvest differences in grain yield, leaf yield, and calcium, zinc, and protein contents were detected both years. Differences among years were significant or highly significant only for leaf yield, number of leaves per plant and panicle length. The leaf yields of all the entries were lower in 2013 (year mean = 11 t/ha) than in 2014 (15.3 t/ha). Four leaf harvests reduced grain yield of all entries by at least 50% but did not affect grain nutrient content except for calcium. Under no-leaf harvest PARIS (A)-Sel and BRESIL (B)-Sel gave the highest grain yield in both years. PARIS (A)-Sel suffered the highest grain yield loss (87%) followed by BRESIL (B)-Sel (85%) in 2013, while BRESIL (B)-Sel showed the highest loss (90%) followed by PARIS (A)-Sel (84%) in 2014. 'Madiira 2' was the lowest grain yielder under both leaf harvest and no-leaf harvest in both years. 'Madiira 1' and 'Madiira 2', black seeded cultivars, gave high Fe and fiber contents except the rank of 'Madiira 2' was less consistent for iron cross the years. Three groups of entries could be distinguished: (1) entries that produced high grain yields only if plants were not defoliated; (2) entries that yielded ample leaves but relatively little grain; (3) entries that gave moderate amounts of grain and leaves. Our study suggests there is potential to develop amaranth cultivars for different purposes to meet the needs of amaranth producers.
In sub-Saharan Africa, including Zambia, rising awareness of the nutrition and health benefits of... more In sub-Saharan Africa, including Zambia, rising awareness of the nutrition and health benefits of traditional African vegetables (TAVs) has raised demand over the past decade. TAVs compete with conventional vegetables in most retail outlets such as supermarkets and small food stores. Yet, there is little information on the retail structure of organic traditional vegetables. This study sought to identify the trading structure of organic TAVs; the determinants of retailers' decision to sell these vegetables and the major bottlenecks to the growth of TAV retailing. Results indicated that it was the expected profits and consumer concerns over food safety that influence the retailers' decision to sell organic TAVs.
Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfol... more Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfolios, and research capacity as well as their capacity building needs and priorities. Therefore, the benefits and services offered by the Africa Vegetable Breeding Consortium (AVBC) to its members should be tailored to their specific needs and priorities-in lieu of "standardized" services and training. 2. Breeding products and high performing lines are the main expected benefits of seed companies from AVBC membership. The Consortium should strengthen its collaboration and partnerships with seed companies to best identify and achieve their breeding product needs (e.g., traits, priority vegetables). 3. The most important and priority crops for seed companies in Africa are tomato, pepper, and onion (in order of importance), which aligns well with WorldVeg' breeding expertise and we are therefore well-placed to support seed companies with breeding products and capacity building. On the other hand, traditional African vegetables have a low priority for seed companies. 4. Most of the seed companies' capacity building needs are related to breeding and seed production (including vegetable breeding for insect pest resistance, disease resistance, abiotic stress tolerance; quality seed production). When offering training to seed companies, it needs to be kept in mind that their capacity building needs are diverse, particulary for small vs. large companies. 5. Seed companies, especially the smaller ones, can be financially constrained and, as a result, face difficulties in starting and or implementing research and development or breeding programs. These financial constraints may also impede smaller companies to join the Consortium due to the membership fees. 6. Efforts should be made to increase the Consortium's visibility and engagement, both institutionally and scientifically. Seed companies suggested WorldVeg breeders engage more strongly with them, which could lead to the development of relevant breeding programs and activities. Many of the seed companies that are not a member of the Consortium are actually not aware of its existence. Efforts should thus be made to promote and increase the Consortium's visibility on the continent, for instance through conferences and other fora attended by seed companies.
Quarterly Journal of International Agriculture, 2015
Vegetables are sources of vitamins, minerals and income for those involved in production and mark... more Vegetables are sources of vitamins, minerals and income for those involved in production and marketing. Having first-hand information about vegetable production and marketing system is essential to devise appropriate strategies aimed at enhancing vegetable value chain development. It was in line with this view that a study was conducted to characterize vegetable production and marketing systems at selected sites in the humid tropics of Ethiopia. Data were collected using participatory primary survey techniques augmented with secondary data. While the area cultivated to vegetables has been increasing over the years due to increasing consumer demand, average yields are far below potential. Major vegetable production and marketing constraints include: lack of access to improved variety seeds, high postharvest losses, lack of reliable market information systems, low bargaining power of farmers, low technological know-how for value chain development and upgrading, all indicating critical...
KEY FINDINGS 1. Seed companies located and/or operating in Africa are very diverse in terms of si... more KEY FINDINGS 1. Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfolios, and research capacity as well as their capacity building needs and priorities. Therefore, the benefits and services offered by the Africa Vegetable Breeding Consortium (AVBC) to its members should be tailored to their specific needs and priorities – in lieu of "standardized" services and training. 2. Breeding products and high performing lines are the main expected benefits of seed companies from AVBC membership. The Consortium should strengthen its collaboration and partnerships with seed companies to best identify and achieve their breeding product needs (e.g., traits, priority vegetables). 3. The most important and priority crops for seed companies in Africa are tomato, pepper, and onion (in order of importance), which aligns well with WorldVeg' breeding expertise and we are therefore well-placed to support seed companies with breeding products and capacity building. On the other hand, traditional African vegetables have a low priority for seed companies. 4. Most of the seed companies' capacity building needs are related to breeding and seed production (including vegetable breeding for insect pest resistance, disease resistance, abiotic stress tolerance; quality seed production). When offering training to seed companies, it needs to be kept in mind that their capacity building needs are diverse, particulary for small vs. large companies. 5. Seed companies, especially the smaller ones, can be financially constrained and, as a result, face difficulties in starting and or implementing research and development or breeding programs. These financial constraints may also impede smaller companies to join the Consortium due to the membership fees. 6. Efforts should be made to increase the Consortium's visibility and engagement, both institutionally and scientifically. Seed companies suggested WorldVeg breeders engage more strongly with them, which could lead to the development of relevant breeding progr [...]
Traditional African vegetables seed production is constrained by many factors such as poor qualit... more Traditional African vegetables seed production is constrained by many factors such as poor quality of the seeds used for production; spatial and time gaps in seed distribution systems and lack of structured seed markets. In response to these weaknesses, seed companies opt to contract farmers for the production of quality vegetable seeds to ensure availability and accessibility. The study analyzed economic potential of contracted farmers producing traditional African vegetable seeds in Kenya using data collected from 153 vegetable seed growers in Western Kenya. Gross margin analysis was used to estimate the profit obtained by contracted and non-contracted seed growers. Findings indicated that, contracted traditional African vegetable seed growers had the opportunity to receive institutional services such as extension, credit, and new technology services from contractors. Contracted farmers received high-profit margin ratio (>50%) compared to non-contracted farmers. The study recommends that public and private organizations should sensitize farmers to enter into contracts with seed companies to get agronomic extension service advantages, ensure quality seeds and increase profits from traditional African vegetable seed production
Onion thrips (Thrips tabaci) was identified as the prominent species infesting onions and tomato ... more Onion thrips (Thrips tabaci) was identified as the prominent species infesting onions and tomato in northern highlands of Tanzania in the current study. As a major pest of onion, it causes considerable leaf damage by direct feeding, and also transmits the Irish Yellow Spot Virus disease. Hence, one of the objectives of this study was to identify the most resistant onion accessions against T. tabaci. One highly resistant (VI038552) and two resistant onion accessions (VI038512 and AVON 1067) were identified against T. tabaci. Besides thrips resistance, the bulb size of VI038512 was also equivalent to one of the commercial varieties, Texus. The highly resistant VI038552 recorded the highest yield, followed by the resistant accession, VI038512. However, the yield of AVON 1067 was significantly lower. The elucidation of bio-physical bases of resistance revealed that there was a significant negative correlation between leaf angle as well as leaf toughness and thrips damage. The total epic...
The importance of amaranth in the fight for nutrition security, especially in developing countrie... more The importance of amaranth in the fight for nutrition security, especially in developing countries, is increasing because of its high nutritional quality and dual-purpose nature. Interest for amaranth leaves as a vegetable and seeds as grain is increasing in rural, per-urban and urban areas in many countries in Africa. However, the number of improved varieties grown by farmers is limited on the continent. Enhancing the access of improved varieties to farmers will increase productivity and production, and availability to consumers. The objectives of this study were to evaluate vegetable amaranth entries for yield, horticultural and agronomic traits, and leaf nutrient contents, and identify promising lines for release as commercial varieties. The materials were evaluated in Tanzania and Kenya in replicated trials in 2016 and 2017. Differences among the entries were significant or highly significant for yield and various agronomic traits in most of the trials conducted in both countries. Two amaranth lines, Ex-Zim-Sel and AM 38-Sel, previously released in Tanzania, were identified as promising in Kenya based on yield performance and preferences of farmers, and were registered as improved varieties in the country in 2017/18. Differences among the evaluated entries in Zn, K and Na contents analyzed in leaf samples collected from trials conducted in Tanzania were significant or highly significant in both years. Four Amaranthus dubius entries were recognized for their consistent high Zn and Na contents in 2016 and 2017. The high nutrient content entries are useful for further evaluation and use in breeding programs. Currently, nutrient contents are not considered in variety release procedures and should be something breeders push for in future variety release procedures.
The prevalence of micronutrient deficiencies continues to remain alarmingly high in subSaharan Af... more The prevalence of micronutrient deficiencies continues to remain alarmingly high in subSaharan Africa. One potential solution to undernutrition is to promote the consumption of African Indigenous Vegetables (AIVs) that are rich in vitamin A, iron, zinc and other healthpromoting phytochemicals. However, due to limited advances in agronomic practices, seed development, available improved varieties, and access to these indigenous plants in the marketplace, work was needed to drive AIVs into the formal marketplace to meet consumer demand. This paper summarizes the research and activities of a diverse group of stakeholders and researchers who came together to improve research, management, production, distribution, and consumption of nutritious AIVs in Eastern Simon et al.: Improving Income and Nutrition of Smallholder Farmers in Eastern
Amaranths (Amaranthus sp.) are a popular leafy vegetable grown and consumed by resource-poor peop... more Amaranths (Amaranthus sp.) are a popular leafy vegetable grown and consumed by resource-poor people in many African countries. Greater awareness of the importance of nutritious foods has increased demand by African consumers for amaranth. Presently, most African farmers grow low-yielding local varieties of variable seed quality. High-yielding amaranth varieties that are adapted to the major agro-ecologies of eastern and southern Africa possess key traits needed by male and female farmers and meet diverse market preferences are required. The objective of this study was to identify amaranth lines adapted to major amaranth production environments in Kenya and Tanzania using a gender-disaggregated farmers participatory approach to explore possible gender differences in trait and variety preferences. Twenty amaranth entries were evaluated for vegetable yield, agronomic traits, and organoleptic taste tests in replicated, farmer-participatory variety selection trials at one location in Kenya and at four locations in Tanzania. Differences among entries (G), locations (E), and G × E interaction were significant or highly significant for marketable vegetable yield. Location followed by entry was the most important factor that explained differences in yield. G and G × E interaction biplot analysis classified the five locations into two different mega-environments, mainly based on altitude, temperatures, and soil characteristics. Marketable vegetable yield was positively correlated with leaf length, plant height, and the selection scores of female and male farmers at almost all locations. Selection scores of female and male farmers were positively correlated, indicating that male and female farmers shared similar amaranth variety preferences. Farmers identified and ranked important traits that can be used by breeders to design amaranth product profiles and develop amaranth breeding objectives. Lines combining high yield with high farmer and consumer preference scores have been retained for distinctiveness, uniformity, and stability tests for possible release as commercial varieties.
African spider plant, Cleome gynandra, is an economically important source of highly nutritious l... more African spider plant, Cleome gynandra, is an economically important source of highly nutritious leafy greens and traditional phytopharmaceuticals in sub-Saharan Africa. In this study, five genetic accessions of African spider plant were field grown in New Jersey, USA (2015) and Arusha, Tanzania (2016 and 2017). When the spider plant was at full flower and ready for the market, the leaves were manually sampled for nutritional and phytochemical investigation. Elemental analysis was conducted via inductively coupled plasma mass spectrometry to characterize the mineral nutrients of spider plant samples. Spectrophotometric determination of total polyphenol content, ferric reducing antioxidant power, and total flavonoid content provided additional characterization of the phytochemistry. Results showed that spider plant has high antioxidant activity and results from elemental analysis indicate the spider plant is a "source" of iron and a "high source" vegetable for calcium, manganese, and magnesium.
Selection for delayed flowering time in response to long Selection for delayed flowering time in ... more Selection for delayed flowering time in response to long Selection for delayed flowering time in response to long photoperiod to increase vegetative growth and multiple harvests photoperiod to increase vegetative growth and multiple harvests in spider plant (in spider plant (Cleome gynandra)) Follow this and additional works at: https://scholarworks.umass.edu/jmap Part of the Plant Sciences Commons Recommended Citation Recommended Citation Zorde, Martin; David R. Byrnes; Fekadu F. Dinssa; Steve Weller; and James E. Simon. 2020. "Selection for delayed flowering time in response to long photoperiod to increase vegetative growth and multiple harvests in spider plant (Cleome gynandra)."
Amaranthus species are used as grain and vegetable crops. As a C4 plant, amaranth is more toleran... more Amaranthus species are used as grain and vegetable crops. As a C4 plant, amaranth is more tolerant to heat and drought than many other vegetables. The extraordinary nutritional properties of the plant – the seed and leaf protein of amaranth has a composition comparable to milk protein – make it a valuable addition to human diets, particularly in countries where the population has limited access to animal protein sources. Production of this high-value crop can increase the income and improve the livelihoods of resource-poor smallholder farmers. The broader use of amaranth is constrained by the lack of improved cultivars combining disease resistance with high market and eating quality. Little is known about the breeding potential and sustainable use of different Amaranthus species. AVRDC–The World Vegetable Center holds a diverse collection of 800 amaranth accessions and has started to mine this collection for genotypes with farmerand consumer-desired traits for breeding. The most imp...
The importance and increasing awareness of African Leafy Vegetables (ALVs) as a rich source of hi... more The importance and increasing awareness of African Leafy Vegetables (ALVs) as a rich source of high-quality nutritional food as well as medicinal properties has continued to drive demand by families and consumers. Local ALV land races are low yielding prompting efforts to breed improved high yielding varieties. To enhance the adoption of new ALV varieties, farmers need to be involved in the process. In this study, improved varieties of African nightshade (Solanum spp.), amaranth (Amaranth spp.) and spider plant (Cleome gynandra) were sourced from WorldVeg in Arusha, Tanzania and planted at the Kenya Agricultural and Livestock Research Organization in Alupe agricultural experiment station in a randomized complete block trial and replicated three times. The objectives were to (1) determine farmer criteria for selecting ALVs, and (2) to evaluate and select farmers preferred improved varieties of African nightshade, amaranth and spider plant for possible release and commercial seed production. Thirty-two farmers, 28 women and 4 men from ALV producing farmer groups in Busia, Kisumu and Nandi Counties participated in ALV variety selection at Alupe Research Centre. These farmer groups were contributors to the implementation of the HORT Innovation project sponsored by USAID. The appointed farmers completed the preference questionnaires as guided by researchers during the in-person field evaluations. The results of the study indicated that seed viability and germination, yield, leaf color, resistance to pest and diseases were the most important criteria concern by the farmers while selecting the varieties of ALVs. The top three varieties selected by the farmers from each of the three vegetables species were African nightshade (BG-29, SS-52, commercial), amaranth (commercial, AC-45, Ex-Zim) and spider plant (UG-15, commercial, UG-23). Three selected varieties from WorldVeg Ex-Zim, Nduruma, SF-29, and AC 38 were given to farmers for community seed production and were also tested for distinctiveness, uniformity and stability by the national seed regulator and released for commercial seed production by the Kenyan Ministry of Agriculture in 2018.
African nightshade is an indigenous leafy vegetable in Eastern and Western Africa that is valued ... more African nightshade is an indigenous leafy vegetable in Eastern and Western Africa that is valued for its high nutrient content and potential to generate income. Efforts to improve this crop have been hampered by limited information available on intra-and interspecific genetic diversity. Here, we present data on the development and application of polymorphic simple sequence repeat (SSR) markers in a broad collection of entries (gene bank accessions, landraces from farmers, breeding lines and commercial cultivars) from two species of African nightshades, Solanum scabrum (Mill.) and S. villosum (Mill.). Next generation sequencing information was used to develop 16 polymorphic SSR markers that revealed genetic diversity within and between the 54 entries collected from various geographic locations in Sub-Saharan Africa. High levels of polymorphism were detected within entries, indicating gene flow between entries and/or a low intensity of selection during development of breeding lines and improved cultivars. As a consequence, they have retained sufficient variation for further selection within the improved germplasm. The two species were clearly distinct, and S. scabrum was found to be less diverse compared to S. villosum. Furthermore, some entries were identified as probably misclassified based on morphological markers as they can clearly be placed within the gene pool of either S. scabrum or S. villosum using the SSR data. In addition to the diversity studies, we determined the genome size and ploidy of a selection of 29 entries helpful for the design of future NGS-based marker projects. All entries of S. scabrum were found to be hexaploid, whereas entries of S. villosum were tetraploid with a haploid genome size of all samples slightly varying by approximately 1 pg. Finally, we also determined pollen viability parameters, which differed significantly between the two species but did not correlate to any of the other parameters measured.
Amaranth (Amaranthus sp.) is an important leafy vegetable in Africa where most farmers grow unimp... more Amaranth (Amaranthus sp.) is an important leafy vegetable in Africa where most farmers grow unimproved landraces. Information about amaranth genetic diversity and its adaptation to different environments will help breeders develop improved commercial varieties that meet market requirements. The objectives of this study were to investigate the performances of amaranth entries for vegetable yield across locations and seasons, assess the relative contributions of genetic vs. environmental sources of variation to yield, and cluster locations into mega-environments (MEs) to suggest future test sites. Twenty-six diverse entries were evaluated for vegetable yields in replicated trials at five locations in wet-cool and hot-dry seasons in Tanzania. Season explained the highest proportion (52.1%) of the total sum of squares followed by entries (24.9%) and locations (23.0%). Mean yield across the hot-dry season trials (27.7 t·ha−1) was 47.3% greater than the mean yield across wet-cool season t...
International Journal of Tropical Insect Science, 2018
Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and ... more Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and Africa. However, various foliar lepidopteran pests and stem-mining weevils hinder amaranth production. Insect-resistant cultivars can enhance the productivity of this crop. Here, we report on the performances of amaranth varieties screened for their resistance to insect pests under the field conditions at The World Vegetable Center stations in Asia and sub-Saharan Africa. We conducted two preliminary screening trials with a total of 263 entries from around the world in Taiwan and a third preliminary screening trial with 49 African-indigenous entries in Tanzania. Promising entries from these preliminary trials were collectively evaluated in an advanced screening trial in Tanzania, to identify lines resistant to foliar and stem-boring pests in East Africa. Four entries exhibited moderate resistance to foliar pests: TZ51 and TZ53 (Amaranthus cruentus), TZ34 (A. dubius) and TZ39 (Amaranthus ...
The importance of traditional African vegetables is increasing with the rising awareness of their... more The importance of traditional African vegetables is increasing with the rising awareness of their contribution to food security, human nutrition and income diversification, particularly in economically and environmentally marginal areas. Under the impetus of renewed donor interest, more research and development organizations are engaging in activities along the African traditional vegetable value chain, and these crops are receiving greater improvement research. From its regional office for Eastern and Southern Africa in Arusha, Tanzania, AVRDC-The World Vegetable Center commenced vegetable research and development in sub-Saharan Africa in 1992. We highlight significant achievements in germplasm collection, conservation, improvement and development activities regionally, and outline future breeding strategies for priority traditional African vegetables. The breeding strategy starts with selection within landraces or germplasm accessions and creation of genetic variability, and continues through to gender-disaggregated participatory plant breeding, in which selections are made within the target environment with the participation of local users, ensuring that the target production environment and the needs of the end users are fully taken into account. This paper defines the roles of partners at various stages of the breeding program (germplasm development, evaluation and cultivar release) and in subsequent development activities (cultivar deployment and seed systems) for more effective and sustainable research and development in traditional vegetables.
Amaranth (Amaranthus spp.) is a popular crop grown throughout sub-Saharan Africa, where both the ... more Amaranth (Amaranthus spp.) is a popular crop grown throughout sub-Saharan Africa, where both the grain and leaves are consumed. Amaranth cultivars that offer multiple options to small-scale farmers to produce high foliage yields, high grain yields, or both high foliage and grain yields would be desirable. The objective of this study was to determine the effects of multiple leaf harvests on grain yield and grain nutrient content of diverse amaranth entries (breeding lines and cultivars). Trials were conducted at the World Vegetable Center in Arusha, Tanzania in 2013 and 2014. Seventeen amaranth entries were evaluated for grain yield without defoliation, or after four leaf harvests. Grain samples of 10 entries were evaluated for calcium, iron, zinc, protein, sugar, and fiber content. Highly significant entry and leaf harvest differences in grain yield, leaf yield, and calcium, zinc, and protein contents were detected both years. Differences among years were significant or highly significant only for leaf yield, number of leaves per plant and panicle length. The leaf yields of all the entries were lower in 2013 (year mean = 11 t/ha) than in 2014 (15.3 t/ha). Four leaf harvests reduced grain yield of all entries by at least 50% but did not affect grain nutrient content except for calcium. Under no-leaf harvest PARIS (A)-Sel and BRESIL (B)-Sel gave the highest grain yield in both years. PARIS (A)-Sel suffered the highest grain yield loss (87%) followed by BRESIL (B)-Sel (85%) in 2013, while BRESIL (B)-Sel showed the highest loss (90%) followed by PARIS (A)-Sel (84%) in 2014. 'Madiira 2' was the lowest grain yielder under both leaf harvest and no-leaf harvest in both years. 'Madiira 1' and 'Madiira 2', black seeded cultivars, gave high Fe and fiber contents except the rank of 'Madiira 2' was less consistent for iron cross the years. Three groups of entries could be distinguished: (1) entries that produced high grain yields only if plants were not defoliated; (2) entries that yielded ample leaves but relatively little grain; (3) entries that gave moderate amounts of grain and leaves. Our study suggests there is potential to develop amaranth cultivars for different purposes to meet the needs of amaranth producers.
In sub-Saharan Africa, including Zambia, rising awareness of the nutrition and health benefits of... more In sub-Saharan Africa, including Zambia, rising awareness of the nutrition and health benefits of traditional African vegetables (TAVs) has raised demand over the past decade. TAVs compete with conventional vegetables in most retail outlets such as supermarkets and small food stores. Yet, there is little information on the retail structure of organic traditional vegetables. This study sought to identify the trading structure of organic TAVs; the determinants of retailers' decision to sell these vegetables and the major bottlenecks to the growth of TAV retailing. Results indicated that it was the expected profits and consumer concerns over food safety that influence the retailers' decision to sell organic TAVs.
Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfol... more Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfolios, and research capacity as well as their capacity building needs and priorities. Therefore, the benefits and services offered by the Africa Vegetable Breeding Consortium (AVBC) to its members should be tailored to their specific needs and priorities-in lieu of "standardized" services and training. 2. Breeding products and high performing lines are the main expected benefits of seed companies from AVBC membership. The Consortium should strengthen its collaboration and partnerships with seed companies to best identify and achieve their breeding product needs (e.g., traits, priority vegetables). 3. The most important and priority crops for seed companies in Africa are tomato, pepper, and onion (in order of importance), which aligns well with WorldVeg' breeding expertise and we are therefore well-placed to support seed companies with breeding products and capacity building. On the other hand, traditional African vegetables have a low priority for seed companies. 4. Most of the seed companies' capacity building needs are related to breeding and seed production (including vegetable breeding for insect pest resistance, disease resistance, abiotic stress tolerance; quality seed production). When offering training to seed companies, it needs to be kept in mind that their capacity building needs are diverse, particulary for small vs. large companies. 5. Seed companies, especially the smaller ones, can be financially constrained and, as a result, face difficulties in starting and or implementing research and development or breeding programs. These financial constraints may also impede smaller companies to join the Consortium due to the membership fees. 6. Efforts should be made to increase the Consortium's visibility and engagement, both institutionally and scientifically. Seed companies suggested WorldVeg breeders engage more strongly with them, which could lead to the development of relevant breeding programs and activities. Many of the seed companies that are not a member of the Consortium are actually not aware of its existence. Efforts should thus be made to promote and increase the Consortium's visibility on the continent, for instance through conferences and other fora attended by seed companies.
Quarterly Journal of International Agriculture, 2015
Vegetables are sources of vitamins, minerals and income for those involved in production and mark... more Vegetables are sources of vitamins, minerals and income for those involved in production and marketing. Having first-hand information about vegetable production and marketing system is essential to devise appropriate strategies aimed at enhancing vegetable value chain development. It was in line with this view that a study was conducted to characterize vegetable production and marketing systems at selected sites in the humid tropics of Ethiopia. Data were collected using participatory primary survey techniques augmented with secondary data. While the area cultivated to vegetables has been increasing over the years due to increasing consumer demand, average yields are far below potential. Major vegetable production and marketing constraints include: lack of access to improved variety seeds, high postharvest losses, lack of reliable market information systems, low bargaining power of farmers, low technological know-how for value chain development and upgrading, all indicating critical...
KEY FINDINGS 1. Seed companies located and/or operating in Africa are very diverse in terms of si... more KEY FINDINGS 1. Seed companies located and/or operating in Africa are very diverse in terms of size, crop portfolios, and research capacity as well as their capacity building needs and priorities. Therefore, the benefits and services offered by the Africa Vegetable Breeding Consortium (AVBC) to its members should be tailored to their specific needs and priorities – in lieu of "standardized" services and training. 2. Breeding products and high performing lines are the main expected benefits of seed companies from AVBC membership. The Consortium should strengthen its collaboration and partnerships with seed companies to best identify and achieve their breeding product needs (e.g., traits, priority vegetables). 3. The most important and priority crops for seed companies in Africa are tomato, pepper, and onion (in order of importance), which aligns well with WorldVeg' breeding expertise and we are therefore well-placed to support seed companies with breeding products and capacity building. On the other hand, traditional African vegetables have a low priority for seed companies. 4. Most of the seed companies' capacity building needs are related to breeding and seed production (including vegetable breeding for insect pest resistance, disease resistance, abiotic stress tolerance; quality seed production). When offering training to seed companies, it needs to be kept in mind that their capacity building needs are diverse, particulary for small vs. large companies. 5. Seed companies, especially the smaller ones, can be financially constrained and, as a result, face difficulties in starting and or implementing research and development or breeding programs. These financial constraints may also impede smaller companies to join the Consortium due to the membership fees. 6. Efforts should be made to increase the Consortium's visibility and engagement, both institutionally and scientifically. Seed companies suggested WorldVeg breeders engage more strongly with them, which could lead to the development of relevant breeding progr [...]
Traditional African vegetables seed production is constrained by many factors such as poor qualit... more Traditional African vegetables seed production is constrained by many factors such as poor quality of the seeds used for production; spatial and time gaps in seed distribution systems and lack of structured seed markets. In response to these weaknesses, seed companies opt to contract farmers for the production of quality vegetable seeds to ensure availability and accessibility. The study analyzed economic potential of contracted farmers producing traditional African vegetable seeds in Kenya using data collected from 153 vegetable seed growers in Western Kenya. Gross margin analysis was used to estimate the profit obtained by contracted and non-contracted seed growers. Findings indicated that, contracted traditional African vegetable seed growers had the opportunity to receive institutional services such as extension, credit, and new technology services from contractors. Contracted farmers received high-profit margin ratio (>50%) compared to non-contracted farmers. The study recommends that public and private organizations should sensitize farmers to enter into contracts with seed companies to get agronomic extension service advantages, ensure quality seeds and increase profits from traditional African vegetable seed production
Onion thrips (Thrips tabaci) was identified as the prominent species infesting onions and tomato ... more Onion thrips (Thrips tabaci) was identified as the prominent species infesting onions and tomato in northern highlands of Tanzania in the current study. As a major pest of onion, it causes considerable leaf damage by direct feeding, and also transmits the Irish Yellow Spot Virus disease. Hence, one of the objectives of this study was to identify the most resistant onion accessions against T. tabaci. One highly resistant (VI038552) and two resistant onion accessions (VI038512 and AVON 1067) were identified against T. tabaci. Besides thrips resistance, the bulb size of VI038512 was also equivalent to one of the commercial varieties, Texus. The highly resistant VI038552 recorded the highest yield, followed by the resistant accession, VI038512. However, the yield of AVON 1067 was significantly lower. The elucidation of bio-physical bases of resistance revealed that there was a significant negative correlation between leaf angle as well as leaf toughness and thrips damage. The total epic...
The importance of amaranth in the fight for nutrition security, especially in developing countrie... more The importance of amaranth in the fight for nutrition security, especially in developing countries, is increasing because of its high nutritional quality and dual-purpose nature. Interest for amaranth leaves as a vegetable and seeds as grain is increasing in rural, per-urban and urban areas in many countries in Africa. However, the number of improved varieties grown by farmers is limited on the continent. Enhancing the access of improved varieties to farmers will increase productivity and production, and availability to consumers. The objectives of this study were to evaluate vegetable amaranth entries for yield, horticultural and agronomic traits, and leaf nutrient contents, and identify promising lines for release as commercial varieties. The materials were evaluated in Tanzania and Kenya in replicated trials in 2016 and 2017. Differences among the entries were significant or highly significant for yield and various agronomic traits in most of the trials conducted in both countries. Two amaranth lines, Ex-Zim-Sel and AM 38-Sel, previously released in Tanzania, were identified as promising in Kenya based on yield performance and preferences of farmers, and were registered as improved varieties in the country in 2017/18. Differences among the evaluated entries in Zn, K and Na contents analyzed in leaf samples collected from trials conducted in Tanzania were significant or highly significant in both years. Four Amaranthus dubius entries were recognized for their consistent high Zn and Na contents in 2016 and 2017. The high nutrient content entries are useful for further evaluation and use in breeding programs. Currently, nutrient contents are not considered in variety release procedures and should be something breeders push for in future variety release procedures.
The prevalence of micronutrient deficiencies continues to remain alarmingly high in subSaharan Af... more The prevalence of micronutrient deficiencies continues to remain alarmingly high in subSaharan Africa. One potential solution to undernutrition is to promote the consumption of African Indigenous Vegetables (AIVs) that are rich in vitamin A, iron, zinc and other healthpromoting phytochemicals. However, due to limited advances in agronomic practices, seed development, available improved varieties, and access to these indigenous plants in the marketplace, work was needed to drive AIVs into the formal marketplace to meet consumer demand. This paper summarizes the research and activities of a diverse group of stakeholders and researchers who came together to improve research, management, production, distribution, and consumption of nutritious AIVs in Eastern Simon et al.: Improving Income and Nutrition of Smallholder Farmers in Eastern
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Papers by Fekadu Dinssa