The response of short-duration pigeonpea lines to variation in temperature under field conditions in Kenya

Field studies with pigeonpea (Cajanus cajan (L.) Millsp.) were conducted at four locations in Kenya varying in altitude and where temperature decreased with increase in altitude. Warm temperatures (most inductive temperatures, mean 23.5°C) hastened the times from sowing to flowering (f) and maturity (m), and between flowering and maturity (fm). Cool temperatures (17.8°C) delayed f, m, and fm but the delay was most pronounced for fm. In the least inductive cool environment, variation in f, m and fm was greatest among 63 lines developed in India. Compared to the most inductive temperature, the delay in cool environment was 2.2 for f, 3.1 for m, and 5.5 for fm, which indicates that fm is the most sensitive phase to low (sub-optimal) temperatures. Equations that describe the rates of development (1/f, 1/m, and 1/fm) were used to determine progress to different stages of development. Results revealed that optimum temperature for fastest time to flowering varied from 23.1 to 26.1°C. The 1/f at mean temperature of 26.8°C was slower, indicating that the mean temperature experienced was supra-optimal. Since the mean temperature of 26.8°C was not very different from the range considered optimal, further analysis revealed that this was mainly due to the high night temperatures. The 1/fm was strong and positive in the range of temperature tested indicating that warm temperatures shortened the duration between flowering and maturity. The optimum temperature range for this effect varied from 24 to 32°C. Cool temperatures at Kabete retarded plant growth while warm temperatures enhanced i

Genetic diversity in pigeonpea [Cajanus cajan (L.) Millsp.] Landraces as revealed by simple sequence repeat markers

Genetic relationships among 88 pigeonpea accessions from a presumed centre of origin and diversity, India and a presumed secondary centre of diversity in East Africa were evaluated using six microsatellite markers. Forty-seven (47) alleles were detected in the populations studied, with a mean of eight alleles per locus. Populations were defined by region (India and East Africa) and sub-populations by country in the case of East Africa and State in the case of India. Substantial differentiation among regions was evident from Roger’s modified distance and Wright’s F statistic. Greatest genetic diversity in terms of number of alleles, number of rare alleles and Nei’s unbiased estimate of gene diversity (H) was found in India as opposed to East Africa. This supports the hypothesis that India is the centre of diversity and East Africa is a secondary centre of diversity. Within East Africa, germplasm from Tanzania had the highest diversity according to Nei’s unbiased estimate of gene diversity, followed by Kenya and Uganda. Germplasm from Kenya and Tanzania were more closely related than that of Uganda according to Roger’s modified distance. Within India, results did not indicate a clear centre of diversity. Values of genetic distance indicated that genetic relationships followed geographical proximity

Pigeonpea Technology Exchange ñ Strategies, Experiences, and Lessons Learnt in Eastern and Southern Africa

The Pigeonpea Improvement Project for Eastern and Southern Africa was initiated in 1992 with the goal of increasing pigeonpea productivity in the region. By 1996, the project had made significant progress in developing improved varieties, understanding markets, and identifying constraints to consumption. How could the technologies and knowledge developed through the combined efforts of ICRISAT and its collaborators be disseminated to achieve widespread impact

Potential of Grain Legume Fallows to Address Food Insecurity and Boost Household Incomes in Western Kenya

A pigeonpea fallow-maize crop rotation trial was carried out over a period of 4 seasons in western Kenya. The trial compared six high altitude long duration pigeonpea varieties i.e. ICEAP 00020, ICEAP 00040, ICEAP 00048, ICEAP 00053, ICP 9145 and ICP 13076 and a medium duration variety i.e. ICP 13211 for productivity, post fallow maize crop yield and financial returns indicators. Long duration pigeonpea varieties take 140-180 days to mature while medium duration varieties take >200 days to mature. Continuous maize cropping acted as a control. Depending on the variety, pigeonpea grain yield ranged between 1.3 and 1.9 t ha-1. Post fallow maize grain yield from each of pigeonpea variety plot was approximately 3 fold higher than yield from continuous maize plots. The medium duration pigeonpea plots yielded significantly higher maize grain than the long duration (ICEAP 00053, ICEAP 00040) pigeonpea variety plots. Relative to the control, incremental returns to land were highest for medium duration pigeonpea fallow plots (619 USD ha-1) and lowest for ICEAP 00040 fallow plots (305 USD ha-1). We estimated that by selecting an appropriate pigeonpea variety for a fallow-maize rotation system, a household could produce sufficient food for consumption and remain with a surplus of approximately 2.8 tons for sale. For widespread adoption of pigeonpea based technologies in western Kenya, there is a need for policy improvement on issues related to improved seed production systems, cost of fertilizers, extension services, and market for the end products

Response of pigeonpea genotypes of different maturity duration to temperature and photoperiod in Kenya

Pigeon pea (Cajanus cajan) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where daylength varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeon pea in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying in altitude where temperature decreased with increasing altitude, and variation in photoperiod was achieved through artificial lighting (approximately 12.6 h, natural daylength, 14.5 h and 16.0 h). The genotypes used were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long-maturity durations) and major pigeon pea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 h, rates of progress towards flowering were influenced by temperature in five genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7°C for the extra-short-duration genotype, 23.1°C for the short-duration genotype, 23.8 and 22.2°C for medium-duration genotypes and 18.3°C for the long-duration genotypes, 22.2°C for medium-duration genotypes and 18.3°C for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on the rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long-duration genotypes (ICEAP 00040 and T-7) were the most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hour increase in daylength

Determinants of Agricultural Technology adoption: the Case of Improved Pigeonpea Varieties in Tanzania

If dryland legumes are to meet the expectations of reducing poverty and hunger in the semi-arid tropics, there will be need for a full understanding of their potential for diffusion and the barriers to adoption. We apply a program evaluation technique to data obtained from Tanzania to derive estimates of the actual and potential adoption rates of improved pigeonpea varieties and their determinants. The study reveals that only 33% of the sampled farmers were aware of the improved pigeonpea varieties which consequently restricted the sample adoption rate of improved varieties to only 19%. The potential adoption rate of improved pigeonpea if all farmers had been exposed to improved varieties is estimated at 62% and the adoption gap resulting from the incomplete exposure of the population to the improved pigeonpea is 43%. We further find that the awareness of improved varieties is mainly influenced by attendance of Participatory Variety Selection activities. The adoption of improved varieties is more pronounced among farmers with smaller landholdings suggesting that farmers facing land pressure intensify pigeonpea production through the adoption of improved high yielding varieties. The findings are indicative of the relatively large demand for improved pigeonpea varieties suggesting that there is scope for increasing their adoption rate in Tanzania once the farmers are made aware of the existence of the technologies

Tropical Grain Legumes in Africa and South Asia: Knowledge and Opportunities

There are about 30 species of economically important legumes grown in the tropics (Baldev et al. 1988; Raemaekers 2001; Gowda et al 2007). Among the major ones are chickpea (Cicer arietinum), common bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), groundnut (Arachis hypogaea), pigeonpea (Cajanus cajan), and soybean (Glycine max). Others that are important in one or other regions of the tropics include faba bean (Vicia faba), lentil (Lens culinaris), field pea (Pisum sativum), Bambara groundnut (Vigna subterranea), hyacinth bean (Lablab purpurea – also known as Dolichos lablab), Kerting’s groundnut (Macrotyloma geocarpum), lima bean (Phaseolus lunatus), yam bean (Sphenostylis stenocarpa), mung bean or green gram (Vigna radiata), black gram or black bean (Vigna mungo), moth bean (Vigna aconitifolia), rice bean (Vigna umbellata), and horse gram (Macrotyloma uniflorum). More than 101 million households (HH) in Sub-Saharan Africa (SSA) and 39 million HH in South Asia (SA) grow one or more of the major tropical legumes for food security, income generation, improved nutrition, and maintaining soil fertility. An estimated 27 million ha in SSA and 40 million ha in SA are planted to these crops each year; annual production is estimated at about 19 million metric tons (MT) in SSA and 30 million MT in SA, valued at about US$9.3 billion and US$ 15.1 billion, respectively. Despite their importance, investment in tropical legumes research and development has been low. However, this situation has been changing for the better in recent years. The Tropical Legumes II project (TL II), funded by the Bill & Melinda Gates Foundation, aims to improve the livelihood of smallholder farmers in SSA and SA through improved productivity and production of the six major grain legumes mentioned above. Improved systems and partnership approaches between national programs and CG centers have shown positive changes in some countries (Abate et al 2011) that could serve as examples of good practice

Evaluation of the shoot regeneration response in tissue culture of pigeonpea (Cajanus cajan [L.] Millsp.) varieties adapted to eastern and southern Africa

Seven varieties of pigeonpea (Cajanus cajan [L.] Millsp.) of varying growth durations and adapted to a wide range of environments across eastern and southern Africa were evaluated for their shoot regeneration response in tissue culture. On a standardized shoot regeneration medium, the short duration varieties (ICPV 88091 and ICPV 86012) generally responded faster and better than the medium duration (ICEAP 00554 and ICEAP 00557) and long duration (ICEAP 00020, ICEAP 00040 and ICEAP 00053) varieties. However, all the tested varieties produced healthy rooted plants in vitro that could be transferred to the greenhouse where they exhibited normal growth, flowering and viable seed set. This study established the basis for genetic engineering of African pigeonpea varieties

The Role of Vegetables and Legumes in Assuring Food, Nutrition, and Income Security for Vulnerable Groups in Sub-Saharan Africa

Rising food and nutritional insecurity threatens the livelihoods of millions of poor people, particularly in sub-Saharan Africa. Vegetable and legume production and consumption are a potent mechanism for small-scale, disadvantaged farmers to obtain the required nutrients in their diets and to generate much-needed income through trade. Vegetables and legumes are key sources of nutrients and health-promoting phytochemicals, providing higher micronutrient contents and a wider spectrum of essential compounds to meet nutritional and health needs than other food sources. Diversifying diets with vegetables and legumes is a cheaper, surer, and more sustainable way to supply a range of nutrients to the body and combat malnutrition and associated health problems than other approaches that target only a single or a few nutritional factors. Furthermore, vegetables and legumes often accompany staple crops in meals, and most staple crops are less palatable without vegetable or legume accompaniments. As a growing world population demands more and higher quality foods, and as environmental problems such as soil degradation, water scarcity, biodiversity loss, and climate change become more acute, the need for innovative vegetable and legume research solutions to improve food and nutritional security cannot be overemphasized

An overview of chickpea breeding programs in Kenya

Chickpea is a new crop in Kenya and its potential has not been fully utilized. The chickpea grain yields generally range between 1.2 to 3.5 tons/ha at farmers‟ fields, indicating that chickpea has a potential of becoming an important export crop in Kenya. The chickpea breeding program in Kenya is still at infant stage and being established with support from International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). Four chickpea varieties have been recently released from the breeding material supplied by ICRISAT. Efforts are being made on evaluation of germplasm and breeding lines, application of modern molecular breeding tools and techniques in chickpea breeding and establishment of effective seed system for establishing a sustainable chickpea production system in the country