Kamara A.Y.,International Institute Of Tropical Agriculture |
Ekeleme F.,Michael Okpara University of Agriculture |
Omoigui L.O.,Makurdi University Of Agriculture |
Ajeigbe H.A.,International Crop Research Institute for the Semi Arid Tropics ICRISAT
Experimental Agriculture | Year: 2012
Soybean (Glycine max) is a major cash crop in the savannas of Nigeria although productivity is typically constrained by poor soil fertility. The objective of this research was to determine the interactive effect of N and P on soybean productivity in the northern Guinea and Sudan savannas of northeast Nigeria. Experiments were conducted using locally adapted early and late maturing cultivars. Two rates of N and three rates of P fertilizer were also compared at both sites over two years. At both sites, pods plant -1 and seed yield were higher in 2006 than in 2007, possibly due to better rainfall distribution in 2006. Nitrogen fertilizer had no significant effect on seed yield or pods plant -1. Application of P fertilizer increased pods plant -1 by 40-66%. Averaged across site and year, seed yield with no P was 1057.2 kg ha -1 while yield with 20 and 40 kg ha -1 P were 1941.0 kg ha -1 and 2371.5 kg ha -1, respectively. No significant interaction effect between N and P fertilizer on seed yield and pods plant -1 was observed. The late maturing cultivar yielded less than the earlier maturity group cultivar in 2007 likely due to moisture stress. For optimum seed yield 40 kg of P fertilizer ha -1 is recommended for soybean production in both locations. Our results suggest that N fertilizer is not critical for soybean production in this area. © Copyright Cambridge University Press 2011.
Deu M.,CIRAD - Agricultural Research for Development |
Sagnard F.,CIRAD - Agricultural Research for Development |
Sagnard F.,International Crop Research Institute for the Semi Arid Tropics ICRISAT |
Chantereau J.,CIRAD - Agricultural Research for Development |
And 9 more authors.
Theoretical and Applied Genetics | Year: 2010
The dynamics of crop genetic diversity need to be assessed to draw up monitoring and conservation priorities. However, few surveys have been conducted in centres of diversity. Sub-Saharan Africa is the centre of origin of sorghum. Most Sahel countries have been faced with major human, environmental and social changes in recent decades, which are suspected to cause genetic erosion. Sorghum is the second staple cereal in Niger, a centre of diversity for this crop. Niger was submitted to recurrent drought period and to major social changes during these last decades. We report here on a spatio-temporal analysis of sorghum genetic diversity, conducted in 71 villages covering the rainfall gradient and range of agro-ecological conditions in Niger's agricultural areas. We used 28 microsatellite markers and applied spatial and genetic clustering methods to investigate change in genetic diversity over a 26-year period (1976-2003). Global genetic differentiation between the two collections was very low (Fst = 0.0025). Most of the spatial clusters presented no major differentiation, as measured by Fst, and showed stability or an increase in allelic richness, except for two of them located in eastern Niger. The genetic clusters identified by Bayesian analysis did not show a major change between the two collections in the distribution of accessions between them or in their spatial location. These results suggest that farmers' management has globally preserved sorghum genetic diversity in Niger. © 2010 Springer-Verlag.
Kamara A.Y.,International Institute Of Tropical Agriculture |
Ewansiha S.U.,University of Benin |
Ajeigbe H.A.,International Crop Research Institute for the Semi Arid Tropics ICRISAT |
Omoigui L.O.,Makurdi University Of Agriculture
Archives of Phytopathology and Plant Protection | Year: 2013
Insect pests are major constraint to cowpea production in northern Nigeria causing yield losses up to 70%. Several cowpea varieties have been developed and delivered to farmers by IITA over the past four decades. These varieties have varying degrees of resistance to insect pest attacks. A field study was established in northern Nigeria to determine the response to insecticide spraying of old cowpea varieties developed in the late 1970s and new varieties developed in the 2000s in order to determine whether new varieties have lesser requirement for spraying with insecticides than the old ones. The result revealed that the new cowpea varieties developed in the 2000s require more spraying than the old varieties developed in the 1970s. Infestations by the insect pests, maruca (Maruca virata Fabricius) and flower thrips (Megalurothrips sjostedti Trybom) were significantly less at zero and 1 spray for old varieties than for the new varieties. Old varieties also produced significant higher grain yield at zero and 1 spray compared with new varieties. Newer varieties require more spray to maximise yield gain. © 2013 Copyright Taylor and Francis Group, LLC.
Pedzisa T.,University of Pretoria |
Rugube L.,University of Pretoria |
Winter-Nelson A.,University of Illinois at Urbana - Champaign |
Baylis K.,University of Illinois at Urbana - Champaign |
Mazvimavi K.,International Crop Research Institute for the Semi arid tropics ICRISAT
Journal of Sustainable Development | Year: 2015
This paper examines the determinants of abandonment of conservation agriculture (CA) techniques among smallholder farmers in Zimbabwe. The analysis uses four rounds of a balanced panel from a survey aimed at monitoring CA adoption among farmers who participated in CA promotion projects. Findings indicate that a large share of farmers who had adopted CA during the period of active promotion eventually abandoned the practice in the absence of support from non-governmental organisations (NGOs). Households with more farming experience, bigger household sizes and a greater number of cultivated plots were less likely to stop using CA. In turn, wealthy households and farmers in the drier areas were more likely to stop using CA. The finding that persistent adoption is more prevalent among the poor, supports claims that CA is a pro-poor technology. Lastly, we find a strong, negative and robust relationship between continued NGO support and abandonment of CA. This finding suggests that improved support institutions are necessary to ensure that farmers continue to use CA as a productivity-boosting and sustainable farming method. © 2015 by the authors.