Search

Background: The genetic yield potential of groundnut (Arachis hypogaea L.) has been continuously challenged by several diseases including early leaf spot (ELS). Methods: In the current study, we evaluated groundnut mini core collections under artificial and natural disease epiphytotics in six environments to identify stable elite sources for ELS resistance and pod yield. Mixed model analysis was done to adequately capture the variance component as a result of genotype (G), environment (E) and G x E interaction (GEI). Result: Highly significant (p <0.001) effects for G and GEI on ELS and pod weight were observed. The parametric and non-parametric stability models ranked the genotype differently for their stability to ELS. The GGE biplot identified ICG 1519 as a stable genotype for the ELS resistance. For pod weight, ICG 8896 and ICG 7897 were consistently stable from all the stability models including the GGE biplot. ICG 9449 and ICG 4540 were identified as stable genotypes for both ELS and pod weight. These elite sources of ELS resistance identified in the current study will be useful in the development and deployment of groundnut varieties with resistance to ELS and high pod yielding potentials. [ABSTRACT FROM AUTHOR]

Drought, infestation of cereal crops by the parasitic weed Striga hermonthica, and poor soil fertility are the major constraints to maize production by smallholder farmers in the Sudan savannas of northern Nigeria. Four innovation platforms (IPs) were therefore established in 2008 in the Sudan savanna (SS) agroecological zone of northern Nigeria to create a stakeholder forum to address these identified food production challenges in the target areas. The IPs comprised researchers from Bayero University, Kano; Institute for Agricultural Research, Zaria; International Institute of Tropical Agriculture; state and local government extension programs in Kano and Katsina states; input and output dealers; community-based organisations; and media organisations in the two states. The current study reports on the effects of legume integration on maize performance in farmer fields and the adoption of Striga management technologies introduced in the IPs over a four-year period. The deployment of drought- Striga-tolerant and early-maturing maize varieties along with legume rotation reduced Striga infestation by 46–100% when cowpea was rotated with maize, 80–97% when groundnut was rotated with maize, and 59–94% when soybean was rotated with maize. Grain yield of maize increased by 63–88% when cowpea was rotated with maize, 69–128% when groundnut was rotated with maize, and 9–133% when soybean was rotated with maize. Participatory and detailed questionnaire-based adoption surveys showed high adoption of improved maize varieties, five years after program interventions. The maize variety 99EVDT-W-STR C0 was the most popular among all the IPs because it is early maturing, Striga-resistant, and drought-tolerant. The high maize yields and high adoption rates suggest that the IP approach was effective in disseminating maize technologies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM PUBLISHER]