Influence of Fertilizer Application on Yield and Morphological Traits of Green Grams in Taita Taveta, Kenya

Abstract

Green grams (Vigna radiata (L.)) is a nutrient-rich legume which thrives in arid drylands. Its production has been declining due to low soil fertility and a mismatch between variety and environments. A trial was set up in dry lowlands (Bura) and wet highlands (Ngerenyi) of Taita Taveta County to assess the effect of fertilizer on the yield of green gram under different tillage methods. The experimental design was a split–split plot with three replications. Fertilizer was the main plot, tillage methods as sub plots and varieties (N-26, Karembo, and KS-20) as sub-sub plots. Data on 100-seed weight, yield per plant, number of pods, and pod length, among others were analysed. Varieties and sites had significant effects on yield traits. KS-20 had the highest yield (5.27g and 2.80g) in both sites. Interaction of tillage methods with the varieties significantly affected yield (P=0.05). Ngerenyi had taller plants (53.28 cm) than Bura (23.28 cm). KS-20 has previously been released officially for commercial production and can be promoted among dryland farmers in Taita Taveta. It is recommended to assess the effectiveness of combining fertilizer treatment and tillage methods on introduced green gram varieties on-farm.