Abstract

The interaction between genotypes and environments results in significant differences in the performance of genotypes when tested in various environments. Fifteen soybean [Glycine max (L.) Merr.] genotypes were evaluated for yield and protein content in Kenya aiming to quantifying and identifying high yielding genotypes for human food and livestock feed. The study was conducted in Eldoret (0° 35¢N, 35°18¢E), Lanet (0°18¢S, 36° 09¢E), Nakuru West (0° 33’S, 36° 0’E) and for two seasons at Njoro (0° 20¢S, 35° 56¢E). The results indicated significant (p ≤ 0.01) effects due to genotype, environment and genotype ´ environment interaction for days to flowering harvest maturity, plant height, number of pods per plant, number of nodes per plant, seed yield, oil and protein content. The mean seed yield was 1267.8 kg ha^-1. Genotype Nyala produced the highest yield across environments. The mean protein content ranged from 40.3% for genotype TGX 1740-2F (DPSB 19) to 35.2% for genotype 931/5/34 across the five test environments with the highest mean protein being recorded at Njoro and the lowest at Nakuru West. Genotype Nyala and SBH 7/1/1 may be recommended for production for their relatively high grain yield across the sites.

Key words: Soybean, yield, genotype, environment, protein.