ABSTRACT
Sorghum is mainly grown in the Semi-Arid Tropic of the world, particularly under rain fed conditions. It forms the most staple food crop for millions of people in these areas. Sorghum production is highly influenced by the environment where it is grown, thus, the genotype by environment interaction is highly significant when breeding for specific adaptation. This study is aimed at identifying suitable genotypes for release to farmers in Nigeria and for further genetic manipulations. Grain yield performances and stability indices for twenty diverse sorghum genotypes evaluated for three years (1998-2000) at five locations in the savanna agro-ecological zone of Nigeria. The environments, genotypes, genotype x environment interaction, genotype x environment (linear) and deviation from regression component significant were highly significantly different. Genotypic means and linear regression coefficient (b-value) were used to measure production response, while deviation from regression (s2d), coefficient of determination (r2) and ecovalence (W) were used as stability indices. The highest yielding sorghum genotype was NR 71168 (3.02 t/ha) while NR 71138 had the least average grain yield (0.63 t/ha). Based on stability indices, NR 71156, NR 71158, NR 71165, NR 71167, NR 71168 and NR 71182 were desirable, stable and adapted to wide range of environments in the savanna agro-ecologies. These genotypes may be released to farmers for cultivation.
