Evaluation of traits’ performance contributing to drought tolerance in sorghum

Sorghum (Sorghum bicolor [L.] Moench) is an important food crop for people in semiarid Africa. The crop is affected by post-flowering drought; therefore, the study was conducted to screen traits contributing to drought tolerance using BC₂ F₄ sorghum genotypes in stressed and unstressed water conditions in a split-plot design. Water stress (0 mm/day) was applied at post-flowering to plant maturity in water-stressed treatment. The genotype SE438 produced the highest grain yield (2.65 ton ha⁻¹) in water-stressed environment and NA316C yielded highest (3.42 ton ha⁻¹) under well-watered (7 mm/day) environment. There were significant differences of most traits evaluated at p < 0.01 across environments. The mean squares of traits for genotypes by environments revealed interactions at p < 0.05 and p < 0.01. The indices geometric mean productivity (GMP) and mean productivity (MP) were highly correlated with yield under well-watered (YP) and water-stressed condition (YS) and each other. The first principal axis (PC1) explained 59.1% of the total variation. It is the best indicator of yield potential and drought tolerance of sorghum genotypes in this study. Therefore, further improvement is needed to strengthen drought tolerance and yield in sorghum.