Effect of plant density on grain yield and yield stability of sorghum hybrids differing in maturity

Abstract

The extent and significance of the maturity x density interaction in dryland grain sorghum, and its implications for yield stability, were examined for 3 hybrids over 6 locations. Site mean grain yield ranged from 0.44 to 4.96 t/ha. Early maturity was superior in environments truncated by water stress, while late maturity was superior in favourable environments. Mid-season maturity provided greater stability of grain yield. Maximum yield by each hybrid at each yield level did not differ significantly from yield at a density of 75 000 plants/ha. The highest grain yields should be obtained with plant densities of 50000-100000 plants/ha under rainfed conditions, where yield expectations range from 0 to 5.0 t/ha. The results demonstrate the stability of sorghum grain yield over a wide range of plant density and crop maturity. Regression analysis aided data presentation and interpretation.