Effect of trees on grain yield of dry season sorghum [Sorghum bicolor (L.) Moench]

Abstract

The effect of three tree species, Balanites aegyptiaca, Prosopis juliflora and Acacia nilotica on biomass production and grain yield of dry season sorghum [Sorghum bicolour (L.) Moench] was investigated in 100-day old sorghum. Sorghum was planted between trees which were pruned or unpruned. Significant differences (P<0.05) in biomass and yield components were observed. Treatment effect on 100 grain weight and grain number per panicle were observed between treatments, but individual grain weights were not affected by the treatments. Unpruned B. aegyptiaca had no depressing effect on biomass or grain yield, while unpruned P. julifora depressed yield but pruning this species increased both biomass and consequent grain yield only over the unpruned treatment. However, A. nilotica whether pruned or unpruned inhibited biomass production and grain yield in the crop. Competition for limited moisture, light and nutrients between the crop and trees was responsible for depressing biomass and consequently grain yield in the crop. The result has shown the potential of sustainable agroforestry system in the semi-arid area using B. aegyptiaca and with managed P. julifora.
Key Words: Sorghum (Sorghum bicolor); Grain yield; Dry season; Tree-crop integration.