Effect of Regulated Deficit Irrigation on Growth and Yield of Sorghum

Abstract

The effects of regulated deficit irrigation technique on growth and yield of sorghum was examined in a greenhouse at the Faculty of Agrotechnology and Food Science Research Farm, University Malaysia Terengganu. The experiments regulated deficit irrigation (RDI) consisted of a factorial combination of irrigation regimes and soil types laid in a randomised complete block design with eight treatments for each experiment which resulted into a total of sixteen  treatments. Irrigation regimes were at four levels namely: I₁₀₀, I₇₅, I₅₀ and I₂₅ and the soil types were at two levels namely: Rhu Tapai and Rengam soil series. The treatments were randomly assigned to experimental pots and replicated four times. A total of thirty two pots were used for the study. All agronomic practices starting from land preparation to harvesting were adhered to and growth parameters were recorded for both experiments. The result of the study shows that sorghum performance improved under regulated deficit irrigation techniques. The results further revealed that, irrigation regimes I₁₀₀ and I₇₅ performed better in terms of growth parameters, crop water use efficiency, economic performance and profitable measures under RDI and compared to I₅₀ and I₂₅ irrigation regimes. The study also revealed that there were interaction effects of deficit irrigation and the two types of soil on some of the parameters used for the study. The study, therefore, recommended the use of I₇₅, for optimizing sorghum growth in this agro ecological zone.

Keywords: Regulated deficit irrigation, Growth, Yield, Sorghum, Water use efficiency