Effect of Regulated Deficit Irrigation on Water Use and Economic Benefit of Processing Tomato (<i>Solanum lycopersicum</i>) in an Arid Environment

Abstract

An experiment was conducted to determine the effect of regulated deficit irrigation (RDI) on water use and economic benefit of processing tomato in an arid environment. The results indicated that seasonal total irrigation water applied to processing tomato was significantly (p<0.05) saved by 14.3% to 42.9% under RDI compared to full irrigation. The irrigation water use efficiency (IWUE) of processing tomato was significantly improved with 32.4% and 57.2% in RDI plots respectively subjected to high and low water deficits at seedling as well as 26.1% in RDI plots subjected to low deficit at late fruiting compared with full irrigation, but no difference (p>0.05) occurred between fully irrigated crops and RDI plants subjected to water deficits at full fruiting as well as low deficit at late fruiting. However, in comparison with fully irrigated crops IWUE was significantly reduced with 20.5% and 22.2% in RDI plants both subjected to water deficits at flowering. Compared to full irrigation, the net income was significantly reduced with 11.3% to 45.3% in RDI plots except that subjected to low water deficit at seedling. Therefore, low water deficit RDI at seedling while full irrigation during flowering to late fruiting could be used to effectively reduce irrigation water application and improve IWUE of processing tomato without causing economic benefit reduction in arid areas.