The Effect of Deficit Irrigation on Yield and Water Use Efficiency of Several Main Crops in Jiroft

ABSTRACT In order to investigate the yield and water use efficiency of wheat (Chamran 2), rapeseed (Hyola 50), potato (Sante) and corn (704) under different levels of irrigation, the present research was carried out in two years 2017-2018 and 2018-2019 as complete randomized block design with four replications at Agricultural Research Center of Jiroft. Irrigation levels were 50, 75 and 100 % of the crop's water requirement. The Yield, biomass, harvest index and water use efficiency were investigated for the proposed crops. The results showed that the effect of irrigation levels was significant during two years on grain yield, biomass and water use efficiency at 1% level and on harvest index at 5% level. By increasing irrigation water, both grain yield and biomass were increased significantly in all crops. Potato and rapeseed had the highest (0.65-0.74) and the lowest (0.20-0.25) water index, respectively. On the other hand, potato and rapeseed showed the highest (10.68-22.76 kg/m3) and the lowest (1.29-1.84 kg/m3) water use efficiency, respectively. The 75% irrigation level is recommended due to lower decrease in yield and higher increase in water use efficiency. In general, according to the results of this study, the highest water use efficiency was observed in potato, wheat, maize and rapeseed plants, respectively. Overall potato and maize rotation is recommended due to higher water use efficiency in Jiroft.