Influence of drought on water use efficiency in wheat in semi-arid regions of Punjab

Drought imposed study on wheat in semiarid regions of Punjab was under taken to see the effects of cultivars and irrigation regimes on water use efficiencies calculated for total water applied and crop evapotranspiration. Four irrigation i.e. l(0) = control, l(1) = irrigation up to stem elongation, l(2) = irrigation from stem elongation to maturity and l(3) = full irrigation treatments based on soil moisture deficit were applied to each cultivar. Irrigation treatments were managed to induce a range of drought from full irrigation to nil irrigation from emergence to physiological maturity. Relationship between grain yield and ET was observed and concluded that for each mm of crop ET 3.27 g m(-2) TDM was produced. Inqlab-91 increased yield by 10.7% over MH-97. Fully irrigated crop produced 93.18% higher yield over control treatment. In treatments where drought was imposed before or later Anthesis, the primary cause of reduced efficiencies was a decrease in intercepted light which ultimately reduced its efficiency into economic part.