DETERMINATION OF OPTIMUM TIME OF FIRST IRRIGATION FOR HIGHER YIELD AND MONETARY RETURN OFWHEAT CROP

The research was conducted at Arid Zone Research Farm Bahawalpur during 2003-04 to study theeffect of different irrigation schedules on water use and yield of wheat. The experiment was conducted usingwheat variety Inqilab-91, with five irrigation intervals i.e. 10, 20, 30, 40 and 50 days after sowing. Results ofyield and its components indicated that there was significant effect of irrigation intervals on grain yield, fertiletillers plant-1, spike length and grains spike-1. Among the treatments, application of irrigation at 30-40 daysafter seeding significantly produced the maximum production of yield components i.e fertile tillers (3) plant-1,spike length (10.1 to 10.4 cm), grains (40-42) spike-1 and seed yield (3210 to 3356 kg ha-1) as compared toobtaining the lowest yield components i.e fertile tillers (2) plant-1, spike length (8.2 to 8.7 cm), grains (32 to 34)spike-1 and seed yield (2576 to 3030 kg ha-1) in the treatments where crop was irrigated early at 10-20 days orlate 50 days interval after seeding. Similarly the highest monetary return of Rs.25170 ha-1 and Rs.24075 ha-1and cost benefit ratio (CBR) of 3.4 and 3.2 were obtained from the crop where first irrigation was applied at 30-40 days interval after sowing. It was concluded that for maximum yield of wheat, the crop may be irrigated after30 to 40 days of sowing. Earlier or later than this period can not be beneficial for the optimum yield of wheatunder the ecological zone of Bahawalpur where seasonal rainfall is 250-300 mm.