Impact of growth substances applications on yield parameters of wheat under water stress

A green house experiment was conducted during three consecutive years at Ayub Agricultural Research Institute, Faisalabad (Pakistan) to find out the effect of drought stress on yield parameters of wheat. From the study it was reported that water deficit decreased grains per spike; 1000-grain weight, total biomass, grain yield and harvest index significantly while application of growth substances improved them. Pre-sowing seed soaking in ethephon solution produced the highest 1000-grain weight of 44.39 g, increased per hectare yield by 37 percent and harvest index by 8 percent in comparison with control. Biological yield was significantly decreased by shortage of moisture supply. While number of productive tillers per plant was decreased under moisture stress conditions by 6 percent, this was enhanced by application of growth substances. Growth substances application though was found not to be much beneficial under normal moisture supply, but under moisture stress economic returns were enhanced significantly. Thus, the maximum increase of 36 percent in net income was obtained from ethephon application under drought stress.