Yield And Yield Attributing Character Of Nepalese Wheat Genotypes Under Combined Rainfed And Heat Stress Conditions

Wheat is the third most important cereal crop in Nepal. The area and production of wheat in Nepal has been increased dramatically after the introduction of semi dwarf varieties and now it has significant contribution to the national food supply. The aim of evaluating twenty elite wheat genotypes under combined heat stress condition field research was conducted using alpha lattice design at Bhairahawa, Nepal. The limiting factor of wheat in Nepal is irrigation and heat stress. Heat stress is the critical factor that directly affect the grain yield and productivity of crop. Drought significantly affects the yield of wheat. The selected parameters to determine yield and yield attributing character in wheat were plant height, spike weight, spikelet per spike, thousand grain weight, number of tillers per square meter and yield. The path analysis identified biological yield per plant in tillers per meter square as the major direct positive contribution towards expression of grain yield per plant. The results of correlation showed highly positive significant association with TPM (0.575879) and SW (0.355878) and negative significant association with SPS (-0.03118) can help breeding programs that are subjected to heat stress by revealing which traits have a major impact on yield. The highest positive correlation (.640**) was appeared on tillers per meter square and the negative correlation (-.138) was appeared on spike length. The highest value of direct effect of yield with plant height was followed by TPM and the least value of direct effect of yield was (.138 9). Multilocation and multiyear yield trials are required for more validation of additional trials involving many sites and years are required to confirm the selection of these characteristics for increased yield. The result presented here encourage the productivity in sustainable way in the heat stress and drought farming system.