The Effect Of Drought Stress And Plant Density On Yield And Yield Components Of Wheat Cultivars In Lorestan Provinve, Iran
Abstract
Drought stress and plant density are two crucial factors that affect winter wheat yield and its components. This study was laid out in order to evaluation of drought stress and plant density on yield and its components of winter wheat cultivars in two temperate region of Lorestan province (Borujerd and Dorud sites), Iran during 2018-19. The experiment was laid out in a split-factorial arrangement based on completely block design with three replications. Drought stress factor was stand in main plots in three levels (control, irrigation to grain filling and irrigation to heading). Also, plant density (300, 400, 500 and 600 plants/m2) and cultivar (Mihan and Baharan) were stans in sub plot as factorial. The results showed that drought stress and plant density had significant effect on yield components of winter wheat. Based on the mean comparison results, drought stress reduced plant height and spike length due to reduction of plant growth. Under higher plant density, the height and spike length were increased. In both Mihan and Baharan cultivars, the number of tillers and 1000 grain weight was influenced by drought stress and plant density at Borujerd and Dorud sites. Maximum grain yield was founded in non-drought stress treatment (10120 kg.ha-1), which was 34 and 35% higher than irrigation to grain filling and irrigation to heading treatments respectively. The maximum wheat biomass was recorded in non-drought stress treatment (35314 kg.ha-1) and 400 plant per m2 (33958 kg.ha-1). Also, results showed that highest harvest index was founded in non-drought stress treatment (30.25%). maximum LAI in 50% heading was founded in 300 plants per m2 with non-drought stress treatment (29.6) and its difference was significant in comparison with other treatments. In general, the results of the present study demonstrated that drought stress reduced grain yield of Mihan and Baharan cultivars in temperate region of Lorestan province. For achieving to higher winter wheat biomass can cultivate 400 plant/m-2 at non-drought stress condition.
