Impact of Irrigation Schedules on Yield-Related Traits of Wheat Under Semi-Arid Region

Water shortage is the most important environmental constraint to the wheat crop. Optimum irrigation scheduling ensures high productivity. Water scarcity is a serious problem in many developing countries, including Pakistan, which requires drought-tolerant wheat varieties. A field experiment was conducted for two consecutive wheat growing seasons 2018–19 and 2019–20, at Cereal Crops Research Institute Pirsabak Nowshera to study the effect of irrigation schedules on yield and related attributes of wheat genotypes. The experimental material consists of seven wheat genotypes viz. PR-110, 112, 115, 118, 119, 120, and Pirsabak-13 were evaluated at five different irrigation levels i.e., I₀: Control (No irrigation), I₁: irrigation applied at seedling stage (one irrigation), I₂: irrigation applied at seedling + booting (two irrigation), I₃: irrigation at seedling + tillering + booting (three irrigation) and I₄: irrigation at seedling + tillering + booting + grain development stages (four irrigation levels). The experiment was set up using a split-plot design with a randomized complete block structure, with irrigation schedules applied to the main plot and different wheat genotypes to the subplot. Pooled analysis of variance for yield and related characters of wheat genotypes for five irrigation levels over two years revealed significant (P ≤ 0.05) differences. Likewise, the effect of year, irrigation, genotypes interaction of year × genotypes and irrigation × genotypes were found significant. However, the non-significant effect of year for thousand grains weight and interaction of irrigation × genotypes for grains spike⁻¹, year × irrigation, and year × irrigation × genotypes was also estimated. Principal component analysis identified genotypes PR-112, PR-119, PR-110, and PR-115 as superior (Group-A) for grain yield and related characteristics. Furthermore, irrigation applied at seedling + tillering + booting + grain formation stages (I₄) produced significantly (P ≤ 0.05) maximum yield and related traits during both of experimental years. In addition, it was observed that wheat yield losses might be mitigated during water scarcity with irrigation throughout the seedling and booting stages. According to the findings, the selected wheat genotypes that have been found may be applied in upcoming breeding activities to generate drought-tolerant wheat cultivars.