International Journal of Plant & Soil Science

Wheat is one of the most important cereal crops providing food to one fifth of the world population. Wheat cultivation faces numerous challenges, including climate change impacts like heat stress and water scarcity, biotic stresses such as diseases and pest and soil degradation. The food security under limited resources and global climate change has become a major challenge for sustainability. Therefore, the present field investigation was conducted in wheat crop during rabi 2021-22 at Irrigation and Water Management Farm of Department of Soil Science, CSK HPKV, Palampur to study the effect of regulated deficit irrigation on the growth and yield attributes of wheat (Triticum aestivum L.). The treatments consisted of selected combination of four deficit levels viz. high (50% ET_C), medium (70% ET_C), low (90% ET_C) and free from deficit (100% ET_C) and three phases of application viz. phase I (CRI and jointing), phase II (flowering) and phase III (dough stage). A total of eight combinations viz. FFF: Free from deficit at all three phases; LLL: Low deficit at all three phases; MMM: Medium deficit at all three phases; FMM: Free from deficit at phase I, Medium at phase II, Medium at phase III; HFM: High at phase I, Free from deficit at phase II, Medium at phase III; MFH: Medium at phase I, Free from deficit at phase II, High at phase III; MFM: Medium at phase I, Free from deficit at phase II, Medium at phase III; HFH: High at phase I, Free from deficit at phase II and High at phase III, were tested under randomized block design, replicated thrice. The soil of the experimental site was silty clay loam in texture, acidic in reaction, medium in organic carbon, available potassium, high in available phosphorus and low in available nitrogen. Results revealed that among all regulated water deficit schemes the low deficit LLL scheme of 90% ET_C application at CRI and jointing, flowering and dough stage resulted in higher plant height (105.4 cm), higher dry matter accumulation (763.1 gm^-2), more no. of tillers per meter square (236.4), more no. of ears per meter square (224.0), more no. of grains per ear (38.3), higher 1000 grain weight (42.6 g), higher grain yield (3129 kg ha^-1), higher straw yield (4558 kg ha^-1), higher values of biological yield (7687 kg ha^-1) and harvest index (40.8) that was statistically similar to the wheat cultivation under water deficit free condition at all critical stages of growth (FFF) having values (107.0 cm, 780.3 gm^-2, 242.7, 231.0, 39.5, 43.3 (g), 3320 kg ha^-1, 4785 kg ha^-1, 8105 kg ha^-1, 41.0 g for plant height, dry matter accumulation, no. of tillers per meter square, no. of ears per meter square, no. of grains per ear, 1000 grain weight, grain yield, straw yield, biological yield and harvest index, respectively). Any water deficit below 90% ET_C especially a high deficit of 50% ET_C at phase I (CRI and jointing) and phase III (dough) (HFH) resulted in significant decrease in yield.