Effect of sowing time, planting methods and irrigation scheduling on yield response, water and radiation-use efficiencies of wheat (Triticum aestivum) in Punjab, India

A field experiment was conducted during the winter season (rabi) of 2016-17 and 2017-18 at Ludhiana, Punjab, to evaluate the photosynthetically active radiation (PAR) interception, yield response, water and radiationuse efficiencies of wheat (Triticum aestivum L.) in response to sowing time, planting methods and irrigation treatments. Wheat variety ‘WH 1105’ was sown on 2 dates (10 and 30 November) under 2 planting methods (flat planting and bed planting) and 3 irrigation treatments (I₁, 3 post-sowing irrigations at crown-root initiation (CRI), flag-leaf emergence and soft dough stages; I₂, I₁ + 4^th irrigation during the last week of March; and I₃, recommended 4 post-sowing irrigations) with 4 replications. Crop sown on 10 November under bed planting with I₂ irrigation treatment had the maximum dry matter accumulation, leaf area index, number of effective tillers, ear length, grains/ ear and 1,000-grain weight as compared to the other treatments. The PAR interception was also higher in 10 November sowing under bed planting in I₂ irrigation treatment, which had direct effect on radiation-use efficiency (RUE) of the crop. Water-use efficiency (WUE) was higher (12.5 and 11.4 kg/ha/mm) under I₁ treatment followed by I₃ treatment (12.3 and 10.6 kg/ha/mm) and the lowest in I₂, treatment (10.5 and 9.3 kg/ha/mm). The grain yield, WUE and RUE were higher by 5-10, 10-15 and 1-5%, respectively under bed planting compared to flat planting during both the seasons. Significant and positive correlation (r) of grain yield with yield-attributing characters, viz. no. of effective tillers (0.71), grains/ear (0.76), ear length (0.74), 1,000-grain weight (0.65), water (0.76) and RUE (0.69) were observed with pooled analysis.