Indian Journal of Agronomy

A field experiment was conducted during the winter (rabi) seasons of 2010–11 and 2011–12 on sandy-loam soil at New Delhi, to study the effect of sowing dates and irrigation regimes on growth parameters, yield attributes, yield and water-use efficiency (WUE) of wheat [Triticum aestivum (L.) emend. Fiori & Paol.], and influence of prevailing temperature on grain yield. The experiment was laid out in split-plot design with 3 replications involving 4 sowing dates, viz. S₁, 1 November; S₂, 16 November; S₃, 1 December; S₄, 16 December in main-plots and 4 irrigation regimes, viz. I₁, 25% maximum allowable depletion (MAD) of available soil moisture (ASM); I₂, 50% MAD of ASM; I₃, 75% MAD of ASM; I₄, based on 4 critical growth stages, in subplots. Significantly highest grain yield was obtained in 1 November sowing (5.20 t/ha) and was at par with 16 November sowing (5.05 t/ha). Yield attributes were also the highest under 1 November sowing. Amongst the irrigation regimes, irrigation scheduling at 25% MAD of ASM resulted significantly more grain yield (4.93 t/ha), followed by I₂, I₄ and I₃ treatments. The I₁ treatment resulted in 27.4% more yield than I₄ treatment. Intermittent irrigation with small amount of water applied in I₁, resulted higher grain and straw yields. The grain yield reduction was 43.7% due to high seasonal mean temperature (+2.2°C) in 16 December sowing over 1 November sowing. The highest water-use efficiency (15.0 kg/ha/mm) and benefit: cost ratio (2.16) were recorded in 25% MAD of ASM and 50% MAD of ASM respectively.