Influence of date of sowing and irrigation regimes on crop growth and yield of wheat (Triticum aestivum) and its relationship with temperature in semi-arid region

A field experiment was conducted during the winter (rabi) seasons of 201011 and 201112 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 pre- vailing temperature on grain yield. The experiment was laid out in split-plot design with 3 replications involving 4 sowing dates, viz. S , 1 November; S , 16 November; S , 1 December; S , 16 December in main-plots and 4 irriga- 1 2 3 4 tion regimes, viz. I , 25% maximum allowable depletion (MAD) of available soil moisture (ASM); I 50% MAD of 1 2, ASM; I , 75% MAD of ASM; I , based on 4 critical growth stages, in subplots. Significantly highest grain yield was 3 4 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 I , I and I treatments. The I treatment 2 4 3 1 resulted in 27.4% more yield than I treatment. Intermittent irrigation with small amount of water applied in I , re- 4 1 sulted higher grain and straw yields. The grain yield reduction was 43.7% due to high seasonal mean temperature (+2.2C) 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.