Optimizing Sowing Windows for Wheat (Triticum aestivum L.) in the Sub-temperate Climate of the North-western Himalayas of India

A field investigation was carried out at the Research farm of the Department of Agronomy, CSKHPKV, Palampur during the winter season to evaluate the suitability of variable owing windows under limited irrigation regimes with two wheat cultivars. The five sowing windows 15th, 30th October, 15th, 30th November and 15th December along with two wheat cultivars i.e., HPW-349 and HPW-155 were investigated under a factorial randomized block design with three replications for each treatment. The timely sown crop on 15th October resulted in significantly higher values for growth attributes such as plant height, leaf area index, number of tillers per meter square and yield attributes such as spike length, number of grains per spike and test weight. The grain yield consequently was recorded to be the highest for the timely sown crop i.e., the 15th October sown crop. The timely sown crop sown on 15th October resulted in a 21.6% higher grain yield as compared to the 15th December sown crop. Furthermore, delaying the sowing date by one month from 15th October to 15th November, the wheat grain yield declined by 12%, similarly, delaying the sowing date from 15th November to 15th December resulted in yield reduction by 7%. The highest gross, net returns and benefit-cost ratio were also recorded to be the higher for the timely sown crop i.e., 15th October.