Effect of weather on yield, heat and water use efficiency of wheat crop in a semi-arid environment

Abstract

Wheat (Tritium aestivum L.) is the major food crop of India contributing 12 per cent of the total food grain production, covering an area of 31.5 Mha with production and productivity of 86.5 Mt and 2.8 tha-1 respectively (http://eands.dacnet.nic.in/). In India, wheat is grown during November to March, as it requires cool and moist weather during the vegetative phase, and warm and dry weather during reproductive phase. Cardinal (minimum, maximum and optimum) temperature is one of the most critical parameter that decides fate of crop productivity in wheat. However, wheat sowing after rice is delayed because of late harvesting of rice, large turn around time and poor soil tilth of seed bed which forces delaying of wheat sowing to varying degrees. Wheat yield under such circumstances is mainly affected by terminal heat and water stress.Reproductive phase is the ultimate determinant of yield, if faces high temperature stress shows a significant impact on yield (Mitra and Bhatia, 2008). Different wheat cultivars take different time from germination to maturity under varied agro-climatic condition. Therefore, crop development phases alone cannot be considered as a good predictor for measuring abiotic stress. The more scientific way of characterizing abiotic stressis through meteorological indices like growing degreedays, heat use efficiency, etc. Considering all these, a study was undertaken to investigate the impact of sowing date on yield, heat and water use efficiency of three wheat cultivars in Indo-Gangetic Plains of India.