Delayed Sowing and its Ramifications: Biophysical, Yield, and Quality Analysis of Wheat Cultivars in the north‐west Indo‐Gangetic Plains

The continuous cultivation of Rice-Wheat (R-W) in the same field is a key element of double-cropping systems in the Indo-Gangetic plains (IGP). Yields of such cropping systems are increasingly challenged as climate change drives increases in temperature, terminal stress, uneven rainfall, delaying rice harvesting and subsequent delay sowing of wheat.In this paper, we evaluate the optimum sowing dates to achieve the high grain yield and quality of wheat cultivars in northwest India.Three cultivars of wheat HD-2967, HD-3086, and PBW-723 were sown on three different dates at the research farm of ICAR-IARI, New Delhi, to generate different weather conditions at different phenological stages. The different biophysical attributes, photosynthetic rate, stomatal conductance and transpiration rate, were measured at different phenological stages. Yield and grain quality parameters such as protein, starch, amylopectin, amylose, and gluten were measured in different cultivars sown on different dates.Biophysical parameters were found to be higher in timely sown crops followed by late sown and very late sown crops. Further, the different sowing dates had a significant (p<0.05) impact on the grain quality parameters such as protein, starch, amylopectin, amylose, and gluten content. Percentage increase in the value of starch and amylose content under timely sown were ~7% & 11.6% and ~5% & 8.4%, compared to the very late sown treatment. In contrary, protein and amylopectin content were found to increase in ~9.7% & 7.5% and ~13.8% & 16.6% under very late sown treatment.High-temperature stress during the grain-filling periods significantly decreased the grain yield. Reduction in the grain yield was associated with the reduction in starch and amylose content in the grains. The protein content in the grain is less affected by the terminal heat stress. Cultivars, HD-3086 had higher growth, yield as well as quality parameters, compared to HD-2967 and PBW-723 in all treatments, hence could be adopted by farmers in North-West India. This article is protected by copyright. All rights reserved.