Grain yield and quality attributes of wheat (Triticum aestivum L.) as influenced by heat stress during the reproductive phase due to delayed sowing

Abstract

Terminal heat stress during the reproductive stage of wheat is one of the limiting factors affecting both production and grain quality and it is expected to gradually increase under the current climate scenario. To investigate this issue, a field experiment was conducted to assess the performance of wheat varieties for grain yield and qualitative traits. Seeds were sown under two conditions: normal (November 20) and late (December 20), allowing for a comparative study of heat stress during the later stages of plant growth. The results showed that grain weight per spike and test weight progressively decreased due to high temperatures experienced during the grain-filling period, which was associated with the delayed sowing date. High temperatures during the later stages of crop growth, particularly in the reproductive phase, adversely affect both the rate and duration of grain development. This results in forced maturity, leading to shriveled, immature and small grains with poor quality parameters, including reduced protein, starch, gluten content and sedimentation value.