The Effect of Sowing Dates on Grain Yield and Quality in Spring Wheat (<i>Triticum aestivum</i> L.)

The impact of sowing dates on wheat (<i>Triticum aestivum</i> L.) quality and yield was investigated comprehensively across two locations during the growing seasons from 2020 to 2022. The study revealed contrasting effects of temperature on grain protein content and glutenin composition. The increase in temperature during the grain-filling period, caused by delayed sowing dates, led to an increase in grain protein content and wet gluten, while concurrently decreasing SDS and Zeleny sedimentation volumes, indicative of reduced gluten strength. This opposing trend underscores the complex relationship between temperature and wheat grain quality, influenced by the synthesis and polymerization of glutenin proteins critical for dough elasticity and baking performance. Furthermore, a negative relationship between ambient temperature and grain yield was observed across locations and years, highlighting the detrimental impact of heat stress on wheat productivity. Early sowing dates, which extended the grain-filling period under cooler conditions, favored higher grain yield and superior gluten quality, characterized by higher SDS and Zeleny values. In contrast, delayed sowing dates, exposing wheat to higher temperatures during grain filling, resulted in increased grain protein content and wet gluten but compromised gluten strength. The findings underscore the importance of optimizing sowing dates and developing heat-resilient wheat varieties to mitigate the adverse effects of climate change on wheat production.