Wheat Productivity as a Function of Cultivar, Planting Date, Powdery Mildew and Weather Interplay

Background and Objective: Wheat productivity is influenced by an intricate interplay of cultivar selection, planting dates, disease pressures like powdery mildew, and weather conditions. Understanding these interactions is critical for optimizing yield and ensuring food security. This study aims to evaluate the combined impact of these factors on wheat growth and productivity to identify optimal management strategies. Materials and Methods: During 2013-2017, wheat yield was modeled using powdery mildew progress patterns, planting and maturity date, weather, and wheat resistance were examined in eight cultivars registered in Iran across 282 field plots. Studies were conducted using a split plot design having three replicated plots per experimental treatment. Datasets were analyzed by H-test, factor analysis, and linear regression. The significance level was determined at the 5% (p-value<0.05) probability level. Results: Early planting of wheat cultivars in October resulted in slower powdery mildew progress and higher yields, with a 12% greater yield compared to November, 70% more than December, and 185% more than January plantings. The highest yield was observed in the first study year (2013-2014). Factor analysis (81% variability) highlighted yield increases with later disease onset, faster disease progress, earlier planting and maturation, favorable weather conditions, and greater genetic resistance to powdery mildew. Conclusion: Such findings advance our knowledge for future attempts in estimating yield for breeding studies and sustainable production.