Effects of genotype, weather, and select pesticides on flour quality, gluten strength, and protein composition of hard red spring wheat in Western Canada

The impact of crop management practices on wheat quality and gluten strength has received relatively little attention in the literature. The main objective of this study was to evaluate the effects of two widely used pesticides (fungicide and glyphosate) and their interactions with growing conditions and genotype on the leading commercial class of wheat in Canada. Six Canada Western Red Spring (CWRS) wheat varieties were grown in replicated field trials at four locations across the Canadian prairies over three growing seasons to capture a wide range of environmental conditions. Four pesticide treatments comprised a control (untreated), prothioconazole/tebuconazole fungicide applied at anthesis to mitigate effects of Fusarium head blight (FHB), glyphosate applied at physiological maturity, and application of both fungicide and pre-harvest glyphosate. Basic milling quality of samples was evaluated and gluten strength was assessed by dough mixing and gluten protein composition. Increasing level of precipitation was associated with reduced gluten strength based on dough properties and reduced content of high molecular weight polymeric glutenin and could be the effect of higher Fusarium damaged kernels (FDK) in wetter growing seasons. Siteyear and genotype were the most significant factors affecting all quality parameters. In contrast, pesticide treatments had minimal or no effects and were not statistically significant for any dough mixing or protein quality parameter. Thus, when used at recommended rates and timing, the pesticide treatments were not significant sources of variation of gluten strength for CWRS wheat. In contrast, growing season weather and wheat genotype were much more important factors.