Impact of drought stress on spring wheat grain yield and quality

Drought stress (DS) at different growth stages of spring wheat (Triticum aestivum L.) may affect its grain yield and end-use quality differently. The impact of drought stress at different growth stages on yield has been widely studied, but the impact on grain quality has not been thoroughly investigated. A 2-year field experiment was conducted to evaluate the effects of DS at different growth stages on end-use quality and grain yield in different spring wheat classes (soft white 'Alturas,' hard red 'Coho,' and hard white 'Dayn'). The treatments included DS (from tillering to stem elongation, booting to heading, and anthesis to soft dough) plus a fully irrigated (well-watered) check. We found significant differences between the three wheat classes in most end-use quality parameters. Relative to the well-watered conditions, DS from tillering to stem elongation and from booting to heading did not affect grain yield and most end-use quality parameters. Flour protein, lactic acid and sucrose solvent retention capacities, and mixograph peak time were more impacted by post-anthesis DS. These changes in end-use quality were correlated and, thus, directly or indirectly affected baking performance. Our results indicate that reduced irrigation at early growth stages can maintain grain yield and end-use quality of spring wheat of different classes, for example, grain yield of 437 g m(-2) and flour protein of 13.2-16.4 g kg(-1) across different classes subject to DS at early growth stages compared to 379 g m(-2) and 13.9-17.9 g kg(-1) subject to post-anthesis DS.