Assessing variety mixture of continuous spring wheat (Triticum aestivum L.) on grain yield and flour quality in Northeast China

Wheat (Triticum aestivum L.) variety mixtures represent a relatively unexplored avenue for maintaining yield and improving flour quality. A field experiment was conducted to examine the responses of three spring wheat varieties in pure variety and in variety mixtures under continuous cropping in Northeast China. Three modern spring wheat varieties, along with a three-variety mixture and a two-variety mixture of equal proportions, were planted during the growing seasons of 2006 to 2009. The mixtures were chosen mainly to have complementary traits of yield potential and grain quality. Wheat yield was not affected by continuous cropping but by growing conditions, varieties and variety mixture. Yield stability of 3-variety mixture exceeded that of the pure varieties. The 3-variety mixture consistently out-yielded the means of the respective components (mid-components), with a mean advantage of 0.17 t ha-1 over the different growing conditions. Variety mixture offers greater yield advantages over lower-yield but good-quality variety and improves dough rheological properties and some chemical properties over the higher-yield variety. The 1:1:1 variety mixtures have greater environmental plasticity and potential application in improving flour quality than pure varieties and are therefore recommended for use to Northeast China’s wheat growers even in the absence of severe disease.