Field Blending of Hard Red Spring Wheat Cultivars.

The blending of hard red spring wheat varieties at planting continue to be of interest to producers as a means of maximizing genetic diversity and capturing high yield potential, good quality characteristics, and lodging resistance not commonly found in a single, geographically adapted cultivar.  The idea of purposely blending varieties of wheat is more than 50 years old and first proposed and tested to reduce the impact of stem and leaf rust.  Recent research in Kansas (Bowden et al. 2001) and North Carolina (Cowden et al. 2007) indicated a number of winter wheat blends displayed slight yield advantages and stability than that of individual cultivars.  The North Carolina group also found blends neutral to beneficial for incidence and severity of diseases.  We initiated a blending study in Minnesota with the objective of validating the reported advantages in hard red spring wheat using regression analysis rather than means separation.  Traits of interest were grain yield, grain protein content, lodging, and incidence of leaf diseases.  Cultivar blends of Faller/Glenn, Bigg Red/RB07, and Rush/Traverse are seeded and evaluated in ratios of 1:1, 1:3, and 3:1.  Initial analysis of the data indicated that for grain yield, the response to blending was linear for all three blends and therefore additive in nature.  Similarly, the response for grain protein, test weight, and lodging was linear for all three blends.   Two of the three blends displayed a significant slowing of leaf disease infection with the increase of the more resistant cultivar.  Initial single year results suggest there is little to no incentive to blend varieties to create yield advantages or improve grain protein that cannot be accomplished by growing two adjacent pure stands.