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Blending two or more small grain varieties before
planting is a question that is commonly brought up by producers and is actually a production practice for a few in Minnesota and the Dakotas. In Kansas, winter wheat variety blends are currently the fourth leading
variety planted. In the absence of a single variety that possesses all the desirable genetic traits, the idea is to blend varieties to maximize individual strengths and mask weaknesses. A few identified approaches
to accomplish this are; combining high yield and high protein varieties, lodging resistant with susceptible varieties, and disease resistant with susceptible varieties. The idea again is to maximize yield while
limiting quality discounts by artificially increasing genetic diversity. This update is a follow-up on the initial report in the April 2009 Issue of Prairie Grains. The concept of blending is best defined as the
intentional mixing of multiple varieties and seeded across a field in hopes it will outperform the individual components. This would not include spring cleanup dumping when the intent is to use up the remaining seed
at the conclusion of planting. Others have blended at harvest for protein purposes either by combine or at storage. The mixing of the seed for planting can take place with the elevator at the time of purchase or on
the farm. The perceived advantages of this approach include yield stabilization, compensation effect, and reduction in pest pressure. The disadvantages include seed mixing (redone each year), variety incompatibility
(flowering and harvest), and losing the ability to manage each variety separately. Bowden et al. (2001) found that three-way hard red winter wheat blends in Kansas were slightly higher yielding than individual
varieties, displayed more yield stability, and found that those advantages were greatest in adverse conditions. Cowden et al (2008) reported that blends of soft red winter wheat out yielded pure varieties by 3.2%
and were either beneficial or neutral in leaf disease severity. This information along with annual inquiries about the concept initiated our research project.
Our objective was to test whether the reported advantages of blending varieties can be captured with hard red spring wheat in West
Central and Northwest Minnesota. Materials and methods included three testing locations over a two year period (Fergus Falls 2008, Foxhome 2009, and Perley 2009) with three replications at each site. We implemented
two way blends mixed in ratios of ¾ to ¼, 1 to 1, and ¼ to ¾ and compared to pure cultivars. Blend “1” consisted of Faller/Glenn for combining yield and protein, Blend “2” was Bigg Red/RB07 mixed for leaf disease
reaction, and Blend “3” of Rush/Traverse blended for straw strength. It should be noted that our study, as well as previous research selected varieties for blending by targeting compatibility for height and
maturity. To compare blends to pure varieties, we collected data on disease incidence and severity (10 flag and penultimate leaves rated 0-100%), lodging (0-9 scale with 9 flat), grain yield (Bu/A), test weight
(Lbs/Bu), and protein (%).
With two years of data compiled, we have found the following to date; Grain yield, protein, incidence and severity of leaf diseases,
and lodging all responded linearly (I try to clarify linearly at the end of the paragraph) to blending Analysis of grain yield and protein show no pattern that suggests blends were more stable than pure stands.
Thus, there were no advantages to blending hard red spring wheat cultivars to improve performance or reduce variability in comparison to pure stands. Seeding a mix of low protein and high protein varieties achieved
what you would likely achieve if you mixed them in the bin after harvest. A strong straw variety did not help a weak straw variety from lodging. And seeding a 1 to 1 mix of disease resistance with disease
susceptible varieties means you only have half the plants in the field to scout for disease problems, but the “good traits” did not positively influence the “bad traits”.
Our research to date has not yielded the advantages reported in Kansas or North Carolina and is more in line with work done in
Montana with three way blends of HRSW and barley that didn’t show any significant responses on the same measured traits. Researchers in Kansas contribute the positive response of blending in winter wheat to
differences in winterkill, yield compensation, and an extended growing season. We are considering increasing the blending units to three vs two and wonder how extreme growing conditions such as a heat, drought, and
pests need to be before experiencing advantages similar to those reported in other regions can be detected. The question then becomes whether such conditions occur frequently enough to warrant cultivar blending as
an economic option.
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