Developing guidance for wheat variety blends on UK farms

Research suggests that cereal variety blends (mixtures) can potentially deliver a range of benefits (compared to single-variety stands), such as: Increased yield and yield stability (across years and locations) Lessened disease severity Reduced fungicide spray intensity (saving costs and slowing the development of fungicide resistance) Prolonged durability of disease resistance genes However, it is a complex area, which involves numerous genetic and environmental interactions (many of which are currently difficult to predict). The uptake of varietal mixtures is increasing in Europe, most notably in Denmark, where winter wheat blends are now the most common 'variety'. The provision of yield, quality and disease data via its national variety trials provides farmers with the evidence and confidence to try blends. Additionally, Denmark enforces strict limits on fungicide use, which encourages the use of integrated pest management (IPM) to suppress disease. In Denmark, most of the winter wheat crop is used for animal feed (about 90%). In the 2023/24 growing season, the first commercial winter wheat milling variety mixture was authorised (comprising varieties all individually approved for milling-wheat production), which will underpin the use of blends in this market. Although there is some concern that grain from blends may fail to meet uniformity requirements of end-users, there is evidence that grain from mixtures can have equal or superior quality characteristics. Interest in blends has increased in the UK, although no area information is available. The need for robust information on variety blends was identified in the most recent review of the AHDB Recommended Lists for cereals and oilseeds (RL). Prior to the RL review, AHDB started activity in this area, introducing the variety blend tool for winter wheat in 2021, which adds value to RL agronomic data and uses pedigree information. The relatively simple approach used in the tool can help identify three-way or four-way blends. However, it does not account for complementarity of traits of each variety in the blend (the data is from varieties grown as straights, not in blends) - in other words, it does not guarantee that a mix will be greater (or less than) the sum of its parts, but it can identify potentially useful mixes to trial.