Mixing varieties can have many benefits. We know that different varieties carry different traits and levels of resistance to diseases.
According to FranceAgriMer, there has been an increase in the use of mixtures in bread-making wheat. In 2020, 12% of the crop was grown as a mixture, up from 5% in 2017.
A number of Irish farmers are mixing varieties quite successfully. Where varieties are mixed, the difference can be quite pronounced, with one disease clearly visible on one plant and not on the next.
This can reduce disease spread and can help to reduce fungicide application rates. However, varieties grow and mature at different rates, so this can make it difficult to apply certain products like plant growth regulator at the optimum time, for example, or at harvest, some varieties may be ripe before others.
The Agriculture and Horticulture Development Board (AHDB) has released a tool to help farmers to decide what varieties to mix.
Bastian Brak has used data from the recommended lists to build a variety blend tool for winter wheat.
The tool allows for three and four-way mixes to be developed.
“For the selected components, the tool simply adds together the associated values and divides the total by the number of varieties in the mix – the bigger the average score, the potentially stronger the mix,” Brak explained.
While many of the diseases carry values from 1 to 9, some of the other traits like Hagberg Falling Number have larger values and the tool converts these into a score from 1 to 9.
If you’re considering mixing varieties, make sure to check that the buyer will accept a mixture. Brak also notes that the data from the recommended list used in the tool is based on single varieties, so interactions between varieties are not taken into account.
The tool can be viewed on the AHDB website.