Fusarium head scab continues to be one of wheat’s most costly diseases. Its most significant impact is that it often leads to the creation of a mycotoxin called DON. Both soft red and soft white wheat growers experienced the disease during the 2013 season and some incurred a price discount because of excessively high DON levels. Michigan State University Extension recommends growers plant varieties that show at least some level of tolerance to the disease.
All popular varieties grown in Michigan are considered to be susceptible to head scab. However, there are differences in the level of susceptibility. When estimating a variety’s susceptibility, the best references are the results of DON testing when they are available. The second best indicator of susceptibility is the variety’s scab index, which is a rating based on the incidence and severity of the disease.
To express differences in levels of susceptibility, varieties might be categorized as being susceptible, moderately susceptible or moderately resistant, or they may be assigned a relative numerical ranking. The ranking of varieties commonly grown in Michigan can be found within the Michigan State Wheat Performance Trials report (see Table 3). Perhaps a more user-friendly reference is the “Susceptibility of wheat varieties to common diseases” fact sheet.” Here the author has combined the results from DON testing and MSU’s disease index to arrive at a relative numerical rating.