By Ashley McFarland
Fusarium head blight, commonly referred to as head scab, can be a disastrous disease to high-quality malting barley production in Midwest climates.
One of the predominant reasons malting barley production is concentrated in the arid, western states is the disease Fusarium head blight (FHB), also referred to as head scab. This disease thrives in humid climates throughout the Midwest and can lead to decreased yields and quality of malting barley. FHB leads to the development of mycotoxins in the kernels - specifically, deoxynivalenol (DON) is measured for quality. This is also common in wheat. Levels over 1 ppm in barley grain often lead to rejection by malthouses because of potential human health concerns and the phenomena known as gushing, or the excessive foaming of beer. Although the disease can rarely be avoided altogether, steps in prevention can be taken to alleviate yield and quality degradation in the grain.
The first noticeable symptom of FHB is bleaching of some or all of the grain spikelets while the remaining head is healthy and green.
Martin Nagelkirk, field crop educator for Michigan State University Extension, has developed guidance for management of FHB in malting barley, which can be accessed at the MSU Extension malting barley website. The fact sheet outlines ways to prevent FHB from occurring, which includes selecting varieties that exhibit levels of resistance to the disease; using appropriate crop rotations to avoid following other grass crops, including corn, that can host the disease; and finally, employing an aggressive fungicide program that follows strict timing and application guidelines. Suggestions made by Nagelkirk are well supported by the MSU Upper Peninsula Research and Extension Center‘s research on fungicide use in malting barley, conducted in 2013.
Head scab is a growing issue in Midwest states, as malting barley re-emerges in these minor growing regions. In response to consumers demanding use of more localized ingredients, even in the beer they drink, the industry has responded with a resurgence of local craft malthouses that process the raw malting barley grain into a form that is usable by brewers. They are seeking out high quality malting barley free of DON, which at times can be very difficult to source. Proper management of Fusarium head blight is going to be a critical element to the local craft movement, especially throughout the eastern U.S.