Managing fusarium in cereals

Fusarium head blight (FHB) is a fungal disease of wheat (including durum), barley, oats, other small cereals grains and corn. On cereals, it is recognized by premature bleaching and salmon-coloured fungal growth on the heads of crops it has infected. FHB reduces yields, decreases grain quality and may limit crop marketing opportunities.

When FHB infects cereal crops, it can produce mycotoxins such as deoxynivalenol (DON), commonly known as vomitoxin. As most importing countries have strict maximum limits of DON in grain, the presence of DON restricts the grain’s end uses and marketing potential. Shipments that exceed acceptable levels of DON could be rejected at tremendous cost to the industry and may impact Canada’s reputation as a producer of high-quality cereal grains.

To help keep marketing options open for your harvested grain Keep it Clean recommends the following best practices to manage FHB:

Plan crop rotations to manage fusarium. Fusarium can overwinter in crop stubble. It is crucial that you plan crop rotations that allow adequate time for residues to decompose before returning to cereal crops. Rotate away from cereal crops for at least one — and preferably two or more — years on fields recently infected by FHB. Keep in mind corn is also infected by Fusarium and should be considered if you have corn and cereals in rotation.
Grow varieties with the highest FHB-resistance available. Growing resistant varieties is one of the most important decisions in managing the disease. The use of resistant varieties is especially important in areas at risk for FHB. Cereals also vary in their susceptibility: durum is the most susceptible to FHB, barley is less susceptible than wheat and oats are the least susceptible cereal crop.
Establish a strong stand by using high quality, vigorous seed and appropriate seeding rates. If possible, time seeding so that the crop will not be at a susceptible stage (flowering, early kernel development) during warm, humid weather.
Scout for stage, not symptoms, to know when the crop is susceptible to FHB infection. The risk of fusarium infection increases when hot, humid, or wet conditions persist during head emergence and flowering.  
Apply fungicide when there is an elevated risk of FHB. If there is risk of FHB, follow the label when applying fungicide. Timely application of foliar fungicide with a specialized nozzle or nozzle combination for maximum head coverage can help protect crops from FHB at critical stages. Make use of the provincial-specific materials available, including risk maps, to help assess risk and inform your decisions.
During the summer months, risk maps for the Prairie provinces can be found here:

• FHB Risk Mapping Tool
• Alberta FHB Risk Map
• Saskatchewan FHB Risk Map
• Manitoba FHB Risk Map

If FHB is identified, send samples of harvested grain for testing to detect the presence of mycotoxins. Mycotoxins, such as DON, can limit the end-use of your harvested grain. Contact your grain buyer to discuss your marketing options. At harvest, use a higher combine wind speed to help separate the lighter, damaged kernels. Finely chop straw and chaff, spreading it evenly to accelerate break-down.

Applying best management practices can reduce and limit the spread and severity of fusarium outbreaks. Growing disease resistant varieties, applying fungicides and rotating crops may have the highest impact.

Managing disease pressures is one of 5 Tips to keep your crops ready for market. By limiting the spread and severity of FHB in the field, you can protect your investment and help keep marketing options open for cereal grains.