Producers must avoid planting seed that is infected with F. graminearum. The seed of susceptible crop species must be tested by a seed testing laboratory and only seed with non-detectable levels of F. graminearum is to be used for seeding purposes.
Although infected seed can cause seedling blight, it typically does not directly give rise to head blight symptoms in one growing season. The fungus will move from the infected seed to the root, crown, and stem base tissues of the plant that develops from the infested seed, thus creating potential sources of infested residue that can impact subsequent crops. The buildup of the pathogen would typically be favoured by the production of successive host crops and favourable weather.
To help slow down the buildup of infested crop residues a crop rotation away from cereals to non-hosts, including canola, pulses, and forage legumes should be considered for at least 2 years. This will allow enough time for the infested residue to decompose before the next cereal crop is seeded.
Using the least susceptible varieties will help to reduce the risk of fusarium head blight and perhaps the potential for buildup of F. graminearum. For more information on FHB reactions of registered cereal varieties see the Varieties of Cereal and Oilseed Crops for Alberta document.
Producers growing small grain cereals under irrigation may be able to reduce the risk of head and seed infection and mycotoxin contamination by careful water management and integrating this with crop rotation, choosing a resistant variety if available, and using fungicide if warranted. If possible, irrigation should be avoided during the flowering period to help prevent humid conditions that favour infection. In addition, it is recommended that producers consider increasing seeding rates, which helps to reduce tiller formation and shorten the flowering period for the entire crop, thus reducing the time that irrigation should be avoided. For further information on using irrigation management to minimize FHB, see the ARD Factsheet.
In-crop fungicide application may be considered, but may only provide suppression of the disease at best. Application before infection, as well as sprayer and nozzle settings, will be critical. Consult provincial chemical guides and extension publications for more information.