Fusarium head blight (FHB) is a big concern for wheat growers each season, but some years, like 2020, the risk is incredibly high for a huge portion of the Prairies.
The provincial FHB risk maps were lit up red and yellow for much of the growing season until about now. For many, early August may be too late to spray a fungiide, but it’s important to scout after the fact, says Jeremy Boychyn, agronomy research extension specialist with Alberta Wheat and Barley Commissions.
“Most of anthesis has already occurred in western Canada, we did have some high risk areas in Alberta and Saskatchewan, so we did have some spraying going on,” says Boychyn. “Hopefully some of the varieties that some of the producers are using has some level of resistance, and then with an application we’re hopefully mitigating some of that risk of fusarium,” he adds. (Story continues below video)
But even with a fungicide application, and a resistant variety, you won’t get full control of FHB.
The severity of symptoms of the disease will depend on when infection occurred and when the spikelet got infected with FHB. Generally, you’re looking for premature bleaching throughout the head, but it can appear at the top, the middle, or on the bottom spikelets of the head. Under wet or humid conditions, spikelets can be salmon pink to orange coloured, too. The severity of infection all depends on the number of spores that were present at infection.
“If you’re seeing it in the fields this year, it means you’re going to have those spores in the field which will be a risk for next year,” says Boychyn.
Different fields will have different maturity times, which means FHB can be managed according to infection severity and maturity timing. There are some things farmers can do to decrease incidence or severity of the disease in the grain, such as upping the combine fan speed to blow “tombstone” kernels out the back.