Stripe rust: have you checked your wheat?
The concerning disease threatens wheat yields in southern Ontario
By Jennifer Jackson
Stripe rust is back in Ontario’s winter wheat, ahead of its typical schedule. In fact, agronomists found the disease in wheat, two weeks earlier than found in spring of 2016, according to Emma Epp, agronomist for Cargill.
Epp scouts in Essex County and south Kent, where in past years the disease made its appearance once the crop has reached maturity and did not significantly affect yields; 2016 was an exception.
“Last year, (stripe rust) infected the plants before flag leaf (emergence),” she said. “We saw yield losses around 50 per cent for those that did not spray fungicide.”
Stripe rust blows in from the southern U.S. with seasonal winds. The warmer U.S. winters in the past couple of years contributes largely to the prevalence of the disease, says Epp. The mild weather allows stripe rust to overwinter further north in the U.S.
In her territory, Epp and her coworkers found evidence of stripe rust in Stoney Point, Tilbury and Princeton – some cases are awaiting testing confirmation.
The disease is very distinctive in wheat, according to Epp. Infected plants will display bright orange pustules in stripe formations on the leaves – typically in the top of the canopy.
Photo: Emma Epp
As warm – yet wet – weather occurs in southern Ontario, producers may find more cases of stripe rust develop.
“Its very important to get (out and scout) and know what you have out in your field,” she says. “The T2 (flag leaf) stage will be over soon, if not over already – we need to move onto a T3 (heading) fungicide.”
In 2016, farmers who sprayed early after finding the disease in their wheat saw approximately 20 per cent yield loss, says Epp. Those who sprayed proactively prior to disease pressure on average experienced near 0 per cent yield loss to disease.
In addition to stripe rust, the warm and wet weather is inviting other unwanted cereal diseases. Farmers should keep an eye out for powdery mildew and fusarium, according to Epp. The best way to defend your crops from disease induced yield loss starts by getting out in the field.
“It’s important to identify what you have in the field,” says Epp. “You need to be proactive and not reactive.”