SASKATOON — May and June showers bring not only flowers, but sclerotinia stem rot.
And with a wet spring in many parts of the Prairies, canola growers could be in the market for large volumes of Benlate, the only registered anti-sclerotinia fungicide.
The company that makes it is scrambling to ensure there is enough product available to avoid the kinds of shortages that have been reported for other canola pesticides like Muster.
“We are monitoring the orders that distributors have placed very closely and linking those to our plants in the U.S. for production,” said Dupont Canada Inc. oilseeds manager Brian Toole last week. “We have production occurring as we speak.”
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He said it’s hard to predict the demand for a product like Benlate, since the incidence of sclerotinia is so dependent on weather conditions. Nevertheless the company is expecting “a fair demand” this year.
Nick Underwood, crop production co-ordinator for the Canola Council of Canada, said because it has been quite wet in some parts of the Prairies, producers, especially first-time growers, should familiarize themselves with the signs of sclerotinia and be prepared to take action.
Manitoba worst hit
“I will be very surprised if we don’t get quite a bit of disease pressure, in southern Manitoba for sure and also around the Fort Saskatchewan (Alta.) area,” he said.
Sclerotinia spreads via a fungus which uses canola petals as an initial food source, then infects leaves and stems. The disease develops when soil and foliage are moist for 10 days prior to flowering.
If left unchecked, yield losses can be significant and given current prices, that can hurt.
“I was certainly aware last year of a number of fields that were not sprayed that would have probably been suffering 10 to 30 percent yield loss or maybe even more,” said Underwood. “If you’re looking at a third of the value of the crop, you’re talking big bucks.”
Spraying with Benlate when 20 to 30 percent of the flowers have opened delays the disease development for about nine days, long enough to ward off a full-blown infection.
Farmers can test for the presence of the fungus by using a petal test kit available from the University of Saskatchewan, although supplies are running out fast.
Can’t meet demand
“Demand has been tremendous. We can’t keep up,” said biologist Robin Morrall, who developed the patented testing process.
The university has already sold more than 800 of the kits this year, more than ever before. Many of them have been bought by agricultural service companies that perform the tests for a fee.
Orders are backed up and if conditions are favorable for the disease, it’s likely some farmers won’t be able to get the kits. However, Morrall said demand could drop off considerably if it’s hot and sunny at the end of June and beginning of July. (For more information about the kits, phone 306-966-4425.)
