Chemical companies concede fungicides have their limitations

Posted on 2017-04-07
Producers cannot control fusarium head blight with fungicides alone, say spokespeople for Bayer CropScience and BASF.

Cereal growers in Western Canada should be using a diverse array of tactics to keep fusarium in check because a single strategy will not work.

“Growers need to implement integrated practices for fusarium, especially once fusarium becomes endemic in a certain area,” said Jared Veness, field marketing manager with Bayer CropScience. 

“This particular pathogen is difficult to control…. If you use just one component of an integrated approach, the probability of good results is (limited).”

Last summer was a wet and horrific growing season in Western Canada for diseases in cereal grains, including fusarium.

Veness said spraying the crop with fungicides does protect cereal crops from fusarium damaged kernels and deoxynivalenol (DON), a mycotoxin caused by fusarium. 

However, Bayer testing of its Prosaro fungicide shows that the product can only do so much.

“In terms of reducing DON or FDK, you get about 55 percent reduction,” Veness said.

That means cultural practices, such as longer crop rotations, using the most resistant varieties and appropriate seeding rates are critical for fusarium control.

Glen Forster, a BASF technical specialist for fungicides, said fungicide is an important tool for fusarium management, but there’s more to controlling the disease than spraying with a BASF product such as Caramba.

“You have to take a look at fus-arium from seeding to right to harvest,” he said, which means having a strategy before the crop goes in the ground. 

One tactic is increasing the seeding rate, so most of the field flowers at the same time and makes a fungicide application more effective.

Organic producers may be using more strategies to control disease because anecdotal reports suggest that fusarium wasn’t a significant problem for organic growers in Saskatchewan last year.

Forster said the organic philosophy of “many little hammers” might have some merit in conventional production.

“I think the many little hammers analogy is good,” he said. “When you think of fusarium, it is about the entire disease triangle. The pathogen is only one thing. Host and environment (are also factors).”

Another risk reduction tool could be seeding date. Rather than seed all cereal crops at the same time, growers might consider an early and later date.

Veness said organic growers tend to seed later, and their cereal crops might have flowered at a time when fusarium risk was lower.