Canola producers will have to decide whether to play it safe and avoid using lambda cyhalothrin for any purpose this year
It’s never a good thing when tools go missing, especially when those tools allow you to make a quick fix or avoid a potentially costly mistake.
Prairie grain and oilseed farmers know the feeling well.
Within about the past two years, farmers have lost a few important tools from their crop protection toolbox.
Most recently, those lost tools include lambda-cyhalothrin products (Matador and Silencer), which were widely used for foliar control of flea beetles in canola, and chlorpyrifos (Lorsban), a go-to ingredient for chemical control of wheat midge, grasshoppers, cutworms and bertha army worms.
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Now, pulse growers are also bracing for a potentially costly decision on chlorothalonil (Bravo and Echo), a first-line fungicide that’s used to control Ascochyta in chickpeas.
Lambda-cyhalothrin products (Matador and Silencer) are still commercially available in Canada.
But after a re-evaluation by Canada’s Pest Management Regulatory Agency, their use will be prohibited on many crops effective April 29. Specifically, its use is prohibited on any crops that could be destined for domestic livestock feed markets.
This would presumably include at least some of the canola grown in Saskatchewan, given that much of the canola harvested each year is now crushed domestically and the resulting meal is used in livestock rations.
There are effective alternatives to lambda-cyhalothrin for control of flea beetles in canola.
However, during a recent Keep It Clean product advisory webinar, canola council agronomist Ian Epp said the PMRA decision is challenging for growers and grain handlers.
While lambda-cyhalothrin is prohibited for use on crops that may be sold into domestic livestock feed markets, its use is still permitted on crops that will be exported or used for human consumption or industrial applications, such as biofuel production.
“This is a really challenging decision from the PMRA,” Epp said.
“There’s a lot of interconnectedness in the grain value chain — there’s food, there’s feed, there’s blending, there’s screenings. There’s all sorts of things happening. So it’s really challenging for a grower to know (whether) any crop entering the grain-handling system could be eligible for livestock feed.”
“So this becomes a risk. This could be… an off-label use,” Epp added.
“Not knowing where the (crop) will end up specifically (means that) any product entering the grain-handling system could be turned into (feed), which is, again, challenging for grain-handling companies (and) challenging for growers. It’s a challenging decision for everyone.”
This raises questions about whether canola producers should play it safe and avoid using lambda-cyhalothrin for any purpose in 2023.
The Canola Council of Canada was not immediately available for comment.
Flea beetle spraying can be emotional decision
Alternatives to lambda-cyhalothrin for flea beetle control in canola include products whose active ingredients include carbaryl (Sevin XLR), cypermethrin (Decis), malathion and permethrin (Pounce, Perm-Up, IPCO Synchro, Ambush). These provide control of all pests that can also be controlled using lambda-cyhalothrin, the canola council said in a February statement.
Manufacturers of alternative products are said to be increasing production in anticipation of the lambda-cyhalothrin restriction, so supplies of flea beetle control products are expected to meet demand this year.
SaskCanola has a booklet outlining lambda-cyhalothrin alternatives available here.
The case of chlorpyrifos may be more concerning to farmers in areas that typically face high wheat midge pressure.
Health Canada announced in late 2020 that chlorpyrifos products such as Lorsban would be gradually phased out. Retailers were permitted to sell chlorpyrifos products until the end of December 2022 but retail sales have been banned since Jan. 1.
Farmers who have supplies of chlopyrifos products may use them in 2023 but as of Dec. 31, 2023, the use of chlorpyrifos products will be prohibited.
Chlorpyrifos products such as Lorsban were widely used in Western Canada for chemical control of wheat midge, grasshoppers, cutworms and bertha army worms, among others.
Recent assessments by the PMRA and the U.S. Environmental Protection Agency suggest the chemical poses an unacceptable health risk to other insects and to birds and small mammals further up the food chain.
The removal of chlorpyrifos comes at a difficult time for some western Canadian producers, especially those who are typically affected by wheat midge.
John Gavloski, a provincial entomologist with Manitoba Agriculture, said prairie farmers have effective chemical alternatives for controlling grasshoppers and cutworms.
But losing chlorpyrifos could be problematic for some growers.
“It was probably one of the better products for wheat midge,” Gavloski said.
“It killed the adults but it also killed the eggs, whereas with dimethoate, which is the other product that’s registered for wheat midge, it will kill the adults but not the eggs.”
Gavloski said wheat growers who typically face high wheat midge pressure should consider switching to midge-tolerant wheat varieties.
“Right now, there’s so many of these midge tolerant varieties on the market and really, there is not a yield penalty for using them.”
Chlorothalonil, which includes foliar fungicides such as Bravo ZN and Echo, is another important tool that could go missing from the farmer’s tool box.
Chlorothalonil is being be re-evaluated by the PMRA and a decision is expected soon.
“Domestically, here in Canada, the PMRA did come out with a proposed re-evaluation decision a couple of years ago where they were proposing to cancel chlorothalonil, which would be extremely devastating for chickpea growers,” said Greg Bartley, director of crop protection and crop quality with Pulse Canada.
“We’re still waiting on the PMRA to provide their final decision on this product and we continue to hope for a positive outcome….”
