Seed agent reduces dust concerns

Neonicotinoid use | New product replaces talc and graphite used to seed corn

Bayer CropScience says a new seed fluency agent designed to reduce the amount of insecticide-laden dust emitted from corn planters will be available for growers next year.

The product is a replacement for talc and graphite, which seed companies have used for years to help irregularly shaped corn flow through planters.

The new agent is needed because widespread bee deaths in Ontario and the U.S. Midwest have been linked to insecticide contaminated dust from corn planters during spring seeding.

Almost all of the corn seed in North America is coated with a class of insecticides called neonicotinoids, which protect the corn from insects and soil-borne pests.

Research suggests neonicotinoids are toxic to bee colonies, and this year the federal Pest Management Regulatory Agency concluded the insecticide was responsible for killing bees at hundreds of bee yards in Ontario in 2012 and 2013.

Consequently, the PMRA announced in September that “the use of neonicotinoid treated corn and soybean seed are not sustainable.”

In the same document, PMRA scientists recommended the use of safer seed flow lubricants to reduce dust emissions from planters and the likelihood of bee kills.

Bayer said laboratory tests show the new agent, which is a polyethylene wax substrate, reduces planter dust by 90 percent.

It posted a video on its website in November featuring positive testimonials from North American farmers who used the new fluency agent in field trials this year.

The video also said the new lubricant reduced the amount of insecticides in the dust by 60 percent.

A Bayer spokesperson said the amount of active ingredient in the dust wasn’t reduced by 90 percent because only a portion of dust contains insecticides.

“When compared to the amount of total dust that is generated during corn seed planting, there is a much smaller fraction of dust containing active ingredient because of the binders that are used in the seed treatment application,” she said.

“Total dust is measured by physically weighing the dust as it is emitted by the vacuum meter, including organic seed-related dust and planter lubricant-related dust. This is independent of any potential seed treatment-related dust, where the amount of active ingredient is determined using chemical analysis.”

The Ontario Beekeepers’ Association (OBA) and a coalition of other groups, including the Sierra Club, have said a new fluency agent for corn and soybean seed will not protect bees from neonicotinoids.

Tibor Szabo, a beekeeper from Moffat, Ont., and OBA vice president, said he’s tired of the focus on dust at seeding time. Instead, he wants more research on the systemic environmental risks associated with neonicotinoids.

“Has anyone ever actually traced all of the neonics found on dead bees, stored pollen and water sources to the dust at planting time? Is there any real evidence to support this assumption?” he said in an email. “Since 80 to 90 percent of active ingredients do not enter the target crop and that (neonics) are persistent and water soluble, it seems to me that this source is more likely at the core of a number of bee losses…. This selective concentration on one aspect (dust)… serves only to limit discussion and the development of appropriate science-based policy and responsive programs.”

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