Planting soybean seeds with a neonicotinoid seed treatment offers zero yield benefits, says the U.S. Environmental Protection Agency.
In a memorandum released Oct. 15, EPA’s biological and economic analysis division reviewed published data and EPA proprietary data on soybeans and neonicotinoids, a class of insecticides applied as a coating to the seed. The EPA determined the benefits of neonic seed treatments are the same as doing nothing.
“This analysis provides evidence that U.S. soybean growers derive limited to no benefit from neonicotinoid seed treatments in most instances,” EPA scientists and economists noted in the memo.
“Published data indicate that most usage of neonicotinoid seed treatments does not protect soybean yield any better than doing no pest control.”
The Ontario Beekeepers Association said the EPA report validates its position, which is that the Ontario government should limit the use of neonicotinoids.
“The EPA study is more evidence that pesticide manufacturers are operating irresponsibly,” said OBA vice-president Tibor Szabo.
“By pre-treating seed with pesticides, farmers pay for their product whether they need it or not. The loss of our insect pollinators is the price we pay for their profit.”
Neonics, which are applied as a seed treatment to almost all of the corn and canola in North America and a portion of the soybeans, have been linked to bee colony losses across the United States and Canada.
In September, two Ontario beekeepers filed a class action suit against neonic manufacturers Syngenta and Bayer Crop Science, claiming $450 million in bee colony, pollination and honey production losses dating back to 2006.
The OBA has repeatedly said that neonics offer minimal to no yield benefit because the insecticides are applied to seeds regardless of the level of insect pressure in the field.
“This (EPA) finding confirms the Ontario Ministry of Agriculture, Food and Rural Affairs’ own crop specialists’ observations that only 10 to 30 percent of corn, soy and winter wheat acreage actually need some form of assistance for pests,” the OBA said in a news release.
The EPA said neonic seed treatments are ineffective against the major soybean pests in the U.S.: soybean aphids and the bean leaf beetle.
“This is because the limited period of (neonic) bioactivity in soybeans (three to four weeks) does not usually align with periods of soybean aphid presence/activity,” the EPA report said. “Similarly, neonicotinoid seed treatments are not effective in controlling bean leaf beetles as this pest occurs too late in the season.”
EPA scientists said thiamethoxam and imidacloprid, two widely used neonic seed treatments, cost farmers about $7.50 an acre.
The agency said soybean growers would be wiser to skip the neonic seed treatment and apply an equivalently priced foliar insecticide, when needed.