The Trouble With Talc

Planting can be dusty work, but a little housekeeping is in order to protect pollinators this spring. The continued use of insecticidal seed treatments may depend on it.

The problem is planting lubricants such as talc can mix with minute amounts of the insecticides contained within seed treatments. Bees come into the bargain when contaminated dust blows out of the planter and lands on a flowering plant. Foraging bees carry the contaminated pollen back to the hive.

This may seem a small and potentially obscure sequence of events, but the seed treatment/talc relationship has fueled a movement that threatens use of neonicotinoid insecticides. Growers in Canada have already seen legislated requirements and restrictions. In the U.S., the EPA has made the re-registration assessments of the benefits and risks of neonicotinoid insecticides a priority because of pollinator health concerns.

Ohio State entomologist Reed Johnson and his fellow researchers spent the spring of 2013 collecting pollen from three bee yards in the Ohio counties of Madison, Union and Clark. As farmers in central Ohio started planting corn coated with the insecticides thiamethoxam and clothianidin, the researchers tracked a telling change in the bee's pollen loads.

"We did not see those insecticides in the pollen prior to corn planting or after corn planting," Johnson explained. "We only saw them in pollen during corn planting." Many of the insecticide concentrations in the pollen were high enough to cause a bee kill, he added.

Talc and graphite seed lubricants are recommended by many planter manufacturers to reduce friction among seeds and improve planting consistency. Seed needs to move smoothly through the planter, or it won't be placed uniformly within each row.

NEW AGENT

Bayer CropScience is marketing Fluency Agent, a new planter seed lubricant that helps reduce the amount of dust emissions containing the active ingredient in seed treatments during planting. In laboratory tests, the company said Fluency Agent reduces total dust emissions by 90% and reduces the release of active ingredient by 65% compared to talc.

Growers in Canada who use seed lubricants are now required to use Fluency Agent, and the product is also available in the U.S., but not as widely. "Although full commercial details have not yet been finalized, we remain confident that Fluency Agent will be made available to farmers for the 2015 planting season," said Kerry Grossweiler, Bayer SeedGrowth equipment and coatings manager.

PROVIDING THE PRODUCT

Great Plains Manufacturing, for example, makes the Bayer product available to all of its dealers. However, the bulk of its demand and supply is still with Canadian dealers, said Mike McClure, the product development manager for the company.

"We are primarily selling the talc and graphite mixture seed lubricant to U.S. dealers," he said.

Farmers who use corn seed from Beck's Hybrids might be surprised to discover their seed already contains Bayer's Fluency Agent, said Jim Herr, Beck's processing, inventory and wholesale manager.

After testing the product last summer, the company found a rate of application that improved the flow and uniformity of planted corn seed just as well as talc, Herr said. Since then, it has added that rate to every corn hybrid available for sale in 2015 as part of its Escalate seed treatment. The company is not advertising Fluency Agent as a replacement for seed lubricants just yet.

"We are adding this product, but we're not telling our farmers to refrain from using the normal lubricants that their planter manufacturer suggests," Herr explains. "But we are trying to inform our growers that they are welcome to experiment on their farms without talc. If they're willing, we think it's worthwhile and could save them some time and money, and reduce dust."

(PS/AG)

Copyright 2015 DTN/The Progressive Farmer. All rights reserved.