Before this brief cold wet weather some planting got started over the last week in some areas. The warmer weather had brought spring on into full bloom including dandelions, coltsfoot and some trees including maples, willows, popular and even fruit trees. With the flowers come the bees to forage, setting up the potential for the interaction of bees and neonicotinoids during planting again this year. We need to do our best to minimize the risk of bee exposure to contaminated dust during planting or “dust drift”.
Dust drift is a real issue. Published research conducted here in Ontario over the last three years has quantified the neonic residues escaping from vacuum planters during corn planting. Contaminated dust from treated seed is being rubbed off and distributed into the air via the vacuum planter manifolds. This dust drift gets blown outside of the field, onto the nearby flowering resources that bees are relying on this time of year.
What Growers Can Do to Mitigate Dust Drift at Planting Include:
- Use fluency agent – Only a dust-reducing fluency agent is permitted with corn or soybean seed treated with neonicotinoid insecticide. Talc and graphite are not permitted to be used as a seed flow lubricant for corn or soybean seed treated with these insecticides.
- Use deflectors – Install equipment to direct exhausted air from the planter vacuum fan towards the ground.
- Communicate with beekeepers – Let local beekeepers know when you intend to plant, as well as beekeepers let growers know where their hives are so they know which locations are at risk. If notified in time, beekeepers can take action to temporarily protect or re-locate their hives.
- Consider conservation tillage – Reduce soil movement/erosion during spring field activity. Soil can contain neonic residues that can also blow onto foraging resources.
- Practice Integrated Pest Management – Use insecticide treated seed only in fields that need protection because of high risk factors or that have a history of soil insect issues. Growers planting neonic treated corn or soybean seed are required to follow the requirements for neonicotinoid-treated corn and soybean seeds under the Pesticides Act.
- Manage in-field flowering weeds – ensure blooming weeds are controlled prior to planting to keep bees from foraging within fields and pay particular attention to flowering trees and plants that are downwind from the field. Dust drift can be carried more than 100 meters from the field, depositing the residues onto these flowering resources
Other initiatives under way to minimize dust drift:
- Polymers – Placing a finishing coat on the seed during the treatment process can stop products from rubbing off during planting. Efforts are underway by the University of Guelph Ridgetown Campus, the Canadian Seed Trade Association and polymer developers to find the correct polymer and rate that achieves this goal.
- Providing clean air going into the manifold – Results from University of Guelph Ridgetown Campus has identified that dry soil from the field is also being sucked into the planters through intakes just under the seed hoppers. This dust is also contributing to the abrasion of the seed. Research is underway to design effective filters to deliver clean air into the planters. Information on these filters will be made available as soon as possible.
Much research and collaboration is still underway by Dr. Art Schaafsma at the University of Guelph Ridgetown Campus to mitigate the dust drift issue. The goal is to completely mitigate dust drift during planting through the use of filters, seed polymers and by encouraging IPM and conservation tillage. Until all of the solutions are readily available, growers need to be proactive at managing dust drift during planting to reduce the risk to pollinators.