Comments Invited on Use of Vydate® L on Onions

Release Date: April 25, 2019

​Media Contact:  Donna Gilson, Communication Specialist, (608) 224-5130

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MADISON – Members of the public may comment through Thursday, May 2, on a proposed special registration that will allow use of an insecticide to control insects and nematodes on dry bulb onions.

The special registration by the Wisconsin Department of Agriculture, Trade and Consumer Protection will allow growers to use Vydate® L on onions. The product is not otherwise labeled for use on onions in Wisconsin. It is a restricted-use product, meaning that it must be applied by a certified pesticide applicator.

Vydate® L contains the active ingredient oxamyl and is registered with the U.S. Environmental Protection Agency by DuPont Crop Protection. It has previously been used in Wisconsin under special registration, which expired Dec. 31, 2018. It is also used in several other states for pest control in onions.

Onion thrips are insects that drain plant cells by sucking on them, stopping photosynthesis and killing plant tissue. Nematodes are microscopic worm-like parasites that reduce root growth even when present in very low numbers. Onion growers need a range of pesticides to prevent thrips and nematodes from becoming resistant to the chemicals. Vydate® L is the only product to control nematodes that can be applied both at planting and after the plants have developed foliage.

The preliminary environmental assessment indicates that the proposed registration will not require a full environmental assessment. This special registration will expire Dec. 31, 2023.

For a copy of the assessment, contact Alyssa Foss, DATCP, P.O. Box 8911, Madison, WI, 53708-8911, (608) 224-4547, email It is available for review at the department Monday-Friday, 7:45 a.m.-4:30 p.m., 2811 Agriculture Dr., Madison, second floor. Comments received on or before 4:30 p.m., May 2, will become part of the preliminary environmental assessment record. Send comments to Alyssa Foss by mail at the above post office address or email address. 

The special registration process allows states to register additional uses of pesticide products without prior federal approval. It helps growers address local pest problems that cannot be adequately controlled by any available federally registered product. These problems include insect outbreaks, fungal diseases, and grasses and weeds that outcompete crops. Details about the special registration process are available here.


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