DCPA (Dacthal) Use in California

Date: Thursday, July 24, 2003
To: Harold Coble
Agronomist, USDA/ARS/OA
Office of Pest Management Policy
From: Rick Melnicoe
Subject: Re: DCPA (Dacthal)

Harold,
There would be serious problems with a number of minor crops in California. Green onions and cole crops rely on DCPA for weed control. Green onions need a good material because young onions are very poor competitors with weeds. Some of the Chinese Cole crops have few, if any alternatives. DCPA was unavailable for awhile and it was a real problem. I am attaching a use report (Excel chart) for 2001 in CA for DCPA so you can see all the crops that use the chemical.

Rick Melnicoe Director, Western Region Pest Management Center
Director, Office of Pesticide Information and Coordination (UC Statewide Pesticide Coordinator)
One Shields Avenue
University of California
Davis, CA 95616-8588
Telephone: (530) 754-8378
FAX: (530) 754-8379

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Response to:

Date: Thursday, July 24, 2003
To: Rick Melnicoe
From: Harold Coble
Subject: DCPA (Dacthal)

I got a call from Jill Bloom of EPA, CRM for DCPA. DCPA is a herbicide used on Cole crops, onions, and some other crops. Apparently there are serious cancer and groundwater issues with this chemical. EPA needs to know if there would be hardships created by cancelling the registration of DCPA. Can you check with the minor crops people in your regions to see what the story is on DCPA use and what alternatives are available and/or used?

Harold Coble
Agronomist, USDA/ARS/OA
Office of Pest Management Policy
320 Scott Hall, Box 7608
N.C. State University
Raleigh, NC 27695-7608
Voice: 919-513-2124
Fax: 919-515-3928