Proposed Cancellation of MSMA Use on Turfgrasses 

Tim Murphy, UGA Extension Weed Scientist

On August 10, 2006, EPA issued a notification that “all uses for MSMA, DSMA, CAMA and cacodylic acid (organic arsenical herbicides) are ineligible for reregistration.” EPA’s primary concern is the potential for applied organic arsenical products to transform to a more toxic inorganic form of arsenic in soil with subsequent transport to drinking water. The Reregistration Eligibility Decision (RED) document that discusses this decision may be accessed at: 

http://www.epa.gov/oppsrrd1/REDs/organic_arsenicals_red.pdf 

If this decision stands, these herbicides will no longer be available for use in cotton and turfgrasses. When EPA announces decisions of this type, it solicits comments from the public for a 60 day time period. I encourage you to send your comments on this decision to EPA no later than October 10, 2006. Comments can be mailed to EPA or submitted at the following website: 

http://www.epa.gov/fedrgstr/EPA-PEST/2006/August/Day-09/p12905.htm 

Directions are given at this website on how to submit either mailed or electronic comments. 

MSMA and DSMA have been, and are still very important herbicides for weed management in turfgrasses. Since the 1950s, these organic arsenicals have been the “backbone” of postemergence grass weed control in bermudagrass (/Cynodon dactylon/) and zoysiagrass (/Zoysia/ spp.) turfgrasses with miscellaneous uses in certain cool-season grasses such as tall fescue (/Festuca arundinacea/)/. /Fortunately, for most turfgrasses, alternatives have been introduced in recent years. However, for bermudagrass, no comparable substitute for the organic arsenical herbicides is available to control dallisgrass (/Paspalum dilatatum/), thin (or bull) paspalum (/Paspalum setaceum/), vaseygrass (/Paspalum urvillei/), foxtails (/Setaria/ spp.) and fall panicum (/Panicum dichotomiflorum)/. In addition, the organic arsenicals also control many annual sedges (/Cyperus /spp.), Kyllinga species (/Kyllinga/ spp.), and a number of annual broadleaf weeds. 

Dallisgrass is considered the most troublesome perennial grass weed in warm-season turfgrasses and tall fescue. To date there is not a suitable alternative available for control of this weed. Registration cancellation of the organic arsenical herbicides places an undue hardship on golf course superintendents and turfgrass managers attempting to control a weed that severely lowers the value of his/her property. Superintendents and turf managers are under enormous pressure to provide acceptable conditions as their employers/customers have little patience or sympathy of the perceived “excuse” that a vital tool has been withdrawn from the market. Without the organic arsenicals no selective herbicide will be available to control dallisgrass and numerous other weedy grasses. The only options will be spot treating with a non-selective herbicide such as glyphosate or hand removal, both of which are unacceptable alternatives in most turfgrasses.

NOTE that the University of Georgia Cooperative Extension Service is not taking an official position on this decision. However, I encourage you to send your comments to EPA on how this decision will affect your ability to control various problem weeds in turfgrasses.

Dear Membership,    Attached is a scholarship opportunity from Aquatrols for "children of turf management professionals" that our board member, David White, thoughtfully forwarded to me. I know if any of you have children in college you will be interested in this. Look forward to seeing you at the Annual meeting on Tuesday! Melanie Bonds      205/967-0397

Dear Members,

Thank you,      Melanie Bonds