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517-355-0271 Ricardo Jones Chemical Review Manager Risk Management and Implementat ion Branch I (RMIB 1) Pesticide Re-evaluation Division (PRD) Office of Pesticide Programs US Environmental Protection Agency

Dear Mr. Jones October 5, 2014

This a letter to support maintenance of the current recommended application rates for Chipco Signature (fosetyl-Al), which currently is applied twice monthly, or at a rate of 17.6 lbs active ingredient (AI) per acre per month. My understanding is the EPA is looking to reduce the amount of fosetyl-Al. Since most turfgrass managers ar e well aware of the fact that other phosphite products, sold as fertilizers, can substitute for Chipco Signature, there would be an increase in the use of unregulated phosphite products if fose tyl-Al were rendered ineffective due to low application rates. Would it not be better for the EPA to have some control on the amount phosphite products used for disease control as is the case with Chipco Signature?

I find it hard to understand the EPA re commendation for reduction in the use rate of Chipco Signature. The product is, in reality, a phosphite. It has low mammalian toxicity and low environmental impact. It is also primarily used on putting greens, whic h normally amounts to around 2 1⁄2 acres of an entire golf course.

Chipco Signature is one of the ma instays of many disease and plant health programs on golf putting greens. Whereas the fosetyl-Al has a direct effect in controlling Pythium blight, caused by Pythium aphanidermatum, it has also been shown to provide the plant with induced systemic resistance (ISR). This allows for other fungicides to be used at lower rates or extended applic ation intervals thus reducing the environmental impact of more toxic fungicides. Chipco Signature also contains a green pigment that reduces the stress on the turfgrass plant. By reducing the stress on the plant, it makes the turfgrass plant healthier and less likely to be susceptible to mi nor diseases. This can also reduce the fungicide load put into the environment.

Fungicide resistance is becoming huge problem on golf courses for important diseases like dollar spot, caused by Sclerotinia homoeocarpa

, and crown rot anthracnose, caused by Colletotrichum cereale

. S. homoeocarpa has become resistant to the benzimidazole, dicarboximide
and DMI chemistries of fungicides while C. cereale has become resistant to the benzimidazole, QoI and DMI cla sses. Of these chemistries, onlythe DMI chemistries can still be us ed for these diseases because the resistance expressed to the DMIs is a shortening of the interval of control. This requires the DMI fungi cides to be applied more frequently and, often times at higher rates, to achieve adequate control. There is also resistance to mefenoxam by the Pythium blight pathogen, Pythium aphandermatium, which Chipco Signature effect ively controls at current application rates. There has never been any reported resistance by any turfgrass pathogen to Chipco Signature. It is important for golf course superintendents to have fungicides like Chipco Signature where resistance is not a problem.

For the sake of the turfgrass indus try, I would like to ask you to reconsider your potential recommendati on and allow Chipco Signature to be applied at its current application rate of 17.6 lbs. AI per acre.

Sincerely yours,

J M Vargas Jr. Ph. D
Professor Dept. of Crop, Soil, and Mi crobial Sciences Michigan State University