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thiophanate-methyl (Topsin M)
NYS DEC Letter - Specific Exemption Request for Use 3/03

New York State Department of Environmental Conservation
Division of Solid and Hazardous Materials

Bureau of Pesticides Management, 9th Floor
625 Broadway, Albany, New York 12233-7254
Phone: (518) 402-8788     FAX: (518) 402-9024

March 19, 2003

Mr. Dan Rosenblatt
Acting Team Leader
USEPA / Office of Pesticide Programs
Emergency Response Team (7505C)
Document Processing Desk
Crystal Mall 2-- 2nd Floor
1921 Jefferson Davis Hwy.
Arlington, VA 22202

Dear Mr. Rosenblatt:

Re: Specific Exemption Request for Use of Thiophanate-methyl (Topsin-M WSB, EPA Reg. No. 4581-377 or 73545-8 or 4581-408) to control fungal diseases of blueberry crops in 2003

    The New York State Department of Environmental Conservation, as the State lead agency for pesticide matters, hereby requests approval of the referenced application (see enclosure) under Section 18 of the Federal Insecticide, Fungicide and Rodenticide Act, as amended. The enclosed application includes the information required in 40 CFR, Part 166, Subpart B (166.20). Also enclosed is the use report from the 2002 Section 18 use (Appendix 13).

    This is the second year we are requesting thiophanate-methyl (Topsin M) for use to control various fungal diseases of blueberries. Phomopsis twig blight and canker (Phomopsis vaccinii) is a serious problem in New York. The most conspicuous symptom is "flagging" or wilting and death of individual stems during the summer. The causal fungus overwinters in infected twigs and canes, and produces infective spores, which are spread during rainy periods. More than half the fruit-bearing twigs can be lost due to twig blight in a severe year.

    Benlate (benomyl) has been widely relied on for management of Phomopsis twig blight and canker as an eradicant. With the loss of this fungicide, growers are left with only protectants such as Captan, Ziram, Bravo and Abound. Azoxystrobin (Abound) has a limited number of applications because it is prone to resistence development in target fungi. Fosetyl-Al (Aliette) is a systemic fungicide, but it is costly and has yet to achieve more than limited efficacy. Studies done in Michigan in 2001 show that the best control can be achieved when an eradicant such as Benlate is tank mixed with a protectant like Captan (appendices 5 through 9).

    Topsin M is considered a replacement for Benlate because the chemical site and mode of action is similar. A field efficacy study has shown that Topsin M + Captan or Ziram is as effective against Phomopsis blight and canker as Benlate + Captan (appendix 1). Indications, at this point, are that thiophanate-methyl (Topsin M) will perform similarly to benomyl.

    A maximum of three foliar applications, using ground equipment, of Topsin M per season is requested. The first application is to be made beginning at green tip and continued on seven-to ten-day intervals through petal fall. The recommended rate is 1 lb. product of Topsin M Fungicide/acre (.71b. ai/A). It is estimated that all of the 700 acres of blueberry in bearing age may be treated. Nearly all of this acreage is contained within the following counties: Niagra, Ontario, Monroe, Wayne, Oswego, Cayuga, Seneca, Schenectady, Albany, Saratoga, Dutchess, Columbia, and Ulster counties. Therefore the maximum anticipated use of Topsin M is 2,100 lb of product or 1,470 lb of active ingredient. There is a PHI of seven days. All applicable restrictions currently on the label would apply.

    Cerexagri, Inc., the manufacturer of Topsin M Fungicide, fully supports our efforts to obtain an emergency exemption for the use of Topsin M on blueberries in New York State (see Appendix 12 of enclosure). The company, in conjunction with the IR-4 Project, continues to make progress towards new registrations with petitions pending at EPA for the use of thiophanate-methyl on blueberries and a variety of other crops.

    The anticipated use season for thiophanate-methyl on blueberries in New York State is from April 1st through September 30, 2003. Therefore, your attention to this request is appreciated.

    Please contact Robin Hackett, of our Pesticide Product Registration Section, at (518) 402-8768 if you require further assistance on this request.


Maureen P. Serafini
Bureau of Pesticides Management

cc: w/enc. - A. Enache, EPA Region II
cc: w/o enc. - G. Good\W. Smith, Cornell University, PMEP
R. Zimmerman\R. Mungari, New York State Dept. Of Ag & Mkts.