Section 18 Specific Exemption granted for Kasumin for fire blight control

Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.

EPA has granted a Section 18 Specific Exemption for the use of Kasumin 2L (kasugamycin) for the control of the blossom blight phase of fire blight. This use is for orchards where streptomycin-resistant fire blight bacteria are present. The Section 18 is applicable to Berrien, Cass, Ionia, Kent, Montcalm, Newaygo, Oceana, Ottawa and Van Buren counties.

The conditions and restrictions of the Section 18 specific exemption appear to be very similar to those effective for Agry-Gent in 2008. These include the following:

1) Apply Kasumin only when the pathogen is resistant to streptomycin. We have documented streptomycin resistance in all of the counties listed above.

2) Kasumin 2L should only be applied when the fire blight state experts and/or disease forecasting model determine that the weather conditions favor disease epidemics. Thus, the use of this material is limited to epidemic conditions; if these conditions are not present this year, other fire blight control materials such as Mycoshield should be used.

Authorization for use will come from Michigan State University Fruit Horticultural Educators and Tree fruit disease specialists via web, radio, recorded message, telephone, email and handout. Code-a-phone messages (see numbers below) are the preferred method to get information on use authorizations. Code-a-phone numbers are as follows: Berrien, Cass, and Van Buren counties (269-657-6380 or 269-944-1477 x805); Ionia, Kent, Montcalm, Newaygo, and Ottawa counties (616-451-8065); Oceana County (888-345-0515). Authorizations will be specific to county affected.

3) A maximum of two sequential applications of Kasumin can be made at a rate of 2 quarts (64 fl. oz.)/acre. Applications are restricted to ground equipment and cannot be made through any type of irrigation system.

4) A maximum of three applications of Kasumin can be used, if authorized. Treatments can be made no later than petal fall.

5) Do not apply Kasumin as the first spray of the season. It should be applied only after the first spray of registered alternatives (usually oxytetracycline or Serenade MAX).

6) Do not use in orchards in which the soil has been fertilized with animal manure. This restriction addresses concerns that kasugamycin resistance could be transferred to E. coli bacteria present in animal manure.

7) Upon expiration of the exemption, all unopened and unused product must be returned to the dealer where purchased or to the manufacturer or disposed of in accordance with Resource Conservation and Recovery Act regulations following the expiration of the Section 18 exemption.

Kasumin 2L (kasugamycin), from Arysta, is an alternative antibiotic for fire blight management. Kasumin 2L will work equally on streptomycin-resistant and streptomycin-sensitive strains. The label rate is 2 quarts/acre. I am not aware of any potential issues such as pH sensitivities of Kasumin or possible incompatibilities with other spray materials at this time.

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