Section 18 Specific Exemption granted for Kasumin for fire blight control in 2014

EPA has granted a Section 18 Specific Exemption for use of Kasumin 2L (kasugamycin) on apples for control of the blossom blight phase of fire blight in 2014.

A Section 18 Specific Exemption has been granted by EPA for the use of Kasumin 2L (kasugamycin) for the control of the blossom blight phase of fire blight on apples in 2014. This use is for orchards where streptomycin-resistant fire blight bacteria are present. The Section 18 exemption is applicable to Antrim, Berrien, Cass, Grand Traverse, Ionia, Kent, Leelanau, Montcalm, Newaygo, Oceana, Ottawa and Van Buren counties.

This Section 18 exemption only applies to counties where we have detected streptomycin-resistant isolates of the fire blight pathogen Erwinia amylovora. We currently have not detected any streptomycin resistance in eastern Michigan, for example.

Kasumin 2L should be available in each region this year in time for bloom sprays. Michigan State University Extension advises growers to make sure you have the Section 18 label in hand when you are applying Kasumin 2L. Do not apply Kasumin through any irrigation system.

Conditions and restrictions of the Section 18 specific exemption

  • Apply Kasumin only when the pathogen is resistant to streptomycin. We have documented streptomycin resistance in all of the counties listed in the first paragraph above.
  • Do not apply Kasumin as the first spray of the season. It can only be used after a first spray of a registered alternative. These can include copper, oxytetraycline, Serenade MAX, or other biological control agents.
  • Kasumin 2L may only be applied when the following condition is met: Only when the disease forecasting model or fire blight state expert determine that the weather conditions favor a disease epidemic.

This condition is similar to previous years. We have typically utilized the MaryBlyt fire blight prediction model and have called for Kasumin applications when the Epiphytic Infection Potential (EIP) number from the MaryBlyt model reaches or exceeds 100. This model is available on the MSU Enviro-weather website; use the weather station closest to your orchard location to get local conditions. Make sure to document the MaryBlyt EIP prediction by printout or screen capture to include in your spray records. Also, make sure you document the EIP number when you make the decision to spray – since this number is predicted for the next few days out, the number can change as current conditions and predictions change.

In summary, the use of Kasumin 2L is limited to potential epidemic conditions; if these conditions are not present this year, other fire blight control materials such as oxytetracycline should be used.

  • A maximum of two sequential applications of Kasumin can be made at a rate of 2 quarts (64 fluid ounces) per acre. Applications are restricted to ground equipment and cannot be made through any type of irrigation system.
  • A maximum of three applications of Kasumin can be used (64 fluid ounces per acre) if authorized. Treatments can be made no later than petal fall.
  • Alternate row applications are not allowed. This requirement of the Section 18 exemption is for resistance management and was instituted in 2012.
  • Do not apply Kasumin as the first spray of the season. It should be applied only after the first spray of registered alternatives.
  • 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.
  • Upon expiration of the exemption on May 31, 2014, 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 per acre.

Please note that my lab will also be conducting resistance monitoring in selected orchards this year that use Kasumin. This is to satisfy an EPA directive that we monitor for the occurrence of kasugamycin resistance, and also the potential for resistance to other related antibiotics. We will be taking leaf and soil samples from approximately 10 orchards throughout the state. These monitoring experiments will be conducted after petal fall. We have conducted these monitoring studies for the past three years in support of the Section 18 application. Our results have shown no risk of an increase in antibiotic resistance because of the Kasumin applications.

As always, I want to thank Brian Verhougstraete, pesticide registration manager of the Michigan Department of Agriculture, for his support of this Section 18 request. Verhougstraete submits our request each year and serves as our liaison to EPA.

Dr. Sundin’s work is funded in part by MSU’s AgBioResearch.

Related Articles

Related Resources