Kasumin registered by EPA for fire blight control on pome fruit

Kasumin 2L is now fully registered on pome fruit in the United States for control of fire blight. This product provides excellent control of blossom blight and is critically needed, especially in orchards impacted by streptomycin resistance.

Kasumin 2L has been registered by the Environmental Protection Agency (EPA) for fire blight control on pome fruit crops in the United States. I anticipate that this material will be available in Michigan for the 2015 season. We have had Kasumin available in Michigan via a Section 18 specific exemption since 2010 in counties impacted by streptomycin resistance in the fire blight pathogen. The overall grower experience with this product has been excellent for fire blight control in orchards with streptomycin resistance, and Michigan State University Extension field trials continue to show excellent efficacy for blossom blight control.

What are the significant changes in the Section 3 label from the Section 18 label?

  • Kasumin 2L can be used throughout Michigan, i.e., use is not restricted to counties with streptomycin resistance.
  • Kasumin 2L can now be used on pears as well as apples.
  • There is no longer a requirement for state experts to indicate potential epidemic conditions for fire blight prior to an application. However, I strongly suggest that growers continue to use the fire blight disease prediction model available on the MSU Enviro-weather website and only apply Kasumin when predicted EIP values are 100 or greater.

Similarities between the new Section 3 and previous Section 18 label:

  • Do not apply Kasumin in orchards in which the soil has been fertilized with animal manure.
  • Do not apply after petal fall.
  • Do not use alternate row applications.

Information on the new Kasumin 2L label:

  • The use rate is 64 fluid ounces (2 quarts) per acre. Using 64 fluid ounces in 100 gallons of water is optimal; reduced spray volumes can be used for smaller trees.
  • Do not apply after petal fall. There is also a 90-day pre-harvest interval (PHI).
  • A maximum of four applications can be made. I strongly suggest not applying more than three applications per season for resistance management purposes.

This is great news for the pome fruit industry in Michigan; however, we must always remain cognizant of how we got this material in the first place. The occurrence of streptomycin resistance in the 1990s in southwest Michigan and in the 2000s in the Fruit Ridge area and progressing northward has had severe impacts on the industry. Thus, it is critical that we protect Kasumin from the prospects of resistance development. The first step in this regard is to not overuse the material.

Throughout the state during the winter and early spring, I will be outlining use strategies and resistance management options for Kasumin leading into next season.

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

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