Tart cherries receive 24 (c) for use of Bravo Weather Stik (chlorothalonil) beyond shuck split

Michigan growers will have extended use of chlorothalonil for cherry leaf spot control for the 2012 growing season.

Because of increased cherry leaf spot incidence and a minimal number of products to control this important disease of tart cherries, the Cherry Industry, Michigan State University, EPA, MDARD, and Syngenta have worked together to obtain a 24 (c) special local need registration (SLN) for use of Bravo Weather Stick (chlorothalonil) beyond shuck split. Traditional timing of chlorothalonil for cherry leaf spot has been prohibited past the shuck split timing prior to this newly registered use. With the 24 (c), growers must follow a series of restrictions in order to use this product legally throughout the growing season to ensure that post-shuck split applications do not result in illegal residues (less than 0.5 ppm).

The SLN No. MI-120001 allows for the post-shuck split application of Bravo Weather Stik to mechanically harvested tart cherries with the following restrictions:

  • The minimum preharvest interval is 21 days.
  • Cherries must be mechanically harvested.
  • Cherries must spend at least two hours on the cooling pad.
  • The initial flow rate on the cooling pad must be 8 to 10 gallons of water per minute (gpm). After this initial period, the flow rate may be reduced to 4 to 6 gpm.
  • Rinsed water generated during the cooling process must not drain or channel toward aquatic areas.
  • Cherries cannot be used fresh. They must be processed by a commercial processor.

Growers should know these important facts before they consider making chlorothalonil applications under this SLN registration. First, growers should be aware that cherries harvested 21 days after the last application of Bravo will have illegal residues, and to ensure the residues on the fruit are reduced to a legal level (less than 0.5 ppm), growers MUST carefully follow all label directions. The cooling pad procedures on the SLN label are key to reducing residues to a legal level. Illegal residues not only violate federal law, but they have serious consequences for growers, processors, and the Michigan tart cherry industry.

Although a more permanent solution is underway for the 2012 season, growers should obtain the Training Affidavit by going to MDARD’s Cherry SLN webpage and complete Steps 2 and 3. MSU Extension will be available to help growers work through this educational step to be able to use chlorothalonil beyond shuck split by using the MDARD website. Growers with questions or those in need of assistance can call theNorthwest Michigan Horticultural Research Station at 231-946-1510.

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