With welcome, warm, sunny weather, we are seeing epiphytic infection potential rise in virtually all orchards around the state. We are expecting by Thursday or Friday to have high enough populations of bacteria to cause fire blight infections on trees with open blossoms. That will include most orchards in the state which may either be just beginning to bloom or starting to end their bloom. Growers should plan to apply streptomycin to all blooming orchards on Thursday or Friday this week. Streptomycin works best when applied with a non ionic surfactant. There is also good potential for apple scab infection this weekend, so application of an appropriate fungicide would also be prudent. Next week we’ll discuss options for insect management and thinning at petal fall.

The UVM Tree Fruit and Viticulture Program is supported by the University of Vermont Agriculture Experiment Station, UVM Extension, USDA NIFA E-IPM Program, and USDA Risk Management Agency.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the United States Department of Agriculture. University of Vermont Extension, Burlington, Vermont. University of Vermont Extension, and U.S. Department of Agriculture, cooperating, offer education and employment to everyone without regard to race, color, national origin, gender, religion, age, disability, political beliefs, sexual orientation, and marital or familial status.

Where trade names or commercial products are used for identification, no discrimination is intended and no endorsement is implied. Always read the label before using any pesticide. The label is the legal document for the product use. Disregard any information in this message if it is in conflict with the label.