Early season apple disease management

April 9, 2014

Terence Bradshaw, UVM Tree Fruit and Viticulture Specialist
Spring looks to be here, as temperatures are gradually warming up, or at least staying out of the frigid zone. At the UVM Hort Farm, trees are still dormant, although I’ve seen a little swelling on Empire and Macoun. Still, green tip looks to be a week or two off (more likely two) in the Champlain Valley. There’s a great article in the April 7 Scaffolds Newsletter from Terence Robinson and Mario Miranda at Cornell University that walks us through the dormancy and bud development process to predict bud break: http://www.scaffolds.entomology.cornell.edu/2014/SCAFFOLDS%204-7-14.pdf.

In the next few weeks, get your pruning wrapped up, brush pushed out, and sprayers calibrated and tuned up. Leaves can still be flail mowed or urea applied to leaf litter to aid in scab inoculum decomposition. Copper will be ready to be applied any time now that you can get into the orchard. Anyone with concern about fire blight in their plantings should be applying copper at label rates between silver tip and green tip to reduce overwintering inoculum. Copper also acts as your green tip scab spray, so this isn’t an extra trip through the orchard.

To help you plan your 2014 fungicide schedule, here’s nice overview article on Fungicide Considerations for Tree Fruit in 2014 from David Rosenberger and Kerik Cox, also from Cornell University. Go to page four of the March 24 Scaffolds newsletter: http://www.scaffolds.entomology.cornell.edu/2014/SCAFFOLDS%203-24-14.pdf. Remember that the article was written for a New York audience, and so does not reference some of the other fungicide options available to Vermont growers. The SDHI fungicides Luna Sensation and Merivon most come to mind.

Happy spring, now get beck to work!

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