Rhode Island Apple IPM

May 29, 2007 Recorded Pest Message in Print

We are at the end of primary scab season, but we need a wetting rain to release the last ascospores of the season. This means keep your trees protected with a fungicide. It is really a good idea to keep your trees protected with a fungicide for 2 weeks after primary apple scab season. This will protect your trees from any lesions that may show up from primary scab season.

If you are finding scab lesions now, you will need to keep your trees protected with a fungicide for several weeks. Each scab lesion can produce spores for about 3 weeks. So if you have scab lesions, and you keep your trees well protected for 3 weeks, the scab lesions should die without spreading. Unfortunately, for one reason or another, trees aren’t well protected and the scab lesions continue to spread, especially if we get a lot of wet weather. That is why I hope this dry, dry weather continues for a few more weeks – stopping the scab from spreading.

If you find scab lesions now, apply full rates of Captec, Syllit or Flint now and repeat in 7 days.

Plum curculio. This warm weather is hurrying us through plum curculio season. If the weather continues as is generally forecasted, the last spray for plum curculio needs to be applied 5/30 or later in the Greenville area, or June 2 or later in Newport County. This is because we expect plum curculio to stop migrating into orchards around June 9th in Greenville and June 12th in Newport County and insecticide applications made 2 weeks before the last migration date should protect fruit through the end of pc migration.

Fire blight, I have not seen any fire blight showing up, but it is still early. Fruit infected fire blight could have started appearing 5/26 and shoot infections could start appearing 6/5 in Greenville. This is from the 5/10 fire blight infection period.

Newport County trees that may still be in bloom are at risk for fire blight infections yesterday, 5/28, as well as June 1-3. If your trees are still in bloom, fire blight infections can occur during periods of hot weather. See Cougarblight and MaryBlyt models on Orhcard Radar, www.ur.edu/research/ipm.

European red mites are primarily eggs now. We expect these eggs to start hatching the first week of June. Next week will be a better time to scout ERM’s.

Thanks for calling – next message will be recorded Tuesday, June 5.