Recorded Apple Pest Message – June 11,2010

June 11, 2010
Sorry this message is late – things keep coming up!

I only made it to one orchard this week – and it looked good! We are at the time when spores of summer diseases, fly speck and sooty blotch, start coming into the orchard from adjacent woods and hedgerows such as trees, shrubs, vines, and particularly wild brambles. Captan can be used alone for 2 weeks of protect ion or mixed with Topsin-M to give you 3 weeks of protection. The strobies, Flint, Sovran and Pristin, also protect well against summer diseases. Remember there are limits to the amount of Topsin-M and strobies that can be applied in one season. Topsin-M is limited to 64 ounces per acre per year; the strobies are limited together to 4 applications per season and no more than 2 in a row. Plan to have your final spray before harvest contain either a strobie or Topsin-M. I just learned today that rather than mix captan with Topsin-M, you can also mix captan with a phosphate fungicide such as Prophyte. This combination seems to be as effective as captan plus Topsin-M.

I am a bit concerned about obliquebanded leafroller. Last year we found obliquebanded leafroller in 2 orchards in August. The concern is that we could have leafroller populations that are resistant to commonly used insecticides. New York has had resistant populations of OBLR for decades, and western Mass started a few years ago. The orchard I was in today was one of the two orchards where we found OBLR last year. We did not find any newly hatched larvae today. Look for tiny caterpillars on terminal leaves or chewing on skins of apples that are bunched together. Insecticides to control OBLR include Delegate, Altacor, Intrepid, Proclaim, Rimon and Dipel.
I was hoping to set up apple maggot fly traps this week, but that didn’t happen. Hopefully I’ll be successful next week. I’m curious when AMF will show up in orchards. I have not heard of any reports of AMF.
At the end of last week I saw powdery mildew on peaches. Powdery mildew makes dime size white fuzzy spots on peach skins. Sulfur protects peaches from powdery mildew.
I’m looking forward to seeing everyone at our third and last twilight meeting of the season. It will be on Thursday, July 17 at 5:30 at Pippin Orchard in Cranston.
And next message will be on Friday, June 18th.