European red mites have caused bronzing in many orchards this season. And I have not seen many predator mites. It is best to treat trees before the leaves bronze – a bronzed leaf never turns green again. The threshold for this time of year is 2.5 European red mites per leaf or 65% of leaves with mites. We have several good miticides, including Nexter, Zeal and Acramite.
Another orchard in Rhode Island has reported fire blight, this time on Gala apples. That makes four orchards in RI that I know about. Continue to check your trees for fire blight strikes and prune 12 inches below where the brown leaves are attached to the branch. Among the more susceptible apple varieties are Fuji, Gala, Golden Delicious, Granny Smith, Gravenstein, Jonathan, Mutsu, and Pink Lady.
I am sorry to inform you that I have not set up apple maggot traps yet this year! That being said, early maturing varieties are probably now at risk from apple maggot fly injury. If you have apples maturing before McIntosh, it is probably a good idea to spray with a half rate of an insecticide. McIntosh and later maturing varieties probably do not need to be sprayed until around July 20th. Apple maggot flies are relatively easy to kill, so half rates of insecticide are all that is necessary.
This muggy weather is perfect for fly speck and sooty blotch infections. Captan sprays generally protect apples for 2 weeks and Sovran, Flint or Captan plus Topsin M generally protect for 3 weeks. The Sovran, Flint and Topsin M will also give some kick-back action. These fungicides can kick-back for 50 hours of wetness. These 50 hours accumulate from day to day, so you depending on the weather, 50 hours may take just over two days or may take over a week to accumulate. See Orchard Radar to help you decide if your trees are protected. On Orchard Radar you look on a chart for when you applied a fungicide and how long your trees should be protected according to the weather we’ve been experiencing. To see Orchard Radar go to www.uri.edu/research/ipm and click on the Orchard Radar closest to your orchard – Greenville or Newport County.
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