Learn how to control common apple pests including diseases and insects.
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Apples are the quintessential Vermont tree fruit because they grow so well in our climate. Unfortunately, even after watering, fertilizing, protecting and generally pampering your trees, sometimes for years to get fruit, you only end up with misshapen, small fruits with black spots on the skin. While apples grow well here, so do their pests.
The first step to growing apples without cursing or resorting to harmful chemicals is to plant disease resistant varieties. ‘Liberty’, ‘Williams’ Pride’ and ‘Priscilla’ are some of the apple scab, fire blight, cedar apple rust and powdery mildew resistant varieties available that will reduce the need for spraying.
Insects, though, are another matter. Apple maggots and codling moths are the chief culprits responsible for those wormy, misshapen apples. To prevent the apple maggots from infesting your crop, hang 2 to 3 red spherical balls coated with tanglefoot (a sticky, vaseline-like substance), on your trees starting in late June. These red balls will lure the apple maggot fly to the tree to lay eggs only to have them get stuck on these fake apples and die. Although they won’t provide complete control, this trap will reduce the amount of bad apples.
There are traps to control codling moths as well. Commercial traps look like a tent hanging from your tree. Hang one trap per dwarf fruit tree starting at bloom time. Another way to reduce codling moth numbers is to wrap a 2 to 3 inch wide piece of corrugated cardboard (corrugated side in) around the trunk of your tree and staple it together. The larvae like to pupate in the cardboard, so you can check it every few weeks to remove any codling moth cocoons you find there.
From the Vermont Garden Journal