I have a Harroldson apple tree. It gives fruit essentially every other year....

Asked May 5, 2015, 12:59 PM EDT

I have a Harroldson apple tree. It gives fruit essentially every other year. My problem is the apples are dented and mis-shapen. Also there are dark spots within the apples. I have suspected apple maggots. I have sprayed with Bonide Fruit Tree spray. I have also used sticky red spheres to trap the flies. I get a lot of flies but they don't seem to have the classic wing pattern of the apple maggot. Also, last year the apples were dented by mid June which seems early for apple maggots. Last year I sprayed 5 times. Now I read on the bottle I shouldn't spray more than twice. However the spray chart on the bottle lists 6 different times to spray. Would you also clear this up for me. Thank you very much. Tom Kraft

Hennepin County Minnesota

1 Response

Many apple trees produce heavy blooms and set too many fruits. Remove all excess fruits after the time of the last natural drop. In thinning, leave only one apple per cluster and space the apples not closer than 6 inches apart. This may remove more than three-fourths of the apples on the tree. Although this practice may seem drastic, it is essential for good-sized apples at harvest and development of fruit buds for next year's crop. This operation can be done by hand or with chemicals. Your apples may have codling moth. It is a good practice to rotate the chemicals used to control insects and diseases so resistance does not develop.

http://www.extension.umn.edu/garden/diagnose/plant/fruit/apple/fruitdeform.html

http://www.extension.umn.edu/garden/diagnose/plant/fruit/apple/fruitholes.html

http://www.extension.umn.edu/garden/yard-garden/fruit/apple-pest-management/

http://extension.psu.edu/plants/tree-fruit/commercial-tree-fruit-production/crop-load-management/chemical-thinning-of-apples