|I have a dwarf MacIntosh apple tree that produces apples with yellow/rusty lines inside and brown spots on the outside. As the summer progresses, the leaves curl and get brown spots and look dry. I really want edible apples but since I have dogs I don't want to use anything poisonous. I have tried dormant oil in the spring but it hasn't helped. I have been told to try it again and then use Safer every 10 days. Does this sound reasonable?
|It sounds like your apple tree is suffering from a fungal infection. Neither oil, nor Safer will help control this.
Oil suffocates insects, and Safer is an insecticide. Both of these will help keep your apple tree insect free, but it sounds like youreally need a fungicide!
You need to be fastidious about removing affected leaves and fruit since the fungus is most often spread by splashing rain. When you prune the trees (preferably in late winter), prune out any branches that seem diseased and be sure no old fruit is clinging to the branches. Also prune in such a way that you open up the tree to sun and air movement.
In the spring, spray with a fungicide using the quantity and schedule recommended on the product directions. Gardener's Supply (ph# 800-863-1700, web site www.gardeners.com)sells a product called "Fruit Tree Spray" which is an organic combination fungicide/insecticide.
By the way, fungicide should not bother your pets.