Fruits & Nuts - Apple Tree Diseases
Back to Fruits & Nuts

  Every May, my three year old apple trees develop yellow spots, ringed in orange on the leaves. I have tried wet and dry sprays, to no avail. I would like to resolve this problem, and prevent the spots. Can you help?

  The problem you have is a disease called Cedar Apple Rust. When you see the spots, there is no control. This disease is prevalent in the state. This disease has two hosts--the apple tree and the cedar tree. Earlier this spring, the cedar tree had the disease spores on it, in the form of orange gelatinous globs. These harden into balls and spores are released into the air to infest the apple trees. Timed sprays when the trees first begin to grow until petal fall of either Funginex or Bayleton will prevent the spots. During the growing season, the disease may cause some defoliation and some spotting on the fruit, but it shouldn’t kill the tree. Repeated infestations and subsequent defoliation can weaken the tree and make it more susceptible to dying, so try to prevent it next season. To get a copy of the fruit spray guide, call your local county extension office.

  We need help!! We have an apple tree that has five different varieties grafted on to one tree. It has been in the ground two years, and this year it has about 20 apples from all varieties. It also is infected.

  Your apple trees have cedar apple rust, another common problem. Once the spots are on the trees, it is too late to do anything about it. Apples and cedars are co-hosts to this disease, sending spores back and forth. There is no way to eradicate the cedars in the area, so be sure to pay attention to a timed spraying of a fungicide. When the flowers are in the pink stage, spray with a fungicide such as Bayleton. Then spray again in bloom, when the petals fall, and again two weeks later. This should prevent any problem with the disease.

  I have apple trees and this year I have been getting a lot of bad fruit. I read somewhere that the best time to spray your fruit trees is before the blooms fall off. The problem with this, is during that time period there are hummingbirds around. I don't want to harm the birds. This has happened two years and I really need to spry them. What do you suggest I do?

  One application of a fruit spray is not going to give you blemish free fruit. There are spray guides available from your local county extension office, but the sprays typically begin when two_thirds of the flower petals fall off, and continue every two to three weeks until harvest, depending on which fruit crop. By bloom period sprays I think you are referring to fireblight sprays which are applied during bloom. Fireblight doesn't damage the fruit as much as it damages the trees, with dieback on the branches. If your trees aren't being damaged by this, those sprays won't be needed. As for the hummingbirds, I doubt they would be in the trees past bloom time, so sprays should not affect them then.

Back to Fruits & Nuts