Take all the care in the world not to damage that backyard apple tree. Apple tree crown gall (Agrobacterium tumefaciens) is a disease caused by a bacterium in the soil. It enters the tree through wounds, often wounds inflicted accidentally by the gardener. If you have noticed crown gall on an apple tree, you’ll want to know about apple crown gall treatment. Read on for information on how to manage apple crown gall.
Crown Gall on an Apple Tree
Crown gall bacteria live in the soil, just waiting to attack your apple tree. If the tree suffers wounds, whether from natural causes or caused by the gardener, they serve as an entryway.
Typical wounds that apple tree crown gall bacteria enter include mower damage, pruning wounds, cracks caused by frost, and insect or planting damage. Once the bacteria enters, it causes the tree to produce hormones that cause the galls to form.
Crown galls generally appear on the roots of the tree or on the apple tree trunk near the soil line. It is the latter you are most likely to spot. Initially, apple tree crown galls look light and spongy. Over time they darken and turn woodsy. Unfortunately, there is no apple crown gall treatment that cures this disease.
Your best bet for how to manage apple crown gall is to take great care not to damage the tree during planting. If you fear inflicting a wound while moving, you might consider fencing the tree to protect it.
If you detect apple tree crown galls on a young apple tree, the tree is likely to die of the disease. The galls can girdle the trunk and the tree will die. Remove the affected tree and dispose of it, together with the soil around its roots.
Mature trees, however, can usually survive apple tree crown gall. Give these tree plenty of water and top cultural care to help them.
Once you have had plant with crown gall in your yard, it is wise to avoid planting apple trees and other susceptible plants. The bacteria can remain in the soil for years.