How to Cure Cytospora Canker on Peach Trees

Healthy trees are more capable of resisting diseases and pests.

Cytospora canker is a destructive fungal disease that infects a variety of fruit trees, including peach. The disease, caused by Cytospora spp., infects the weak or stressed trees through the bark, creating yellow, orange or black patches that eventually start to secrete a gummy substance. Cankers develop that slowly encircle the branch and kill it. Black fungal spores in the form of small speckles appear in the affected areas. You can manage the disease through a number of strategies that include taking preventive measures.

Things You'll Need

• Small sharp knife

Instructions

Curative

1. Locate a canker and place your knife at least an inch above the outer margin of the diseased tree tissue. Mark an area all around the canker by digging straight into the wood through the bark, maintaining the one-inch margin all around it.

2. Press the knife under the bark through the marked margin and start removing all the diseased bark tissue. You don't have to dig into or remove the wood from the clean, healthy lower hardwood area.

3. Keep the cuts at the margins clean to allow the tree to heal later. Make sure that you have removed all of the sick tissue, both in depth and diameter of the canker. Once cleaned, you should be able to see healthy wood in the cleaned area.

4. Avoid the application of any wound-healing materials such as oil-based or latex paints; these are unnecessary.

5. Prune infected smaller branches all the way back to the trunk. Perform tree surgery and pruning during dry weather to minimize the spread of fungal spores to other tree areas. Dispose of all diseased material carefully and away from other landscape trees.

Preventive

1. Keep your peach tree in good health with adequate water and fertilizer. Make sure the tree is in a well-drained, full sun area with enough room for growth.

2. Plant a resistant fruit-tree variety to minimize chances of infection. Although, even resistant trees can contract the disease if they are under stress or poorly managed.

3. Avoid unnecessarily wounding trees with weed trimmers or lawn mowers, as these injuries may become a site for infection. Try not to plant new trees near other landscape trees known to have cytospora infection.

Tips & Warnings

• Pruning and removal of cankers and diseases areas is the main method of managing cytospora canker, according to the Iowa State University Extension. There are no chemical control options for controlling the infection once it has occurred.

References

• Colorado State University Extension; Cytospora Canker; W.R. Jacobi; March 2009
• Iowa State University Extension; Cytospora Canker; July 2010
• Penn State College of Agricultural Sciences: Cytospora Canker of Stone Fruit