Peach tree disease or pest

Asked March 13, 2015, 3:32 PM EDT

The two photos below show a gelatinous mass that has developed at the base of one of my two peach trees. It started last year and I cleaned it up, dug up and removed the soil around the base of the tree. I then put gravel all around the base of the tree to discourage development of larvae in the soil. The tree produced a huge amount of peaches as usual which I thinned out but nearly all were infected with what I think is plum curculio. The gelatinous mass has recently reappeared at the base of the tree. What is this? Is it related to the plum curculio infestation? How do I get rid of it?

Montgomery County Maryland

1 Response

In general, fruit trees are a challenge to grow because they can be susceptible to insect and disease problems. From your photo it looks like the gelatinous mass may be due to possible borer activity. Peach tree borer activity results in the oozing of gum by the tree. Borers attack stressed trees. Trees attacked by borers frequently die within a few years. Monitor for borer holes usually in May. Scrape away gum and dead bark from the lower trunk and look for new gum and frass deposits. Make vertical cuts with a sharp knife through these entrance holes. Then, insert a stiff thin wire and stab larvae; repeat in 1 week and then mound soil over the damaged area (if low on the trunk). There are no chemical controls.

Remove the gravel from around the trunk. Mulch or gravel should not be piled around the trunk as this can encourage vole activity and promote bark deterioration at the soil line. The tree may limp along but not produce fruit.

In general, peach trees are not long lived. They are susceptible to brown rot, a fungal disease as well as pest insects. Keep peach trees in good health through proper planting, watering, fertilization, pruning, and pest management.

The plum curculio is not related to the possible borer activity. Peach trees can be susceptible to several pest insects. You will have to look for this by cutting open the fruit. This weevil-like insect will cut a small crescent-shaped hole in the skin of developing stone fruits and lay an egg in the hole. The fruit drops prematurely and the hatching larva feeds on the decaying fruit.

See the following publications for more information:

It may be helpful to look at this link from Penn State on Stone Fruits: Peaches, Nectarines, Plums, Apricots, and Cherries.