How to prevent and treat gummosis in peach trees? A detailed guide to practical methods

Peach gummosis is a physiological disease that occurs frequently on peach trees, mainly on the branches and trunk, and in severe cases it has a great impact on the growth and development of the peach tree. Besides peach, stone fruit trees such as apricot, plum, Japanese apricot (ume) and cherry also suffer from it.

Symptoms of damage: This disease can occur on any part of the peach tree's branches and shoots. The diseased part swells slightly, the wood tissue turns brown, and then a transparent gum-like substance oozes from the lenticels or wounds; after contact with air it gradually turns yellowish-brown to brown, and finally becomes a black hard lump. The bark of the diseased part is rough and cracked, heals with difficulty, and easily becomes an egg-laying site for the red-necked longhorn beetle, inviting damage by the red-necked longhorn beetle. When the disease is severe, the tree's vigor quickly declines and it may even die. Besides branches and shoots, gum oozing also occurs on the fruit.

Pattern of occurrence: Gum oozing is a physiological disorder of peach trees. There are many causes of gum oozing; any condition that hinders the normal growth and development of the tree, such as damage by diseases and pests, improper fertilization (lack of fertilizer or excessive nitrogen fertilizer), heavy clay soil, poor drainage, excessive summer pruning, planting too deep, excessive fruiting, continuous cropping, as well as damage from hail, freezing injury and sunscald, can all cause gum oozing in peach trees.

Gum oozing can occur throughout the entire growing period of the peach tree, but it occurs most often in rainy seasons such as the plum rain and typhoon periods. Older trees and weak trees are affected more severely.

Control methods:

(1) Strengthen fertilization, drainage, disease and pest control and soil management, carry out reasonable pruning and training, prevent excessive fruiting, avoid continuous cropping, and pay attention to preventing freezing injury and sunscald, so as to promote strong tree vigor in peach trees; this is the fundamental measure for preventing or reducing gum oozing.

(2) After gum oozing occurs, scraping treatment can be carried out in winter; disinfect the wound with 5-10 degrees Baumé lime sulfur mixture or 100-fold copper sulfate solution, and apply coal tar for protection, or brush the wound with 1:4 alkaline water, which has a certain curative effect.