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

1. Distribution: Peach gummosis, also known as resin disease, occurs commonly in all peach-growing regions of our country, and is especially severe in the south. The causes are complex, and it is not easy to completely control. Gumming weakens tree vigor, affects fruit quality, and can even kill branches and trees.

2. Symptoms: This disease mostly occurs on the branches and trunk of peach trees, and is most likely to occur at the main trunk and the forks of main branches. In the early stage, the diseased part swells slightly and gradually exudes a translucent gum, which worsens after rain. Afterwards the gum gradually becomes jelly-like, turns yellowish-brown after losing water, and becomes dark brown when dry. In severe cases, the bark cracks, the cortex necroses, growth weakens, leaves turn yellow, fruit is small and bitter, and branches may even die.

3. Disease pattern: The reasons why peach trees develop gummosis are still not very clear. Any factor that hinders the normal growth and development of peach trees may cause gummosis. According to research in China and abroad, the following factors can cause gummosis in peach trees:

(1) Due to the damage caused by parasitic fungi and bacteria, such as dieback, rot disease, anthracnose, scab, canker, and shot hole disease, all of which can cause gummosis.

(2) Root diseases such as crown gall, root-knot nematode disease, silver leaf disease, and viral diseases weaken tree growth and reduce resistance, making gummosis more likely to occur.

(3) Branches, trunks, and fruit being bored and fed on by pests such as red-necked longhorn beetle, jewel beetle, green leafhopper, and cicada, causing gummosis on the main trunk, main branches, and small branches; peach fruit borer, stink bug, and snail feeding causes fruit gummosis, etc.

(4) Mechanical injuries, pruning and saw cuts, hail damage, freezing injury, sunscald, and heavy pruning can also cause gummosis.

(5) Poor environmental conditions, such as poor drainage, improper irrigation, heavy clay soil, soil salinization or acidification, soil magnesium deficiency, airborne sulfur damage, and ammonia damage, cause physiological disorders in peach trees and can also cause gummosis.

(6) Poor compatibility between rootstock and variety, such as using Nanking cherry rootstock or apricot rootstock to graft peach, makes gummosis likely to occur.

When pathogenic bacteria cause damage, the bacterial spores spread through wind and rain and invade through wounds and lateral buds. After gummosis occurs in the tree due to non-infectious diseases, it is easy for the tree to then become infected by infectious diseases, especially after rain, and the tree rapidly weakens.

4. Prevention and control methods:

(1) Strengthen the management of soil, fertilizer, and water, improve the physical and chemical properties of the soil, increase soil fertility, and enhance the resistance of the tree.

(2) Timely prevent and control various diseases and insect pests in the peach orchard.

(3) After pruning and saw cuts and scraping off diseased spots, apply 843 rehabilitation agent.

(4) After leaf fall, whitewash the trunk and large branches to prevent sunscald and freezing injury, and also to sterilize and control insects. Preparation method of whitewash: quicklime 12 kg, salt 2-1.5 kg, soybean juice 0.5 kg, water 36 kg. First slake the high-quality quicklime with water, then add soybean juice and salt, and stir into a paste.

(5) In the early stage before bud swelling, spray 5-degree lime sulfur mixture plus 80% sodium pentachlorophenate at 200-300 times dilution to eliminate overwintering pathogens.