Prevention and treatment of root cancer disease of jujube

The disease is a bacterial disease, which occurs in jujube areas in the north. After root damage, the aboveground parts grew slowly and the plants were short. In severe cases, the leaves turned yellow and early, and the shoots became weak or even withered, but rarely caused the whole plant to die. The pathogen not only harms jujube trees, but also harms apples, pears, peaches, chestnuts, persimmons, plums, walnuts, poplars, willows and so on.

(1) symptoms

It mainly occurs in the neck of jujube root, and also occurs on the main root and lateral root, some of which can occur above the ground. The injured part forms a cancer, which is bluish gray or fleshy red at first, smooth and soft, then turns brown or dark brown as the tumor grows, and becomes hard in nature, with a rough, cracked or uneven surface. Some cancers become decaying in the later stage.

(2) pathogen

A root cancer bacteria belonging to the genus Rhizoctonia. The mycelium is short rod-shaped, solitary or chain-shaped, 1.2 microns long and 0.6 microns wide, with 1 Mel and 4 weekly flagella. There is a capsule, no spores. Gram staining was negative.

(3) the regularity of the disease

Root cancer bacteria overwintered in the cortex of the cancer on the remnants of the diseased tumor in the soil. Through Rain Water and irrigation water for transmission, the activities of underground pests also play a certain role in transmission. Diseased wood is an important way of long-distance transmission. Bacteria invade from the wound, stimulate plant cells to divide rapidly, produce a large number of meristems, and form cancer symptoms. Under the condition of moist and warm soil, or many wounds caused by alkaline soil or underground pests, it is beneficial to the disease. Grafting can also spread disease.

(4) Prevention and control methods

1. When grafting, do not take scions from diseased trees

two。 Do not raise seedlings in diseased areas when raising seedlings

3. When the seedlings were transported, strict plant quarantine was carried out, the diseased seedlings were removed and burned, and the healthy seedlings were disinfected and sterilized by soaking the roots with 0.5% copper sulfate or 800 times thiophanate methyl and carbendazim for 10 minutes.

4. Mildly diseased plants can dig up the root soil, expose the roots, remove the diseased tumor and disinfect it with 0.1% mercury water, and then apply Bordeaux solution to protect the wound.

5. Strengthen the prevention and control of underground pests.