Root rot of Lycium barbarum and its control

The occurrence of Chinese wolfberry root rot is common and the harm is serious. 3% of the plants die due to the disease every year, which causes great losses to the production of Chinese wolfberry.

According to research by Lu Zhankui and others of Ningxia Academy of Agriculture and Forestry, there are two types of root rot symptoms:

(1) root rot type. The root or root neck decayed and peeled off in varying degrees, and the vascular bundles of the stem turned brown, and the white or pink mildew layer appeared when the disease was wet. It can be divided into lobular type and yellowing type.

① leaflet type: the leaf spreading time is late in spring, the leaves are small, the branches are dwarf, the buds and fruits are thin, often falling buds, and the whole plant dies in severe cases.

② yellowing type: leaves yellowing, wilting and non-wilting, often a large number of fallen leaves, seriously withering the whole plant, and some sprouting new leaves after falling leaves, withering after repeated times.

(2) rotten type. The cortex of the root neck or stem turns brown or black rotten, and the vascular bundles turn brown. The leaf tip is yellow at the beginning, gradually scorched and rolled upwards. When the rotten cortex surrounds the trunk, all the leaves above the diseased part fall off, the trunk dies, and some leaves suddenly wilt and die, and the dead leaves are still hanging on the tree. This phenomenon often occurs in the high temperature season from July to August.

The above various types are often shown as half of the crown disease and half of the wilt or only one branch of the disease and wilt. Some tree trunks die of disease, and new tillering seedlings grow at the neck of the root.

Pathogens overwintered with living diseased plants, and could also overwintered and spread with diseased plant residues and diseased fruit seeds in topsoil and soil. The bacteria invade directly into the plant tissue from the wound or through the tissue cortex, causing the disease. The incubation period of the disease is also different with different pathogens and different infection methods. Under the condition of 20 ℃, the incubation period of Fusarium oxysporum under the condition of host wound was 3 days, while that of uninjured was 19 days, that of Fusarium solanacearum was 5 days and 19 days respectively, and that of Fusarium homochromis was 5 days under the condition of host trauma. Stagnant water in the field is an important reason to increase the incidence of disease. The soil with poor ventilation increased by 9% Mel 22.5% compared with the sandy loam with good ventilation; the root damage caused by intertillage operation was beneficial to the invasion of pathogens.

The method of prevention and control is to improve the tillage conditions, flatten it as a cultivation ridge, reduce the stagnant water in the rhizosphere of Chinese wolfberry, and avoid injuring the root during tillage; irrigate the root with 45% Dysenamine 500 times dilution, and each plant uses 10 Mel 15 kg potion.