Occurrence and control of strawberry verticillium

Strawberry is a common fruit in our daily life. It tastes sweet and delicious, and is rich in nutrients. In the process of strawberry planting, some diseases will inevitably occur. Among them, verticillium wilt is a common one. This article will introduce the techniques of drug control for strawberry verticillium wilt.

Verticillium wilt is caused by the infection of the fungus, the genus Trichosporon. The new leaves of the infected plants of strawberry verticillium turn yellow-green, twisted into a boat shape, and the surface is rough and dull. Of the three leaflets, there are often 1-2 leaves that become smaller and deformed. Malformed leaves occur on one side of the plant, presenting a "half body wilting" symptom. Then the lower leaves turn yellowish brown, and the upper leaves begin to dry from the leaf margin until the whole plant dies. The cross-section of the roots, petioles and fruit stalks of the affected plants was cut, and the vascular bundle browning was observed. The root system is reduced, the roots become dark brown, and even spoiled, but the center column does not change color. The difference with strawberry wilt is that the verticillium wilt does not develop in the summer high temperature season, and the heart leaves are not deformed yellow.

[Pathogenesis]: The pathogens in the host disease are overwintered in the soil with mycelium or chlamydospores or sclerotia, and generally survive for 6-8 years. The contaminated soil is the main source of disease infection. When the environmental conditions are appropriate, the pathogens are transmitted by the diseased mother plant, soil, water source and agricultural implements, and invade from the root wounds of the plants or directly from the epidermis and root hairs of the young roots, and propagate in the vascular bundles of the plants, and continuously spread to the leaves and roots of the plants. , causing systemic disease of the plant, and finally died dry. The pathogens prefer a warm and humid environment, and the most suitable climatic conditions are 25°C-28°C, and the relative humidity is 60%-85%. The onset of strawberry verticillium is in the middle and late stages of nursery, pseudo-planting and early planting. The disease is highly harmful and is a stubborn soil-borne disease. Poor soil permeability, over-dry and wet, multi-year continuous cropping, excessive nitrogen fertilizer or damage caused by wireworms may lead to serious occurrence of verticillium wilt.

[Control methods]: (1) Implement strawberry and rice rotation to avoid continuous cropping. (2) The use of Zhang Ji, red cheeks and other varieties with strong disease resistance. (3) Remove the sick body and burn it in time. (4) Chemical control. Before the strawberry planting, the soil was disinfected with 80% chloropicrin or solar energy, and then the seedlings and colonization were carried out with good effect; after planting, the soil was dripped with 0.2% benomyl WP, which had obvious effects in the same year and the second year; In the early stage of the disease, the diseased area can also be treated with 10% anti-lingering agent 80 times liquid.