Common diseases of eggplant and prevention and control of eggplant diseases

When we cultivate eggplant, some diseases often occur. So how can we better prevent and control them at this time? Here are some methods for preventing and controlling eggplant diseases:

Eggplant Verticillium Wilt

Symptoms

Eggplant Verticillium Wilt will develop soon after planting. If it is planted at low temperatures, the disease will develop early and be severe, but the disease area is the largest and the disease is the most serious after fruit setting. In the early stage of the disease, the leaf margins and veins of the lower half of the plant near the petiole turn yellow, and then gradually develop into half a leaf or the whole leaf, with the leaf margins slightly curled upward. Sometimes the lesions are limited to half a leaf, causing the leaves to be distorted. In the early stage of the disease, the eggplant plant appears wilted, and can recover in the morning and evening or after rain. Later, the leaves turn brown, the whole plant wilts, the leaves fall off, and the whole plant dies. In severe cases, the whole leaf often turns yellow, turns brown and dies. Most of the diseases are caused by the whole plant, and a few still have some healthy branches without disease. When the disease occurs: it mostly develops gradually from the lower part of the plant to the upper part. In severe cases, the leaves of the whole plant fall off. The diseased plants are short, the plant shape is not stretched, the fruit is small, and the long fruit is sometimes bent. The longitudinal section of the rhizome can be seen to change the color of the xylem vascular bundle, which is yellow-brown or brown-brown.

Disease pattern:

Verticillium wilt of eggplant is caused by fungal infection. The pathogen overwinters in the soil with dormant hyphae, thick-walled spores and microsclerotia along with diseased residues, becoming the primary source of infection the following year. The pathogen is transmitted to disease-free fields through fertilizers mixed with diseased residues, contaminated soil and Solanaceae weeds, wind, rain, people, livestock and farm tools. In the second year, the pathogen invades from the wounds of the roots or directly from the epidermis and root hairs of the young roots, then reproduces in the vascular bundle and spreads to the branches and leaves. The disease does not repeat infection in the same year. The optimum temperature for the onset of the disease is 19℃~24℃, and the hyphae and sclerotia are lethal after 10 minutes at 6℃. Generally, the temperature is low, and the root wounds heal slowly during planting, which is conducive to the invasion of pathogens; low-lying terrain, application of uncomposted organic fertilizers, improper irrigation and continuous cropping lead to severe disease.

Prevention and treatment methods:

1. Rotate with non-Solanaceae or melon crops for 3 to 4 years;

2. Choose disease-free seeds and disease-resistant varieties; apply sufficient decomposed organic fertilizer;

3. Remove diseased plants promptly, bury them deeply or burn them, and inject medicine into the root zone soil to disinfect and sterilize.

4. Disinfect the seeds. Pre-soak the seeds in cold water for 3 to 4 hours, then soak them in 55℃ warm water for 15 minutes, and dry them in the shade for later use.

5. Chemical control method: Apply pesticides when planting: Soak the roots of eggplant seedlings with 1000 times solution of 1 mycorrhizal solution when planting, and irrigate the roots with this solution after planting, 250 ml of solution per plant. 500 times solution of 70% dichlorodiphenyltrichloroethane wettable powder, 500 ml per plant, once every 10 to 15 days, and irrigate 2 to 3 times in a row.

Eggplant bacterial leaf spot

Symptoms

The disease mainly harms leaves. The lesions mostly start from the leaf margins and expand inward along the veins. The lesions are irregular in shape, some look like lightning or branches of rivers, and are light brown to brown. The symptoms of the affected part are not obvious. Before the dew dries, the surface of the lesions feels sticky when touched.

Disease pattern:

The pathogen of this disease survives the winter in the form of mycelium left in the soil with diseased body parts. It spreads by splashing rainwater and invades through water holes or wounds to cause disease. Warm, humid weather and poor ventilation are conducive to the disease.

Prevention and treatment methods:

1. Rotate crops with Solanaceae vegetables for more than 3 years. Treat seeds with hot water at 78-85 ℃.

2. Select sterile and high-quality strains and disinfect them.

3. Sterilize and disinfect the greenhouse and soil.

4. Implement all-round mulch covering to prevent over-watering and ensure timely ventilation and moisture removal.

5. Chemical control: In the early stage of the disease, spray 50% 1000 times liquid of Yeyeqing wettable powder, once every 7-10 days.

Brown streak disease, cotton blight

Grafting has solved the problems of soil pests and diseases such as Verticillium wilt, damping-off, bacterial wilt, and root-knot nematode disease, which has laid the foundation for the establishment of an eggplant production model without pesticide residues. For the prevention and control of diseases of the aboveground parts, such as brown streak disease and cotton blight, it is also necessary to adopt prevention and control methods permitted by food safety, such as physical plant protection technology, environmentally safe greenhouses, and permitted pesticides. Physical plant protection technology is to prevent diseases encountered by the aboveground part of eggplant by setting up a space electric field.