Symptoms and Prevention of Eggplant Verticillium Wilt

Eggplant verticillium wilt, also known as eggplant wilt disease, is a fungal disease caused by Verticillium spp. It affects eggplants by causing symptoms such as:

• Oval-shaped, light brown spots at the base or lower-middle part of the stem

• Occasional concentric rings on the spots

• Pale brown, powdery mold growth on the spots when moist

• Gradual collapse of affected areas upon dehydration

• Severe cases may exhibit lesion expansion around the stem for about a week

• In the early stages, wilting during the day and recovery at night; later stages show stem and leaf wilting and eventual death

The fungus overwinters in soilborne structures such as mycelia or sclerotia and can survive in soil for 2 to 3 years, making it a primary cause of seedling damage. It can directly invade host plants and spread through water flow or contaminated tools. The fungus thrives in temperatures between 13°C to 42°C, with the optimal range being 24°C.

Prevention and Control of Eggplant Verticillium Wilt

1. Early-stage treatment with fungicides: Apply 70% methyl thiophanate wettable powder at a dilution of 800 times or 50% chlorothalonil wettable powder at a dilution of 500 times to control the disease.

2. Select fields with convenient drainage systems to avoid water accumulation and reduce humidity.

3. Choose disease-resistant varieties and practice crop rotation with non-solanaceous vegetables for 2 to 3 years.

4. Use sterile soil for seedling cultivation, sterilize soil before sowing, and cover the soil with straw or dry soil after sowing.

5. Remove weeds promptly and burn or compost them. Deep plow and expose the soil to sunlight to decompose diseased residues and reduce pathogen sources.

6. Control pests in a timely manner to minimize plant wounds and reduce the spread of pathogens. Remove and burn diseased leaves and plants when the disease occurs, and apply lime or fungicides to the diseased holes.

7. Use non-drip film-covered greenhouses to improve light conditions and increase light intensity, enhancing seedling resistance to disease.

8. Strengthen field management and cultivate robust seedlings. Maintain a daytime temperature of 25°C to 30°C and a nighttime temperature of 10°C to 15°C after sowing to prevent cold spells. Avoid excessive humidity in seedbeds or greenhouses during rainy or snowy weather.

9. Mix 40% seed dressing powder with 50% carbendazim powder at a ratio of 1:1, or mix 70% methyl thiophanate or 50% chlorothalonil wettable powder with dry soil at a ratio of 1:50. Apply the mixture as covering soil after sowing for better results. This method can prevent sudden wilt and verticillium wilt simultaneously.

FAQs on Eggplant Verticillium Wilt

What are the symptoms of eggplant verticillium wilt?

The symptoms of eggplant verticillium wilt include oval-shaped, light brown spots at the base or lower-middle part of the stem, occasional concentric rings on the spots, pale brown, powdery mold growth on the spots when moist, gradual collapse of affected areas upon dehydration, and severe cases may exhibit lesion expansion around the stem for about a week. In the early stages, wilting during the day and recovery at night are observed, while later stages show stem and leaf wilting and eventual death.

How does eggplant verticillium wilt spread?

Eggplant verticillium wilt spreads through soilborne structures such as mycelia or sclerotia, which can survive in soil for 2 to 3 years. The fungus can directly invade host plants and spread through water flow or contaminated tools.

What are some preventive measures for eggplant verticillium wilt?

To prevent eggplant verticillium wilt, you can:

• Apply fungicides in the early stages of the disease.

• Choose fields with convenient drainage systems to avoid water accumulation.

• Select disease-resistant varieties and practice crop rotation with non-solanaceous vegetables.

• Use sterile soil for seedling cultivation and sterilize soil before sowing.

• Remove weeds promptly and burn or compost them.

• Control pests in a timely manner to minimize plant wounds.

• Use non-drip film-covered greenhouses to improve light conditions.

• Strengthen field management and cultivate robust seedlings.

• Apply appropriate seed dressing or soil amendments.

How can I control eggplant verticillium wilt if my plants are already infected?

If your plants are already infected with eggplant verticillium wilt, you can:

• Apply fungicides according to recommended dosages and intervals.

• Prune and remove infected plant parts, and burn or bury them away from the field.

• Improve soil drainage and avoid overwatering.

• Provide proper nutrition and care to strengthen plant resistance.

• Monitor the field regularly and take prompt action against pests and diseases.