What is the symptom of tomato leaf mold? What is the method of prevention and control?

Tomato is our favorite vegetable. But for growers, some diseases can reduce tomato production. It's a real headache. So let's talk about the prevention and control of tomato leaf mold today. Let's take a look.

Symptoms of tomato leaf mold

Tomato leaf mold occurs throughout the plant. But the most sick place is on the leaves. In the early stage of the disease, some chlorotic spots will appear on the back of the leaves, and in the later stage, they will become gray or black-purple irregular mildew layer, the front of the leaves will fade to yellow in the corresponding parts, and in severe cases, the leaves often appear dry and curl.

Second, the harm of tomato leaf mold

Tomato leaf mold mainly harms leaves and, in severe cases, also harms stems, flowers and fruits. In the early stage, yellow-green spots appeared on the front of the leaves, and the gray-white mildew layer appeared on the back of the leaves, and then the mildew layer became light brown to dark brown. When the humidity was high, the mildew layer could also grow on the leaf surface. The disease often occurs from the lower leaves and gradually spreads upward. When the disease is serious, the mildew layer is not full of the back of the leaves, the leaves will bend, and the leaves of the whole plant will show yellowish brown dry.

III. Conditions for the occurrence of tomato leaf mold.

Tomato leaf mold likes the environment of high temperature and high humidity, the climatic condition of the disease is 23 degrees and the relative humidity is more than 95%. The main peak periods of the disease in Zhejiang and the middle and lower reaches of the Yangtze River are spring, July and autumn, November. The susceptible growth period of tomato is the flowering and fruiting period, and the disease is more serious in the fields with continuous cropping for many years, poor drainage, poor ventilation, too depressed in the field and high air humidity. The disease is more serious in early spring when it is cold and rainy, continuous rainy or rainy. The disease is more serious in late autumn when the temperature is too high and it is rainy.

IV. Control methods of tomato leaf mold

1. Rational rotation

It is best for tomatoes to rotate with non-eggplant crops for more than three years to reduce the number of bacteria in the soil. At the same time, disease-resistant varieties are selected and seedlings are raised strictly. The varieties promoted in the market are highly resistant to leaf mold, such as Jiafan 15 and 16, which can be selected on the basis of the place.

2. Strengthen the management

Timely ventilation, proper control of watering, timely ventilation will be wet after watering. The cultivation method of double-ridge plastic film mulching and irrigation under plastic film can not only increase the soil moisture, but also significantly reduce the air humidity in the greenhouse, thus inhibiting the occurrence and infection of tomato leaf mildew. And plastic film mulching leaves can effectively prevent the spread of bacteria in the soil.

All right, the above is the prevention and control of leaf mildew brought by the editor of Tuliu.com. I'll see you next time.