Control methods of common diseases and insect pests in lettuce planting process

Lettuce is a kind of green vegetable with high nutritional value. It can be cultivated either in soil or in water, and it is relatively simple to grow. Lettuce can not only be stir-fried, but also can be salad, delicate and smooth taste. In the process of lettuce planting, it is easy to cause the occurrence of diseases and insect pests due to improper management. let's take a look at the prevention and control methods.

1. Lettuce Sclerotinia sclerotiorum

This kind of disease which harms the base of lettuce stem, at the beginning of the disease, the lettuce stem will appear yellow-brown waterlogging, slowly turn brown, and finally extend to the whole stem, resulting in the phenomenon of stem rot, serious will spread to leaves and other parts, and then slowly die.

Control methods: once the occurrence of Sclerotinia sclerotiorum disease, it has a great impact on the yield of lettuce. To prevent the disease, thoroughly remove the fallen leaves after the lettuce harvest, and then dig deeply. The second round of planting should be reasonably close planting, so that the humidity in the field can be reduced and the conditions for the occurrence of diseases can be reduced. Generally selected agents are tebuconazole, propiconazole, etc., sprayed once every half a month, two or three times in a row.

2. Lettuce downy mildew

When lettuce downy mildew occurs, it will first harm the leaves, especially the lower leaves, and then slowly spread upward. In the early stages of the disease, there will be yellowish round spots or polygonal spots on the leaves. When the humidity is too high, white mildew spots will appear on the back of the leaves, serious ones will appear on the front of the lettuce leaves, and the whole lettuce will wither if the disease is too serious.

Control methods: after the lettuce harvest, carefully clean up the fallen leaves in the soil, carry out reasonable close planting, and remember not to water too much. If you encounter a season with more precipitation, it is necessary to drain the excess water in the ditch in time to avoid too much humidity in the field.

3. Lettuce soft rot

This disease is a bacterial disease, especially easy to appear in the middle and later stage of lettuce. If the disease occurs, the leaves of lettuce will rot and become transparent, and there will be a strong smell. Soft rot occurs because the leaves of lettuce are damaged, and then the bacteria flow into the body of lettuce through the wound, resulting in infection.

Prevention and treatment: when you find lettuce leaves with germs, you should dispose of them in time, and then do a good job of ploughing to ensure their sunlight exposure, so that you can effectively kill germs.

4. Lettuce aphid disease

Aphids are common not only in lettuce, but also in many vegetables.

Prevention and control method: the mixture can be made with washing powder, urea and water according to the ratio of 4-1-100, and then evenly sprayed on the front and back of the leaves, which can not only control aphids, but also promote the growth of leaves.