What are the methods for preventing and controlling lettuce pests and diseases? Learn it all in one article

Lettuce is a vegetable with relatively high economic value, and it has extremely high edible and cultivation value. It is relatively commonly grown in China, but once it is invaded by pests and diseases during cultivation, it basically becomes inedible, so pest and disease control must be taken seriously during cultivation. So what pests and diseases does lettuce have? Let's take a look below at the common methods for preventing and controlling lettuce pests and diseases.

1. Soft rot

Soft rot mainly occurs in the late growth stage or heading stage of lettuce. Its pathogen mainly overwinters dormant in the soil or on diseased plants, and spreads infection through watering and fertilizing. Generally, when a plant has a wound, the infection enters through the wound. In the early stage of the disease, the infected area appears water-soaked and semi-transparent. As the disease develops, irregular water-soaked lesions form. There is also a brown sticky substance at the lesions, accompanied by a foul odor, and finally the entire head rots.

Control methods: Plow and prepare the soil, use the sun to sterilize, remove diseased plants, reduce pathogens, strengthen fertilizer and water management, apply organic fertilizer, improve disease resistance, and pay attention to drainage after rain to avoid root damage caused by waterlogging in the field. When diseased plants are found, pull them out promptly and take them out of the field, then disinfect the diseased holes. In the early stage of the disease, spray with 50% Kechade wettable powder at 500 times dilution or streptomycin sulfate at 5,000 times dilution for control, once a week, with the number of sprays determined by the severity of the disease.

2. Downy mildew

Downy mildew is a major disease in lettuce production. It generally occurs in spring and autumn, and can damage plants from seedlings to mature plants, with mature plants suffering more severely. It mainly harms the leaf parts of lettuce. When the disease occurs, light yellow lesions appear on the leaves. In humid environments, a downy mildew-like mold layer appears on the underside of the leaves, and in severe cases it can spread to the leaf surface. In the late stage of the disease, the leaves wither and die.

Control methods: Rational crop rotation to reduce the severity of the disease, adopt high-ridge cultivation or plastic film mulching cultivation, choose varieties with strong disease resistance, and disinfect seeds before sowing. Strengthen fertilizer and water management, apply organic fertilizer as base fertilizer, apply sufficient base fertilizer, and apply as little or no topdressing as possible. Plant at a reasonable density to increase air permeability and reduce the probability of disease occurrence. When diseased plants are found, pull them out promptly and take them out of the field for centralized burning, and at the same time spray Jinlei and Previcur liquid agents for control.

3. Sclerotinia rot

Sclerotinia rot mainly harms the base of the lettuce stem. When the disease occurs, yellow-brown water-soaked lesions appear at the base of the stem. As the disease develops, it gradually spreads to the entire stem, causing rotten leaves and rotten hearts, and finally the whole plant wilts and dies. At high temperatures, cotton-like mycelial masses also form at the diseased area, which later turn into black mouse-dropping-like sclerotia.

Control methods: After harvest, clean the field, clear away diseased residues and fallen leaves, deeply plow the soil to bury the pathogens deep in the soil, then spread quicklime, plow the land, make ridges, water, and finally cover tightly with plastic film. Use this method to kill the pathogens in the soil. When it occurs, spray with 40% sclerotinia wettable powder at 500 times dilution or 45% Tecto suspension concentrate at 800 times dilution for control.

4. Insect pests

Lettuce is a leafy vegetable, and because its leaves are green and tender, not only do we like it, but aphids are also especially fond of it. They often gather on the leaves and continuously suck the leaf sap, causing the mesophyll tissue to disappear and leaving only a layer of epidermis, and finally the plant withers and dies.

Control methods: When aphids break out, use 10% imidacloprid wettable powder at 1,500 times dilution or yellow sticky traps to trap and kill them.

The above are methods for preventing and controlling lettuce pests and diseases. We hope this can help you. If you want to learn more about vegetable cultivation knowledge, please follow us.