Although cold vegetables are still prone to disease in winter, how to control vegetable diseases in winter

Control of vegetable diseases and insect pests in winter

I. vegetables in the open field

Cruciferous leafy vegetables are the main vegetables in winter, while aphids and downy mildew are the most common in cruciferous vegetables in winter, such as sunny and dry in winter, which is conducive to the occurrence of aphids and heavy aphids, such as more overcast and rainy days in season, which is conducive to the occurrence of downy mildew.

1. Downy mildew. Harm to pakchoi and lettuce, such as winter drought, the problem is not big, such as continuous rain, commonly known as "rotten winter", the occurrence of downy mildew is serious, the lower (base) leaves of vegetables are yellowed, resulting in vegetable stagnation and even death. At present, the temperature is low and there is much rainfall, which is conducive to the occurrence of downy mildew. Prevention and treatment drugs: Metalaxyl, mancozeb, thiram combined with new high lipid membrane.

2. Aphids. Aphids are the heaviest occurrence and pest control on open-field vegetables in winter, which can be harmed until late December. Although the temperature is low, the rainfall is high, and the number of insects in the field is low, it is beneficial to the occurrence of aphids as the weather returns to normal. Special attention should be paid to the fact that the authoritative department expects this year to be a warm winter, which will aggravate the occurrence of diseases and insect pests, especially aphids. At present, the general rate of insect trees in the field is 2mur8%, and there are 10 insects per leaf, which are clustered on the back of the leaves or in the shelter of cabbage heart from the rain. The rate of insect plants in the field is 35%, and there are hundreds of worms per leaf, resulting in yellowing or death of vegetables. Key points of prevention and control: cruciferous vegetables that have never prevented aphids; control indicators: the rate of insect plants is more than 10%; control drugs: acetamiprid, imidacloprid, pyrethroid pesticides combined with new high lipid membrane, tree protection general.

2. Vegetables in greenhouse

Because of the high humidity and high temperature in the shed, the disease is widespread and serious, so it is very important to control the disease. The main diseases are blight, anthracnose, powdery mildew, soft rot and downy mildew. With the gradual harvest of fruits and vegetables, the vegetables in the greenhouse gradually increase in seedling stage. Botrytis cinerea, anthracnose and blight will occur seriously. Greenhouse disease prevention and control should be strictly controlled, especially in seedling stage and flowering stage, conservative control and prevention should be given priority to, once every 10 days, diseased branches and leaves should be found, and should be picked and burned in time. If the disease is serious and humidity is high, smoke control should be changed. Winter shed pests, mainly aphids, because of their rapid reproduction, and cause wounds, spread the virus, found to be timely treatment. The warm winter weather will aggravate the occurrence of vegetable diseases and insect pests in the greenhouse, and vegetable farmers should pay attention to it. In order to really control greenhouse diseases, it is inseparable from cultivation and management, such as narrow furrow, soil disinfection, aseptic seedling transplanting, plastic film mulching, no dripping film, timely opening of greenhouse for ventilation, ventilation and so on.

Prevention and treatment drugs: blight: copper master or Longke bacteria combined with new high lipid membrane; powdery mildew: Fenxiu Ling (triadimefon) tree protection general; Botrytis cinerea: grey gram or Sukeling combined with new high lipid film; anthrax: anthrax Fumei or chlorothalonil and new high lipid membrane mixed spraying.