The Chinese cabbage grown in my hometown has a two spotted leaf mite, what are the dangers to the Ch

The necessary conditions for the occurrence of bacterial diseases and fungal diseases are that the humidity in the environment is large, and the occurrence of bacterial diseases will be more serious, especially when the crops have wounds, because the infection ability of bacteria to crops is relatively weak, and there are more diseases that need to invade Chinese cabbage with the help of plant wounds, among which downy mildew, virus disease, and soft rot are more common and serious, and there is a common disease is Chinese cabbage dry heartburn, and the occurrence of diseases often causes Chinese cabbage yield to be reduced.

<> the following according to the previous experience to explain that the insect pests of Chinese cabbage mainly include aphids and some cabbage moths, etc., these pests will mainly eat the leaves and cabbage juice of cabbage, when the juice of cabbage is sucked away, so the cabbage will not last long to dry up, if not treated in time, the cabbage is easy to die, so such as box mold may appear in the whole growth process of Chinese cabbage, the occurrence of downy mildew is related to climate, variety and other factors, the main symptom is to produce water immersion on the bottom leaves, Pale yellow polygonal lesions, and slowly enlarge, turning yellowish-brown, if slightly neglected, soft rot is commonly known as rotten pimples. At the beginning of the disease, the base of the cabbage gang formed a water-soaked yellowish infiltration zone, which gradually turned yellowish-brown, sticky and soft rot, the leaves wilted, and finally the rhizome rotted and had a foul smell.

Generally, it occurs from the rosette stage to the heart stage, and the disease is selected by soft rot to resist varieties; Avoid continuous cropping; Sowing at the right time, appropriate sparse planting; Morning seedlings, late seedlings, moderate squatting seedlings; Frequent irrigation of small water, timely drainage after rain; Apply foot fertilizer, increase phosphorus, potassium, calcium fertilizer, Jiamei dividend, internal potassium virtue, enhance seedling potential; After the diseased plant was found, it was removed in time, and there were no obvious symptoms in the mold layer and the front of the leaves, and the seedling leaves and cotyledons turned yellow and died when it was severe. The adult plant is damaged, and the back of the leaf shows white downy mildew, and the front of the leaf shows pale green lesions, and gradually turns yellow to yellowish-brown. The enlargement of the lesion is often limited by the veins and forms a polygonal shape.

The cabbage is destroyed after entering the core stage.

The two-spotted leaf mite sucks on the back of the leaf. At the beginning of the affected leaves, there were green spots on the leaf surface, and then gradually joined into patches, and finally the whole leaf was scorched and fell off. When the insect quantity is large and the damage is serious, most of the leaves fall off in August, and even bloom for the second time, which affects the yield of the year, and more importantly, causes the weakening of the tree, affects the yield of the next year and even the next few years, and is easy to cause the epidemic of bark rot disease because of the weakness of the tree.

Peanuts also need to play mequat during the period of lush branches and leaves, which is to prevent the branches and leaves from flourishing, only seedlings do not bear fruit, so planting Chinese cabbage must be left in advance of the spring land, and be prepared to plant Chinese cabbage, otherwise it will really lead to many diseases and disasters of Chinese cabbage! The possible reason for this may be that it is more likely to be confused by vegetable farmers with other diseases. Now, the rural fireflies will review some knowledge about the prevention and control of Chinese cabbage white spot disease with everyone, so as to be a prepared vegetable farmer for the prevention and avoidance of white spot disease when planting Chinese cabbage in the coming year.

As the disease worsens, the lesions will gradually expand, and the color will slowly change from gray-brown to white, and a pale green halo will appear around the lesions, until finally the disease is severe, and the lesions will become translucent due to drying, expanding and contiguous, causing the leaves to dry up and die.

The outer edge of the lesion is pale yellow halo, there is a light gray mold layer on the back of the lesion when the humidity is high, the lesion becomes thin and translucent in the later stage, and the perforation and rupture when drying, and the leaf is dried up when the lesion is more, which directly affects the yield and quality of cabbage, and is a common disease of cabbage planting. In the process of growth and development, such a good Chinese cabbage is often infected by white spot disease, resulting in leaf spots. Blight, how can we prevent and control vitiligo?

This article introduces the identification, harm, transmission, occurrence conditions and prevention methods of vitiligo.

Cabbage virus disease (the main symptoms are: seedlings are sick, and the heart leaves appear bright veins or rock leaf veins lose green, and then produce pale green mosaic leaves or mottled symptoms.) The disease occurs at the adult stage, and the damage is mild or the disease can catch the ball in the later stage, but the manifestations are different, and small brown lesions appear on the veins and petioles of the leaves).

The pathogen overwinters on the soil or vegetables with the residual disease, and germinates and infects the seedlings when the conditions are suitable in the spring of the following year, and the average temperature of the epidemic is about 16 °C, and the lesion expands the fastest at 16 to 20 °C. It is easy to occur when there is low temperature and rain, high and low temperature, large temperature difference between day and night, and large dew.

The lesions on the leaves are scattered at first, the gray-brown round small spots, it will expand into white amorphous lesions when it grows up, there are light yellow-green halos around the lesions, and under humid conditions, the back of the lesions produces a sparse light gray fog layer after the lesion, and the white translucent leaves die in advance after the lesion is roasted and fire-like.

The lesions on the leaves are scattered gray-brown round small spots at first, and then expand into gray-white amorphous lesions, with pale yellow-green halos around the lesions. Under wet conditions, a sparse pale gray mold layer develops on the back of the lesion. Later, the lesions become white and translucent, often ruptured and perforated.

When there are many lesions, the leaves die early. The leaves of the diseased plant are dried up layer by layer from the outside to the inside, like a fire.

Whiteflies, leafhoppers, planthoppers, blind bugs, thrips, etc.

Leaf-eating pests with borrowing: diamondback moth, heartworm, cotton bollworm, beet armyworm, cabbage worm, etc.

Underground pests Ground tigers, grubs, needleworms, etc. Please refer to it.