What are the symptoms of black rot in Chinese cabbage? How to prevent and cure?

Cabbage is a very common vegetable, which is planted all over our country, and there are many ways to eat it, whether it is stir-fried or pickled, it has its unique flavor. Chinese cabbage has low requirements for the planting environment and is easy to manage. The common disease of Chinese cabbage is black rot, which will cause serious nutrition to its quality once it occurs. What are the symptoms of black rot in cabbage? How to prevent and cure?

First, what are the symptoms of black rot in cabbage?

Black rot of Chinese cabbage occurs in all stages of cabbage growth. The cotyledons of the seedlings became sick, the edges were flooded, the root pith blackened and died quickly. At the adult stage, pathological changes appeared from the edge of the leaf and gradually expanded inward, forming a "V"-shaped black-brown spot, the surrounding yellow, and the boundary between the disease and the healthy part was not obvious. the veins of the reticular leaves in the lesion turned brown or black. Petiole disease, upward development along the vascular bundle, can form brown dry rot, leaves tilted to one side, half of the leaves yellow. most of the leaves of seriously affected plants withered or collapsed.

Pathogenic bacteria can survive the winter on seeds and the remains of diseased plants in the field, as well as on seed-collecting plants or overwintering vegetables. Infected seeds are the most important source of primary infection. Spring spread to the leaves through Rain Water, irrigation water, insects or farming operations, and invaded through water holes on the edge of the leaves, leaf wounds, and insect wounds. The most suitable disease environment is the temperature of 20: 30 ℃ and the relative humidity of more than 90%. The most suitable growth period is from rosette stage to pericardial stage. It often happens badly after a storm. Under the conditions of low-lying land prone to stagnant water, land with too much irrigation, continuous cropping, application of unripe farm manure, over-dense planting, long leaf dew time, leaf margin spitting, extensive management, overgrowth or early senescence of plants, and serious occurrence of insect pests, the disease is more serious.

Second, how to prevent and cure the black rot of cabbage?

The main results are as follows: 1. The seeds of disease-free plants are collected and disinfected when sowing. The seeds can be soaked for 20 minutes with 45% sulfamethonium solution, washed and dried, or soaked in 50 ℃ warm water for 20 minutes, cooled with cold water, or mixed with 50% Fumishuang wettable powder of 0.3% seed weight.

2. 2-3 years rotation with non-cruciferous crops.

3. Sowing at the right time, watering at the seedling stage, squatting seedlings reasonably, pulling out the diseased plants in time and taking them out of the field and burying them deeply, and disinfecting the diseased holes with lime.

4. Chemical control. In the early stage of the disease, timely spraying "Tianda 2116" liquid + "Tiandanuoshi" 1000-fold solution, 72% agricultural streptomycin soluble powder 4000-fold solution, neophytomycin 4000-fold solution, 47% Jia Ruinong wettable powder 800-fold solution, 70% Dixone soluble powder 1000 times, and so on.

Therefore, the majority of growers should pay attention to the selection of appropriate varieties, suitable soil and correct management points when planting cabbage, so as to effectively prevent the occurrence of cabbage black rot.