Harm and control methods of root swelling disease of Chinese cabbage
Chinese cabbage root swelling disease is a kind of serious damage to Chinese cabbage. It will often occur from seedling emergence to adult stage. Chinese cabbage root swelling disease will greatly harm the production and quality of Chinese cabbage. So how to prevent and control Chinese cabbage root swelling disease?
In the early stage of the disease, the surface of the tumor was smooth and clean, but in the middle and later stage, the surface was not smooth, uneven and significantly cracked. The main root malignant tumor is as big as raw egg, the total number is reduced, the main root malignant tumor is not big, the root hair malignant tumor is usually a string, as large as more than 20.
The root of the key injury, resulting in the main root or main root of different sizes, nearly finger-shaped, short rod-shaped or spherical tumor. The leaves slowly turn yellow from the bottom up, and the main stem withered around the afternoon on a sunny day seems to be lack of water or lack of nutrition.
III. Prevention and control of agriculture and animal husbandry
1. It is forbidden to ship seedlings, vegetables and fruits from wards in order to maintain no wards, strictly select pre-seedlings in disease-free or newly reclaimed land, and pay attention to replacing diseased seedlings when planting and planting.
two。 Improve the alkalization of soil. It has been found that * soil alkalinization is one of the key factors causing root swelling of Chinese cabbage. The actual effect of using raw lime powder and silicon powder to adjust the acidity and alkalinity of soil ph to control the disease is good. In order to adjust the pH of soil ph, 100kg of quicklime powder was used at the seedling stage before planting, and then wet irrigation was used to keep the PH value between 7 and 7.5. the soil was alkaline at the seedling stage, and the incidence of root swelling disease of cabbage seedlings was significantly reduced, which is a simple and feasible technical measure.
3. Disease-resistant varieties were used. It is the best way to deal with root swelling disease from the source. At present, the resistance types of marketing promotion in the sales market are Dafeng No. 2, Qingza No. 3, improved Qingza No. 2, Chengyang District Qing, Lufeng No. 2, Lvxing 70, Jiaobai 10 and so on. It can be adopted in all parts of the country according to the times.
4. Rotation and stubble. In the countryside where the disease is relatively serious, it is necessary to rotate non-cruciferous crops such as bracts, wheat, rice and other Cyperaceae crops, or legume crops such as soybeans and beans for more than three years. In general, eggplant beans, melons and legumes can be planted in spring and summer, and spinach, bamboo shoots and onions, ginger and garlic vegetables and fruits can be changed in autumn and winter.
5. Dry the soil and choose the tall box to plant. Sunny days should be selected for colonization, and sunny days with 1-2 weeks after colonization can greatly alleviate the disease; such as rainy days during colonization or rainy days not long after colonization, 2% lime paste is applied to reduce the incidence of the disease. When collecting vegetables, it is best to pull up the roots, and bury the crux of the problem in a pit 45-60 cm deep, apply lime powder, and then carry out covering * to promote the rot of vegetable roots and the death of pathogens. Pay attention to the coordinated application of nitrogen, phosphorus and potassium, do not overapply basic fertilizer, and pay attention to the environmental hygiene of the field and remove cruciferous weeds immediately.
6. Appropriate use of quicklime powder, ploughing when 1 mu of lime powder 75-100 kg to adjust * soil to slightly alkali. The lime powder can be evenly applied 7-10 days before planting. After the occurrence of diseases and insect pests on the street, it can be drenched with 2% aluminum chloride, and then drenched every seven days, which can greatly alleviate the injury. Or in the long-term prosperity of cabbage, irrigate the root with 1% raw stone for 2 times.
IV. Drug prevention and treatment
1. Seed disinfection
The seed disinfection solution was carried out by using 25g / L fipronil floating seed coating agent 500ml, water 2KG, and carrying out seed disinfection solution. The actual effect of disease prevention was good.
2. * disinfection and sterilization of soil or seedlings
Before planting, the solution of disinfection and sterilization of soil at seedling stage should be solved as follows: wet * spray 18KG with formalin solution of 100 times formalin solution per square meter, dry * spray 36KG solution with 100 times formalin solution per square meter before planting, and then cover it with plastic film or herb. Can use 95% sodium sulfonate wettable agent 0.3 kg, mix fine * 30 kg into the direct seeding ditch, cover * and then plant. Or apply 70% pentachloronitrobenzene or 50% methyl topiramate wettable powder symmetrically before planting cabbage, about 1.5 kg per mu, or irrigate 50% methyl topiramate wettable powder 500 times before planting vegetables and fruits, 250 grams of irrigation solution per tree, and irrigate it again one month later. Or before planting, after planting, the Chinese cabbage was irrigated with 2000 times of its diluent solution, 1 mu of 300KG, and then irrigated the root once in 7-10 days. When planting fields are irrigated with fixed root water, the roots are sprayed. Or soak the roots of vegetables in 800-fold solution of 10% cyanofrozole suspension for 20 minutes before planting.
3. Disease field prevention and control
In the early stage of the disease, when a small number of diseased plants were seen in the field, the roots were irrigated with 50% methyl topiramate wettable powder 500 times or 50% triadimefon wettable powder 500 times, which has a good disease control effect. Each tree uses 0.5 kg of liquid medicine. Or point the 1000-fold liquid of 20% quinolone wettable powder to the tip sprayer of the disease, which has a good preventive effect.
To sum up, it is the content of the prevention and treatment of Chinese cabbage root swelling disease. Chinese cabbage growers can refer to learning and training, and we should be cured in the early stage of the disease, but there is no way to repair it in the middle and later stage.