How to control Chinese cabbage diseases and insect pests, Chinese cabbage diseases and insect pests control technology

Chinese cabbage is a common vegetable in northern China. Chinese cabbage tastes good and has high nutritional value. However, Chinese cabbage is easily affected by plant diseases and insect pests in the process of planting and growth, which leads to yield reduction. Therefore, the problem of pests and diseases of Chinese cabbage should be paid attention to. So, how to control the pests and diseases of Chinese cabbage? Today, Bian Xiao will introduce the pest control technology of Chinese cabbage to you.

Pest control technology of Chinese cabbage-disease control

1, downy mildew. It mainly harms leaves, which form yellow patches and turn light brown after expansion. When the humidity in the field is high, white mildew spots appear on the back of leaves, and finally the leaves turn yellow. The temperature is high and low, the temperature difference between day and night is large, the temperature is high, and it is easy to happen when it is exposed to fog. Sowing was too early and the density was too high. Baneda Bika applied high nitrogen fertilizer, which led to serious drainage in the field. At the initial stage of the disease, 40% ethyl phosphate 800 times solution, 58% metalaxyl manganese zinc 500 times solution or 1.5% propafenone 1000 times solution can be sprayed on the leaves, 2-3 times per week.

2. Soft rot. Most diseases occur at the bulbous stage. At the beginning of the disease, the base of peripheral leaves or shortened stems are soaked in water, and then the leaves wilt and collapse, and the bulbs are exposed. Sometimes, they rot outward from the shortened stems, sticky and smelly. Bacteria are mainly spread by insects, rain or irrigation water, and invade from wounds. Low temperature, rain and water accumulation, weak plants, easy to get sick. Using high ridge plastic film mulching cultivation and crop rotation can reduce the incidence rate, at the same time, it is necessary to prevent excessive squatting and flooding of seedlings and reduce wounds and mechanical injuries. At the beginning of the disease, 72% agricultural streptomycin 3000 times solution, 3% Kejunkang 1000 times solution or 20% Longke 500 times solution can be sprayed alternately, once a week/kloc-0 times, 2-3 times in total.

3. Viral diseases. Symptoms are divided into mosaic type and shrinkage type. After sowing, Chinese cabbage encountered high temperature and drought, which inhibited the growth and development of root system and reduced its disease resistance. In addition, high temperature and drought are conducive to the occurrence of aphids. The virus disease of Chinese cabbage is spread by aphids, so it is very important to control aphids. Spraying 2000 times of 10% imidacloprid 1 time every 7- 10 days, 2-3 times in total. After the onset of Chinese cabbage, spray 800 times 1.5% Bingzhiling No.2 solution or virus buster foliar spray, once a week 1 time, 2-3 times in total.

4, black spot disease. Starting from the rosette leaves, a nearly round grayish brown lesion with obvious concentric wheel lines is produced. At the initial stage of the disease, 500 times of 50% carbendazim solution was sprayed every 5-7 days 1 time for 2-3 times continuously.

5. Dry burning heart disease: it usually occurs in the rosette stage of Chinese cabbage, and the young leaves show dry edges. At the fruiting stage, the symptoms are obvious, the upper leaves gradually dry and turn yellow, the mesophyll is dry and paper-like, and the veins are yellow-brown to black. The location of the disease is mainly in the middle of lobar lobe. The disease is a physiological disease, which is mainly caused by the deficiency of calcium and manganese nutrients. Control measures: (1) Increase the application of organic fertilizer; (2) Chemical control: spraying 0.7% manganese sulfate and Lvfenwei No.3 before seedling stage, rosette stage or filling stage of Chinese cabbage.

6, white spot disease. Mainly harmful to leaves. At the time of onset, there are many gray-white nearly round lesions scattered on the leaves, and there are 1-2 irregular wheel lines in the center. Finally, the lesion was white and translucent, as if it had been burned. Avoiding continuous cropping, increasing base fertilizer and preventing water accumulation in the field can reduce the occurrence of diseases. At the beginning of the disease, 50% carbendazim 500 times solution or 70% mancozeb 500 times solution were used for prevention and treatment, and sprayed every 10 day/time, 2-3 times in total.

Pest control technology of Chinese cabbage Ⅱ —— Pest control

1, aphids and whiteflies

Damage characteristics of (1): Both of them suck the juice of Chinese cabbage as adults and nymphs, which leads to yellowing, wilting and even death of the whole plant. Secreted honey dew seriously pollutes the leaves, causes mildew, and makes Chinese cabbage lose its edible value. In addition, it can spread viral diseases.

(2) Control method: ① Physical method: yellow boards are set in the field to trap and kill aphids and whiteflies, and 20-25 yellow boards are set in each mu of land, which are fixed on wooden sticks and inserted in vegetable fields. The height of the bottom of the yellow boards is 20cm② higher than the top of the plants. ② Biological method: 45 ml of 3% pyrethrin microcapsule suspension can be sprayed for control. ③ Chemical method: 2000 times of 10% imidacloprid wettable powder, 2500 times of Derrick/kloc-0, and 2500 times of 98% Bataan wettable powder can be sprayed alternately every week 1 time, 2-3 times in total, and medicine should be taken in the morning and evening.

2. Pieris rapae, Spodoptera exigua and Plutella xylostella

(1) Damage characteristics: All three pests feed on leaves by larvae, and Pieris rapae can eat the whole leaves after the third instar, leaving only veins, which seriously affects the growth and core of Chinese cabbage, leading to yield reduction; Spodoptera exigua mainly webs on the back of newly hatched larvae and feeds on mesophyll, leaving transparent pores on the epidermis. After the 4th instar, the food intake increases greatly, the leaves are eaten into holes or nicks, and in severe cases, only the veins and petioles are left, which has a great influence on the yield and quality. Plutella xylostella can eat leaves into holes and nicks. In severe cases, the whole leaves are eaten into a net, and the central leaves are often damaged at seedling stage, which affects the cabbage heart.

(2) Prevention and control methods: ① Physical methods: Using the phototaxis of pests, set a frequency-vibrating insecticidal lamp or black light lamp every 40-50 mu in the field to trap and kill pests; You can also use the sex pheromone tropism of Spodoptera exigua and Plutella xylostella to put a set of sex attractants in each mu of land to trap and kill pests. (2) biological method: biological agent BT250-500 times can be used to control juvenile pests; ③ Chemical method: 3000 times of 15% Anta SC, 1500-2000 times of Aandahl and 1500-2000 times of 4.5% beta-cypermethrin EC can be sprayed alternately for control.

Timely pest control of Chinese cabbage can not only ensure the quality of Chinese cabbage, but also ensure the yield per mu!