Pest control of winter broccoli
There are many kinds of pests harmful to broccoli, including aphids, whiteflies, diamondback moth, cabbage butterfly and beet armyworm. In recent years, whiteflies, diamondback moths and beet armyworm have been seriously damaged. First, the damage characteristics 1, locusts: adults and nymphs are generally gathered in the back of the leaves and heart and other parts of the sucking juice, so that yellow cauliflower leaves and even fall off, and can spread viral disease, the plant yellow, slow growth, and even death . 2, Whitefly: Hi clustered on the young leaves feeding damage, the victim leaves yellow, wilt, and even the whole plant withered. Whitefly also secretes honeydew, causing soot, affecting plant respiration and photosynthesis. In addition, viral diseases can also be transmitted. 3. Plutella xylostella: Newly hatched larvae can be fed into the leaf tissue to feed on the leaf. After the 2nd instar, the foraging leaves leave a layer of epidermis. In 3rd and 4th instar, the leaves form a hole and a nick. In severe cases, only the leaf veins remain. Great harm. 4. Pieris rapae: The first-instar larvae feed on the mesophyll, forming transparent pores, which are dispersed after the 2nd instar, feeding the mesophyll, leaving only petiole and main veins in severe cases. 5, Spodoptera exigua: high temperature and drought years are harmful. When the larvae hatch, they are damaged by a dorsal cluster near the egg mass. After 2nd age, it began to disperse, and after 3rd instar, it entered the gluttony period. The amount of food leaves accounted for more than 90% of the total larval feeding period. Second, the law of harm 1, the period of harm: aphids, cabbage butterfly, diamondback moth, whitefly can be harmed throughout the growth period of cauliflower, and beet armyworm in the late growth of cauliflower. 2. Habits: Aphids and whiteflies are overlapping in generations, and various forms of insects can be seen in the same period. Among them, maggots can reproduce 1 generation every 5-6 days, whitefly generally produce 1 generation every 10 days, and each spawns 300-600 grains. . Cabbage butterfly spawns an average of 120 capsules each time, up to a maximum of 500 capsules. Plutella xylostella can occur from one generation to several dozen generations in one year, and the number of reproduction is large. Each female lays 100--600 eggs. The larvae of Plutella xylostella, Pieris rapae, and Spodoptera exigua lived in a pseudo-dead form and fell to false death after being frightened. This caused great difficulties in prevention and control. III. Comprehensive prevention and control measures 1. Agricultural control: timely removal of weeds, diseases, and old leaves of field weeds and crops in the winter and spring, and centralization of deep-buried or destroyed, can eliminate most of the overwintering earthworms and reduce the number of population bases; use the phototaxis and tendencies of adults. Chemical, black light or sweet and sour liquid for trapping, can also be used soybean cake, sweet potato fermentation broth added a small amount of trichlorfon to kill. 2. Chemical control: The principle of timely, appropriate, scientific allocation, and alternate use. In the initial stage and time of the pests, 7.5% of decantl is used as a 1500-fold solution, 18.5% of Derick WP is used as a 1500-fold solution, and 0.5% of Defence EC is used as a mixture of 750-times. Beta-cypermethrin pesticides can also be used. Conduct prevention and treatment. Do not use Bataan and other carbamate insecticides during the prevention and treatment to avoid injury. China Agricultural Network Editor