Harmful symptoms and control measures of greenhouse vegetable whitefly
Whitefly is a kind of pest that makes many farmers and farmers have a headache. If you want to control it, you should solve it from the habits of whitefly. The following points hope to help the farmers. Morphological characteristics The life cycle of greenhouse whitefly can be divided into four stages: egg, nymph, cockroach, adult, and its formation time is: whitefly can produce 9-10 generations a year, about 30 days in a generation, and 100 eggs can be laid at a time. The eggs are yellowish brown, ovate-shaped and scattered on the back of the leaves. If the nymph's body is elliptical, the first-instar larvae that are hatching will crawl to find the proper position, and then fix it on the back of the leaf, and the mouthparts will penetrate into the plant to suck. The adult body is covered with a layer of white wax, which uses its sucking mouthparts to absorb plant juice. 2. Hazard symptoms The growth of nymphs and adult worms can cause the leaves to fade, curl and shrink. The nymphal secretions often induce plant mildew and cause the leaves to be covered with a black mildew, which leads to normal photosynthesis and respiration of the leaves. Interference, plants are weak and dead. In addition, whitefly is often the media of viral diseases. 3. Prevention measures (1) Keep good seedlings and cultivate insect-free seedlings. The pre-emergence fumigation greenhouse removes residual insects, removes weeds, and adds a layer of nylon yarn to the greenhouse vent to avoid foreign insect sources. (2) Try to avoid mixing: especially cucumbers, tomatoes, and beans cannot be mixed. It is also an effective method to adjust the production of cornices, that is, the head lice arrange white cabbage, such as celery and sweet pepper, to harm light vegetables, and then plant cucumbers and tomatoes. (3) The branches and dead leaves laid in production are disposed of in time. Older nymphs are mostly distributed in the lower leaves, and some of the old leaves are properly removed when the solanaceous fruit is pruned, buried or burned to reduce the population. (4) Release of Lily wasp or Grasshopper: When the adult whitefly is less than 0.5 head/plant, 15 times of the bee is released into the bee every 15 weeks. (5) Verticillium can parasitize whitefly, and cause population diseases to be prevalent. The greater the population density of whitefly, the better the infection, spread and prevalence of the fungus. (6) Using yellow plates to trap adult worms, yellow has a strong trapping effect on adult white cockroaches, set yellow plate in the greenhouse (1 m × 0.7 m fiberboard or cardboard, painted orange peel yellow, and then coated with a layer of viscous oil per The use of 32-34 acres), the effect of trapping adults is significant. The yellow plate is placed between the rows and the height of the plant is equal. The viscous oil is generally adjusted with No. 10 oil and a little butter, and reapplied once every 7-10 days. Take care to prevent oil droplets from causing burns on the crop. (7) Chemical control: When averaging 3 adult per worms, use 3% acetamiprid emulsifiable concentrate 1200 times solution, 70% Emerald water dispersion granules 15000 times solution, 25% Aketai water dispersion granules 3000 Double solution, 25% buprofezin (Pulsin) wettable powder 2000 times solution, 10% imidacloprid wettable powder 1500 times solution and Tianda 2116 mixed spray 1-2 times, and prevent viral diseases and powdery mildew, the effect Significant. For the wonderful pictures and hot comments on the prevention and control of greenhouse whitefly, you may be interested in the following recommended contents. Welcome to read. X Ray Straight Lead Neck Protection,Lead Neck Collar,X Ray Thyroid Shield Collar,Radiation Thyroid Shields Collar Longkou Kangxie Medical Instrument Co., Ltd , https://www.lkmradiology.com
