Whitefly, its population base is large, its reproductive ability is strong, its growth cycle is short, and it has the characteristics of wide parasitic range, high outbreak rate and long time of harm. Especially the difficulty of prevention and control, it is difficult to completely cure after pests. It can be said that it is a very troublesome pest. So how to prevent whitefly? In order to completely solve the hazards of whitefly, on the one hand, we must adhere to the principle of combining prevention and control to prevent and cure. Do not wait until the pests occur, and then hold the Buddha's feet temporarily. On the other hand, through the combination of physical, biological, and pharmaceutical measures, the effect is controlled. Only when it is more ideal, on the one hand, the majority of farmers’ friends must understand the characteristics of the disease hazards in the prevention and control of any pests and diseases, and take correct measures to achieve the best prevention and control purposes. Here are the following questions to share with you: 1 the incidence of whitefly mites; 2 the harmfulness of whitefly; 3 why can't control whitefly; 4 how to effectively prevent whitefly. First, the incidence of whitefly 1. Whitefly is harmful to most crops (can survive more than 300 kinds of plants), especially for all kinds of vegetables. Whether it is a protected area, a greenhouse, or an open field, it is easy to cause harm. The suitable temperature is generally 28-30 degrees. Since the temperature of the greenhouse is generally maintained at about 20 degrees, the greenhouse is most seriously affected by insects. 2, whitefly è™± can overlap the hazard of generations, in the shed indoors more than 10 generations a year, the breeding algebraic root temperature has a close relationship, the higher the temperature, the faster the reproductive reproduction speed: the next generation of 18-20 environment takes 30 days Around the world, the next generation of 24-25 degrees takes about 25 days, and in the 27-degree environment, the next generation takes only about 22 days. 3, the population of whitefly mites is very large, and the number of females is quite amazing. One female lays about 100 eggs at a time, and the total number of eggs laid in a lifetime is as high as 3,500. The population of one generation can increase by more than 100 times. After ten generations of breeding, the number of whitefly mites directly doubled into a geometric index, and the number is very terrible! Don't look at the white powder, but no crop can withstand its high number of hazards. 4. Whitefly has a strong tendency to tenderness, and its distribution on crop plants is also regular. Adults and nymphs generally prefer to live in the back of the crop leaves, from the top of the plant to the lowermost part, and the layers are yellowish eggs, black eggs, nymphs of the first age, nymphs of the old age, and insects. To understand this, everyone can have better targeted prevention and control when using different drugs to control whitefly in different periods. 5. Although whitefly grows and grows all the year round (especially in greenhouses), it has two distinct breeding peaks. One is in the spring greenhouse from mid-April to late May, and the other is the autumn shed, the open field from late July to late September, in which the insulation shed can last until the end of November. This is very important for identifying the critical period of prevention and control of whitefly. Second, the harmfulness of whitefly The harm of whitefly can be divided into two types: A sap-sucking hazard—the nymphs and adults on the back of the foliar, pierced into the plant tissue through a self-growing sucker, and continuously harms the leaf juice, the carbohydrates in the plant, and injects toxins into the crop. (If the nymph can be harmed within three days), the plant absorption and photosynthesis will be reduced, the leaves will be green and light, the fruits will be blackened, and the yellow flowers will be wilted. Even if the damage is serious, the whole plant will die. The other is the harm of adult excreta - a large number of adult insects living on crop plants will directly discharge excreta to the leaves and fruits of the crop, which not only makes the fruit quality of the crop seriously damaged, but also induces bituminous diseases and molds. Diseases and other diseases, and whitefly is also the vector of various crop virus pathogens, causing more diseases in crops. 3. Why is it difficult to prevent and control white powder? 1, caused by the characteristics of white powder Whitefly has the characteristics of large population base, fast propagation speed and superimposed damage, and it can not only breed in greenhouses, open fields and protected areas, but also can live on hundreds of crops and plants in 112 families. The breeding hazard is very difficult to completely cure. I have already introduced it above, not much to say. 2, the drug can not comprehensively control the diversified whitefly Whitefly has a strong ability to reproduce. It can be propagated for more than ten generations a year. The same crop is raised. Eggs, nymphs and adults exist at the same time. Sometimes the number of times a farmer friend fights is not as fast as it is, and the market is There is no specific drug that can kill the growth period of different whitefly mites at the same time. The general drug can kill the adult worms at a good time, but the killing effect on the eggs and nymphs is poor, so it is difficult to control. 3, whitefly has certain resistance On the one hand, the whitefly has wings, and it can fly away from the migration when it is sprayed, and then fly back after the effect of the drug subsides; on the one hand, the wings of the whitefly have a waxy layer, if only a single spray of liquid, it can not be very Good to make the liquid adhere to the worm body, can not achieve a better killing effect; on the other hand, because white mites have occurred for many years, farmers' friends use drugs or single drugs every year, causing whitefly to produce strong drugs. The resistance, the common medication method is difficult to obtain a good control effect. Fourth, how to effectively prevent whitefly 1. Prevent in advance and seize the critical period of prevention and control Many farmers lack the corresponding skills in the management of pests and diseases, and can not do a good combination of prevention and treatment. It is often waited until the large area of ​​whitefly is started to prevent and control. This is often uncontrollable; many people are more casual when using drugs. Grasping the critical period of prevention and control, this is also an important reason for poor control. 2, scientific medication In the case of drug control, on the one hand, it is best to spray in the early morning (whitefly cockroach has poor flight ability in the early morning, strong flight ability in the afternoon and afternoon, and escapes during the prevention and treatment of drugs); on the other hand, after the first drug use, the next day is followed. Medication can kill more white mites that flee back. On the other hand, when spraying, it is important to spray the back of the leaf, which can not be swept away, or the dosage is insufficient to maximize the effect of the drug; On the one hand, when spraying and controlling the whitefly cockroach medicine, it is necessary to use the medicine alternately. When using the medicine, some washing powder solution or penetrating agent can be added to make the medicine penetrate into the white powder cockroach body better, and the killing effect is better. In addition, the combination of the control of the whitefly cockroach drug and the fumigant, or the use of mineral oil, can also improve the control effect. Commonly used drugs, such as bifenthrin water emulsion, beta-cypermethrin smoker, high-chlorine, buprofezin emulsifiable concentrate (registered crop protected tomato), imidacloprid, thiamethoxam, acetamiprid, nitenpyram, acetazide , pymetrozine and the like. In addition, the above drugs are mixed with spirotetramat, pyridone, etc., and have the effect of killing both nymphs and adults. You may wish to experiment. 3, the rim is changed, thoroughly clearing the garden In the place where the whitefly is infected, on the one hand, those who are not susceptible to whitefly, garlic, spinach, rape, celery and other crops can be selected for rims. On the other hand, after the crop is fully harvested, the diseased plants in the garden should be completely removed in time. Diseased fruit and weeds of dead branches and leaves, and concentrated incineration or deep burial to reduce the source of insect source transmission. In addition, strengthening the management of water and fertilizer in crops can cultivate strong seedlings and strong trees, improve the physiological resistance of crops, and reduce the occurrence of whitefly. 4, release natural enemy prevention Lily wasp and conservation grasshopper are the natural enemies of whitefly. According to the test, a Lizard was able to eliminate 20-30 white peony powder, and a curing grass mites can eliminate 170 white larvae, so it is very good to release the above two natural enemies at the beginning of the whitefly. The effect of controlling whitefly. Generally, natural enemies can be released once every 10-15 days, and the ratio of natural enemies can be released by 2 to 1, and continuous release is 3-4 times. 5, hanging yellow sticky oil board prevention Whitefly has a strong yellow tendency, and it can suspend whitefly in the insect pests by hanging a plurality of yellow sticky board. Yellow slick board: Use a suitable size of wood, brush a layer of yellow paint, and then apply a thick layer of viscous oil, such as exhaust oil. 6, high temperature smoke shed prevention When the shed is closed in the summer, the drug can be used to kill the whitefly. After closing the shed, raise the temperature of the shed to a temperature higher than 30 degrees, and then use 1 kg of white powder smoky fumigant per acre for 2-3 hours. High Pressure Extension Tubings,high pressure PVC extension tube,Extension Tubings,extension tube medical Anesthesia Medical Co., Ltd. , https://www.jssinoanesthesia.com
