According to the law of occurrence of watermelon pests and diseases, timely and appropriate chemical control, it is possible to control the hazards economically, safely and effectively, and at the same time minimize the possible use. I. Agricultural control Agricultural control is to use comprehensive cultivation techniques to control, to avoid or reduce the occurrence of watermelon pests and diseases. At present, watermelon has entered the medium-term growth stage, and the main measures for agricultural control are: 1. Clean the pastoral area The current cleaned garden is to clean the weeds along the ditch road near the melon field as much as possible, reduce the available hosts in the early stage of the pests, and the pests that have not been killed after applying the chemical pesticides in the melon field have a hiding place; Second, the host of watermelon mosaic virus is widely distributed. After the pests harm the weeds, they may be poisoned into the melon field. Therefore, removing the weeds near the melon field plays an important role in preventing pests and diseases. Third, pay attention to clear the diseased plants of watermelon. The wilt and virus disease of watermelon can not be cured once it is infected. The diseased plants should be removed and buried or burned. Do not drop them in the ditch or on the roadside. This will artificially infect the bacteria to other healthy watermelon plants, and the infected plants will continue to be infected because the blight pathogens can be on the sick. Survived for 10 years. 2. Strengthening field management High temperature and high humidity are two important factors in the pathogenesis. The middle and late stages of watermelon growth are in high temperature and high humidity. Strengthening field management and controlling humidity are important measures to reduce the disease. First, we must dig up the "three ditch" (ie, the ditch, the trough, the lobe) to make the ditch and the ditch communicate, and the ditch and ditch; The second is to rationally pruning the vines to make the stems and leaves evenly distributed, improve the ventilation and light transmission of the leaf layer, enhance the photosynthetic efficiency and disease resistance; Third, when the rain falls too early and the late drought irrigation occurs, pay attention to avoid flooding. The irrigation amount can only account for two-thirds of the depth of the ditch. The length of the irrigation time should be determined according to the nature of the soil. The sand loam time can be shorter and the clay time is slightly shorter. Longer, the water in the ditch should be removed in time after irrigation. The irrigation time is arranged in the evening when the ground is cool and the water is cool. Do not fill the water at high temperatures. Second, chemical control Watermelon is eaten directly, and the amount of food is large. When applying pesticides, pesticides must be selected from the perspective of pollution-free. Scientific application of pesticides not only saves production costs, but also plays a good role in controlling pests and diseases. 1. Sterilization, insecticide and fertilizer mixed fungicides, insecticides and potassium dihydrogen phosphate for foliar application can not be mixed with anti-virus cockroaches, and other fungicides and insecticides can be mixed. The general pesticides can be kept for about 7 days on sunny days. Therefore, pesticides should be sprayed once every 7 days. This can prevent pests and diseases and promote the healthy growth of watermelon plants. At the same time, it is necessary to check the melon fields frequently and find pests early. It eliminates the point and film stage at the initial stage and prevents the spread of the spread, which saves the use of medicinal workers and reduces pollution. 2, the right medicine to first check the disease and insects, watermelon wilt does not need medication, only grafting is the most effective means of prevention and treatment of the disease. Foliar diseases such as blight and anthracnose may be formulated with pharmaceutical liquids depending on the degree of disease. If the disease is mild, it is generally controlled by a single pesticide such as zinc, chlorothalonil, methyl thiophanate or chlorpyrifos. When the disease is heavier, it can be used with Daisen zinc + methyl thiophanate, or Daisen zinc + chlorothalonil, or methyl thiophanate + chlorothalonil. However, after compounding once, one more can be applied. pesticide. Anti-virus cockroaches should not be mixed with the above pesticides. The virus disease is the same as blight, and no need to apply the medicine, as long as the whole branch is removed or buried. As long as the virus disease eliminates the mites, it blocks the media. Insect pests mainly include aphids, yellow squash, red spiders, etc., and generally use pests such as lesben, Kangfuduo, kungfu, depletion, clericide, and worms. 3, master the drug concentration of generally 65% ​​Daisen zinc wet powder 400-500 times, 75% chlorothalonil wet powder 500 times, 50% methyl thiophanate wettable powder 600 times. 64% anti-virus WP can be 500 times. The preparation of the preparation is best done with a scale, packaged into small packets, and directly prepared into the melon field. The above drugs must be used alternately, resulting in resistance to the bacteria. The pesticides are generally applied according to the instructions, especially new pesticides. Use, otherwise the insects are not killed and the leaves are sneeze first. Insecticides should also be used interchangeably with fungicides. Do not allow pests to develop resistance. Tape Tensioner For Circular Knitting Machine Tape Tensioner For Circular Knitting Machine,Tape Tensioner,Poly Tape Tensioner,Polytape End Tensioner Changzhou Longfu Knitting Co., Ltd. , https://www.czcircularmachine.com