Fenfen
Whitefly itself secretes honeydew, which often causes coal contamination in vegetable leaves, such as eggplants, and affects the photosynthesis of the plants, resulting in a decrease in yield. Whitefly is a sucking mouthpart and is an important medium for transmitting viral diseases. The growth, development, reproduction and temperature and humidity of whiteflies are very important. The most suitable temperature for survival is 20°C～28°C. When the temperature is above 30°C, the mortality rate of eggs and larvae is high, the lifespan of adult worms is shortened, spawning is small, and even breeding is not done. In addition, the whitefly is a temperature-changing animal, and its respiratory rate will increase dramatically at temperatures above 30°C, making it easier to inhale more pesticides, which can greatly enhance the efficacy of pesticides. In the three seasons of the spring, summer and autumn, the severity of whiteflies is related to the amount of outside rainfall, especially in the summer. If the weather is heavy, the occurrence of whiteflies is light.
At present, spray insecticides are mainly used for contact toxicity, and a few pesticides have both fumigation and antifeedant effects. Fructus Aurantae attached to the sap of the leaf blade on the back of the leaf, which is easy to form a dead angle that cannot be touched by the pesticide. This is especially true when the plant is flourishing. Moreover, the whitefly will flee away when it is disturbed, so that the contact effect of the liquid will be significantly reduced. Therefore, once the outbreak of whiteflies, spraying alone is difficult to achieve a good control effect. Because the growth and development of the whitefly are closely related to the temperature, the combination of spraying and spraying or fumigation should be adopted. The vents can be closed to ensure that the temperature in the shed can reach 30°C to 33°C for 1 to 2 hours (note that the temperature should not be too high and the time can not be too long, otherwise it will be prone to injury), which can provide better control effects.
Vegetable farmers experience
Pre-stage: point application of insecticide + other crops attract + spray control
First of all, in the pre-planting point systemic drug repellent. For tomatoes, watermelons and other vulnerable types of vegetables, pest control began from the seedling colonization, especially in the autumn, after the colonization is the period of serious damage of Bemisia tabaci, only to start before planting in order to avoid the proliferation of whitefly, Spread the virus. Nowadays, there are already many drugs that can be used in the market, such as the use of biological agents, tablet pesticides with sustained-release components, and so on. Some vegetable farmers chose Aketai and other pharmaceutical acupuncture facilities, and colonization also played a very good effect.
Next, plant some whiteflour-like "foods" between the rows for centralized control. It is also possible to plant some no-acupoints in the greenhouse or on the back wall. The “food†that the mealworms like to see and like, such as melons, tomatoes, cowpeas, etc., can better observe the occurrence of whiteflies, so that the medicine can be used as soon as possible. We control before the outbreak.
Finally, whitefly is suitable for growth under neutral or alkaline conditions. After planting, spray it once every 5 to 7 days with Jiamei gold or vinegar, and spray 3 to 4 times. In addition, attention should be paid to the supplementation of trace element nutrition. Studies have shown that yellowing virus, fern leaf virus and iron, zinc, calcium and other elements are closely related to the lack.
When the plant is large and the application of acupuncture points is insignificant, the space occupied by the whiteflies is greater, and the difficulty in spraying control is greater.
Bemisia tabaci has a strong tropism towards yellow and can be set in the greenhouse to trap and kill adult worms. The yellow board can be purchased directly from the market, or it can be made on its own. Paint the cardboard with a yellow paint, cover it with a transparent plastic bag, apply a layer of viscous oil (add a little oil with a small amount of oil on the 10th motor oil), and reapply a viscous oil every 10 days. In addition to trapping and killing adult worms, the yellow plate is more important for monitoring the occurrence of whiteflies. The armyworm board can be hung above the plant. The bottom of the yellow board is level with or slightly higher than the top of the plant, 40 to 50 pieces per mu. When it is found that the number of whiteflies increases, it is necessary to spray them in time. Can be used acetamiprid, matrine, chlorate cyanide, nitenpyram, etc. with fluocin, rotation medication, to avoid the rapid development of resistance to whiteflies.
Late: Sticky board + spray
Mites
The main damage to vegetables in the greenhouse is mainly the tea plant and the two-leafhopper.
The locust infestation symptoms are very similar to vegetables infected with virus disease and hormonal poisoning and are easily misdiagnosed by vegetable farmers. Locusts, such as the tea tree borer, mainly damage the delicate tissues of vegetables, and suck the stems, leaves, and fruits of vegetables with acupuncture. They mainly damage plant growth points and young fruit, often causing malformation or dehiscence of leaves and fruits, turning grayish or brown. Plant growth is hindered and grows weak, which seriously affects the yield and quality of vegetables. The locusts have a disease center in the field, and most of them occur in sections. After the leaves are invaded, the back surface becomes brownish and shiny, distorted and curled down. This is the most important symptom that distinguishes viral infection from hormonal intoxication. After the victim suffers, the skin appears "rust", yellow-brown, corked, and cracked.
The most suitable temperature for the growth and reproduction of aphids is 16°C～23°C. The high temperature will shorten the lifespan of nymphs and reduce their fertility. Eggs and larvae have higher humidity requirements, and a warm and humid environment is conducive to the occurrence of aphids.
According to the special effect of avermectin on the two-spotted spider mites and the good control effect of alkaloids on the tea-scented alfalfa, it can be used to spray 1500 times of avermectin 2000 times.
Vegetable farmers experience
Control locust "trilogy"
The first step: eliminate the source of insects. The dead leaves, weeds and weeds in the shed are the places where pests live in. Therefore, the first step in preventing and controlling fleas is to eradicate the weeds in the shed, remove the dead leaves, and cut off the sources of infection.
The second step: temperature difference control. If the larvae in the shed are heavier, the larvae can be controlled by adjusting the temperature in the shed (man-made temperature difference). The daytime temperature can be increased to 32 °C ~ 35 °C, maintain more than two hours, the night temperature is maintained at 11 °C ~ 13 °C, in order to inhibit the reproduction of roundworm.
The third step: chemical control. Can be used 1.8% avermectin EC 3000 times solution or 15% ECG EC 3000 times, 20% chlorinated ketone wettable powder 3000 times, alternating use, improve control effect. However, it should be noted that locusts not only tend to be tender, but also tend to concentrate on the back of the leaves. When spraying the acaricide, it should be sprayed and turned down, paying attention to spraying the young part, and turning the sprayer upward to spray the leaves.
螨治螨
Predators particularly like to eat predators, and keeping them in their sheds is a good way to deal with the pests and whiteflies in the shed. Master Li of the Jitai Town of Shouguang City, Shandong Province, has been raising larvae for a year now. He said: “Since I raised this predatory mite (a cockroach blunt), I did not spray pesticides once again this year. It also saves money and produces high-quality vegetables."
In contrast, chemical pesticides can only be effective in a short period of time. Once the efficacy of drugs is over, the disease may start a new round of reproduction and rampant. The use of this method of “treating cockroaches with cockroaches†to control the damage of cockroaches is not only effective and cost-effective, but also very consistent with the requirements of standardized production.
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