Shimen County is one of the most important tea producing areas in northern Hunan. It currently has an area of ​​3,000 hectares and an annual output of about 2,500 tons. It has traditional teas such as “cow to tea†and “really black teaâ€. In recent years, “Dongshan Xiufeng†has also been successively developed. , "Shimen Yinfeng", "Baiyun Yinmao" and other famous tea. Since the 1990s, the county’s tea production has been stagnant for a long time, and the competition for tea products has been weak and the market has shrunk. One of the important reasons is that pesticide residues do not meet the standards. Therefore, it has become an important issue for the plant protection work to explore the comprehensive treatment technology of pests and diseases in tea gardens, reduce pesticide residues and produce pollution-free tea. 1 Occurrence and control status of pests and diseases in tea plantations 1.1 Major pests and diseases The main pests and diseases in tea plants in this county are about 65 species. The important pests that occur year-round are tea green leafhoppers, tea caterpillars, tea saponins, tea sorghum, black locust fly, tea leafhopper, leaf roller moth, tea garden worm, tea leafhopper moth, etc., among which tea green leafhopper, tea caterpillar The disease is widespread and serious; the main diseases are white spot disease, brown spot disease, tea cake disease, tea bud blight disease, tea coal disease, and tea leaf blight. Among them, the occurrence of leukoplakia disease has a large area and serious harm, which seriously threatens the production of spring tea and early summer tea. 1.2 Occurrence characteristics and degree of damage The tea plantations in this county are generally located in middle and high mountain areas, with altitudes between 500 and 1500m, long fog exposure time, short sunshine, low temperature throughout the year, slower temperature rise in spring, and most tea plantations are old 20 years or more. The characteristics of tea plant diseases and insect pests are: spring tea is mainly diseased, summer and autumn tea is mainly pests, and disease losses are more important than insect pests. Tea scab is the most prominent of all diseases and insect pests. It occurs early and has a long epidemic time. It usually begins in late March and is popular from early April to early June and last year. The annual incidence is about 2150 ha. 70% of the total area accounted for 50% to 60% of the total losses of diseases and insect pests caused by economic losses; tea green leafhoppers have a long period of time, population growth is rapid, generation overlaps are difficult, prevention and control are difficult, and annual total area accounts for total tea production. More than 75% of the area, from late May to late June and from mid-September to late October, peak season occurs; the area of ​​tea caterpillars accounts for about 55% to 60% of the total area, from June to July and from September to October. It is the peak period of the larvae; the area of ​​the tea plant in the dry years can reach 60% to 70%; the population of the black locust whitefly has been rising rapidly in recent years and is likely to become the main pest in the tea plantation. 1.3 Abundant resources of natural enemies The county's tea gardens are generally located in the high mountains. They have complex environmental vegetation, ecological diversity, and abundant natural enemies. According to the survey, there are 136 natural enemies of insects, 5 species of natural enemies in amphibians, 3 species of reptile natural enemies, and 32 species of parasitic natural enemies. The dominant populations are Beauveria bassiana, Bacillus thuringiensis, Trichogramma dendrolimi, T. velutipes, small green leafhopper wasps and other parasitic natural enemies and spiders, tiger aggars, grasshoppers, grasshoppers, grasshoppers, tea brown hawksbills, There are more than 10 species of predatory natural enemies, including ladybugs, predators, and predators. 1.4 Low level of pest control, over-reliance on chemical pesticides tea areas are mostly in remote mountain areas, tea farmers have low scientific and technological quality, poor food safety awareness, lack of comprehensive pest management techniques, and often ignore the use of abundant natural enemies when pests are controlled. But relying solely on chemical pesticides, the frequency of application is high, the amount of medication is too large. According to the survey, the main producing tea plant has applied pesticides more than 10 times in all quarters. The main varieties are methamidophos, dicofol, pyrethroids, and other highly toxic and high-residue pesticides. The tea area is even popular after spraying tea and spraying with methamidophos. The addition of urea as a key means of accelerating tea buds has caused a large number of natural enemies to be destroyed. The ecology of the tea gardens has been severely damaged and the pesticides in tea have been seriously polluted. 2 Tea pest control measures for the harmless production of tea In the process of production, tea is inevitably subject to pest damage, so as to control not only pests but also tea leaves without poisonous and harmful substances, it must be taken from the entire tea plantation ecosystem. Starting from the balance, based on the prevention and control of agriculture, full use of ecological control measures and tea plant's own resistance to pests and diseases, the implementation of integrated pest control technology. 2.1 Fitness cultivation and enhancement of tree vigor The tea plant's own resistance to pests and diseases and the harm compensation effect should be fully utilized to destroy the ecological basis of pests and to achieve organic integration of pest control, disease prevention and high yield, and high quality cultivation. (1) Use resistant varieties to eliminate susceptible varieties. Fuding Dabai, Fuyun No.6, and Baihaozao were selected as good varieties for disease resistance, high quality and high yield. (2) Scientifically manage fertilizers to achieve a balanced nutritional supply. Adhere to the combination of underground fertilizer and foliar dressing, promote the use of special compound fertilizer for tea. The winter fertilizer should be applied to the organic fertilizer such as dried cake or human feces and soil miscellaneous fertilizers. Do not apply or reduce the available nitrogen fertilizer to avoid frost damage and white spot disease caused by green tea. (3) Properly dense planting to keep the tea groves airy and light-transmitting, and promote tea tree growth. The tea plantation adopts a double planting method. The planting specifications are 1500m in width, 33cm in narrow rows, and 330m in plant spacing. (4) Do a good job of pruning and update the branches and leaves of the crown. 1 to 3 years of young tea plantations were type-pruned at 30, 50, and 60 cm in height; adult tea gardens were cut at 150 m below the canopy after 5 years of stereotyped pruning, and a layer of chicken claws was cut off; Heavy pruning is carried out at 300m, and the over-age old tea plantation is being renewed. 2.2 Protecting and utilizing natural enemies (1) Store tea gardens, weeds, daylilies, leeks, psyllium and other dwarf ben weeds and cut young tender grasses, spread them between tea trees, and increase tea plantation soil. Organic matter promotes the cooling and moisturizing of tea gardens and optimizes the ecological environment in which natural enemies inhabit. It has been observed that there are 158 spiders, 27 heterochromatic ladybugs, 8 grasshoppers, and 48 predators per 100m tea bushes in the tea gardens where benign weeds are kept, and 68, 7 and 2 bare tea gardens. , 52 only. (2) Copper tea preparations are not used for sterilization of disease in tea gardens. Protecting the beneficial microorganisms such as mycoflora, Verbena spp., and hairy bacilli is beneficial to inhibiting the populations of black locust whitefly, scale beetle and pupa. (3) Artificially assisting predators such as frogs, crickets, spiders, carnivorous ladybugs and other predatory natural enemies, and paying attention to the collection and use of tea plantation silkworms and pathogens to infect worms and other lepidopteran pests such as tea caterpillars, tea worms, and leaf roller moths. 2.3 Scientifically and reasonably carry out chemical prevention 2.3.1 Strengthen pest and disease monitoring, make clear the main attack target technicians and tea farmers to combine with each other, do a good investigation of pests and diseases, grasp the occurrence of pests and diseases, timely control of major pests and diseases, properly relax the minor pests, spring Tea focuses on the prevention and control of white scald disease and tea cake disease. In the middle and early April, the average temperature of 3 days is above 15°C, and the rate of diseased leaves at the shoot is controlled at 5%. Summer Tea focuses on the prevention and control of tea leafhoppers, tea caterpillars, and blackthorn whitefly, while simultaneously treating other diseases and pests. 2.3.2 do a good job in the winter garden, reduce the base number of pests the whole park pruning, remove the branches and leaves of the pests. The use of pesticides such as thawing scorpion and lime sulfur as a plant source and a mineral source for the clearing of the garden will reduce overwintering pests and various germs such as tea tree sap and black locust. 2.3.3 Relaxation prevention and control indicators Make full use of the natural enemy's pest control and disease prevention functions, and reserve certain time and space for the growth and reproduction of natural enemies. Tea green leafhoppers are controlled by 10 lobular insects, tea cultivars are responsible for 10 to 15 broccoli, and tea caterpillars are administered by 3 to 5 lobulins, which are lower than control indicators without drug control. 2.3.4 Control agents The use of methamidophos, dicofol, fenvalerate and other highly toxic, high-residue pesticides, and pesticides with strong natural enemy killing power are prohibited. The use of avermectin, imidacloprid series, and Bacillus thuringiensis (Bt) is promoted. The series, Beauveria bassiana and nuclear polyhedrosis virus were used to prevent and treat maggots, promote the eradication of pathogens, and prevent diseases such as tea disease caused by Dasheng M-45. According to the test and demonstration, the control effect of imidacloprid control for 20 days of small green leafhopper is still 81.2%, the control effect of avermectin for controlling tea astragalus is 92%, and the control effect of Bt against tea caterpillars is 85%. , Dasheng M-45 prevention and treatment of tea white disease 15d more than 82%. 2.3.5 Strictly control the dosage of pesticides and the period of use of the fresh leaves to ensure that the total season pesticides are used less than 3 times, strictly control the dosage and concentration of the pesticides, and ensure that certain picking intervals are carried out during safety intervals.