Application of biological pesticides in tea
The current tea market, especially tea exports, places high demands on the quality and safety of tea. Biological pesticides , including microbial pesticides and plant-derived pesticides, do not pose pollution to tea and the environment, have low toxicity to humans and animals, and do not constitute residual poisons. Therefore, they are suitable pesticides for producing green food tea. In the current production of Grade A green food tea, especially organic tea and AA grade green food tea, the use of the following biological pesticides is worth promoting. Rotenone. Also known as Saito, it is a plant-derived insecticide with a long history of application. It is easy to decompose in the air, low in residual toxicity and environmentally friendly. It has contact and stomach toxicity to pests. It has a wide spectrum of insecticides and a short duration of action, generally 5 to 6 days, and only 2 to 3 days in summer daylight. It can be used for the production of A-grade green tea, and it can be used to control tea mites, tea caterpillars, tea silkworms, leaf moths, moths, hawk moths, small green leaf mites, black thorn mites, and samovar, with 2.5% rotenone EC150~250mL per 667m2. Dilute with water to 300~500 times liquid spray. This pesticide cannot be mixed with alkaline pesticides. Rotenone is highly toxic to fish and should be used to prevent contamination of fish ponds. Matrine. Also known as oxymatrine, it is an alkaloid preparation prepared by extracting the root of Chinese herbal medicine Sophora flavescens and fruit with an organic solvent such as ethanol. It is easily degraded in the environment and has almost no residue. Control tea black moth, tea caterpillar, in the 1st, 2nd instar larval stage, or egg hatching peak, use 0.2% matrine AS50~75mL per 667m2, add water 50~75L, dilute to 1000~1500 times liquid spray. It can be used in the prevention and control of tea stalks in organic tea gardens. Before the 3rd instar larvae, use 3.2% insecticide net EC (matrine alcohol, cypermethrin mixture) 40~50mL per 667m2, add water 75kg, dilute to 1500~2000 times liquid spray, apply In low residual tea gardens and green food tea gardens. The organic tea garden can be sprayed with 800~1000 times of pure matrine preparation without chemical pesticides. The efficacy of matrine is slow and should be administered 3 to 5 days in advance. Bacillus thuringiensis. The pest is mainly a stomach poison. After feeding through the insect into the digestive tract, it produces parasporal crystals (endotoxin) and exotoxin, which are the main toxins. It usually takes 2~5 days after application to be effective. It has a good control effect on lepidopteran larvae such as tea caterpillars. Control lepidopteran larvae such as tea caterpillars, tea black moths, tea thorn moths, and use 10 billion live spores/g Bacillus thuringiensis WP or 10 billion spores/mL BtEC 75-150 g per 667 m2 in the 1st or 2nd instar larval stage. Dilute with water to 500~1000 times liquid spray. Suitable for use in organic tea gardens. Beauveria bassiana. Beauveria bassiana is a fungal insecticide . The insecticidal effect is caused by spore contact with the worm, and it is germinated under suitable conditions (temperature 24 ° C ~ 28 ° C, relative humidity 90% ~ 95%, neutral or slightly acidic). Infected with insects, multiply, secrete toxins, affect the blood circulation of pests, interfere with the metabolism of pests, die after 3 to 7 days, the body is covered with white hairy hyphae, also known as 'white zombie'. The tea leaf curler, tea caterpillar, and small green leaf mites are used in the early stage of the first and second instar larvae, and 0.5 to 7 billion spores/g of powder 0.5kg per 667m2, 50L of water, spray; Lily weevil, in the peak period of cockroaches, each 667m2 of Beauveria bassiana per gram of spores 5 to 7 billion bacteria powder 1~2kg, mixed into fine soil, applied to the tea tree rhizosphere soil Or in the peak period of adult worms, after the bacteria powder is diluted with water, the leaves are sprayed on cloudy days, rainy days or in the morning and evening when the humidity is high. Nuclear polyhedrosis virus. It is a kind of virus insecticide. The nuclear polyhedrosis virus has a cell-free structure and can only replicate and proliferate in the host to form a crystalline polygonal body. Insects are infected by mouth or wound. The virus enters the worm and is digested by gastric juice. The baculovirus particles are released, enter the body cavity through the intestinal epithelial cells, invade blood cells, fat and body cells, etc., and are embedded in the crystalline protein to form a multi-angle. Body, proliferate in the nucleus, and then infect healthy cells until the insects purgate and die. After the rupture of the diseased faeces and the corpse of the corpse, the polyhedron is released and spread widely by wind, rain, insects and birds, making the virus disease prevalent in the pest population. Mainly parasitic on Lepidoptera larvae. The nuclear polyhedrosis virus is slow in efficacy, but has a long-lasting effect of more than 2 years. In the first, fifth and sixth generation 1st and 2nd instar larvae, when the insect population density is lower than the control index, 1 to 2 billion PIB (protein crystalline polyhedrosis virus) tea scorpion nucleus polyhedron is used per 667m2. Virus AS50mL, spray 1000 times water. When the density of insects exceeds the control index, 50 mL of tea prion and chemical pesticides (such as phoxim WP synergist) can be used, and water is added 1000 times. Spray; control tea caterpillars, in the 1st and 2nd instar larval stage, use 10 to 2 billion PIB tea caterpillar nuclear polyhedrosis virus AS50mL per 667m2, add water 1000 times spray. Or use 25~30 worms per 667m2, mash and spray on water. Whitefly fungal preparations. It is a fungal insecticide that has good control effect on black thorns and white mites under humid conditions. Prevention and control of black thorns, mites, mites, in the 1st and 2nd instar larvae, under humid conditions, diluted with bacteria powder and water into a solution containing 0.1 billion spores per ml (the scorpion still needs wet branches) . Because black sputum is mainly distributed in the back of tea leaves and lower leaves, the back of the leaves should be sprayed when spraying pesticides . Under suitable conditions, the parasitic rate of whitefly fungi is above 70%, and the effective period is 2~3 years. Double J Hook,Double J Hook Straps,Double J Wire Hooks,Double Wire Display Hooks Jiangsu Zhongyi Work Rigging Co., Ltd. , https://www.zy-rigging.com