In recent years, the problem of pesticide residues in tea has attracted wide attention. The main points of use of several plant-derived biocides are described below:
Rotenone plant-derived bio-insecticide Rotenone is extracted from the root of fish vine and crystallized. The drug has a wide spectrum of insecticides. It is easy to decompose in the air, and the residual effect period is short (usually 5 to days, only 2 to 3 days in strong sunlight in summer). Environmentally safe. Rotenone has a contact and stomach toxicity effect on pests. Its pharmacological function is to make the heartbeat weaken and paralyze and die by affecting the cells in the nerves and muscle tissues of the pests. When used, use 1.5% rotenone emulsifiable concentrate 150-250 ml per acre tea garden, and dilute it with water to 300-500 times solution to evenly spray the tea plants, which can effectively kill tea mites, tea caterpillars, tea silkworms, leaf moths, moths and small moths. A variety of tea garden pests such as green leaf mites, black thorns, and samovar. It should be noted that rotenone cannot be mixed with alkaline pesticides; rotenone is highly toxic to fish. It should be protected from "snacks and fish ponds" when used. Store in a cool, dark place, avoid high temperature and exposure, and keep away from fire.
Matrine plant-derived biocide. Matrine is an alkaloid preparation made from the roots and fruits of the Chinese herbal plant Kushen. It has contact and stomach toxicity to pests. The insecticidal mechanism is to make the nerve center of the pest paralyzed, so that the protein of the insect body is suspected, the pores are blocked, and finally the suffocation is killed. Matrine is easily decomposed and has substantially no residue. when using it. Mu with 0.2% matrine water 50 ~ 75 ml plus water 50 ~ 70 liters (diluted into 1000 ~ 1500 times liquid spray, suitable for organic tea garden), can effectively prevent tea black moth, tea caterpillars, etc.: 3.2% insecticide 40 to 50 ml of net emulsifiable concentrate (matrine, cypermethrin), 50-70 liters of water (diluted to 1500-2000 times liquid), evenly sprayed on tea plants, and can effectively kill the main pests of tea trees. It should be noted that the effect of bitteric acid is slow, and should be applied 3 to 5 days in advance to enhance the control effect; if matrine is mixed with high-efficiency, low-toxic quick-acting pesticide, it can significantly improve the medicinal effect.
Nicotine plant-derived bio-insecticide Nicotine is a plant-derived bio-insecticide extracted from nicotine plants. It not only has contact, stomach and fumigation, but also has certain ability to kill eggs and penetrates plants. The effect is rapid insecticidal action, low residual, safe for crops and broad spectrum of insecticides. The insecticidal mechanism is: causing the nerves of the pests to paralyze, and the nicotine vapor enters the body by the pores of the pests, causing them to die due to suffocation. When used, the different parts of the tobacco can be chopped and soaked in water, and then the juice spray can be filtered to effectively kill a variety of tea tree pests such as tea stalks, tea silkworms, samovar, leaf roller moth, hummer, leaf hopper, and planthopper. It should be noted that nicotine plant-derived bio-insecticides are highly toxic to humans, animals, and silkworms, and moderately toxic to fish. They should be protected when used. If a small amount of soap or detergent is added to the tobacco leachate, the agent can be enhanced. Wet spreadability. It is beneficial to improve the efficacy; tobacco leachate is mixed with other high-efficiency, low-toxic insecticides to improve the efficacy.
Compared with single-channel pipettes, multi-channel pipettes simplify all the tasks associated with microtiter plates that often occur in immunology, biochemistry, clinical diagnosis and food analysis. Multi-channel pipettes generally have 8 and 12 heads. The gun body can be rotated at 360°C, and each part can be disassembled and repaired separately. The lower half can be sterilized at 121°C. The dimpled housing ensures a firmer grip for the operator. Can be quickly calibrated.
how to use multi channel pipette,best multi channel pipette,multi channel pipette for 384 well plate
Yong Yue Medical Technology(Kunshan) Co.,Ltd , https://www.yongyuecellculture.com