Preservatives refer to natural or synthetic chemical ingredients. When used in cosmetic formulations, it can effectively inhibit microbial growth or corruption caused by chemical changes to ensure the safety and stability of the product during its shelf life. Dmdm Hydantoin Perservative,Glydant High Performance Preservative,Glydant Ltd Preservative Xi'an Hersoncare Bio-Tech Co., Ltd , https://www.hersoncarebio.com
Control methods:
(1) Replacement of nursery measures. Select a site with high topography and dry well drainage as seedbed; apply adequately decomposed fertilizer or use high-quality culture soil; control the amount of irrigation at seedling stage, the soil should not be too wet; timely sowing, do not make the seedlings affected by inappropriate temperature; cutting propagation For the flowers, the cuttings should be air-dried and then cut to facilitate wound healing; the seeds should not be overly dense, and the seedlings should be seeded to keep the seedbeds well ventilated; the flowerbeds with serious diseases should be kept from continuous cropping, or the soil should be disinfected before sowing; Excellent nursery measures, nurturing strong seedlings to enhance disease resistance, and reduce the harm of damping-off.
(2) Soil treatment. Because turbid pathogens can survive in the soil for a long period of time, it is of great significance to control pathogens by directly destroying pathogens in the soil. If the old seedbed is used, the seedbed soil can be disinfected with chemicals. Can use 50% carbendazim, or 50% thiram, or 40% seed dressing double, 6-8 grams per square meter of medication, when the first use of the amount of drugs weighed, and then mixed with the appropriate amount of fine sandy soil are mixed with pharmaceutical land . Some of the medicinal soil was sowed in the sowing line before sowing, and the remaining part of the medicinal soil covered the seeds. Can also be used 40% formaldehyde by 30 ml per square meter, add water 60 to 100 times spray wine seedbed, and then cover the seedbed with plastic film, remove the cover after 5 to 7 days, after 1 week until the smell can be scattered before sowing.
(3) Chemical control. The timely spraying of bactericide at the early stage of disease can effectively control the epidemic. The commonly used bactericides are 50% carbendazim WP 500 times, 25% metalaxyl (Drumys) wettable powder 800 times, 40% ED Aluminum (swine cream) WP 200~400 Doubling liquid, 75% chlorothalonil wettable powder 600 times liquid, etc., pay attention to spraying shoots and central diseased plants and the nearby sick soil. Every 7 to 10 days of medication 1, continuous spraying 2 to 3 times, or depending on the condition may be.
There are roughly three types of anti-corrosion principles for preservatives:
1. Interfering with the enzyme system of microorganisms, destroying their normal metabolism, and inhibiting enzyme activity.
2. Causing solidification and denaturation of microbial proteins, interfering with their survival and reproduction.
3. Changing the permeability of the cell plasma membrane, inhibiting the elimination of enzymes and metabolites in the body, leading to its inactivation.
Prevention of flower seedling damping-off
In the seedling stage, flowers are most likely to suffer from damping-off. The host of the disease is a wide range of hazards, including vegetables, trees and ornamental plants. Among the flower plants are asters, celosia, marigold, snapdragon, string of red, windshead, calendula, clover, pansy, cleome, beautiful cherry, zinnia, violet, nasturtium , carnation, calla lily, chrysanthemum and so on. The seedlings suddenly fell down and died, affecting the survival rate of seedlings and even destroying seedlings. The disease mainly occurred after the seedlings were unearthed, and the base of the young stem was infected by pathogens. At the beginning, the disease was stained with small stains, and then turned pale brown to brown and depressed. The disease department quickly developed around the stem for 1 week, so that when the young leaves are still emerald, they fall down from the base and die. Finally, the diseased seedlings rot or dry. After sowing, the seeds can also be susceptible to germination until they are unearthed, causing bud rot and seed rot, and the lack of seedlings and ridges on the seedbed. When the soil moisture is high, a white flocculent mycelium is often seen on the diseased seedlings and nearby soil surface. Bulimia is caused mainly by Pythium meliloti. The pathogens overwinter in the soil or on the residue of the diseased plants. They have strong saprophytic properties and can survive in the soil for a long period of time. They are called soil-accommodating bacteria. Bacteria are transmitted by irrigation water and rainwater, and they can also be spread by composted compost and seeds. Soil moisture in seedbeds and nursery shallow basins, improper watering, too dense sowing, uncomfortable temperatures, and thin and thin seedling growth are all conducive to the occurrence of damping-off, and even the seedbeds or flowerbeds are seriously affected by the accumulation of soil bacteria. Bumping disease is a typical soil-borne disease.