How Effective Is Chitosan Pesticide? A Full Analysis of Its Practical Applications
How effective is chitosan pesticide? What benefits does chitosan pesticide have? Which crops can chitosan pesticide be used on? Please note that the effects of chitosan pesticide include the following: (1) Improvement of the soil ecological environment. (a) Culture medium effect: chitosan is a nutrient source and health supplement for beneficial soil microorganisms...
The effects of chitosan pesticide include the following:
(1) Improvement of the soil ecological environment
(a) Culture medium effect:Chitosan is a nutrient source and health supplement for beneficial soil microorganisms, a good culture medium for beneficial soil microorganisms, and has a good recognition effect on the soil microbial flora.
According to experimental measurements, after 1 root drenching, measured 15 days later. Beneficial bacteria: cellulose-decomposing bacteria, free-living nitrogen-fixing bacteria, and lactic acid bacteria increased 10-fold; actinomycetes increased 30-fold. Harmful bacteria: common molds were 1/10 of the control, and other filamentous fungi were 1/15 of the control.
(b) Comprehensive effects of beneficial microorganisms:Actinomycetes secrete antibiotic substances that can inhibit the growth of harmful fungi (Pythium, Rhizoctonia, Fusarium oxysporum, Phytophthora, etc.).
Cellulose-decomposing bacteria can accelerate the mineralization and decomposition rate of organic matter in the soil (organic fertilizer, straw, etc.), decomposing it into nitrogen, phosphorus, potassium, trace elements, and forming organic substances such as fulvic acid and humic acid, providing sufficient nutrition for plant growth; free-living nitrogen-fixing bacteria can fix nitrogen from the air, raise the nitrogen level in the soil, and reduce the amount of nitrogen fertilizer used.
(c) Soil improvement:The massive reproduction of microorganisms can promote the formation of soil aggregate structure, improve the physical and chemical properties of the soil, enhance air permeability and water and fertilizer retention capacity, thereby providing a good soil micro-ecological environment for the root system, keeping various nutrients in the soil in an effectively activated state, improving nutrient utilization efficiency, and reducing the amount of chemical fertilizer used.
(d) Chelating trace elements:The molecular structure of chitosan contains -NH2 (amino groups), which can produce a chelating effect with trace elements such as iron, copper, manganese, zinc, and molybdenum, increasing the available trace element nutrients in fertilizers, and at the same time releasing trace element nutrients fixed by the soil for crop absorption and utilization, thereby improving fertilizer efficiency.
(2) Overall regulation of the plant itself and activation of cells
(a) Induced disease resistance and stress resistance:Chitosan induces structural disease resistance in plants, such as thickening plant cell walls or enhancing the degree of lignification; it can rapidly activate cells and induce plants to produce various resistance substances in a short time, such as phenylalanine ammonia-lyase (PAL), superoxide dismutase (SOD), peroxidase (PO), polyphenol oxidase (PPO), phytoalexins, etc., and pathogenesis-related proteins such as chitinase and β-1,3-glucanase, etc.; it induces a series of defense responses in plants, improving the plant's disease resistance and ability to withstand adverse environmental conditions.
(b) Activation of cells and induction of overall regulation of endogenous hormones:When sprayed on plant leaves, it has the effect of improving air permeability and retaining water; when sprayed on leaves or applied to the soil, it can promote the division of root cells, make the root system well developed, enhance the plant's drought resistance and lodging resistance, shorten and thicken stem nodes, make leaves dark green and lustrous, significantly improve photosynthesis, and promote the directional transport of photosynthetic products.
Introduction to the effects of chitosan pesticide
Chitosan has broad-spectrum antibacterial properties. Research shows that chitosan has good inhibitory and killing effects on most genera of Gram-negative bacteria and Gram-positive bacteria. Chitosan induces crops to produce various resistance substances and is effective in controlling diseases caused by viruses, fungi, bacteria, and other pathogens.
Especially important is that the control of viral diseases used to be a difficult problem in plant protection, but the control effect with chitosan pesticide is quite ideal.
Chitosan pesticide achieves the best results when used before crops develop disease. The application of chitosan can both prevent and directly control diseases such as anthracnose, blight, Fusarium wilt and Verticillium wilt, and root rot in crops. When plants suffer from severe attacks by multiple other diseases, it can be combined with externally suppressive pesticides (at reduced doses), providing internal resistance and external suppression with a synergistic effect, and in most cases satisfactory results can also be achieved.
Research has found that applying it to cotton can reduce the number of pathogens in the soil and has a sustained effect. Treating wheat seeds with chitosan can inhibit the occurrence of wheat sharp eyespot, and spraying or injecting chitosan on the leaves of various plants (legumes, tobacco, etc.) can protect the plants from virus infection.
A mixed powder with chitosan as the main component, used to treat rice before sowing, can increase rice resistance to toxins by 30-40 times and increase yield by 13-23%. Soaking tomato seedlings in seed treatment or spraying chitosan, or adding chitosan to the growth substrate, can induce tomato resistance to root rot. Adding chitosan to cucumber aqueous solution can control damping-off caused by Pythium.
Crops that regularly use chitosan also experience fewer pest problems. Chitosan pesticide works best when insects have just hatched into larvae. Chitosan has an obvious contact-killing effect on various aphids, and aphids die within 4 to 12 hours after contact with the pesticide.
A Maryland-based company in the United States, MG0N0, is using chitosan to produce a new type of organic pesticide for killing nematodes, which can play an insecticidal role. This pesticide has no residue, has little impact on natural enemies, and can effectively protect the environment and maintain ecological balance. The Beijing Soil and Fertilizer Work Station applied fertilizers with medicinal functions such as chitosan and calcium cyanamide in protected cultivation, greatly reducing the amount of chemical pesticides, achieving good control effects on nematode diseases, and at the same time improving the composition of the rhizosphere micro-ecological flora. With continuous application of medicinal fertilizers to control nematode diseases, in the first year the incidence rate could be reduced by 40%, yield increased by 45%, and quality significantly improved; in the second year, the incidence rate could be reduced by 60%, yield increased by 32%, and the microbial flora significantly improved.
Chitosan can be used as a drug slow-release agent, extending the duration of drug action and reducing the amount of medication used; it can also form a semi-permeable membrane on the plant surface, preventing the invasion of harmful organisms. Therefore, chitosan and its derivatives can be used as treatment agents for seeds of grain, vegetable crops, etc., stimulating seeds to germinate earlier, promoting crop growth, improving disease resistance, and thereby increasing crop yield.
As a seed treatment agent, chitosan has low dosage, low cost, and no toxic side effects. Taking advantage of chitosan's antibacterial ability and soil-improving effect, chitosan and its derivatives can be used together with some other substances as a soil conditioner.
After chitosan enters the soil, it can greatly promote the proliferation of beneficial bacteria such as nitrogen-fixing bacteria, cellulose-decomposing bacteria, lactic acid bacteria, and actinomycetes, and inhibit the growth of harmful bacteria such as molds and filamentous fungi. It can increase the number of actinomycetes by nearly 30-fold. Chitosan can be biodegraded and converted into high-quality organic fertilizer for crop absorption and utilization, and at the same time can effectively improve soil aggregate structure, effectively improve the soil, and improve the crop's living environment. It is a multifunctional soil conditioner.
Chitosan forms a thin film on the plant surface, acting as a barrier against pathogen invasion, and this film has good moisture-retaining properties and selective air permeability. These characteristics determine that chitosan can become the best raw material for fruit and vegetable preservatives.
At present, the most common application is the preservation of fruits and vegetables. Research on kiwifruit, apples, green peppers, pears, tomatoes, cucumbers, citrus, mangoes, strawberries, etc. has found that using this method can, to a certain extent, delay fruit aging, reduce rot, and extend the storage period.
Although the preservation effect of chitosan is not as good as traditional storage methods such as controlled atmosphere and cold storage, it is convenient to use, low in price, non-toxic and harmless, and as an auxiliary storage method it has great application potential.
Applying chitosan can also improve crop stress resistance, including resistance to cold, high temperatures, drought and waterlogging, salinity and alkalinity, fertilizer damage, gas damage, and nutritional imbalance. For example, among the various resistance substances induced by chitosan in crops, some have the effect of preventing, reducing, or repairing damage to plant cells caused by adverse conditions; it can promote robust crop growth, and robust plants naturally have stronger stress resistance.
Chitosan's yield-increasing effect on crops is also very prominent, because chitosan can activate and strengthen the plant's physiological and biochemical mechanisms, promote well-developed root systems and thick, strong stems and leaves, and enhance the plant's ability to absorb and utilize water and fertilizer as well as photosynthesis. Treating grain seeds with chitosan can increase yield by 5%-15%; using it for fruit and vegetable spraying and irrigation can increase yield by 20%-40% or more.
It can improve crop quality, such as increasing the protein and gluten content of grain and the sugar content of fruits and vegetables. It can thus be seen that chitosan and its derivatives can be used in agriculture as growth regulators, feed additives, seed treatment agents, agricultural product preservatives, pesticide carriers, slow-release agents, resistance inducers, and food additives, among many other aspects, and because of their characteristics of being non-toxic, harmless, pollution-free, and safely degradable, they have broad application prospects.
Diseases that chitosan pesticide can control:
Wheat: Fusarium head blight, powdery mildew, rust; barley: sharp eyespot, smut;
Rice: rice blast, bakanae disease, damping-off; soybean: sclerotinia rot, leaf spot;
Rapeseed: sclerotinia rot, anthracnose;
Tobacco: Fusarium wilt, anthracnose, sclerotinia rot, frog-eye leaf spot;
Cotton: damping-off, anthracnose, Fusarium wilt, root rot;
Peanut: anthracnose, southern blight;
Kidney bean (common bean): brown spot, powdery mildew, anthracnose, rust;
Watermelon: Fusarium root rot, Rhizoctonia damping-off, leaf blight, powdery mildew, sclerotinia rot;
Cucumber: downy mildew, powdery mildew, Fusarium wilt, red mold disease, Phyllosticta leaf spot;
Tomato: brown root rot, black dot root rot, sour rot, red mold disease, spot disease, sooty mold, powdery mildew, Penicillium fruit rot, Colletotrichum anthracnose;
Eggplant: brown spot, fruit rot, Verticillium wilt, early blight, leaf spot, brown ring rot, sooty blotch, black dot root rot, etc.; sweet pepper and chili pepper: gray mold at the seedling stage, root rot, Verticillium wilt, southern blight, etc.
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