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The prevention and control of pests is a key link in agricultural production, running through the whole process of agricultural production, is a problem that every agricultural producer and manager (government) must attach great importance to, therefore, the Ministry of Agriculture held a national plant protection plant inspection work conference in 2006 to specifically study the national plant protection plant inspection work. At this meeting, the Ministry of Agriculture put forward two important concepts, that is, public plant protection and green plant protection.
1. Public plant protection
(1) Concept:
Public plant protection is to take plant protection work as an important part of agricultural and rural public utilities, highlighting its social management and public service functions. Through the implementation of public plant protection, the prevention and control of major diseases and pests will be elevated to government actions, emergency plans for prevention and control will be formulated, public financial support will be strengthened, and an effective emergency work system will be gradually formed.
(2) Importance:
1. There are many types of pests
Crop biological disasters include insect pests, diseases, grass pests and rodent pests, which seriously restrict the sustainable development of China's agriculture. According to statistics, there are 1,648 kinds of common agricultural pests in China, of which 838 kinds of pests, 742 kinds of diseases, 64 kinds of weeds, and 22 kinds of pest rats, and they are widely distributed, sudden, and have a high frequency of disasters.
2. The occurrence of major pests
In 1990, the national pandemic of wheat stripe rust occurred in an area of more than 6 million hectares and lost 2.65 million tons of wheat; in 1991, rice brown planthoppers occurred in China's rice areas with an area of 23.2 million hectares and lost 2.5 million tons of rice; in 1992, a particularly large outbreak of cotton bollworm occurred, causing a harmful area of 4 million hectares, losing 30 million tons of cotton nationwide, and direct economic losses of more than 10 billion yuan; in 1993, the rice blast epidemic in the southern rice area was about 6 million hectares and the loss of rice was 1.1 million tons In 1995, the epidemic of verticillium wilt in cotton became a disaster, resulting in the loss of 3 million quintals of lint; in 1997, the corn borer in Jilin Province occurred, losing more than 1 million tons of grain; in 1998, wheat gibberellosis and blight were widespread throughout the country, with an incidence area of more than 15 million hectares, and so on. In the case of large-scale prevention and control throughout the country, more than 16 million tons of grain, 6 million tons of cotton and more than 1.4 million tons of oilseeds are still lost every year due to various pests and diseases, which is almost an annual ration for 100 million people.
3. Causes of serious occurrence of pests
Crop pests are rising and falling, and it is impossible to prevent them, coupled with the fact that China will enter a new round of frequent biological disasters in the 21st century, so it will pose a great threat to the food security of China's 1.6 billion people. At the same time, China's agricultural ecosystem is relatively fragile, and the types of major pests are constantly mutated, resulting in the continuous loss of resistance of the main planted varieties and the loss of the value of continuing to be used; the early warning capacity of crop biological disasters is poor, the means of disaster reduction are backward, and it is difficult to get rid of the situation of passive coping; the amount of chemical pesticides is too large, environmental pollution, human and animal poisoning, and crop drug damage are becoming more and more serious, the resistance of harmful organisms continues to occur, and the amount of pesticide residues in agricultural products exceeds the standard and the quality declines, which seriously affects the physical and mental health of consumers and the export of foreign exchange The investment in agricultural scientific research is low (China is only 0.17 to 0.27 percent of the total amount of the state's annual financial budget, the world average is 1 percent, and the number of developed countries is more than 5 percent), the basic research on the mechanism of disaster occurrence and the law of catastrophe in some major biological disasters is weak, and the development and application of high and new technologies is lacking, resulting in insufficient staying power for the innovation of key defense technologies; the agricultural science and technology extension service system is not perfect, and the phenomenon of "line breakage, network breaking, and people scattered" has appeared in many places; the quality of peasants is relatively low, the level of disaster prevention and reduction is not high, and the awareness is not strong As a result, the promotion of agricultural science and technology is weak, the conversion rate of achievements is low (less than 30% in China, about 60% in developed countries), and many plant protection scientific research achievements have not yet played an important role in the prevention and reduction of agricultural biological disasters. The above problems are serious challenges facing China's plant protection work, which must not only be faced squarely, but must also be fully studied and solved.
In the new 21 st century, the worldwide agricultural science and technology revolution and China's strategy of rejuvenating the country through science and technology and sustainable development have provided a great opportunity for the development of agricultural science and technology in our country. We believe that the basic way should be: to implement the general principle of disaster prevention and reduction of "giving priority to prevention, combining prevention and rescue, and comprehensive management", to strengthen basic research, develop and apply high and new technologies as the premise, and to innovate key defense technologies and improve the comprehensive disaster reduction capacity of society, and comprehensively carry out research and prevention of biological disasters in crops before, during and after production.
Second, green plant protection
(1) Basic concepts
Green plant protection refers to the methods and measures of plant protection are "green", and many experts also call green plant protection as harmful green prevention and control methods. According to the definition of the National Plant Protection Conference: green plant protection is to take plant protection work as an important part of the harmonious system between man and nature, highlighting its role in ensuring and supporting high yield, high quality, high efficiency, ecology and safety agriculture. At the heart of this definition is the emphasis on plant protection measures to be in harmony with the natural world. Therefore, in a simple and clear sentence, green plant protection is to adopt plant protection methods or measures (means) that are harmonious and friendly with natural ecosystems. Because the plant protection measures are harmonious and friendly with the natural ecosystem, the natural ecological environment will not be destroyed, and the agricultural production and the quality of its products can be guaranteed.
Pest hazards are one of the most serious natural hazards. According to the statistics of relevant departments, compared with the frequency of hazards and the amount of losses, the harm of harmful organisms exceeds that of climate hazards, ranking first among natural disasters. To control pest hazards is to deal with the natural world. In the past, due to excessive dependence on chemical pesticides, especially the use of highly toxic pesticides, resulting in serious consequences of human and animal poisoning, excessive residues of agricultural products, and pollution and destruction of the agricultural ecological environment, not only because of the large number of highly toxic pesticides killing natural enemies or pests to produce resistance, resulting in the recurrence of harmful organisms, forming a vicious circle of increasing the amount of pesticides, increasing the destruction of natural ecology, and rampant pests. Moreover, it poses a threat to the human living environment and human health (many pesticides can damage human immunity and cause cancer and teratogenicity). This kind of disharmony between man and nature is something that every earthling person does not want to see, and many plant protection experts call this plant protection method at the expense of natural ecosystems black plant protection. Today, the very important task of our people is to build a harmonious society, and the specific task of our plant protection workers is to build a harmonious plant protection, and harmonious plant protection includes the harmony of the social system of plant protection work, and also includes the harmony of plant protection measures and natural ecosystems. Therefore, we must vigorously advocate green plant protection methods to eliminate and overcome the phenomenon of black plant protection. Regarding the evil consequences of black plant protection, you can read "Silent Spring", which was compiled by the American marine biologist Rachel Carson, a female scientist known as the "mother of natural ecological protection", who conducted a four-year field investigation on the consequences of ecological damage and environmental pollution caused by the extensive use of DDT in the United States since the 1940s, and made scientific associations, describing rivers as rivers as rivers of death. The singing of birds can no longer be heard in the woods, the tragic situation of crops and flowers, and human beings struggling in pain due to many strange diseases has awakened people's confusion in the use of highly toxic pesticides and laid a milestone in the protection of natural ecological environment.
(2) The basic requirements of green plant protection
Crop diseases, insects, grasses, rats and other pests have many types, wide range of occurrence, and heavy degree of harm, which has always restricted the yield and quality of agricultural products, resulting in an annual yield loss of 15% to 30%, and serious up to 50%. China's agricultural civilization is brilliant and brilliant, and in the process of fighting against crop diseases and insect pests, it has accumulated rich experience in comprehensive prevention and control, which is still of reference significance in contemporary green agriculture. Although the production level of modern agriculture, which is mainly based on fossil energy input, has been greatly improved, it faces a series of problems such as resources, environment, ecology and food safety, which affects the sustainable development of agriculture. Modern science and technology have advanced by leaps and bounds, giving new connotations to crop pest control theory. In particular, the use of green control technologies such as biological, ecological and physical machinery to control pests and diseases has become an important means of sustainable agriculture, and an inevitable choice for pest control in green agricultural production.
Although green plant protection is a method, it has two characteristics: technical and mandatory, and the specific requirements are as follows:
1. The production and use of highly toxic and high-residue pesticides are prohibited.
1.1, the toxicity of pesticides
(1) Concept:
The toxicity of pesticides refers to the degree of harm of pesticides to humans, livestock, poultry, aquatic animals and other beneficial animals.
(2) Grade:
The toxicity of pesticides to humans and animals can be divided into acute toxicity and chronic toxicity. The so-called acute toxicity refers to a dose of pesticide received by oral administration, skin contact or inhalation through the respiratory tract, etc., which can cause acute pathological reactions in a short period of time, such as organophosphorus highly toxic pesticides 1605, methamidophos, etc. can cause acute poisoning. Chronic toxicity refers to pesticides lower than the dose of acute poisoning, which are used continuously for a long time, contact or inhalation into the human and animal bodies, causing chronic pathological reactions, such as chemically stable organochlorine high residue pesticides 666, DDT, etc.
According to the amount of pesticide lethality (LD50), the toxicity of pesticides can be divided into the following 5 levels: 1. Highly toxic pesticides. The lethal median amount is 1 to 50 mg/kg body weight. Such as altomothing, phosphine, methamidophos, Suhua 203, 3911, etc.; 2. Highly toxic pesticides. The lethal median amount is 51 to 100 mg/kg body weight. Such as furandan, fluoroacetamide, cyanide, 401, zinc phosphide, aluminum phosphide, arsenic, etc.; 3. Poisoned pesticides. The lethal median amount is 101 to 500 mg/kg body weight.
Such as Leguo, Leafhopper, Rapid Extinction, Dixone, 402, Permethrin pesticides, etc.; 4. Low toxicity pesticides. The lethal median amount is 501 to 5000 mg/kg body weight. Such as dimethod, insecticidal bis, malathion, octylthion, acetylmethanamide, dimethyl tetrachloride, butyrolamide, glyphosate, tolbuzin, flolein, bendasone, atrazine, etc.; 5. Micro-toxic pesticides. The lethal median amount is more than 5000 mg / kg body weight. Such as carbendazim, bacillus, ethylphosphorus aluminum, zinc daisen, sterilized Dan, simacin and so on.
1.2. Pesticides are prohibited from being produced and used
Since 1983, the state has banned the production and use of pesticides such as: 666, DDT, toxaphene, Aldrin, Die's agent, methamphos, methyl parathion, parathion, sulfonas, phosphorus, phosphoramine, poisonous rat qiang, etc.; other pesticides prohibited from use are: dibromochloropropane, insecticide, dibromoethane, herbicides, mercury preparations, arsenic, lead, diqualt bis, fluoroacetamide, glycine, sodium fluoroacetate, poison rat silicon.
Other pesticides that must not be used in vegetables, fruit trees, tea leaves, and Chinese herbal medicines are: methylphosphorus, methyl isosyphosphos, terbutylthion, phosphorus for the treatment of borers, phosphorus systemic, grambactific, aldicarb, nephrophosphate, fly poison phosphorus, ground worm thiophos, chlorzophos, benzophosphate, etc. Trichlorocarbicide, cypermethrin should not be used on tea trees.
2. Vigorously advocate ecological prevention and control
2.1、 Concept:
A good ecological environment is the premise of healthy plant growth. According to the different requirements of pathogens and vegetables for ecological conditions, the use of crop rotation, regulation of facility temperature and humidity, light, etc. can effectively control many diseases.
2.2. Examples:
For example, some downy mildew and rust bacteria rarely produce spores when the day temperature reaches more than 30 °C and the night temperature reaches more than 20 °C, and the spores of some fungi can only germinate when the water film is present, and the dry soil inhibits the growth of nematodes and other soil-borne pathogens. Ecological regulation of leaf dew in protected area cultivation can effectively control downy mildew and black star disease. Coagulated water droplets on the foliage are a prerequisite for the occurrence of diseases such as downy mildew, and foliar condensation, combined with the right temperature, can spread rapidly. By adjusting ventilation, controlling the temperature and humidity in the shed, reducing leaf condensation, so that the pathogen loses the ecological environment conditions for favorable germination, and reduces the occurrence and spread of diseases.
(3) Specific measures to be implemented
1. Agricultural control (crop rotation, ridge cropping, rational fertilization, irrigation, deep turning and sunning, etc.)
1.1. Crop rotation
(1) Example:
Causes of diseases and pests caused by soybean stubble and yield reduction:
Diseases: soybean root rot; soybean cystic nematode disease; soybean blight;
Insect pests: underground pests; root sneaker flies; heart-eating insects
Nutritional disorders: lack of boron molybdenum, etc
Accumulation of toxic substances
Changing to corn solves the problem.
1.2, new planting methods
(1) Soybean row intermolding:
According to the news from the Department of Planting Industry of the Ministry of Agriculture, Heilongjiang Province, the main soybean producing area in China, has greatly increased the yield level of soybeans through the application of inter-row film covering technology. The demonstration proves that compared with the conventional cultivation mode, the yield increase rate of soybean interline lamination technology can reach more than 30%.
The use of soybean interline lamination technology has two major advantages: heating and water retention. This technique is applied to flat-sown plots, which cover the mulch film between the rows of seedlings. During drought, the previous ineffective precipitation collected into the roots of the seedlings and infiltrated into the seedlings becomes effective precipitation; during the rainy season, the mulch is removed, and the precipitation is fully utilized. At the same time, the effective accumulated temperature required for crop growth can be increased by lamination.
(2) Great Secret:
Harbin Bayan County Agricultural Committee, the county's scientific and technological personnel and the United States soybean expert Professor Ku Bo cooperation, researched out the soybean "big dense" high-yield cultivation mode, this technology is the American soybean flat cropping dense planting technology and China's traditional cropping technology grafted, showing a strong superiority, by domestic and foreign experts praise. The advanced nature of soybean "big dense" cultivation technology lies in:
(1) Improve land utilization rate, and achieve reasonable dense planting by increasing the number of plants to achieve group yield increase.
(2) Expand the green area, improve the utilization rate of light energy, due to the increase in density, the foliar index of soybean increases accordingly, which enhances the effect of light energy utilization and improves the absorption capacity of soil moisture and nutrients.
(3) The soil moisture retention performance is good, which improves the drought resistance, and the soil surface area is reduced by changing the small to large, so that the soil water loss is relatively reduced, which plays a good role in soil preservation.
Soybean "big dense" cultivation technology increased the average yield of 40.4 kg per mu, an increase of 27%, an increase of economic benefits of 72.72 yuan per mu, and the county's 800,000 mu of soybeans can increase grain production by 32.36 million kg, achieving an output value of 290.88 million yuan and an increase in economic benefits of 58.176 million yuan. This technology has been successfully promoted to eight provinces and districts across the country, more than 60 cities, counties and state-owned farms, and has achieved good yield increase effects in Hebei, Inner Mongolia, Liaoning, Jilin and other places, with an average yield increase of 47.6 kg per mu and a yield increase rate of 28.6%. In the demonstration and promotion of more than 30 cities and counties in our province, the average yield per mu reached 202.8 kg, breaking through the mark of 200 kg per mu of soybean production and achieving stable and high yield.
Soybean "big dense" cultivation technology has won the second prize of scientific and technological achievements of the Provincial Department of Agriculture, the first prize of the Provincial Department of Agriculture's harvest plan, the first prize of the municipal government's scientific and technological achievements, won the national patent right, was listed by the State Science and Technology Commission in the "Ninth Five-Year" national science and technology key project - soybean large-area high-yield comprehensive supporting technology research and demonstration, and was listed by the State Planning Commission as a national large-scale commodity grain base construction project.
Practice has proved that this high-yield cultivation mode has high scientific and technological content, large yield increase, strong operability, has been recognized by the majority of farmers, has a good momentum of development, and is a new cultivation method with Chinese characteristics of soybean flat crop dense planting.
(3) Potato large and high plantation
1.3. Scientific fertilizer and water management
2. Biological control (natural enemy control, such as red-eyed wasp control of lepidoptera pests, BT biopesticide control, etc.)
2.1. Concept:
Biological control refers to the theory and technology of using organisms or biological products to control diseases and insect pests, including the selection of disease- and insect-resistant varieties, the use of biological factors, microbial, plant, animal and genetically modified pesticides, as well as crop-induced resistance and cross-protection measures.
2.2. Contents:
Treat insects with insects; treat insects with bacteria; treat grasses with bacteria;
(1) Insect reticoner:
Natural enemy species are parasitic: there are mainly parasitic creatures such as red-eyed bees, golden wasps, golden wasps, golden bees, bees, cocoon bees, parasitic flies, and head flies.
Predatory: predatory creatures such as ladybirds, grasshoppers, mantises, small flower bugs, predatory mites, frogs, farmland spiders, toads, swallows and woodpeckers. So far, about 130 species of natural enemy insects around the world have entered the stage of commodity development and large-scale production. Among them, the red-eyed bee is the most researched and widely used egg parasitic wasp in the world's pest biological control technology. There are more than 20 kinds of red-eyed bees are multiplied and released in large quantities, and the annual bee area is more than 30 million hm2, mainly used for corn, rice, sugarcane, vegetables and some forest trees and fruit trees, and crop losses generally drop by 70% to 90%. In addition, it can also use aphid wasps to control greenhouse whitefly, and smoke aphid cocoon bees to control peach aphids and cotton aphids.
Predators: Predatory animals include cats, weasels, hedgehogs, etc., beneficial birds include owls, swallows, magpies, woodpeckers, bats, snakes, lizards, frogs, toads and so on. Birds are so powerful at killing pests that a swallow eats 65,000 locusts in a summer, a nighthawk can catch 500 mosquitoes in a single night, and an owl can prey on 1,000 voles in a summer.
(2) Treat insects with bacteria:
White zombie fungus control corn borer; Suyunjinbacterium control of pests on vegetables; more than 100 species of fungus that prey on nematodes have been found in cultivated soil, and their hyphae are specialized into different forms of catching structures. Arthrobotrys is a predatory fungus that has been commercially produced, and its preparations are used to control mushroom-eating nematodes and tomato root-knot nematodes.
(3) Parasitic biological control of diseases:
Sanford and Broadfoot (1931) were the first to report the direct use of parasitic fungi to control plant soil-borne diseases. To date, the most studied and used species of Trichoderma harzianum, Trichoderma harzianum and T. leptii (Trichoderma harzianum) humatum) can parasitize Limelia and neat small nucleus hyphae; pea and radish seeds are mixed with Trichoderma, which can prevent seedling blight and cataplexy. In addition, Coniothyrium minitans are effective in controlling sclerotia.
(4) Weeding with fungi:
Anthrax bacteria can control soybean silkworms.
2.3. Prevention and control of biological pesticides
Biopesticide refers to the use of living organisms or their metabolites, as well as through biomimic synthesis of pesticide preparations with specific effects, is the future of the pesticide industry in the sunrise industry.
(2) Type:
Biopesticides include: microbial pesticides, agricultural antibiotics, plant-derived pesticides, animal-derived pesticides and new biopesticides. At present, the officially registered varieties of biopesticides are Jinggangmycin, Nongkang 120, Polyantimycin, Antipyridin, Chystemol, Streptomycin Sulfate, Princess Lingmycin, Gibberellin and Bacillus Thuringiens, and the provisionally registered varieties are avermectin (worm mite), Liuyangmycin, cotton bollworm karyotype polykern virus, matrine, neem, etc.
●Microbial pesticides:
Refers to the use of living microorganisms with reproductive ability or biological products of fungal preparations, bacterial preparations, viral preparations, insect pathogen nematodes, insect pathogen Rickettsia and the like.
◆ Bacterial pesticides:
Such as Bacillus subtilis, Bacillus cereus, Pseudomonas fluorescent, Bacillus licheniformis, Bacillus glea, Bacillus polymyxos, etc. Bacillus thuringiensis, B.t.) The preparation accounts for 80% of the sales of the international biopesticide market, and is widely used in the control of lepidoptera pest larvae such as cabbage worms, small cabbage moths, corn borers, cotton bollworms, beet noctuidae moths and so on. Bacillus subtilis is also commercialised under the trade name Bomkiller, which is registered for the control of gray mold in eggplant and tomatoes and for the control of gray mold and powdery mildew in strawberries.
◆ Fungal pesticides:
The main white zombie and Brucellosis white zombie preparations are the mainstay. White zombie insecticides invade through the digestive tract and body wall, which can make insects grow hyphae and form stiff sclerotia leading to pest death, and the area of white zombies to control pine caterpillars and corn borers is more than 700,000 hectares every year. Trichoderma has been successfully developed and registered as a pesticide for the prevention and control of vegetable gray mold. At present, the fungal preparations in the small and intermediate trial stages also include green zombie, penicillium lilac, insect mold and rotifer fungus.
◆ Viral pesticides:
There are two types: plasmic polyhex virus (CPV) and nuclear polykeratovirus (NPV). The recommended pesticide varieties listed in the production of pollution-free agricultural products issued by the Ministry of Agriculture are beet nocturnal moth nuclear polyhet virus, silver moth polyhedral virus, cabbage moth granule virus, tea inchworm nucleus polyhet virus and cotton bollworm nucleus polyhet virus, which are used for the prevention and control of vegetable green worms, twill nocturnal moths, cotton bollworms, tea inchworms, etc.
◆ Insect pathogen nematode preparation:
Accounting for 13% of the sales of the international biopesticide market, second only to the Bacillus thuringiensis products, it is widely used to control important soil and borer pests such as agriculture, forestry, pasture, flowers and hygiene. The application of turnip nocturnema fcltiac for the control of corn borers at the heart leaf stage, the larval mortality rate of 80.4% to 90.5%, small roll moth nema (Steinernema carpocapcapsae) control of casuarina star tianniu, the infection rate of more than 90%.
◆ Insect pathogen Rickettsia:
The most reported is the gill golden turtle Rickettsiella mellolonthae, which can cause a large number of deaths of many scarab beetles.
●Agricultural antibiotics:
Such as chrysomycin, agricultural resistance 120, mesophyticin, Liuyangmycin, streptomycin, etc., has been widely used in the prevention and control of rice blight Jinggangmycin, efficient, broad-spectrum insecticide, acaricide avermectin and so on. China has successfully developed B1asticidins to control rice blast (Pyricularia oryzac), Kasugamycin to control rice blast, Jinggangmycin to control rice blight (Rhizoctonia solani), Gongzhulin to control smut disease, agricultural resistance 120 to control cucumber powdery mildew, watermelon blight, anthrax, etc., Wuyi mycin ( Wumycin) control of fungal diseases such as powdery mildew, black star disease, leaf mold disease, etc., ningnanmycin has a good effect on tobacco mosaic virus disease, rice leaf blight, wheat, vegetables and other powdery mildews have a good effect on disease prevention and yield. Schaeffer et al. reported that the active substances with bactericidal, insecticidal and nematicide isolated from a group of actinomycetes were effective against rice white leaf blight and grape gray mold at a low concentration of 50 ml/L. In addition, avermectin can be used to control small cabbage moths, cabbage worms, spotted flies, etc., and agricultural streptomycin, neophytomycin to control a variety of vegetable soft rot, horn spot disease and other bacterial diseases.
●Plant-derived pesticides:
The use of plant-derived drugs to kill insects has a long history in China. In the 24th year of the Ming Dynasty (1596), Li Shizhen's "Compendium of Materia Medica" described 1892 kinds of medicines, some of which were used to control pests, such as Baibu, Quinoa, Wolf Poison, and Bitter Ginseng. In the "Zhou Li Qiu Guan", it is recorded that "the sources of plant medicines are fish vine, tobacco, pyrethrum, chicken blood vine, lei gong vine, bitter bark, yellow rhododendron, baibu, wormwood, yong, garlic, green onion, yun, oyster, cang ear, coriander, croton, bitter ginseng, appendages, tea leaves, etc." At present, the most successful plant-derived insecticide developed internationally is neem, which has a refusal to eat and gastric toxic effect on a variety of vegetable pests; China has a saponin nicotine soluble emulsion, rotenone emulsion, bisin alkali water agent, anise water agent, nicotine sulfate, neem insecticidal emulsion and "8811" plant pesticides and other formal registration or temporary registration. Plant-derived insecticides such as matrine, cnidium monnieri, artemisia annua, eucalyptus, and ginkgo biloba have also begun to be commercialized. With people's attention to the ecological environment, the development of plant-derived pesticides has also become fashionable, and it is the first choice for green biopesticides.
◆ Plant photoactivation toxins:
In recent years, it has been found that the toxicity of some plant secondary biomass on pests under light conditions can be increased by several times, tens of times or even thousands of times, showing photoactivation characteristics. Since the discovery of the photoactivation properties of Theatrician toxin, a Verancoum (1978), a Verancoum (1978), the plant-derived photoactivated toxins have been discovered for the first time, and the plant-derived photoactivated toxins have great potential as new pollution-free pesticides. At present, polyacetylene compounds have been patented in Canada as pest control agents.
◆ Vegetable essential oils:
It is a class of plant secondary metabolic substances with small molecular weight, which are mainly divided into terpenes, aromatics, aliphatics and nitrogenous sulfur-containing compounds, which mainly have the effects of repelling or luring, refusing to eat, inhibiting growth and development, and poisoning insects. Fennel oil, citronella oil, eucalyptus oil, geranium oil, jasmine oil, lemongrass oil, orange oil, etc. have been commercialized in the United States, and there are very few types of domestic commercialization.
●Pesticides of animal origin:
Refers to the metabolites of the animal body or the biologically active substances with special functions contained in the body, mainly including animal toxins such as spider toxins, wasp toxins, sand silkworm toxins, etc., as well as insect hormones that regulate various physiological processes of insects, insect pheromones such as cotton boll insect sex attractants, sugarcane strip borer sex attractants and natural enemy animal pesticides. Treating the female of the seven-star ladybird with a juvenile hormone analogue can prompt it to lay more eggs and breed more ladybirds to control aphids. Spraying with molting hormone allows the insect to molt prematurely and develop into an infertile adult. The use of insects or synthetic sex attractants can interfere with the normal mating of pests, affect their growth and development and metabolism, cause pests to die slowly, and affect the reproduction of the next generation. The varieties that have been widely promoted and used or are being promoted include insecticide urea, chlorofluorourea (anti-Taibao), Teflonourea (nongment), fiprourea (carame), butyl etherurea (Baolu), rice mite, insect mite nitrile (exhaustion) and so on.
●New biopesticides - genetically modified pesticides:
Refers to the use of transgenic technology to cultivate disease-resistant, insect, grass transgenic crops, such as trans-B.t. virus (B.t. toxin gene expressed in insect virus), transgenic predator mite (Metaseiulus occidentalis), transgenic B.t. gene cotton, corn, potato, trans-Cpt I tobacco, rice, potato, strawberry, anti-virus transgenic bell pepper, tomato, tobacco, rice, etc. Biological engineering technology has injected new vitality into the development of biopesticides, and the development of bioengineered pesticides is undoubtedly a hot spot, but china's green food and organic food are prohibited from using genetically engineered products.
2.4. Inducing resistance and cross-protection
(1) Induction of resistance:
Both biological and biological factors can induce crop resistance, and the mechanism of inducing resistance mainly involves the cell structure changes and physiological and biochemical reactions of the host. Among the induced resistance factors, the biological factors are more studied to antagonize antibacterial, physical induction mainly includes γ-rays, ion radiation, ultraviolet light and hot water treatment, etc., and the chemical inducers mainly include β-aminobutyric acid (BABA), phenylpropiothiazide (ASM), salicylic acid (SA), jaspermic acid (JA) and methyl jasmonate (MJ). So far, many chemical agents have been found to have plant activation effects, many of which have been put into use as pesticide products, such as allylisothiazole (probenazole), fosetyl-aluminium (fosetyl-aluminium), chitosan (chitosam), activator ester (acibenzolar-S-methy1) and so on.
It has also been found that many natural substances have anti-disease activation effects, especially various bacteria or fungal microorganisms. Chitin (chitin) is widely present in the shell of shrimp, crab, insect skin and fungus cell wall, the study found that chitin can open a variety of signaling pathways in plants, induce crops to produce a variety of resistant substances, with the effect of preventing, mitigating or repairing the damage of adversity to plant cells, the application of chitin pesticides to anthrax, diseases, viruses, wilt, root rot and other diseases can be prevented and directly controlled. Chitin pesticides have obvious contact killing effects on various aphids, and aphids die 4 hours to 12 hours after being struck. 0.4% oligosaccharides are widely used in various crop, grassland, forest and other fungal diseases such as gibberellosis, rice blast, striped blight, rust, blight, carbosis, canker disease, rot disease, scab disease, black star disease, downy mildew, powdery mildew, leaf spot disease, leaf blight prevention and control; from Dalian Baolubao Marine Life Science R&D Center Co., Ltd. using chitosan oligosaccharide citrate callus to prevent and control fruit tree root cancer, the effect is as high as 99% In our research, we also found that chitosan has a certain inhibitory effect on Phytophthaloccus capsicum and rice seedling fungus.
Experiments such as Cai Xinzhong et al. (1996) proved that salicylic acid (SA) foliar spray can reduce the occurrence of rice blast in rice seedlings. Liu Fengquan et al. (1998) showed that after treating rice plants with the toxic gene deletion mutant Du728, the disease prevention effect reached 49.1% to 50.2%. Liu Fengquan et al. (2000) induced rice seedlings with salicylic acid, and the incidence of rice leaves, the length of disease spots and the disease index were significantly lower than those of qingshui control. After cotton is infested with cotton worms, the content of the main insect-resistant substances (gosypols and tannins) in the plant increases, which reduces its palatability to cotton bollworms and disrupts the normal physiological metabolism of the insects. Fava beans, cucumbers, and melons can be induced to systematically protect against fungi, bacteria, and viruses by inoculating them with infestations that produce local spots.
(2) Cross-protection effect:
Interaction protection refers to the phenomenon of inoculation of weakly toxic microorganisms to induce the disease resistance of plants, thereby resisting the infestation of strongly toxic pathogens. A very successful example is the biological control of citrus virus disease in Brazil, Argentina and Uruguay, where citrus trees can resist the infection of strongly toxic strains by inoculation of weak strains. China has been induced by nitrite to the weakly toxic mutant strains of tobacco mosaic virus N11 and N14, cucumber mosaic virus weak strain S-52, and the weak strain has been inoculated with pepper and tomato seedlings by pressure spray, which can induce interactive protective effects, and has been used for field control of viral diseases. In addition, the South China Agricultural University Virus Room reported that the weak strain of melon ring spot virus (PRV) was controlled against PRV, and Wu Xunyi of Shandong Agricultural University reported that the weak strains of cotton verticillium wilt, V6-3 and V8-I, had an interactive protective effect on the strongly toxic strains. It can reduce the disease by 8.1% to 61.2%; Lu Suyun et al. of Beijing Agricultural University reported that the treatment of cotton seeds with several Fusarium isolated from cotton vasculature can delay and alleviate the occurrence of cotton blight, and the control effect of the community trial is 39.8% to 90.7%; the weak pathogenic strain of Chestnut Blight pathogen (Cryphonectria parasitica) has a contagious fungal virus, which has been used to prevent and treat chestnut blight.
3. Ecology contro1
3.1. Concept:
Ecological control of pests and diseases refers to the creation of environmental conditions conducive to the growth and development of crops through cultivation and management measures, but not conducive to the reproduction and spread of diseases and insects, so as to achieve the purpose of avoiding or controlling diseases and insect pests. The earliest written record of the ecological control of pests is found in the Spring and Autumn Warring States.
3.2 Measures:
(1) Timely sowing:
The occurrence and harm of diseases and insect pests have a certain optimal period and environmental conditions, under the premise of not affecting the growth and development of crops, appropriate changes to the sowing period can avoid the most appropriate period of disease and insect infestation and pest, thereby reducing the harm of diseases and insects. The prevention and control of sclerocystia by oil sunflower is a kind of disease avoidance, due to late sowing, the flowering period of sunflowers is staggered with the radiation stage of ascospores, which alleviates the immersion; chinese cabbage sowing too early often leads to downy mildew, soft rot, viral disease, and leukoplakia, and timely sowing can not only reduce the harm of diseases and insects, but also avoid the untruthfulness caused by late sowing.
(2) Reasonable layout and rotation:
A rational variety layout can limit the spread and spread of pests and diseases, delay or mitigate pests and diseases. Crop rotation is not only conducive to crop growth, but also can reduce the accumulation of disease sources in the soil and the food source of mono-olivoretic pests, especially the effect of water and drought rotation is remarkable. In production, according to different species and varieties, the implementation of planned crop rotation stubble and intercropping sets can not only change the physical and chemical properties of the soil, improve fertility, but also reduce the accumulation of pathogenic sources and insect sources and reduce harm. Continuous vegetable cropping is an important cause of causing and aggravating pests and diseases. Rotating with onions and garlic stubble can alleviate fungal, bacterial and nematode diseases of fruits and vegetables, and water and drought rotation can significantly reduce diseases such as tomato canker disease, green blight, melon wilt and various nematode diseases.
(3) Use of patients:
Fellow and G1yun (1934) found suppressors of total wheat erosion in the United States and the United Kingdom, respectively, and Ger1agh (1968) verified the existence of wheat total erosion inhibitory soils in the Netherlands. Acidic soils are conducive to trichoderma spore germination and enhance the inhibition of Perpendicular filamentum, while alkaline soils are conducive to inducing bacterium fluorescens pseudomonas. In the diseased field of continuous wheat cultivation for many years, the total erosion disease has been alleviated year by year, or even disappeared, which is due to the accumulation of a large number of beneficial microorganisms such as fluorescent Pseudomonas in the soil and has become a disease-suppressing soil. Studies on many diseases have shown that bacteriostatic soils are common in nature, and the development and utilization of bacteriostatic soils is another important area of disease biological control.
(4) Biodiversity control of pests and diseases:
In the past, farmers mostly cultivated a variety of vegetables, fruits and cereals on a piece of land, and this humble "see the seam and insert seedlings" and "use every inch of land" stingy planting method not only saved land, but also eliminated the large-scale invasion of pests and infectious diseases, so that crops were saved from the disaster. Studies have shown that the diversification of cultivated varieties can play a major role in natural protective barriers. Zhu Youyong et al. (2003) found that the diversity of rice varieties and mixed interplanting have a very significant control effect on rice blast, especially the highly susceptible local rice varieties in mixed interplanting have a significant decrease in the incidence and disease index of rice blast, and the prevention and control effect is 83% to 98%.
(5) Select disease- and insect-resistant varieties
The selection of disease- and pest-resistant varieties is the most cost-effective measure for the control of plant pests and diseases. Jia Sixun recorded 86 varieties of millet in the "Qi Min Zhi Shu Seed Valley Third", of which 14 were "early maturing and drought-tolerant, early ripening and insect-free". Detoxification seedling breeding technology is an effective method for the prevention and control of viral diseases, and the use of potatoes, garlic, sweet potatoes and other detoxified seedlings to prevent and control viral diseases has been widely promoted and applied, and good results have been achieved. Grafting technology can effectively alleviate the pests of many vegetable diseases and insect pests, melons, eggplant vegetables grafting can effectively control melon blight, verticillium wilt, green blight and other diseases, such as the use of black seed pumpkin grafting cucumber, the effect of control of blight is 95%.
(6) Rice-duck co-breeding (co-cropping) technology:
Rice-duck co-breeding is the use of ducks in the rice field to continuously forage for food activities, play a multi-functional effect such as catching insects, eating (stepping on) grass, cultivating and stimulating the robust growth of rice. The use of weeds, insects, aquatic plankton and benthic organisms in rice fields to raise ducks not only ensures the growth of ducks, but also plays a good effect of weeding, pest control and field purification, but also has the effect of returning to the field and increasing soil fertility. Therefore, rice-duck co-breeding can greatly reduce the amount of chemical fertilizers and pesticides, save costs, and help purify the ecological environment of farmland, which is an effective way to carry out organic rice production.
4. Physical and mechanical contro1
4.1. Physical prevention and control
It mainly uses physical factors such as heat, freezing, drying, electromagnetic waves, ultrasonic waves, nuclear radiation, and lasers to inhibit, passivate or kill pathogens to achieve the purpose of preventing and controlling diseases.
(2) Measures:
The use of heat to treat virus-infected plants or asexual propagating material is an important way to produce virus-free seedlings. Treating seeds and asexual propagation materials with hot water can kill pathogens lurking on the surface of seeds and inside seeds, and warm soup soaking seeds is to soak seeds in 55 °C warm water for 30 minutes, during which they are stirred non-stop. After the cotton rod is develered by sulfuric acid, it is soaked in hot water at 55 ~ 60 ° C for half an hour, which can kill the cotton wilt bacteria and a variety of pathogenic bacteria that cause seedling disease, and soaking citrus fruits in hot water can effectively control the rot during storage. The appropriate temperature for the treatment of dormant potato tubers for the treatment of leaf curl disease is 35 to 40 °C, higher temperatures (40 to 45 °C) may passivate bacteroidal pathogens, and citrus seedlings and scion are treated with 49 °C humid hot air for 50 minutes to treat huanglongbing disease. Dry heat sterilization is to put the seeds in a 70 °C incubator and dry heat treatment for 72 hours, which can better prevent the disease spread by seeds with bacteria. The dry heat treatment method is mainly used for vegetable seeds, and has a control effect on a variety of species-borne viruses, bacteria and fungi. Cucumber seeds were treated with dry heat at 70 °C for 2 to 3 days to inactivate the green mosaic virus (CGMMV). Tomato seeds treated at 75 °C for 6 days or 80 °C for 5 days kill seed-borne Verticillium tricorpus. Hot steam is also used for soil treatment of seeds, seedlings and greenhouses and seedbeds, usually with 80 ~ 95 ° C steam treatment of soil for 30 to 60 minutes, can kill most of the pathogenic bacteria; high temperature shed, can alleviate the facility cultivation of diseases and insect pests, such as 35 ~ 40 ° C high temperature shed, can control the spread of cucumber downy mildew.
Cryotherapy is also a common method of controlling post-harvest diseases of plant products (especially fruits and vegetables), and although freezing itself cannot kill pathogens, it can inhibit the growth and infection of pathogens. Low doses of UV light on fruit and vegetable products such as peaches, mangoes, strawberries, grapes and bell peppers can significantly reduce postharvest diseases. Nuclear radiation has a sterilization and food preservation effect in the dose range. 60 cobalt-γ radiation device is simple, low cost, strong γ ray penetration, mostly used for processing storage period agricultural products and food. Microwave is heating suitable for rapid sterilization of small amounts of seeds, grains, foods, etc. Using an ER-692 microwave oven, 10 minutes at 70 °C can kill the corn blight pathogenic bacteria carried by corn seeds.
4.2, Insect Repellent Instruments
Deworming devices go through a process from simple to complex. Simple instruments include wire, wooden poles, shoe soles, etc. In the agricultural book, it is recorded that moths in tree holes are killed with wire hooks, inchworms are shot down from trees with wooden sticks, and locusts are used to beat locusts with the soles of shoes. Later, some more complex insect control instruments appeared, such as Liu Yingtang's "Suoshan Agricultural Genealogy" recorded a kind of insect comb that specializes in the treatment of rice buds, "Tian Jia Struggling to comb the arm, (insects) are tired and harmful, and the flesh and blood are combed", and the effect of insect treatment is better. Chen Chongping's "Book of Controlling Locusts" records a kind of sled that specializes in the treatment of armyworms, and one person pushes the scooter into the ridge, "then inserts a ruler on both sides to copy the seedlings, rolls the insects into the cloth bag, and changes the ridge to push it, which can be exhausted several times", until the 1950s in North China.
4.3, physical machinery:
Commonly used is the manual use of simple machinery such as bamboo poles, brooms, net pockets, etc., using the habits of the insects such as suspended death and clustering to eliminate pests.
4.4, bagging cultivation:
Bagged vegetables without disease and insect pests, no pesticide pollution, excellent varieties, high yield, good efficiency, if the product, cucumber bagging, can directly block the pest of diseases and insects, is conducive to the formation of vitamin C, long shelf life, resistant to storage, and increased production by more than 10%.
4.5. Booby Trap Techniques:
The tendency of pests is mainly used to lure pests to one place and concentrate on killing. Commonly used booby traps are:
(1) Lighting enticing method,
Mainly using the phototropism of pests, incandescent lamps, high-pressure mercury lamps, black lights, frequency vibration insecticidal lamps, etc. are used to trap lepidopteran pests, so as to kill adult insects, reduce the amount of eggs dropped in the field, lower the pest base, and control their pests.
(2) Swatch lure collection method,
Mainly using the color of pests for enticing, such as white can lure thrips, with yellow trap plates can trap aphids, whiteflies, spotted flies, etc., with blue trap plates can trap palm thrips, laying or hanging silver gray film in the field can drive away aphids to migrate and spread poison, reduce the occurrence of viral diseases; laying black mulch film during high temperature in summer, absorbing daylight energy, heating up the soil, and killing a variety of pathogenic bacteria in the soil.
(3) Sweet and sour inducement method,
The use of pest chemotaxis for enticing, the main inducement of nocturnal moths pests, such as small ground tigers, twill noctus, etc., the ratio of sugar and vinegar is: sugar 3, vinegar 3, wine 1, water l0, in order to improve the control effect, can also be added to the appropriate amount of pesticides in the sweet and sour.
(4) Sexual attractant enticing method,
In the pest-prone season, every 667 m2 discharge basin 3 to 4, the basin put water and a small amount of washing powder or insecticide, above the water surface l ~ 2 cm hanging insect attractant core, can trap a large number of insects to find matemate, has been commercially produced twill nocturnal moth, beet nocturnal moth, small vegetable moth, small land tiger and other sexual attractant core.
(5) Cover the insect net, film, etc. to directly prevent pests from being pests:
Cover plastic film, shade net, insect net, rain shelter, shade, insect isolation cultivation, reduce the occurrence of diseases and insect pests. After the vegetables are covered with insect-proof nets, they can basically eliminate the pests of various pests such as vegetable green insects, small cabbage moths, kale nocturnal moths, beet nocturnal moths, twill moths, cotton bollworms, bean borers, melon silk borers, yellow curly stripe jumpers, ape leaf bugs, twenty-eight star ladybirds, aphids, American spotted flies and other pests, control the occurrence of viral diseases caused by the spread of pests, and also protect natural enemies.
5. Artificial prevention and control
In ancient China, there are records of trenching and trapping, artificial hunting and egg digging methods for artificial pest control and reduction of harm. Taking advantage of the fact that the locust wings have not grown, can only jump and cannot fly, ditch and trap to kill locusts. Xu Guangqi of the Ming Dynasty recorded in great detail in the "Complete Book of Agricultural Politics and Preparation for The Examination of Wilderness": "If you have become a salamander and jump, you must open a ditch and hunt it." The Locust Catching Examination records the methods of manually catching locusts. "Locusts are the hardest to kill... It is advisable to use old leather soles... And so on, squatting on the ground and killing each other, and narrow without hurting the seedlings.
Artificial control is the oldest and still used effective pest control method, is a labor-saving, cost-saving, pollution-free, practical way, including manual capture, removal of disease and insect branches and cleaning of idyllic dead branches and other measures to reduce the incidence of diseases and insect pests. Ploughing and irrigation in the rice field in winter can reduce the overwintering base of borers; manual removal of borer egg blocks can be used at the seedling stage to reduce the source of three borers and two borers in the Honda stage; artificial methods such as artificial hunting of adult insects, egg smashing, and killing of larvae are used to control the adult insects, eggs of the cloud-spotted tianniu and the small larvae of the year that were harmed before entering the xylem, which are both economical, simple, and efficient, and without pesticide pollution; people can use the activity rules of rat burrowing and stealing, set up clever organs, and adopt methods such as blocking, digging, irrigation, burning, and catching rats.
(4) The basic method of realizing green plant protection
How can green plant protection be achieved? There are four ways to start:
1. Strengthen scientific research.
The focus is on the study of the occurrence and growth law of agricultural pests, the study of future occurrence trends, the study of prevention and control technologies (especially the research on genetic control, ecological control, biological control, and control standards should be regarded as the top priority), and the monitoring of agricultural ecological environment. Scientific research is the foundation is the premise, without this foundation and premise, green prevention and control is difficult to achieve.
2. Formulate a scientific implementation plan.
On the basis of scientific research, according to the basic requirements of green plant protection, it is necessary to formulate a scientific and feasible green plant protection work plan, and refine the prevention and control strategies, prevention and control target requirements, technical measures, organizational safeguard measures, and work processes.
3. Strengthen publicity and training.
Through publicity and training, let our government leaders, agricultural technical cadres, the broad masses of farmers and relevant social groups have a clear and clear understanding of the significance, measures and methods of green prevention and control, so as to consciously support or devote themselves to green prevention and control work.
4. Grasp the implementation and summarize and improve.
First of all, the administrative departments should uniformly arrange and deploy green prevention and control work, and should take the form of signing a letter of responsibility for target management to rely on solid tasks; secondly, they must form a strong green prevention and control implementation team (including excellent technology and excellent setting); the third is the guarantee and support of funds, green plant protection serves the country and the whole society, and the required financial departments must guarantee it; the fourth is to supervise and inspect and summarize, find problems and correct them in a timely manner, and summarize valuable experience to exchange in a timely manner.
(5) The development trend and existing problems of green control technology
Although the green control technology measures for crop pests have made great progress, there are still some outstanding problems in research and development and application. Whether it is the control speed or the control effect, it is inferior to that of chemical pesticides, and its use often requires a long-term and comprehensive vision, and sometimes it is necessary to sacrifice local interests. But with greater awareness of the drawbacks of chemical pesticides and the importance of developing sustainable agriculture, green control technologies will surely be accepted by the public. The coordinated application of various technologies will certainly be able to exert its effectiveness and benefit future generations.
To be continued, stay tuned!