The Potential of Botanical Pesticides in China

Farms that produce vegetables mainly use protective facilities. In large-scale facility cultivation, plant-based pesticides that are safe to humans and animals and have no special irritating odors have become the first choice for farmers. The high efficiency, low toxicity and broad spectrum characteristics of plant-derived pesticides are also one of the reasons why plant-derived pesticides are competitive. In recent years, China has begun to vigorously research and develop biological pesticides. The screening of biological pesticides from plant resources provides China with resource advantages and technological advantages. If it can make full use of it, it will develop high-efficiency, low-toxicity, safe biological pesticides and promote them in traditional medicinal plants, which can improve the international use of biological pesticides in China. Competitiveness.

Biological pesticides that do not include agricultural antibiotics account for only 2.5% of the global pesticide market. According to the more consistent views of experts at home and abroad, the development potential of biological pesticides is huge. In the next few years, it will replace more than 20% of chemical pesticides. Plant-derived pesticides in biological pesticides account for 1% of the global pesticide market, and grow at a rate of 10% to 15% per year. From the perspective of the distribution of bio-pesticides, the current usage in Europe and the United States and other developed countries and regions accounts for 64% of the world's total, and Asia accounts for only 13%.

The status of Chinese biological pesticides

So far, there are more than 150 registered species of biological pesticides in China, accounting for 14% of the total active ingredient varieties; more than 700 types of compound formulations have been used, accounting for 9% of registered pesticide products, and at a rate of 4% per year. The annual output of the preparations is nearly 130,000 tons, accounting for about 11% of the total output of pesticides; the annual production value is about 2.7 billion yuan, accounting for about 9% of the total output value of pesticides; the application area is about 400 million to 500 million mu, accounting for about 10% of pesticide application area.

Plant-derived pesticides are functional parts that use medicinal plants that have properties such as insecticidal, bactericidal, herbicidal, and growth-regulating properties, or their active ingredients are extracted and processed. Because plant-derived pesticides come from nature, they have the advantages of being safe to humans and livestock, not polluting the environment, not easily causing drug resistance, and being easily degraded in the natural environment. Therefore, the research and development of plant-originated pesticides is one of the current research and development of pesticides. Important aspects.

Chinese biological pesticides have obvious advantages

China has thousands of years of experience in the application of medicinal plants. It has a unique theory of Chinese medicine and has traditional Chinese herbal compatibility theory. There are a variety of plant-sourced pesticides. In the 7th century BC to the 5th century BC, China used madder and other plants to kill pests, and Artemisia stalks and leaves fumigate mosquitoes and flies; in the 6th century AD, it was recorded that veratrum was used as an insecticide; in the middle of the 10th century, it was useful; The record of 100 pesticides was used as a pesticide; in the 17th century, plant extracts such as **, pyrethrum, and rattan were used as insecticides. The long process gradually accumulated a lot of extremely useful toxicological and pharmacodynamic data, which provided a solid material, theoretical and technical basis for the development of new types of biological pesticides.

Grainge and Ahemed have reported that about 2,400 species of plants have pest control activity. In laboratory and even field trials, many plants exhibit potential pest control characteristics. The sources of botanical pesticides in China are extremely wide, and more than 1,300 plants have been identified as containing insecticidal and fungicidal active substances. Judging from the results of the present study, the pesticide plants are mainly concentrated in the families of Polygonaceae, Asteraceae, Leguminosae, Euonymus, Euphorbiaceae, Lamiaceae, Magnoliaceae, Aristolochiaceae, Polygonaceae, Oleaceae, Lily Branch, Cucurbitaceae, Cyperaceae, Cruciferae and other plants.

At present, the research focus of herbicides in plants in China is focused on plants such as Mikania micrantha, marigold, wheat, etc. The natural herbicidal compounds isolated and extracted include indole phenols, alkaloids, phenazines, cinnamic acids, and coumarins. More than 10 kinds of natural grass-killing compounds such as thiophenes, nitriles, flavonoids, thione polyacetylenes and terpenes, some of which have been developed into natural herbicides, and have been patented and promoted. The best example of an effective herbicidal effect is the α-tertiary thiophene extracted from plants of the genus Tagetes. In addition to its herbicidal properties, it also has a nematicidal effect.

At present, domestic production and processing of biological pesticides generally use natural renewable resources such as corn, bean cakes, fish meal, wheat bran, or certain plant materials such as agricultural and sideline products. Sources of raw materials are very wide, and production costs are relatively low. The planting of medicinal plants can make heavy use of the barren land on the hilly land, with less investment and large profits, and at the same time it can maintain the water and soil and conserve the water source. The production of bio-pesticides will generally not compete with chemical synthesis products for raw materials, and the pollution of the production process to the environment is relatively small, which is the direction of development that the country encourages and encourages.

This is the source of the competitiveness of biopesticides in the international pesticide market, especially the fundamental reason for the market share of botanical pesticides.

How Domestic Enterprises Improve Their Competitiveness

Only by adhering to the research and development of new products and new formulations, doing a good job of foreign pesticide registration and timely technological innovation, can Chinese biopesticide companies be rewarded in the complex international market competition.

First of all, take new products and new formulations as a breakthrough.

The separation, purification, molecular structure identification and physicochemical properties of effective chemical constituents of plant-originated pesticides were increased. The relationship between the structure and action mechanism of active substances, and the relationship between structure and activity were studied, and new species of plant pesticides were continuously sought.

Increase the study of the effective ingredients. In order to expand the use effect of plant-originated pesticides, plant-sourced pesticides with similar or complementary effects were rationally compounded. If the main insecticidal active substances of the two plant extracts do not conflict in the mechanism of action, and they can indeed expand the control subjects after mixing, and there are significant synergies, the development of the blend can be carried out, and in-depth indoor bioassay and field development can be conducted. The experiment also considers the interaction between the components of the two plant extracts during storage. Such as matrine, pyrethrum, artemisinin, garlic, etc. and azadirachtin compound, with pyrethrum or synthetic pyrethrin compound. Pyrethrin has a broad insecticidal spectrum. The combination with azadirachtin can not only improve the efficacy but also be effective against pyrethrum-resistant pests. At the same time, the combination of the two can not only kill plant pests, but also can be used to prevent and treat pests. Animal ectoparasites.

Improve the stability of plant-derived pesticides. Due to the instability of natural products, it is easily decomposed under ultraviolet light, sunlight and high temperature. Therefore, in addition to avoiding strong light, high temperatures, strong acids and bases, and enzymes, one or more epoxidized vegetable oil stabilizers and para-aminobenzoic acid light stabilizers may be added during formulation to inhibit the heat of natural products. Decomposition and photodegradation. Emulsification stability can also be improved by selecting suitable emulsifiers.

In plants, compounds with biological activity of pesticides are searched for as lead compounds, and novel pesticides are obtained through structural modification or artificial simulation synthesis and screening. The pyrethroid insecticide is derived from the modification of pyrethrins in the Compositae plant. It originates from the pyruvate physostigmine **** phenyl esters from leguminous lentil seeds, antibiotic 402 from garlic allicin, etc. This is the focus of foreign research and development of plant-derived pesticides, and is also the direction of research and development of botanical pesticides in China.

Second, the foreign pesticide registration as an entry point.

In recent years, developed countries have frequently established trade barriers and restrictions on the export of pesticides. As developed countries generally adopt technical barriers such as increasing registration fees and registration requirements, at present, China’s pesticides account for less than 10% of the pesticide market in developed countries. In-depth research on foreign pesticide registration systems, accelerating the establishment of well-known brands for export of pesticides, and training internationally registered personnel are necessary ways to solve the problem of China's international registration of biological pesticides.

Finally, increase the use of high technology.

With the development of science and technology, many new processes and methods have been applied to the research and development of plant pesticides. Beijing Sanpu Baicao Green Plant Preparation Co., Ltd. adopts new technologies such as ultrafine pulverization, air-flow pulverization, and low-temperature crushing to obtain a 10 micron particle size powder, which greatly increases the surface area of ​​raw materials to promote dissolution and leaching of active ingredients. Supercritical fluid extraction, macroporous resin adsorption, ultrafine pulverization, enzyme extraction, molecular imprinting separation, high performance countercurrent chromatographic separation, and countercurrent ultrasonic extraction can be used in the extraction process. For example, the use of supercritical fluid extraction, the replacement of conventional organic solvents with supercritical fluids, and the extraction and separation of active ingredients, can reduce the use of fuels and toxic chemical solvents. In the process of separation and purification, new methods such as flocculation and sedimentation, macroporous resin adsorption, ultrafiltration and high-speed centrifugation can be used to improve the separation and purification efficiency.

In addition, we must continue to improve the level of product quality standards and improve the analysis and detection technology. Analytical instruments and technologies such as high-performance liquid chromatography, high-performance thin-layer chromatography, gas chromatography, gas chromatography/mass spectrometry, and high performance liquid chromatography/mass spectrometry are now widely used, and fingerprinting technology will gradually become a routine test. Technology, which helps to improve the quality control of pesticide products.