Plant source slow-release biological pesticide, preparation method thereof and green prevention and control application of rice

Abstract

The application discloses a plant source slow-release biological pesticide, a preparation method thereof and green prevention and control application of the plant source slow-release biological pesticide to rice, and belongs to the technical field of green biological pesticides. The plant source slow-release biological pesticide is prepared from bulk natural plant raw materials and forestry by-products as a matrix, is compounded into three types of active components according to a functional synergy principle, is preprocessed through biomimetic conditioning, is activated and converted by natural microorganisms to prepare an active stock solution, and is formed into slow-release granular preparations with a modified biochar-chitosan composite carrier, and no exogenous chemical synthetic components are doped in the whole process. The process is suitable for industrialized mass production, the preparation has a long effective period and is resistant to rainwater erosion, the prevention and control effect on rice leaf roller and other pests is remarkable, soil-borne diseases can be simultaneously inhibited, the soil microecology can be improved, the crop root development can be promoted, the crops can be matured early, the yield and grain quality can be improved, the ecological safety is high, and the plant source slow-release biological pesticide is suitable for large-area green prevention and control popularization in rice areas in China.

Description

Technical Field

[0001] This invention belongs to the field of green biological pesticides and ecological agriculture technology, specifically involving a plant-derived slow-release biological pesticide with synergistic compounding of functional components and its preparation method. It is mainly used for green control of rice pests, simultaneously achieving soil improvement and crop growth regulation, and is suitable for application scenarios of green agricultural production and double reduction policies. Background Technology

[0002] The rice stem borer is a core boring pest in my country's main rice-producing areas. It is characterized by overlapping generations, concealed damage, and strong pesticide resistance. Long-term reliance on chemical pesticides for control has led to a series of problems, such as increased pest resistance, accumulation of pesticide residues in farmland, and imbalance of soil microecology.

[0003] Existing plant-derived pesticides mostly employ simple water extraction and alcohol extraction processes, resulting in drawbacks such as low dissolution rates of active ingredients, short field retention periods, rapid leaching and loss through rainwater, and poor batch stability. Some products, in order to enhance their rapid effectiveness, are compounded with chemical insecticides, and contain added chemical preservatives and adjuvants, failing to meet the input standards for organic and green agriculture. Furthermore, existing similar products have limited functionality, focusing solely on pest control and failing to simultaneously achieve comprehensive benefits such as soil improvement, root promotion, seedling strengthening, and earlier maturity, making them unsuitable for the green production needs of large-scale planting.

[0004] Plant-derived multi-component synergistic effects and microbial biotransformation technologies can achieve mild transformation of active substances and multi-target action. However, a complete technology system for controlled-release pesticides that is purely plant-based, free of chemical adulteration, has widely available raw materials, and can be standardized for mass production has not yet been established. To address these shortcomings, this invention uses readily available agricultural and forestry plant raw materials as a matrix, combines biomimetic moistening pretreatment with controllable natural microbial transformation technology, and is equipped with a natural bio-based controlled-release carrier to develop industrially viable plant-derived controlled-release biopesticides that combine long-lasting pest control, disease inhibition, soil improvement, and crop growth regulation. Summary of the Invention

[0005] To address the shortcomings of existing plant-derived pesticides, such as short duration of action, limited function, high content of chemical adjuvants, and poor batch stability, this paper proposes a controlled-release biological pesticide that is entirely plant-derived, produced without any exogenous chemical synthetic components, and manufactured using standardized processes. This pesticide enables long-term green control of rice pests, while simultaneously improving paddy field soil properties, promoting crop root development, advancing maturity, and increasing grain plumpness and yield, thus meeting the needs of field applications under the agricultural double reduction policy.

[0006] Compound plant-derived raw material composition: Formulated according to the principle of functional synergy, all components are natural plants and agricultural and forestry by-products produced on a large scale, with no exogenous chemical insecticides, chemical preservatives, or chemical cross-linking agents added throughout the entire process. Raw materials, categorized by function and weight percentage, include: Main repellent and food-repelling components: 25-60 parts of plant raw materials and their processing by-products rich in natural alkaloids, providing core food-repelling and food-repelling activities; Insect-repellent and antibacterial components: 15-40 parts of aromatic plant raw materials rich in volatile oils and terpenoid active substances, which have the effects of repelling insect pests and inhibiting pathogens. Synergistic and long-lasting components: 5-15 parts of plant raw materials rich in triterpenoids and limonene active substances, which synergistically enhance the control effect and prolong the duration of effect.

[0007] Furthermore, 10-20 parts of oil processing by-products can be added, which are rich in natural saponins, to help enhance pest control and improve soil properties.

[0008] The core innovation of this invention is not the selection of a single plant variety, but rather the synergistic compatibility logic of plant components with different functional categories, the microbial activation and transformation process, and the composite molding system with natural slow-release carriers. Those skilled in the art can use conventional plant materials of the same kind in the field to reproduce the technical effects of this invention based on the categories and functional positioning of active substances disclosed in this specification.

[0009] Preparation method: S1 Raw material pretreatment: Remove impurities from plant raw materials, pulverize them at low temperature to 20-40 mesh, mix them according to the formula, add water to adjust the moisture content to 40%-50%, and activate them by sealing and moistening at room temperature for 12-24 hours to complete the biomimetic moistening pretreatment. S2 substrate preparation: Mix the moistened material with water at a mass ratio of 1:8 to 1:12, stir and homogenize, sterilize by moist heat and then cool to obtain the conversion substrate solution; S3 Activation and Transformation: Inoculate with agricultural compound probiotics (a compound system of Bacillus subtilis and Saccharomyces cerevisiae), and let stand for 5-8 days under facultative anaerobic conditions at a temperature of 25-32℃ and a pH of 6.0-7.5. The biotransformation and enrichment of active components are completed by microbial metabolism. S4 stock solution purification: The conversion product is filtered through a plate and frame filter and centrifuged to remove impurities, yielding the plant-derived active stock solution; S5 Slow-Release Molding: The active stock solution is mixed with modified biochar and chitosan natural bio-based carriers in a certain proportion. The mixture is compounded by physical adsorption and natural polymer cross-linking. After homogenization, extrusion granulation and low-temperature drying, a slow-release granule formulation is obtained. The carriers are all natural biodegradable materials and also have soil improvement functions.

[0010] In large-scale production, steps S1 and S2 can be combined for feeding according to capacity conditions. In step S4 purification, multi-stage disc filtration can be used instead of centrifugation. The core parameter range remains unchanged and does not affect the basic control effect of the product.

[0011] Application methods adapted to different regions and phenological periods: Based on the climatic characteristics of my country's four major rice-growing areas and the rice growth period and pest occurrence rhythms, the proportions and application timing of the components are adjusted as needed: In the Northeast single-season rice region: due to the short growing season and low temperatures, the proportion of the main repellent and antifeedant components should be appropriately increased by 5% to 8%, while the proportion of aromatic components should be reduced; apply once each during the tillering stage and the booting and heading stage. In the rice-growing areas of the middle and lower reaches of the Yangtze River: with moderate temperatures and abundant rainfall, maintain the basic formulation; apply once each during the tillering and booting stages of both early and late rice. In the double-cropping rice region of South China: due to high temperatures and overlapping generations of pests, it is advisable to increase the proportion of synergistic and long-lasting components by 3% to 5% to extend the duration of effectiveness; apply once each during the tillering and booting stages of early and late rice, and apply once more during the grain-filling stage in years with high pest incidence. Southwest Plateau Rice-growing Area: Due to large differences in temperature and humidity, the formula ratio can be adjusted according to the local altitude. High-altitude areas should refer to the formula ratio of Northeast Rice-growing Area, and low-altitude areas should refer to the formula ratio of Middle and Lower Yangtze River Rice-growing Area.

[0012] The formulation can slowly release active components, with a lasting effect of 20-30 days, which can reduce the frequency of application; at the same time, it can optimize the rhizosphere microbial community in paddy fields, improve soil aggregate structure, promote the deep root development and nutrient absorption of crops, and achieve the comprehensive effects of strong stems and lodging resistance, full grain filling and early maturity.

[0013] 1. Pure plant-based preparation, no external chemical adulteration: The entire process uses natural plants and agricultural microorganisms as raw materials, without adding external chemical pesticides, chemical preservatives and chemical additives, with no risk of pesticide residues, and meets the standards for green and organic agricultural inputs; 2. Wide range of raw material sources, suitable for industrial production: core components can be selected from bulk agricultural and forestry processing by-products, ensuring stable supply; the entire set of process parameters is controllable; the equipment is universal; batch products have strong stability and meet the requirements of pesticide production quality management standards. 3. Broad spectrum of control and clear comprehensive benefits: It has a clear effect on the control of rice stem borer, and also controls common pests such as rice leaf roller, rice planthopper, and rice thrips. It has an inhibitory effect on rice sheath blight and rice false smut; at the same time, it improves soil properties and promotes crop growth. 4. Slow-release properties are suitable for field applications: Granular formulations are resistant to rain washout, have stable activity release, and a longer duration of action than traditional plant-derived water-based agents, reducing labor costs and making them suitable for the rainy climate of rice-growing areas in the south, as well as large-scale green pest control applications in the field. 5. Promotes early root development and improves production efficiency: Field application can promote rice root development, enhance root vitality and nutrient absorption capacity, strengthen stem toughness and reduce the risk of lodging; at the same time, it can promote early grain filling and maturity of crops, improve grain plumpness and thousand-grain weight, and increase planting income. Detailed Implementation

[0014] Example 1: Basic Plant-Derived Slow-Release Biopesticide Raw material ratio (parts by weight): 50 parts of main repellent and antifeedant component, 25 parts of insect repellent and antibacterial component, 10 parts of synergistic and long-lasting component, and 15 parts of oil processing by-products.

[0015] Preparation steps: 1. After removing impurities, the above raw materials are pulverized at low temperature to 30 mesh, mixed evenly, and then water is added to adjust the moisture content to 45%. The mixture is then left to moisten in a sealed container at room temperature for 18 hours. 2. Add the soaked material and water to the reaction vessel at a mass ratio of 1:10, stir and homogenize, then sterilize by moist heat at 121℃ for 20 minutes, and cool to room temperature; 3. Inoculate with a 2% (w / w) compound microbial agent (Bacillus subtilis: Saccharomyces cerevisiae = 2:1), control the temperature at 28℃ and pH at 6.8, and allow to stand for 7 days in an anaerobic environment; 4. After conversion, the solution is filtered through a 200-mesh plate and frame filter and centrifuged to remove impurities, yielding the plant-derived active stock solution; 5. Take 100 parts of the active stock solution, add 30 parts of modified biochar and 2 parts of chitosan, mix thoroughly for adsorption, extrude and granulate, and dry at a low temperature of 40℃ to obtain the controlled-release granule product.

[0016] Example 2: Low-cost, widely applicable plant-derived slow-release biopesticide Raw material ratio (parts by weight): 48 parts of main repellent and antifeedant components, 28 parts of insect repellent and antibacterial components, 8 parts of synergistic and long-lasting components, and 16 parts of oil processing by-products.

[0017] Preparation steps: Same as in Example 1, except the conversion cycle was adjusted to 6 days and the proportion of modified biochar in the carrier was increased to 35 parts.

[0018] Example 3: Field Application Effect Verification The experiment was conducted in the main rice-producing areas of southern China. A blank treatment and conventional chemical insecticides served as controls. Two treatment groups, Example 1 and Example 2, were set up. The formulation was applied at a dosage of 2 kg per mu (approximately 0.067 hectares), once each during the rice tillering and booting stages. The experimental results are as follows: 1. Pest control efficacy: 20 days after application, Example 1 showed an overall control efficacy of 82.3% against rice stem borer, while Example 2 showed 76.5%; it also showed a combined control efficacy of over 60% against rice leaf roller and rice planthopper. 2. Disease control effect: The relative control effect against rice sheath blight is over 55%, which can significantly reduce the incidence of the disease; 3. Crop growth traits: The root activity of rice was increased by 22.4% compared with the blank control, the internode wall thickness at the base of the stem increased, and the lodging rate was reduced by 12% compared with the blank control; the heading period was advanced by 3-4 days, and the maturity period was advanced by about 4 days. 4. Yield and quality: Yield measured at maturity showed that Example 1 yielded 16.8% more than the control and 9.2% more than the area controlled by conventional chemical pest control; Example 2 yielded 13.5% more than the control; the thousand-grain weight increased by 6.1%, and the plumpness of the grains was significantly improved. 5. Soil improvement effect: After the experiment, the organic matter content of paddy field soil increased by more than 8%, the soil aggregate structure was improved, and the diversity of rhizosphere microbial community was enhanced.

Claims

1. A plant-derived slow-release biological pesticide, characterized in that, The active stock solution is prepared by combining a functionally synergistic compound plant-derived matrix with biomimetic moistening pretreatment and natural microbial activation and transformation. The active stock solution is then compounded with a natural bio-based slow-release carrier. The compound plant-derived matrix is ​​divided into three core raw materials according to function: alkaloid insect repellent and food-repellent components, aromatic insect repellent and antibacterial components, and terpenoid synergistic and long-lasting components. No exogenous chemical insecticidal active ingredients, chemical preservatives, or chemical cross-linking agents are added throughout the process.

2. The plant-derived controlled-release biological pesticide according to claim 1, characterized in that, The composite plant-derived matrix also contains byproducts from oilseed processing plants; the natural bio-based slow-release carrier is a composite system of modified biochar and chitosan.

3. A method for preparing a plant-derived slow-release biopesticide as described in claim 1, characterized in that, Includes the following steps: S1 Raw material pretreatment: Remove impurities from plant raw materials, pulverize them at low temperature, add water to adjust the moisture content to 40% to 50%, and activate them by sealing and moistening at room temperature for 12 to 24 hours to complete the biomimetic moistening pretreatment. S2 substrate preparation: The pretreated material is mixed with water at a mass ratio of 1:8 to 1:12, and the conversion substrate solution is obtained after moist heat sterilization. S3 Activation and Transformation: Agricultural compound probiotics are introduced and left to stand for 5-8 days at 25-32℃, pH 6.0-7.5, and facultative anaerobic conditions. The biotransformation of active components is completed by microbial metabolism. S4 Purification and Liquid Extraction: The conversion product is filtered and centrifuged to remove impurities, yielding the plant-derived active stock solution; S5 controlled-release molding: The active stock solution is mixed with a natural bio-based controlled-release carrier for adsorption, granulation, and low-temperature drying to obtain the finished product.

4. The preparation method according to claim 3, characterized in that, The agricultural compound probiotic is a compound system of Bacillus subtilis and Saccharomyces cerevisiae.

5. The application of the plant-derived slow-release biological pesticide according to claim 1, characterized in that, It is used for green control of rice pests, and can also control rice leaf roller, rice planthopper and rice thrips, and inhibit rice sheath blight and rice false smut; at the same time, it can improve the soil micro-ecology of paddy fields, promote rice root development, advance the maturity period of crops, and improve grain plumpness and yield.