Biological agent for efficiently preventing and controlling red spiders

Abstract

The invention belongs to the technical field of plant protection and biological prevention and control, and particularly relates to a biological preparation for efficiently preventing and controlling red spiders. The biological agent for efficiently preventing and controlling red spiders, provided by the invention, is prepared from the following raw materials in parts by mass: 5 to 10 parts of lactic acid, 10 to 15 parts of ethanol, 8 to 15 parts of chitosan, 12 to 25 parts of marigold extract, 3 to 8 parts of clove extract, 1 to 3 parts of cationic surface active agent, 1 to 3 parts of VC and 30 to 60 parts of deionized water. The invention has a triple action mechanism of charge repulsion, biological inhibition and physical plugging, and can efficiently prevent and control red spider pests.

Description

Technical Field

[0001] The present invention belongs to the technical field of plant protection and biological control, and particularly relates to a biological preparation for effectively preventing and controlling red spider mites. Background Art

[0002] Red spider mites, commonly known as giant spiders or dragon spiders, are a common agricultural pest. They have a varied diet and harm a wide range of crops. Their piercing and sucking mouthparts suck sap from plants, destroying chlorophyll and causing plant weakness and leaf drop. Leaf wounds also make plants susceptible to pathogenic bacteria. Red spider mites are widely distributed throughout China, and if not effectively controlled, they can significantly reduce agricultural production.

[0003] Currently, the prevention and control of red spider mites mainly relies on the use of chemical pesticides such as cypermethrin, triazotin, and fenbutatin. Once used in excess, they will cause serious damage to plants and affect soil fertility. The residues of chemical pesticides will also cause serious environmental problems. Moreover, as red spider mites become more resistant to chemical pesticides, the prevention and control effect is getting worse and worse. Therefore, there is an urgent need to develop a biological agent that can effectively prevent and control red spider mites. Summary of the Invention

[0004] The purpose of the present invention is to provide a biological preparation for effectively preventing and controlling red spider mites.

[0005] The present invention adopts the following technical solutions to achieve its purpose:

[0006] A biological preparation for effectively preventing and controlling red spider mites comprises the following raw materials in parts by weight: 5-10 parts of lactic acid, 10-15 parts of ethanol, 8-15 parts of chitosan, 12-25 parts of marigold extract, 3-8 parts of clove extract, 1-3 parts of cationic surfactant, 1-3 parts of VC, and 30-60 parts of deionized water.

[0007] Furthermore, the preparation process of the biological agent for effectively preventing and controlling red spider mites includes:

[0008] (1) After mixing lactic acid and ethanol, add chitosan and stir until completely dissolved;

[0009] (2) Continue to add marigold extract and clove extract and use a homogenizer to disperse at high speed;

[0010] (3) Add cationic surfactant, VC, and ionized water, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 to obtain the biological agent for effectively controlling red spider mites.

[0011] Furthermore, the cationic surfactant is cetyltrimethylammonium bromide.

[0012] Furthermore, the preparation process of the marigold extract includes:

[0013] (1) crushing dried marigold flowers to prepare marigold granules;

[0014] (2) adding the marigold particles into a marigold extraction solvent and performing ultrasonic extraction to obtain a marigold ultrasonic extract;

[0015] (3) The marigold ultrasonic extract is subjected to reduced pressure distillation to remove the marigold extraction solvent to obtain the marigold extract.

[0016] Furthermore, the mass ratio of the marigold particles to the marigold extraction solvent is 1:8.

[0017] Furthermore, the marigold extraction solvent consists of 75% by volume of ethanol and propylene glycol, and the mass ratio of the 75% by volume of ethanol to propylene glycol is 25:3.

[0018] Furthermore, in the ultrasonic extraction, the ultrasonic power is 300W and the ultrasonic frequency is 40kHz.

[0019] Furthermore, the preparation process of the clove extract includes:

[0020] (1) crushing cloves to obtain clove crushed material;

[0021] (2) soaking the crushed cloves in deionized water for 30 minutes, and then performing microwave extraction to obtain a clove microwave extract;

[0022] (3) Concentrating the clove microwave extract to 1 / 5 of its original volume to obtain the clove extract.

[0023] Furthermore, the mass ratio of the clove crushed material to deionized water is 1:10.

[0024] Furthermore, in the microwave extraction, the microwave power is 400W.

[0025] The beneficial effects of the present invention are: 1. Chitosan is compounded with lactic acid, marigold extract, and clove extract to form a green biological agent with a triple action mechanism of "charge repulsion + biological inhibition + physical blocking", thereby achieving targeted prevention and control of red spider mites, while having little environmental residue and high safety.

[0026] 2. The ethanol-lactic acid mixed dissolution system of the present invention enhances the cationic activity of chitosan, and the dissolution efficiency, stability, cationic group exposure and other indicators are more excellent.

[0027] 3. The microwave-assisted extraction of plant active ingredients of the present invention has higher extraction efficiency and better retention of active ingredients. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0029] Preparation Example of Marigold Extract

[0030] (1) Grinding dried marigold flowers through a 60-mesh sieve to prepare marigold granules;

[0031] (2) adding marigold granules to marigold extraction solvent (the marigold extraction solvent is composed of 75% by volume of ethanol and propylene glycol in a mass ratio of 25:3), with the mass ratio of marigold granules to marigold extraction solvent being 1:8, and performing ultrasonic extraction under the following conditions: power 300 W, frequency 40 kHz, extraction temperature 55°C, and time 40 min (extraction is performed twice, the marigold granules are filtered out, and the filtrate is combined to obtain marigold ultrasonic extract;

[0032] (3) The marigold ultrasonic extract was subjected to reduced pressure distillation (45° C., −0.08 MPa) to remove the marigold extraction solvent. The resulting dark yellow paste extract was the marigold extract (yield 19.2±0.8%).

[0033] Effective ingredient indicators of marigold extract: core components are detected by GC-MS: α-terthiophene content is not less than 27.3% (inhibits mitochondrial activity of red spider ovarian cells and blocks germ cell division); lutein ester content is not less than 18.5% (interferes with the binding of red spider aggregation pheromone receptor protein and reduces the group aggregation rate by more than 90%); terpinen-4-ol content is not less than 15.2% (acts on antennae olfactory receptors and inhibits the conduction of neural signals related to mating behavior); the total content of the three active components is not less than 85%.

[0034] Specific effect test of marigold extract on red spider mites: (1) Reproduction inhibition experiment: After treatment with marigold extract, the hatching rate of red spider mites eggs dropped to 12% and the sperm deformity rate was 78%.

[0035] (2) Behavioral rejection experiment: The Y-type olfactometer test showed that 92% of adult red spider mites chose to avoid the area containing the scent of marigold extract.

[0036] Preparation Example of Clove Extract

[0037] (1) crushing cloves to obtain clove crushed material;

[0038] (2) Soaking clove crushed material in deionized water for 30 minutes, wherein the mass ratio of clove crushed material to deionized water is 1:10, and extracting for 15 minutes at a microwave power of 400 W (extracting twice, filtering out the clove crushed material and combining the filtrate) to obtain a clove microwave extract;

[0039] (3) The microwave extract of cloves was evaporated to 1 / 5 of its original volume by rotary evaporation (50°C, -0.06 MPa) to obtain a brown clear liquid, which was the clove extract (yield 11.5±0.5%).

[0040] Clove extract active ingredient indicators: Core components detected by high performance liquid chromatography (HPLC): Eugenol content is not less than 58% (destroys the lipid bilayer of bacterial cell membranes, and the antibacterial rates against Escherichia coli and Alternaria are both >95%); clove oleoresin is not less than 22% (forms a hydrophobic protective film on the plant surface, blocking direct contact between pest mouthparts and plant tissues, and reducing infections caused by mechanical damage).

[0041] Field protective effect of clove extract: (1) Wound antibacterial experiment: After spraying a preparation containing 5% clove extract, the bacterial infection rate of mechanical wounds on plant leaves dropped from 67% to 8%.

[0042] (2) Resistance to secondary invasion: After spraying a preparation containing 5% clove extract on the site damaged by red spider mites, the subsequent attachment rate of red spider mites decreased by 83% and the incidence of fungal diseases decreased by 79%.

[0043] Example 1

[0044] (1) Mix 7.5 parts of lactic acid and 12 parts of ethanol by weight, add 11.5 parts of chitosan (chitosan with a deamidation degree of ≥90% is used in this preparation example), and stir at room temperature (300 rpm) for 6 hours until completely dissolved;

[0045] (2) Add 17 parts of marigold extract and 5 parts of clove extract by weight, and disperse at high speed (8000 rpm, 10 min) using a homogenizer to form a stable emulsion;

[0046] (3) Add 1.5 parts of a cationic surfactant (hexadecyltrimethylammonium bromide is used in this example), 1.5 parts of VC, and 44 parts of ionized water in parts by mass, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 (the optimal range of chitosan charge) to obtain Example 1, a biological agent for effectively controlling red spider mites. The packaging condition is to fill the mixture into brown bottles under vacuum conditions (-0.09 MPa).

[0047] Example 2

[0048] (1) Mix 5 parts of lactic acid and 10 parts of ethanol by weight, add 8 parts of chitosan (this preparation example uses chitosan with a deamidation degree of ≥90%), and stir at room temperature (300 rpm) for 6 hours until completely dissolved;

[0049] (2) Add 12 parts of marigold extract and 3 parts of clove extract by weight, and disperse at high speed (8000 rpm, 10 min) using a homogenizer to form a stable emulsion;

[0050] (3) Add 1 part of cationic surfactant (hexadecyltrimethylammonium bromide is used in this example), 1 part of VC, and 30 parts of ionized water in parts by mass, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 (the optimal charge range of chitosan) to obtain Example 2, a biological agent for effectively controlling red spider mites.

[0051] Example 3

[0052] (1) Mix 10 parts of lactic acid and 15 parts of ethanol by weight, add 15 parts of chitosan (chitosan with a deamidation degree of ≥90% is used in this preparation example), and stir at room temperature (300 rpm) for 6 hours until completely dissolved;

[0053] (2) Add 25 parts of marigold extract and 8 parts of clove extract by mass, and disperse at high speed (8000 rpm, 10 min) using a homogenizer to form a stable emulsion;

[0054] (3) Add 3 parts of cationic surfactant (hexadecyltrimethylammonium bromide is used in this example), 3 parts of VC, and 60 parts of ionized water in parts by mass, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 (the optimal charge range of chitosan) to obtain Example 3 of a biological agent for effectively controlling red spider mites.

[0055] Example 4

[0056] (1) Lactic acid (9 parts) and ethanol (14 parts) were mixed by weight, and chitosan (13 parts) (chitosan with a deamidation degree of ≥90% was added in this preparation example) was added, and stirred at room temperature (300 rpm) for 6 hours until completely dissolved.

[0057] (2) Add 20 parts of marigold extract and 7 parts of clove extract by mass, and disperse at high speed (8000 rpm, 10 min) using a homogenizer to form a stable emulsion;

[0058] (3) Add 2 parts by mass of a cationic surfactant (hexadecyltrimethylammonium bromide is used in this example), 2 parts of VC, and 50 parts of ionized water, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 (the optimal charge range of chitosan). This is to prepare Example 4, a biological agent for the efficient control of red spider mites.

[0059] Comparative Example

[0060] Comparative Example 1

[0061] The difference from Example 1 is that an equal amount of acetic acid is used instead of lactic acid.

[0062] Comparative Example 2

[0063] The difference from Example 1 is that an equal amount of citric acid is used instead of lactic acid.

[0064] Comparative Example 3

[0065] The difference from Example 1 is that equal amounts of water are used instead of marigold extract and clove extract.

[0066] Performance Testing

[0067] Electrostatic repulsion effect experiment

[0068] Preparation of a negatively charged red spider silk model (surface zeta potential -28.7 mV);

[0069] Data comparison is shown in Table 1

[0070] Table 1

[0071]

[0072]

[0073] Joint dissolution efficiency experiment

[0074] The spider mite limb joints were placed in different preparation solutions and the dissolution rate was measured after 48 hours; the data comparison is shown in Table 2

[0075] Table 2

[0076] Joint lysis rate ％ Example 1 65 Example 2 62 Example 3 64 Example 4 64 Comparative Example 1 40 Comparative Example 2 42

[0077] The comparison of protonation ability is shown in Table 3

[0078] Table 3

[0079]

[0080]

[0081] From the data in Tables 1-3, it can be seen that the lactic acid dissolution system of the present invention is significantly better than the acetic acid dissolution system of Comparative Example 1 and the citric acid dissolution system of Comparative Example 2.

[0082] Field control effect experiment

[0083] Using clean water as the control group, take the same amount of control group, Examples 1-4, and Comparative Examples 1-3, and spray the experimental plants respectively. Before spraying, take 10 plants from each group, and inoculate 100 adult red spider mites on each plant. Count the red spider landing rate 1 day after spraying, and count the pest regeneration rate (newly hatched eggs / newborn individuals) 7 days after spraying. Take the average value for each group, and the statistics are shown in Table 4.

[0084] Table 4

[0085]

[0086] It can be seen from Table 4 that the field control effect of the embodiment of the present invention is outstanding, and its advantages are outstanding compared with the comparative example.

[0087] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein. These modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A biological agent for effectively preventing and controlling red spider mites, characterized in that: The invention comprises the following raw materials in parts by weight: 5-10 parts of lactic acid, 10-15 parts of ethanol, 8-15 parts of chitosan, 12-25 parts of marigold extract, 3-8 parts of clove extract, 1-3 parts of cationic surfactant, 1-3 parts of VC and 30-60 parts of deionized water.

2. The biological agent for effectively controlling red spider mites according to claim 1, characterized in that: The preparation process of the biological agent for effectively preventing and controlling red spider mites includes: (1) After mixing lactic acid and ethanol, add chitosan and stir until completely dissolved; (2) Continue to add marigold extract and clove extract and use a homogenizer to disperse at high speed; (3) Add cationic surfactant, VC, and ionized water, stir until the cationic surfactant and VC are completely dissolved, and adjust the pH to between 4.5 and 5.0 to obtain the biological agent for effectively controlling red spider mites.

3. The biological agent for effectively controlling red spider mites according to claim 2, characterized in that: The cationic surfactant is cetyltrimethylammonium bromide.

4. The biological agent for effectively controlling red spider mites according to claim 1, characterized in that: The preparation process of the marigold extract comprises: (1) crushing dried marigold flowers to prepare marigold granules; (2) adding the marigold particles into a marigold extraction solvent and performing ultrasonic extraction to obtain a marigold ultrasonic extract; (3) The marigold ultrasonic extract is subjected to reduced pressure distillation to remove the marigold extraction solvent to obtain the marigold extract.

5. The biological agent for effectively controlling red spider mites according to claim 4, characterized in that: The mass ratio of the marigold particles to the marigold extraction solvent is 1:

8.

6. The biological agent for effectively controlling red spider mites according to claim 5, characterized in that: The marigold extraction solvent consists of 75% by volume of ethanol and propylene glycol, and the mass ratio of the 75% by volume of ethanol to propylene glycol is 25:

3.

7. The biological agent for effectively controlling red spider mites according to claim 6, characterized in that: During the ultrasonic extraction, the ultrasonic power is 300W and the ultrasonic frequency is 40kHz.

8. The biological agent for effectively controlling red spider mites according to claim 1, characterized in that: The preparation process of the clove extract comprises: (1) crushing cloves to obtain clove crushed material; (2) soaking the crushed cloves in deionized water for 30 minutes, and then performing microwave extraction to obtain a clove microwave extract; (3) Concentrating the clove microwave extract to 1 / 5 of its original volume to obtain the clove extract.

9. The biological agent for effectively controlling red spider mites according to claim 8, characterized in that: The mass ratio of the clove crushed material to deionized water is 1:

10.

10. The biological agent for effectively controlling red spider mites according to claim 9, characterized in that: During the microwave extraction, the microwave power is 400W.

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