阅读说明：本技术 一种农林抗菌杀菌剂的制备方法 (Preparation method of agricultural and forestry antibacterial bactericide ) 是由 张坤 于 2021-09-23 设计创作，主要内容包括：本发明公开一种农林抗菌杀菌剂的制备方法,本发明用有机溶剂二甲基亚砜代替氢氧化钠强碱性溶剂提取腐植酸,设法将产品pH值控制在7左右。本发明制备工艺简单,成本较低,水溶性和油溶性好,其药效与某些常用杀菌剂的药效相当；与常规农药复合后可大幅度减少农药用量,提高药效,降低成本,延长药效期。本工艺无废弃物排放,副产残渣可用作化肥增效剂或土壤调理剂的原料。(The invention discloses a preparation method of an agricultural and forestry antibacterial bactericide, wherein an organic solvent dimethyl sulfoxide is used for replacing a strong alkaline solvent of sodium hydroxide to extract humic acid, and the pH value of a product is controlled to be about 7. The invention has simple preparation process, lower cost, good water solubility and oil solubility, and the drug effect of the invention is equivalent to that of some common bactericides; after the pesticide composition is compounded with conventional pesticide, the dosage of the pesticide can be greatly reduced, the pesticide effect is improved, the cost is reduced, and the pesticide effect period is prolonged. The process has no waste discharge, and the byproduct residue can be used as a fertilizer synergist or a raw material of a soil conditioner.)

1. A preparation method of agricultural and forestry antibacterial bactericide is characterized in that raw materials comprise dimethyl sulfoxide and low-grade coal, and the preparation method comprises the following steps: (1) adding dimethyl sulfoxide and low-grade coal into a reactor, starting stirring, reacting at room temperature of 60 ℃ for 1-3 hours, and then putting reactants into a centrifuge for solid-liquid separation to obtain dimethyl sulfoxide-humic acid compound solution (DMSO-HA) and byproduct residue;

(2) the dimethyl sulfoxide-humic acid compound solution is directly sprayed by adding water;

(3) the volume ratio of the dimethyl sulfoxide-humic acid compound solution to the common bactericide is 2: 8-4: 6 after compounding, adding the pesticide complex and spraying.

2. The method for preparing an agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the ratio of dimethyl sulfoxide to low-grade coal is 1: 2-1: 7, respectively.

3. The method for preparing an agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the low-grade coal is pulverized by a pulverizer and then added into a reactor.

4. The method for preparing the agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the low-grade coal is weathered coal or lignite, and the content of humic acid is more than or equal to 50%, the moisture content is less than or equal to 10%, and the fineness is less than or equal to 0.2 mm.

5. The method for preparing the agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the purity of the dimethyl sulfoxide is 99.5%.

6. The method for preparing the agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the dimethyl sulfoxide-humic acid compound solution contains more than or equal to 10% of humic acid, 80-90% of dimethyl sulfoxide, less than or equal to 5% of water, less than or equal to 0.5% of insoluble substances, and the pH value is 7 +/-0.5.

7. The method for preparing an agricultural and forestry antibacterial bactericide as claimed in claim 1, wherein the rotation speed of the centrifuge is 4000 revolutions per minute.

Technical Field

The invention belongs to the technical field of pesticide chemistry and plant protection, and particularly relates to a preparation method of a dimethyl sulfoxide-humic acid composite agricultural and forestry antibacterial bactericide.

Background

The plant diseases and insect pests are an important factor causing economic loss of agriculture and forestry, and have the characteristics of multiple types, wide range, large influence and frequent outbreak and disaster, wherein the influence degree of the diseases is wider and more serious. The disease of agricultural and forestry crops in China is more than 700, the disease occurs about 17 hundred million acres per year, and common diseases such as wheat powdery mildew and gibberellic disease, rice sheath blight and false smut, vegetable downy mildew and anthracnose, fruit tree rot and the like are serious diseases to the crops. At present, the main measure for preventing and controlling crop diseases is to apply bactericides. The common bactericide has more than 60 varieties and more than 400 preparations, the annual dosage is about 7 ten thousand tons (pure), and the bactericide accounts for about 23 percent of the total dosage of the pesticide. Currently, the low-toxicity bactericide comprises three major classes of triazoles, benzimidazoles and protective bactericides.

With the development of modern agriculture and the requirement of ecological construction, the use of pesticides in China is developing towards high efficiency, low toxicity and reduction. Research and application practice for more than 40 years proves that humic acid (including fulvic acid) extracted from coal is a natural organic bioactive substance, the main component of the humic acid is aromatic hydroxycarboxylic acid, and the humic acid contains a certain amount of carbonyl, quinonyl, enol-group, amino, sulfydryl, phosphino and other active groups. Humic acid not only has antibacterial and antiviral effects, but also has solubilizing, toxicity reducing, slow-release and synergistic effects on chemical pesticides. In recent years, some reports on humic acid compound preparations have been made. For example, CN1593154A discloses a technology for preventing and controlling apple tree rot by a humic acid copper water solution. The preparation has the pH of 8.5-10, and the effective components of 2% of humic acid and 0.12% of Cu²⁺The pesticide effect is better than that of the bactericide asomate, but the toxicity and pollution of arsenic are avoided. The invention CN104322560A and CN104273173A are pesticide (thiamethoxam, dinotefuran and fipronil) synergistic compositions (solid powder or granules) containing humic acid respectively, can obviously improve the insecticidal effect, reduce the pesticide dosage and reduce the use cost. However, humic acid as pesticide or synergistic additive still has fatal defects at present: firstly, humic acid (including fulvic acid) has certain biological activity and pharmacological activity, but lacks bactericidal and insecticidal effects and is not enough to be used as a pesticide alone; secondly, the humic acid is insoluble in water and can only be prepared into alkaline humic acid sodium salt, most of the pesticide is neutral or acidic, and if the humic acid is compounded with the alkaline humic acid sodium salt, the pesticide decomposition is inevitably caused, and the pesticide effect is reduced; thirdly, many pesticides are oil solutions or wettable powders, which lack intersolubility and compatibility with sodium humate aqueous solutions if they are oil solutions or wettable powdersThe compound preparation is prepared by a mechanical mixture, so that the solution forms jelly or precipitates, the 'synergistic' effect is greatly reduced, and the effect of the original medicine is even reduced. Therefore, the invention provides a synergistic pesticide which has low-toxicity pesticide effect and can be compounded and mutually dissolved with various pesticides, and is an urgent need for developing modern ecological agriculture.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention uses the organic solvent dimethyl sulfoxide to replace the strong alkaline solvent of sodium hydroxide to extract humic acid, and tries to control the pH value of the product to be about 7. The bactericidal effect of the humic acid-dimethyl sulfoxide solution is examined in advance, and the effects (such as insect killing and weeding) of other medicines are verified after the other medicines are used. And (3) inspecting and verifying the intersolubility and the pesticide effect of the humic acid-dimethyl sulfoxide solution and the common pesticide preparation.

The scientific basis and the technical verification result of the technical scheme are provided as follows:

1. the chemical composition, biological activity, green environmental protection effect and safety of humic acid to organisms are proved by a large number of researches for decades without verification;

2. dimethyl sulfoxide (DMSO), a weakly basic organic solvent, is also known for its structure and properties, and has the formula (CH)₃)₂-S ═ O, good chemical and thermal stability, water-soluble and mostly organic, with minimal toxicity to animals (less than most low toxicity pesticides, mice oral LD)₅₀16500 to 24000 mg/kg). The developed countries of last century report that dimethyl sulfoxide is used as solubilizer, penetrant and synergist of some pesticides, and the dimethyl sulfoxide not only improves insecticidal and bactericidal effects, but also can improve permeability of biological cells and reduce damage of free radicals to cells.

3. The solubility of dimethyl sulfoxide to humic acid in coal is excellent, the extraction rate of humic acid is equivalent to that of 1% NaOH solution, the extract liquid and the residue are easy to separate, the alkalescent dimethyl sulfoxide and the weakly acidic humic acid are neutralized, and a chemical action (hydrogen bond association, namely (CH) is supposed to occur₃)₂-S＝O┈HOOC-HA-OH]To form an organic compound, and the pH of the solution can be controlled within the range of 6.5-7.5.

4. The dimethyl sulfoxide-humic acid compound solution has good water solubility and oil solubility, and is easy to be mutually soluble with various bactericides. Both water-soluble pesticides, wettable suspension pesticides and oil-soluble pesticides can form transparent solution or homogeneous emulsion with dimethyl sulfoxide-humic acid compound solution, which is easy to spray.

5. The field test shows that the dimethyl sulfoxide-humic acid compound solution has obvious bactericidal efficacy and the control effect is equivalent to that of some common bactericides; the dimethyl sulfoxide-humic acid compound solution and the chemical bactericide are compounded for use, the effect is better than that of the bactericide which is used alone, the pesticide dosage can be greatly reduced, the use cost is reduced, and the effective period is prolonged.

(II) technical scheme

In order to prepare the bactericide, the invention provides the following technical scheme:

a preparation method of an agricultural and forestry antibacterial bactericide comprises the steps of adding dimethyl sulfoxide and low-grade coal into a reactor according to the proportion of 1 (2-7), starting stirring, and reacting at the room temperature of 60 ℃ for 1-3 hours; putting the reactants into a centrifuge, separating at the rotating speed of 4000r/min to obtain a solution, namely a dimethyl sulfoxide-humic acid compound solution compound, and taking the byproduct residue as a fertilizer synergist or a soil conditioner; the low-grade raw material coal refers to weathered coal and lignite, and the content of humic acid is required to be more than or equal to 50 percent, the water content is required to be less than or equal to 10 percent, and the fineness is required to be less than or equal to 0.2 mm; the required dimethyl sulfoxide is the first-class product in industry, and the purity of the dimethyl sulfoxide is 99.5 percent.

The quality indexes of the dimethyl sulfoxide-humic acid compound solution are as follows: humic acid is more than or equal to 10 percent, dimethyl sulfoxide is 80 to 90 percent, water is less than or equal to 5 percent, insoluble substances are less than or equal to 0.5 percent, and pH is 7 plus or minus 0.5; the insoluble residue contains 20% of humic acid, 15% of dimethyl sulfoxide and the balance of coal powder and ash, and can be used as an organic raw material of a fertilizer synergist or a soil conditioner.

The dimethyl sulfoxide-humic acid compound solution has good intersolubility with water and various organic solvents, can be independently used for preventing and treating diseases of crops and fruit trees, and can also be intersolubility with water-soluble, oil-soluble or wettable powder common bactericides. The volume ratio of the dimethyl sulfoxide-humic acid compound solution to the pesticide is changed within the range of 2:8 to 4:6, and the actual ratio is based on ensuring that the pesticide has obvious synergistic effect.

Biological tests show that the dimethyl sulfoxide-humic acid compound solution is independently used as a bactericide, the vegetable disease prevention and control effect is improved by 38-48 percent, and the vegetable disease prevention and control effect is equivalent to the prevention effect of thiophanate methyl; the bactericide is compounded with commonly used bactericides (carbendazim, metalaxyl, mancozeb, thiophanate-methyl and the like) according to the ratio of 3:7 and 4:6, the control effect is improved by 76 to 134 percent compared with that of the corresponding bactericide which is singly used, and the pesticide is saved by 30 to 40 percent. The prevention effect of the dimethyl sulfoxide-humic acid compound solution on the rot disease of fruit trees reaches 73 percent by using the dimethyl sulfoxide-humic acid compound solution alone, and the ratio of the dimethyl sulfoxide-humic acid compound solution to thiophanate-methyl is 3:7, the control efficiency of the composite is improved by 18.2 percent and 24.6 percent respectively compared with that of single use of asomate and thiophanate-methyl, which shows that the dimethyl sulfoxide-humic acid composite solution has extremely obvious pesticide effect on controlling agricultural and forestry diseases and has the synergistic effect of more than 1+1 and 2 after being compounded with common bactericides.

(III) advantageous effects

Compared with the prior art, the invention has simple preparation process, lower cost, good water solubility and oil solubility, and the drug effect of the invention is equivalent to that of some common bactericides; after the pesticide composition is compounded with conventional pesticide, the dosage of the pesticide can be greatly reduced, the pesticide effect is improved, the cost is reduced, and the pesticide effect period is prolonged. The process has no waste discharge, and the byproduct residue can be used as a fertilizer synergist or a raw material of a soil conditioner. The invention provides a novel humic acid pesticide technology which is cheap, efficient, environment-friendly, low in toxicity and easy to realize industrialization for developing modern organic ecological agriculture.

Drawings

FIG. 1 is a flow chart of the preparation process of the present invention

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. With reference to fig. 1, the specific implementation is as follows.

Example 1:

500kg of dimethyl sulfoxide and 168kg of weathered coal with 67.2% of humic acid are added into a reactor. The stirrer was switched on and heated to 45 ℃ and reacted at this temperature for 2 h. The material is put into a sedimentation centrifuge and centrifuged for 30min at 4000r/min to obtain 515kg of solution. The product analysis result is: humic acid 14.1%, water 2.3%, insoluble substance 0.2%, and dimethyl sulfoxide as the rest, with pH 6.8. The residue obtained by centrifugation (152.4 kg) was analyzed as follows: 23.2% of humic acid, 14.8% of dimethyl sulfoxide and the balance of coal powder and ash.

Example 2:

the operation was substantially the same as in example 1, except that 210kg of lignite having a humic acid content of 50.1% was used. After centrifugation, 520.3kg of solution was obtained, which was analyzed as follows: humic acid 12.5%, water 3.2%, insoluble 0.3%, pH 7.2. The residue obtained by centrifugation was 158.0kg, and the analysis result was: humic acid 18.8%, dimethyl sulfoxide 13.4%, and the balance of coal powder and ash.

Example 3:

one of vegetable antibacterial test cases: and (3) field test for controlling tomato phytophthora root rot.

Test site: in a greenhouse of a plant protection station where an inventor is located, the tested soil is clay, the pH value is 7.3, and the organic matter is 1.4%. The incidence rate of the geophytophthora is high, and the incidence degree of the geophytophthora is 4-6 grades in general years;

and (3) experimental design: the tomato variety is 823; cell area 15m²(ii) a The test is repeated for 4 times, clear water and 50% wettable metalaxyl manganese-zinc powder are used as reference, and the two samples are mixed according to the ratio of 50% metalaxyl manganese-zinc to 3:7 and 4:6 as dimethyl sulfoxide-humic acid compound solution and are respectively used as two samples and are arranged in random blocks.

The test method and measures are as follows: the greenhouse adopts heat preservation and moisture preservation measures. Before spraying, phytophthora spore suspension 10 is sprayed⁶And (5) inoculating the strain to the leaf surface artificially per ml. Carrying out disease condition base investigation and grading recording 3 days after inoculation, and then carrying out a pesticide spraying test by using a sprayer; all the medicaments are diluted by 600 times by water, 50kg of the medicament is sprayed every mu every time, the medicament is sprayed every 7 days, and 3 continuous spraying is carried outAnd secondly, observing the disease condition after the pesticide is applied, recording the safety, calculating the disease index and the control effect, and carrying out statistical analysis by using a new range method. The main test results are shown in table 1.

TABLE 1 dimethyl sulfoxide-humic acid compound solution and its pharmacodynamic test result with bactericide metalaxyl manganese zinc compound for controlling tomato phytophthora

As can be seen from the data in the table, the single application of the dimethyl sulfoxide-humic acid compound solution has equivalent efficacy to the single application of metalaxyl manganese zinc, the later efficacy is reduced, but the after effect of the dimethyl sulfoxide-humic acid compound solution is higher. After the two are compounded, an extremely obvious synergistic effect is generated. Although the dosage of metalaxyl manganese zinc is reduced by 30 to 40 percent, the control effect is improved by 76 to 134 percent compared with the single application of metalaxyl manganese zinc. The dimethyl sulfoxide-humic acid compound solution and metalaxyl manganese zinc are compounded to play a role of 1+1> 2.

Example 4:

one of the fruit tree antibacterial test cases: and (3) field test for preventing and controlling apple tree canker.

Test site: the test field of the apple orchard at the inventor site tests the soil property: loess, pH7.8, organic matter 1.3%. The incidence rate of the apple tree canker in the field is high, and the incidence degree in general years is 3-5 grade;

and (3) experimental design: apple variety of Fuji 6^#(ii) a The test is provided with 4 treatments, 10 trees are selected in each treatment, and the disease of the branch and the trunk of 4 grades is generated in the last year. Using 40% asomate wettable powder and 70% thiophanate-methyl suspending agent as reference, taking dimethyl sulfoxide-humic acid compound solution, 50% thiophanate-methyl, 3:7 compound as sample, and randomly grouping. Before use, all medicaments are diluted by 30 times by water to be used as smearing medicaments.

The test method and measures are as follows: scraping disease spots on the trunk before fruit tree germination in spring according to a ratio of 200g/m²The medicine is smeared according to the amount of the medicine, and then the medicine smearing position is wrapped by gauze. Smearing once more after 10 days, and observing after one weekDisease conditions are observed and recorded, disease recurrence index and prevention effect are calculated, and statistical analysis is carried out by a new range method. The main test results are shown in table 2.

TABLE 2 efficacy test of dimethyl sulfoxide-humic acid compound solution and its compound with bactericide thiophanate-methyl for preventing and treating apple tree rot

As can be seen from the data in the table, compared with single use of asomate and thiophanate-methyl, the control effect of the dimethyl sulfoxide-humic acid compound solution on the rot disease of fruit trees is slightly lower, but after the dimethyl sulfoxide-humic acid compound solution and thiophanate-methyl (3:7) are compounded, the control effect is respectively improved by 18.2 percent and 24.6 percent compared with the control effect of the two pesticides singly. The dimethyl sulfoxide-humic acid compound solution has obvious synergistic effect on the bactericide for preventing and treating the fruit tree diseases.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.