JPH08238049A - Method for fumigating soil - Google Patents

Abstract

PURPOSE: To exterminate pests in a soil safely and simply and protect crop plants from damages by diseases, pests and weeds without feeling any stimulation due to an agrochemical active ingredient by fumigating a soil effectively to disinfect the soil under specific conditions by using the agrochemical active ingredient having specific properties. CONSTITUTION: This method for fumigating soil comprises fumigating a soil by making an active ingredient having >=40 deg.C boiling point at an ordinary pressure and >=0.5mmHg/20 deg.C vapor pressure such as ethylene dibromide the state of a gas or a mist and diffusing it between the surface of the soil covered by a gas barrier film having <=8000cc/m<2> , hr atm (25 deg.C, 50%RH) oxygen gas permeability and the film to disinfect the soil. Furthermore, it is preferable to use a vaporizer or an atomizer consisting of a nozzle, a vaporizing dish and a tank for the agrochemical fluid for its gasification or atomization.

Description

Description: FIELD OF THE INVENTION The present invention relates to a pesticide activity for soil fumigation, which has a boiling point of 40 ° C. or higher at atmospheric pressure and a vapor pressure of 0.5 mmHg / 20 ° C. or higher. A component (hereinafter referred to as the pesticide component) is made into a gas or mist and diffused into the soil while diffusing between the soil coated with a gas barrier film and the film, and pests in the soil are safe. It is a simple and effective control method, and is applied to soil disinfection in agriculture. [0002] Agricultural chemical components conventionally used for soil disinfection in order to control pests that damage agricultural crops,
For example, a drug containing chloropicrin, a D-D agent (a mixture of dichloropropane and dichloropropene), ethylene dibromide, carbon disulfide, methyl isothiocyanate and a mixture thereof (hereinafter referred to as the drug) cultivates a field. ,
It is used by pouring it into the soil for leveling, but generally it is sprinkled with water and sealed with water to enhance its efficacy or suppress irritating odor, or it is used as an agricultural film such as polyethylene, polychlorinated. It is coated with vinyl to prevent active ingredients from escaping into the atmosphere. However, when treating chemicals in soil, it is complicated to prepare a special treatment machine, and it is difficult to use in conditions where the air is confined in greenhouses. Therefore, the pest control efficiency is also reduced. In order to make the pesticide components easy to handle, a method of solidifying with a gelling agent or an adsorbent and packaging with a water-soluble film is disclosed in JP-B-47-1799, JP-B-47-1800, and JP-A-62-1800.
192301, JP-A-62-192301, JP-A-63
-230602 and the like. These packaging preparations have advantages such as less irritating odor and can be held by hand, but the method of using the agent in soil is to embed them one by one in the soil or use a special processing-only machine. I won't. In addition, chloropicrin and DD, which are the most used among the agricultural chemicals, are diffusible in the soil, so that the solution or tablet must be embedded in 10 are at 10 cm intervals at intervals of 30 cm or more. Therefore, a simpler and safer method for treating the drug has been demanded. On the other hand, as a soil disinfecting method of treating the pesticide component on the soil surface and covering with a gas barrier film, Japanese Patent Laid-Open No. 56-9664
No. 8, JP-A-59-216534, etc., the pesticide components such as chloropicrin that are not gaseous at room temperature are irrigated into the soil, and then the soil is covered with a gas barrier film to remove the pesticide components from the atmosphere. Although it is said that it is possible to efficiently spread it in the soil by suppressing the escape into the soil, the method of irrigating the drug into the soil inhibits the diffusion of the soil, and the pesticide component does not spread widely, so chloropicrin and D-D must be embedded in 10,000 are or more in 10 ares at intervals of about 30 cm, and even if the amount of drug used can be reduced, the processing work is complicated, so a simpler and safer method for treating the drug is required. It was wanted. SUMMARY OF THE INVENTION It is an object of the present invention to develop a method for controlling pests in soil simply and efficiently by using the agent. The present inventors have arrived at the present invention as a result of earnestly researching a technique capable of satisfying the above-mentioned problems. That is, the present invention, the pesticidal component for controlling pests, if necessary the drug,
By using a vaporizer or mist to make a gas or mist, and diffusing it into the soil surface of a field covered with a gas barrier film coating material, pests in the soil of agricultural crops can be made more efficient than conventional methods. We have completed a technology that can control pesticides and sanitarily and easily treat chemicals. Incidentally, a technique of treating the drug in soil (usually, a depth of 10 to 15 cm) and covering it with a gas barrier film is disclosed in Patent Documents and the like, but the drug is treated with a vaporizer or a mist machine. There is no example of a technology that diffuses into the soil while forcibly diffusing it between the soil and the film in the form of gas or mist, and this technology can significantly reduce the labor time of farm work and the drug cost, In particular, it is a groundbreaking method for soil fumigation in fields such as greenhouses where it is difficult for large machines to enter and gas is easily collected. The present invention will be specifically described below. The pesticide active ingredient which can be used in the present invention has a boiling point of 40 ° C. or higher under normal pressure and a vapor pressure of 0.5 mmHg / 20 ° C. or higher, and has a volatility, and diffuses into the soil in a gaseous state, It has the activity of controlling the insects, weeds, diseases and the like that live for a lifetime or a period of time and are harmful to useful plants such as agricultural crops and humans. In addition, when an agricultural chemical component decomposes | disassembles at the time of use or after chemical | medical treatment and shows biological activity, the decomposition product is considered as the agricultural chemical active ingredient of this invention. Specifically, D-D (1,3
-A mixture of dichloropropene and 1,2-dichloropropane), DBCP (1,2-dibromo-3-3chloropropane), DCIP (dichlorodiisopropyl ether), MITC (methyl isothiocyanate), chloropicrin (trichloronitromethane), ethylene di Examples thereof include bromide, dimethyldichlorovinyl phosphate, carbon disulfide, and the pesticide components are carbam (ammonium methyldithiocarbamate), vapor (sodium methyldithiocarbamate), dazomet (tetrahydro-3,5-dimethyl-1). 3,5-thiadiazin-2-thione) and decomposes in water or soil
A compound that produces ITC and exhibits efficacy is also included, but the agrochemical component is not limited to the above, and one kind or two or more kinds may be used in combination. The pesticidal component of the present invention may be used as it is, but if necessary, a solvent, water, an antioxidant, a surfactant, a stabilizer and the like may be added to the pesticidal component to prepare the drug. The agrochemical component may be fixed by an oil-absorbing resin, a gelling agent, an oil-absorbing carrier such as a mineral substance, or the like to be used as the drug. The solid agricultural chemical component may be dissolved in a solvent or water or dispersed like a flowable agent. The vaporizer that can be used in the present invention comprises a heating part, a nozzle, a blowing part, a chemical liquid tank, pressurized air, etc.
These may be combined into one unit, or each part may be used as a single unit in combination. In short, any device that forcibly diffuses the agricultural chemical component between the soil surface and the gas barrier film may be used instead of relying only on the self-diffusing power of the drug. For the evaporated portion, the chemical solution is directly pumped from the nozzle tip, or it is sprayed with air compressed by an air cylinder, carbon dioxide gas cylinder, or a compressor, or fine particles are dispersed in the air by a rotary nozzle that uses centrifugal force. , Or put it in an evaporating dish and let it evaporate by natural heat or by heating, and if necessary,
Before or after that, a ventilation part is installed to diffuse the pesticide component. The chemical liquid tank may be attached to the main body of the vaporizer, or may be of a cartridge type for easy handling.Also, a bottle or drum of the chemical may be attached to the vaporizer or placed at a place distant from the main body of the vaporizer and dropped or vaporized by a pump. May be supplied to the machine. When the temperature during the treatment of the chemical is low, it is possible to accelerate the evaporation by attaching a heater to the blower to heat the chemical and the air in the coating ridge to heat the chemical. The heating method is selected from exothermic reaction of inorganic substances and the like, gas, steam, electricity and the like, but it is preferable to use electricity because it is easy to control temperature and time. It is preferable that the electric heater be capable of adjusting the temperature, for example, the heating temperature can be adjusted in the range of 50 to 250 ° C. The vaporizer can be equipped with a timer to adjust the starting time and operating time. These vaporizers may be put in a coating film to diffuse the pesticide components in the coating, or, in the case of efficiently fumigating a large field or the like, place the vaporizer outside the coating film, It is also possible to attach a duct to the air outlet to install it in the covering film so as to improve the flow of air and smoothly diffuse the drug. The coating film usable in the present invention is not particularly limited as long as it has a gas barrier property. The gas barrier property varies depending on the properties of the film itself, and also varies depending on the thickness and the number of kinds of laminating. It is natural to consider the strength and economical efficiency for covering the soil,
The higher the gas barrier property, the better the oxygen gas permeability (measurement conditions and method of gas permeability are 25 ° C and relative humidity 50
%, According to ASTM D1434-66, the film thickness is corrected and calculated as being inversely proportional to the measured film thickness as a reference) is 8000 cc / square meter · hr
-Atm or less, preferably 4000 cc / square meter-hr-atm or less. For example, one or two of polyethylene terephthalate, polyamide resin, nylon, vinylidene chloride, vinyl chloride (hard), polyacrylonitrile, polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyethylene, polypropylene, etc.
A film composed of a copolymer or mixture of more than one kind and a mixture or a laminate is selected, but the film thickness is not limited to these, and the thickness of the film is also related to the oxygen permeability, such as polyethylene and soft vinyl chloride. A film having a gas barrier property that is not so high as a single-layer film needs to have a gas barrier property by increasing the gas permeability to be approximately inversely proportional to the thickness. In addition, it is necessary to use a film that is easy to handle, that is difficult to lose its barrier properties due to deterioration due to contact with chemicals used, soil moisture, etc., economically superior film, and the thickness depends on the material. Is 10 μm to 200 μm, preferably 10 μm to 1
About 100 μm is suitable. The method of the present invention for effectively fumigating soil in a field is to cover the cultivated soil surface with a film having a gas barrier property, in which the pesticide component is converted into a gas or mist by a vaporizer or mist. It is generated in the shape of a sheet and sent between the surface of the soil and the film to diffuse horizontally into the air, and at the same time, it diffuses downward as well, and the entire soil is fumigated. For example, polyvinyl chloride or polyethylene, which does not have a very high gas barrier property, penetrates upward with a coating film with a thickness of 20 μm or less, which not only reduces the efficiency of the chemicals, but also works in greenhouses and other horticulture and farm fields near residential areas. People and residents may be affected. Further, in the conventional treatment of the soil depth of 15 to 20 cm, the horizontal diffusion of the pesticide component is small, and the treatment at intervals of about 30 cm is widely used.
In the method of the present invention, it is very convenient and labor-saving because soil fumigation can be done simply by diffusing the drug in the coating film in the form of mist or gas, large machines are difficult to enter, and facilities such as greenhouses that rely on manual labor for gardening Suitable for Furthermore, since the loss of the drug is small, the amount of the drug can be reduced as compared with the conventional method, and the merit is great in various points such as economical efficiency and environmental impact. EXAMPLES Next, examples and test examples will be shown, but the present invention is not limited to these. Example 1 Chlorpicrin 600 was applied to the soil surface of a 4 m × 5 m field.
ml was placed in a heating and evaporating dish and placed in front of a vaporizer having a blowing part, and a polyethylene terephthalate film (thickness;
20 μm, oxygen gas permeability; 230 cc / square meter · hr · atm), and then evaporating dish at 70 ° C.
Then, the blower of the vaporizer was rotated until the chloropicrin was exhausted, and the chemicals were vaporized to perform soil fumigation. Example 2 A spray nozzle was placed on soil cultivated in a field of 4 m × 5 m, and 600 ml of chlorpicrin was placed in a chemical tank, and a polyethylene terephthalate film (thickness: 12
μm, oxygen gas permeability; 230 cc / square meter · h
After covering the whole with r.atm), air compressed by a compressor was sent through a pressure-resistant hose, and atomized and sprayed until there was no chloropicrin, and soil fumigation was performed. Example 3 A film (thickness: 60 μm, oxygen gas permeability: 5 cc or less / square meter · hr · atm) in which an ethylene vinyl alcohol copolymer was coextruded in a sandwich form with polyethylene was used instead of polyethylene terephthalate. Carried out soil fumigation in the same manner as in Example 1. Example 4 Instead of polyethylene terephthalate, a polyethylene film (thickness: 60 μm, oxygen gas permeability: 3290 c)
C. Soil fumigation was performed in the same manner as in Example 1 except that c / square meter.hr.atm) was used. Example 5 Instead of polyethylene terephthalate, a polyethylene film (thickness: 40 μm, oxygen gas permeability: 4940c)
C. Soil fumigation was performed in the same manner as in Example 1 except that c / square meter.hr.atm) was used. Example 6 Soil fumigation was carried out in the same manner as in Example 3 except that Di-Trapex oil was used instead of chloropicrin. Example 7 3000 ml of chloropicrin was placed in an evaporating dish on the soil of a cultivated field measuring 20 m × 5 m and placed in front of the warm air outlet of a warm air blower, and a polyethylene terephthalate film (thickness: 20 μm, oxygen gas) Transmittance; 138cc
/ Square meter · hr · atm) after covering the entire surface,
Soil fumigation was performed by rotating the warm air blower with warm air at 80 ° C. until the chloropicrin was eliminated. Example 8 Soil fumigation was carried out in the same manner as in Example 7 except that 260 g of oleosorb (Nippon Shokubai Kagaku Kogyo Co., Ltd.), an oil-absorbent resin of 3,000 ml of chloropicrin, was placed in the evaporation dish instead of 3000 ml of chloropicrin. went. Example 9 A warm air blower of the type in which warm air passes over an evaporation dish containing chloropicrin and is sent to a connected duct is installed outside the field, and the duct is guided to a field of 20 m × 5 m, Polyethylene terephthalate film on top (thickness: 12μ
m, oxygen gas permeability; 230 cc / square meter · hr
・ Atm) covers the entire surface of the field, and chlorpicrin 150
0 ml was evaporated with warm air at 70 ° C. and diffused in the long-axis direction of the field for soil fumigation. Example 10 A warm air blower of the type in which warm air passes over an evaporation dish containing chloropicrin and is sent to a connected duct is installed outside the field, and the duct is guided to a field of 20 m × 5 m. Polyethylene terephthalate film on top (thickness: 12μ
m, oxygen gas permeability; 230 cc / square meter · hr
・ The entire surface is covered with atm) and chloropicrin 3000m
1 was vaporized with warm air of 70 ° C. and diffused in the long-axis direction of the field for soil fumigation. A duct was also placed inside the coating in the direction opposite to the air outlet and connected to the air inlet of the blower. Control Example 1 In a 4 m × 5 m field, 2.3 ml of chloropicrin was added in an amount of 2.3 ml each.
Soil irrigation at a depth of 15 cm at 0 cm intervals (11,
000 locations / equivalent to 10 ares), polyethylene film (thickness: 50 μm, oxygen gas permeability: 3950 cc /
The entire surface was covered with square meters · hr · atm). Comparative Example 2 Soil irrigation (corresponding to 11,000 points / 10 ares) of polyethylene was carried out in a 4 m × 5 m field by a manual irrigator at a depth of 15 cm at intervals of 30 cm at intervals of 3 ml of Di-Trapex oil. Film (thickness: 50 μm, oxygen gas permeability: 3950 cc / square meter · hr · at
m) was coated over the entire surface. Control Example 3 A chloropicrin tablet (manufactured by Nankai Chemical Co., Ltd.) was embedded in soil at a depth of 15 cm at intervals of 30 cm (corresponding to 11,000 points / 10 ares) in a 4 m × 5 m field, and soft poly was used. Vinyl chloride film (thickness: 100μ
m, oxygen gas permeability; 500 cc / square meter · hr
-Atm / 25 μm) was coated on the entire surface. Control Example 4 Chlorpicrin 600 was applied to the soil surface of a 4 m × 5 m field.
ml was placed in a heating evaporation dish and placed in front of a vaporizer having a blower part, and a polyethylene film (thickness: 20 μm, oxygen gas permeability; 9875 cc / square meter · hr · at
After coating the whole surface with m), the evaporation dish was kept at 70 ° C., and the blower of the evaporator was rotated until the chloropicrin was exhausted to evaporate the chemicals and perform soil fumigation. Test Example Test conditions Sterilization test: Tomato wilt disease soil contaminated with 60 days of cultivation in a soil bran medium was wrapped in dry soil in an amount equivalent to 10 g with gauze,
In the field where the soil depth was 20 or 30 cm, the drug was applied to the soil as in the example and the control example, and after 2 weeks, the coating film was peeled off and a sample embedded in the soil depth of 20 and 30 cm was taken to examine the bacterial density and evaluate the efficacy. An evaluation was made. Test bacterium: Tomato wilt disease evaluation method: Workability evaluation: The impression handled by the operator was recorded. Evaluation of control effect: Culture was carried out for 7 days at 25 ° C. by the dilution plate method, and the density of tomato wilt disease bacteria per 1 g of dry soil was investigated. Test results: Workability evaluation: Control Examples 1 and 2 are irritating to eyes and nose during soil irrigation, and require a gas mask and protective eyeglasses, and Control Examples 1, 2 and 3 have a large number of drug treatment points. Therefore, the work was troublesome, but the other examples could be easily performed. Evaluation of control effect: Table 1 Example Tomato wilt disease bacterial density Soil depth 20 cm 30 cm Example 1 0 0 Example 2 0 0 Example 3 0 0 Example 4 1 5 Example 5 3 2 × 10 Example 60 0 Example 7 0 0 Example 8 0 0 Example 9 0 0 Example 10 0 0 Control Example 4 9 1 × 10 ² No treatment 3 × 10 ⁶ 3 × 10 ⁶ [0027] Compared to Example 4, all of the Examples efficiently controlled wilt of tomato wilt, and the Examples were good in workability, labor-saving and easy to treat with a drug. The control effect was also good. On the other hand, Control Examples 1, 2 and 3 have a problem of workability, and Control Example 4 has a slightly poorer control efficacy. The Examples have good workability and can be treated with labor-saving and simple chemical treatments. Was better. EFFECTS OF THE INVENTION The soil fumigation method of the present invention enables hygienic and simple treatment of chemicals without feeling irritation of the pesticide components, and enables efficient control of pests. .

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location A01N 47/46 A01N 47/46

Claims (1)

Claims: 1. Oxygen gas permeability of a pesticide active ingredient having a boiling point of 40 ° C or higher at atmospheric pressure and a vapor pressure of 0.5 mmHg / 20 ° C or higher at atmospheric pressure, in the form of gas or mist. Is 8000cc
/ Square meter ・ hr ・ atm (25 ℃, 50% RH)
Soil fumigation method characterized by protecting the crop from pest damage and weed damage by diffusing it between the surface of the soil covered with the following gas barrier film and the film to disinfect the soil [Claim 2] A method for soil fumigation according to claim 1, wherein atomization is performed by a vaporizer or mist comprising a nozzle or an evaporating dish and a chemical tank. 3. A gas or atomization method comprising a nozzle or an evaporating dish, a blower and a chemical tank. 4. A method for soil fumigation according to claim 1, wherein the method is performed by a vaporizer or a mist consisting of the same. 4. A method for fumigating soil according to claim 1, wherein the chemical solution can be heated by an electric heater. A method for fumigating soil according to any one of claims 1 to 4, wherein the chemical liquid tank of the vaporizer or mist machine is a cartridge type. A method for fumigating soil according to claims 1 to 5, characterized in that it can be heated by a heater. [Claim 7] A vaporizer having a heating function is placed in the coating film to diffuse the pesticide active ingredient into the coating. The soil fumigation method according to claim 1. 8. The method for fumigating soil according to claim 1, wherein a vaporizer or a mist having a blowing function is placed in the coating film to diffuse the pesticide active ingredient in the coating. 9. The method for fumigating soil according to claim 1, wherein a vaporizer having functions of heating and blowing is placed in the coating film to diffuse the agricultural chemical active ingredient in the coating. 10. The method for fumigating soil according to claim 1, wherein the vaporizer is placed outside the coating film, and the agricultural chemical active ingredient is blown into the coating film through a duct to circulate the air. The soil fumigation method according to claim 1, wherein the machine is placed outside the coating film, and the pesticide active ingredient is circulated through the duct and air in the coating film and a part of the outside air, or the outside air is blown thereinto. A method for fumigating soil according to any one of claims 1 to 11, characterized in that a vaporizer or mist is equipped with a time adjuster. (13) An oxygen permeability of a gas barrier film used as a covering material is 4000 CC / square meter. hr
・ Soil fumigation method according to claims 1 to 12, characterized in that it is atm (25 ° C, 50RH) or less.