JPH11343209A - Pest control agents and pesticides - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pesticide and a pesticide which are effective for controlling pests such as plants and are easy on the environment. The present invention relates to a pesticide and a pesticide for controlling pests such as plants using a photocatalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an agent for controlling pests on plants and the like and an agricultural chemical.

[0002]

2. Description of the Related Art Conventionally, the most widely used method for protecting plants such as agricultural crops from diseases is to spray pesticides. According to the Agricultural Chemicals Control Law, pesticides are "fungicides, insecticides, Other agents and growth promoters, germination inhibitors, other agents used for enhancing or suppressing physiological functions of agricultural products, and natural enemies used for the above control are defined.

[0003] There are a very large number of plant diseases and their causes are various, but fungi such as molds are mainly involved except for physiological diseases and viral diseases. Those originating from microorganisms such as bacteria and mycoplasmas are also known. In addition, it is difficult to prepare an effective pesticide for all the pathogenic bacteria because the types of causative bacteria are various,
It is necessary to prepare pesticides with different mechanisms of action depending on the bacterial species. Some pesticides for insecticide sterilization have both insecticidal and fungicidal effects and preventive effects, and others have only preventive effects. Ideally, all types of pest causes should be completely eradicated, but this requires the use of a common site of action for all pests. Usually, such an action point is common to all living things, so it is necessary to remove only pests without harming plants or affecting other organisms such as human beings. Is not easy.

[0004] Therefore, it is common to use drugs that have the effect of attacking the characteristics of only the desired pest.
With such a drug, tolerance is likely to appear due to continuous use, and its use is limited. Also, no matter what drug is used, as long as it depends on the chemical action, it is inevitable that the drug will pollute the natural environment. For this reason, attempts to utilize biological effects such as natural enemies without depending on drugs are gradually progressing. Environmental pollution by pesticides has become serious and has become a problem on a global scale. On the other hand, it is virtually impossible to mass-produce the food that humanity needs without resorting to pesticides. Under such circumstances, it is significant to develop a pesticide that has as little impact on the environment as possible and a means of controlling pests that can replace the pesticide.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of such circumstances, and is effective for controlling pests.
The present invention also provides a pesticide and a pesticide that have little effect on the environment. The present invention provides a means for controlling pests such as plants using a photocatalyst, and aims to prevent environmental pollution by the above-mentioned pesticides.

[0006]

SUMMARY OF THE INVENTION The present invention provides a means for controlling plant diseases which is physically close to the photocatalytic function of a photocatalyst, rather than a chemical action by a drug. ADVANTAGE OF THE INVENTION According to this invention, pathogenic bacteria and insects, such as a plant, can be controlled effectively in presence of sunlight. That is,
Provided are a pest control agent and a pesticide containing a photocatalyst as a main component. Provided are a pest control agent and a pesticide formulated in a powder or wettable powder of a photocatalyst such as titanium oxide. The disinfection mechanism of the present invention utilizes the Honda and Fujishima effects of the photocatalyst. When the photocatalyst is irradiated with light, electrons and holes are generated, and a part of these actions radicalizes a small amount of water molecules present on the plant surface. Radicals are highly active, have a strong antibacterial activity, and have the effect of killing bacterial cells adhering to the surface of plant bodies and inhibiting their propagation.

[0007] Photocatalysts are known for application to dirt and odor removal, antibacterial, water treatment, and the like. The photocatalyst is doped or supported with other elements, and the photocatalyst is coated on a solid surface. Known are those that are supported, those that have a photocatalyst immobilized on an adsorbent, and those that have been mixed with a photocatalyst and a resin. The effect of the photocatalyst has already been applied for the purpose of imparting antibacterial properties to daily necessities such as sanitary ware. Such an antibacterial device is usually used in an environment where it is usually difficult to receive light, so that it is often difficult to sufficiently exert a catalytic function. In order to maintain the function stably for a long period of time, it is necessary to fix the photocatalyst to the surface of the device. However, since the action of the photocatalyst destroys the fixing agent itself, it is necessary to select a fixing agent that can withstand this. As a result, it is difficult to use an organic fixing agent such as a resin, which hinders practical use.

It is known to use a photocatalyst as a deodorant and an antibacterial agent. However, a photocatalyst as a main component is applied to a plant, animal, or the like by a spraying method, a spray method, a dip method, or the like. It is not known to control pests such as animals. In particular, it is not known as a pest control agent or pesticide for plants. In the control agent according to the present invention, it is not necessary to fix the catalyst to the surface of the plant body for a long period of time, so that there is no particular limitation on the selection of the fixing agent, and materials suitable for formulation can be appropriately selected. In some cases, it is not necessary to use a fixing agent. In addition, plants usually grow under the sunlight, which is advantageous in absorbing light.

The photofunctional catalyst used in the present invention is selected from materials such as titanium oxide, zinc oxide, and selenium, which are so-called optical semiconductors that generate electrons and holes when irradiated with light. Specifically, titanium oxide is the best in consideration of environmental safety, economy and the like. The form is preferably a form in which the function as a catalyst is easily exhibited, and is used in a powder form.
Further, for the purpose of adjusting the functional level of the catalyst, it can be denatured and diluted with an organic or inorganic substance having no catalytic function as needed. In addition, a photocatalyst doped with or supported by another element (1), water, a surfactant, a bulking agent, a dispersant, an adsorbent, a spreading agent, a resin or the like (2), and others. (3), encapsulated (4) or the like immobilized on the base material may be used.

It is also effective to assist the catalytic function by doping a trace amount of a metal such as silver, which has been recognized as a bactericidal agent. Specific dosage forms include powders, emulsions, wettable powders and the like. Known techniques as pesticide formulation techniques can be applied as they are. Speaking of wettable powders, for example, a natural or synthetic resin component is added to powdered titanium oxide as a fixing agent, or a surfactant is added as a spreading agent, if necessary, and the mixture is appropriately diluted with water. ,
It can be used by spraying on plants. The wettable powder is unfavorable due to the effect of powder scattering on workers during dilution work. From some parts. Since the photocatalyst such as titanium oxide used in the present invention exists stably in both the dry state and the wet state, the flowable agent can be freely selected. Further, even if the powder is used in a powder state and scattering occurs, there is no or little adverse effect, so that it is possible to work relatively safely even when used as a powder.

The pesticide and pesticide according to the present invention are particularly excellent in that they are effective against all molds and bacteria because there is no selectivity depending on the bacterial species since the control mechanism is based on physical means. .

[0012]

EXAMPLES The controlling agent according to the present invention will be described in more detail with reference to examples. Example 1 (1) Preparation of spray liquid 100 g of titanium oxide fine powder having an anatase type crystal form and having an average particle diameter of 50 nm was added to 10 g of ethyl alcohol.
And 100 g of water were mixed to obtain a slurry to obtain a preparation. 0.2 g of a neutral surfactant was added to 1 g of this preparation, and 10 g of water was added.
It was diluted 00 times to prepare a spray liquid.

Next, the effect of the control agent of the present invention was examined for rice blast. (2) Preparation of pot seedlings Uncontaminated mountain soil was thoroughly dried and sieved to remove coarse soil. The soil was finely powdered at a ratio of 20 g of ammonium sulfate, 12 g of persulfite, and 4 g of sulfuration per 10 kg of soil, and the soil mixed with the soil was dispensed into pots. A hole was drilled at the bottom of the pot in advance so that the water could well rise to the top by capillary action. Seed paddy was put in a separate container and water was drained to a height about 5 to 6 times that of paddy. This was allowed to stand at 25 ° C. for 3 to 4 days. Immediately before sowing, the pot was immersed in water and sufficiently filled with water by a capillary phenomenon, and then seeded one by one so that shoots slightly emerged on the soil surface. Heat it to keep it at about 20-25 ° C and grow it for about 3 weeks. Five ~
3． Eight-leaf seedlings were obtained. (3) Preparation of inoculation source Powder agar twenty one . 5%, yeast extract 0. 2%,
Distilled water (1,000 ml) was added to soluble starch (1%), dissolved well at 100 ° C., sterilized, and then dispensed into test tubes (10 ml each) to prepare a YS slant medium. The blast fungus was transplanted to the medium, kept in a 25 ° C incubator, and cultured until the fungus covered the entire slope, was colored gray and formed conidia.

Using the conidia, a conidia suspension was prepared by an ordinary method. At this time, the conidia spore suspension was examined under a microscope of 150 ×, and the number of spores in one visual field was adjusted to about 30. (4) Assay The prepared pot seedling was placed on a turntable, and the spray solution of (1) was sprayed while rotating it. The sprayed solution was air-dried, placed in a 25 ° C. inoculation box, and inoculated with the above-described conidia of the contaminated spores by spraying. After the inoculation, it was kept in a humid state for about 2 days, and when the pathogen was sufficiently transmitted, it was taken out of the inoculation room and placed in an aquarium of an ordinary greenhouse to promote the disease. After about 4 to 5 days, the control value was determined when the color of the lesions was sufficiently browned.

The control value was 95 as compared with the untreated control group which was not treated with the control agent. The control value was determined by the following equation. Control value = (1-number of treated areas / number of untreated areas) x 10
0 Example 2 A test was performed in the same manner as in Example 1 using photocatalytic titanium oxide STS-21 (manufactured by Ishihara Techno Co.), and almost the same results were obtained.

[0016]

According to the present invention, a plant containing a photocatalyst as a main component is applied to a plant or the like by a spraying method, a spraying method, a dipping method or the like, so that it is easy for the environment and can control pests such as plants.

Claims (8)

[Claims] A pest control agent comprising a photocatalyst as a main component. 2. The pest controlling agent according to claim 1, wherein a photocatalytic titanium oxide is used. 3. The pest controlling agent according to claim 1, which is a controlling agent for plant pests. 4. The pest control agent according to claim 1, which is formulated in a powder or a wettable powder. 5. An agricultural chemical comprising a photocatalyst as a main component. 6. The pesticide according to claim 5, wherein a photocatalytic titanium oxide is used. 7. The pesticide according to claim 5, which is an agent for controlling plant pests. 8. The pesticide according to claim 5, which is formulated in a powder or a wettable powder.