JPS6127903A - Fungicidal composition - Google Patents

Abstract

PURPOSE:A fungicidal composition, having a preventing and exterminating effect on both bacterial grain rot and rice blast, and composed of combination of a fungicide having a penetration-transfer-type action on plants and an excellent preventing and exterminating effect on a wide range of bacterial plant blights and a fungicide having superior preventing and exterminating effect on the rice blast. CONSTITUTION:A fungicidal composition containing 1-ethyl-1,4-dihydro-6,7- methylenedioxy-4-oxo-3-quinolinecarboxylic acid or its salts exhibiting the preventing and exterminating effect on broad plant blights caused by bacteria except molds and diisopropyl 1,3-dithiolan-2-ylidene malonate having a superior preventing and exterminating effect on the rice blast but no preventing and exterminating effect on Pseudomonas glumae as active ingredients. The composition exhibits a synergistic effect on both blights of bacterial grain rot and the rice blast, is capable of reducing an amount of each component to be prescribed and has safety with a reduced chemical residue in crops.

Description

Detailed Description of the Invention The present invention provides 1-ethyl-1,4-dihydro-6,7-methylenedioxy-4-oxo-3--2-ylidene malonate (hereinafter referred to as compound B). The present invention relates to a bactericidal composition containing as an antifungal ingredient.

Rice is the most important crop in Japan's agriculture, and many fungicides have been developed that are effective in controlling major rice cultivation diseases such as blast and sheath blight, which have led to a decline in rice yields. This greatly contributes to quality improvement. However, rice cultivation diseases are not limited to these, and if one disease is sufficiently controlled, other diseases may cause problems such as decreased yield and deterioration of quality. Therefore, as a fungicide for use in controlling rice cultivation diseases, it is particularly desired to develop a broad-spectrum fungicide that can control a wide variety of diseases.

By the way, in recent years, with the spread of new rice cultivation techniques, especially cultivation techniques using mechanical transplantation, rice blight blight, a rice cultivation disease that was previously limited to a few regions, has become widespread in many parts of the country, and yields are decreasing. Problems have arisen, such as a significant decrease in

Many existing fungicides are used to control this disease, but none of them have a sufficient control effect, and a new rice blight control agent is eagerly awaited.

The present inventors kept these points in mind, and the spectrum was wide.
As a result of extensive research into the development of a fungicide that can also control rice blight, which is extremely difficult to control, we have found that the composition of the present invention is not only highly effective in controlling rice blight and blight. Furthermore, they discovered that it is a powerful and versatile fungicide that is also effective in controlling rice blast, and completed the present invention.

Compound A and its salts, which are one of the active ingredients of the composition of the present invention, are described in Japanese Patent Publication No. 57-48042, and have systemic action on plants, and are effective against a wide range of bacterial plants. Although it is highly effective in controlling diseases, it has the disadvantage that it is less effective in controlling plant diseases caused by filamentous fungi.

On the other hand, Compound B, which is another active ingredient, is known to be an excellent fungicide that can control rice blast mainly due to its preventive effect, but it has no effect on rice blast. Shows no effect.

Although the composition of the present invention contains two types of active ingredients with different activities as described above, the composition of the present invention exerts a mere complementary effect by simultaneously controlling both rice blight and rice blast diseases. Not only that, but surprisingly, it also had a synergistic effect against both diseases. In other words, they found that the control effect was enhanced to an extent that could not be expected from the effects of each single component.

Increasing the synergistic effect by mixing two types of active ingredients like this not only brings efficiency and economic benefits through simultaneous control of two types of diseases, but also makes it possible to reduce the application amount of each ingredient. This is preferable from a safety point of view, since it reduces the amount of chemicals remaining in crops and reduces the risk of environmental contamination.

When using the composition of the present invention as an active ingredient of a disinfectant,
You can leave it as is without adding any other ingredients, but usually,
It is mixed with solid carriers, liquid carriers, surfactants, and other formulation auxiliaries to formulate emulsions, wettable powders, suspensions, powders, liquids, etc. In this case, the composition ratio of the active ingredients, Compound A or its salt and Compound B, is 1:0.2 to 1:2 by weight.
0, preferably 1:0.5 to 1:10, and the active ingredient content in the preparation is 0.1 to 99.9%, preferably 1 to 90%.

The solid carriers mentioned above include fine particles such as kaolin clay, attapulgite clay, bentonite, acid clay, pyrophyllite, talc, diatomaceous earth, calcite, corn cob powder, walnut shell powder, raw paper, ammonium sulfate, and synthetic hydrous silicon oxide. Examples of liquid carriers include aromatic hydrocarbons such as xylene and methylnaphthalene, alcohols such as isopropanol, ethylene glycol, and cellosolve, ketones such as acetone, cyclohexanone, and isophorone, soybean oil, cottonseed oil, etc. vegetable oil, dimethyl sulfoxide, acetonitrile, water, etc.

Surfactants used for emulsification, dispersion, wet spreading, etc. include alkyl sulfate salts, alkyl (aryl)
Anionic surfactants such as sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkylaryl ether phosphate ester salts, naphthalene sulfonate formalin condensates, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene block copolymers, Examples include nonionic surfactants such as sorbitan fatty acid ester and polyoxyethylene sorbitan fatty acid ester. As formulation aids, lignin sulfonate, alginate, polyvinyl alcohol, gum arabic, OMC (carboxymethyl cellulose), PAP
(acidic isopropyl phosphate) and the like.

Examples of formulations are shown below. Note that parts represent parts by weight.

Formulation Example 1 20 parts of Compound A, 2 parts of Compound B, 3 parts of calcium lignosulfonate, 2 parts of sodium lauryl sulfate, and 85 parts of synthetic hydrated silicon oxide are thoroughly ground and mixed to obtain a wettable powder.

Formulation Example 2 10 parts of Compound A, 25 parts of Compound B, 3 parts of polyoxyethylene sorbitan monooleate, 3 parts of CMC, and 5 parts of water
A suspension is obtained by mixing 9 parts and wet milling until the particle size of the active ingredient is less than 5 microns.

Formulation Example 3 1 part of compound A, 2.5 parts of compound B, 86 kaolin clay
．． 5 g and 10 parts of talc are thoroughly ground and mixed to obtain a powder.

These preparations can be applied directly or diluted with water for foliage spraying. Furthermore, by mixing it with other fungicides, it can be expected to increase the bactericidal efficacy. In addition, insecticides,
It can also be used in combination with acaricides, nematicides, herbicides, plant growth regulators, and fertilizers.

When the composition of the present invention is used as an active ingredient of a fungicide, the application amount of the active ingredient is usually 0.5 to 2 per are.
00fi', preferably 1 to 1007, emulsions, wettable powders, suspensions, 0.01 to 0.2%, powders, etc., are applied as they are without any dilution.

Next, test examples will show that the composition of the present invention is useful as a disinfectant.

Test Example 1 Rice Blast Control Efficacy Test A rice blast control effect test was carried out using a field seedling that had been directly sown with paddy rice (variety: Kinki No. 33) according to a conventional method. 1st ward 1r
r1'', three replicate test plots were set up.When rice grew to the three-leaf stage, rice blast fungus (Fyricularia
oryzae), and 1,501 sprays were applied per 10 ares. Two weeks after the drug treatment, the severity of disease in each plot was determined from the lesion area ratio, and the control effect was calculated using the following formula.

The test results are shown in Table 1.

Table 1 Test Example 2 Rice blight bacterial disease control effect test Paddy rice (variety;
A test was conducted on the control effect of rice blight bacterium in t fields after mechanical transplantation of Asominori (Asominori). Test plots were set up with 1 plot 20×11″ and 8 repetitions.

Cultivation management was carried out as usual. The inoculation was carried out two weeks before heading with a concentration of about 107/- of Pseudomonas blight.
As glumae ) suspension per 10 ares 1501! Spray inoculated. The composition of the present invention was applied twice in the form of a powder, at a rate of 4 per 10 ares, or in the form of a wettable powder, diluted with water, at a rate of 1,501 times per 10 ares.
It was sprayed. Two weeks after the final spraying, the ears of 30 plants in the 1 area were investigated for the degree of disease onset according to the following investigation criteria.

In addition, the control value was calculated using the following formula.

The test results are shown in Table 2.

Table 2

Claims (1)

[Claims] Contains 1-ethyl-1,4-dihydro-6,7-methylenedioxy-4-oxo-3-quinolinecarboxylic acid or its salt and diisopropyl 1,3-dithiolan-2-ylidenemalonate as active ingredients. A sterilizing composition characterized by: