JPH0410441B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel soil disease control agent containing two types of fungicidal components having different activities. That is, one type of triazole derivative represented by the following general formula () and N-(trichloromethylthio)-4-cyclohexene-1,2-dicarboximide (captan) or N-(1 , 1,2,2-tetrachloroethylthio)-4-cyclohexene-1,2-dicarboximide (difortan) as an active ingredient. General formula () However, X represents up to two identical or different halogen atoms or lower haloalkyl groups, and Y
represents up to two halogen atoms. The present inventors have discovered that the above-mentioned combination agents exhibit superior synergistic effects against various soil diseases compared to each agent alone. This combination agent not only shows excellent efficacy in controlling soil diseases, especially Fusarium diseases such as cucumber vine splitting disease and radish yellowing disease, which are considered difficult to control, but also shows excellent effects on controlling Fusarium diseases such as Pythium and Rhizoctonia. It has a wide and excellent control effect against soil diseases caused by major soil pathogens such as Rhizoctonia. Captan and difortan used as active ingredients of the present invention are described in, for example, sections 81 to 85 of "Modern Pesticide Course" (published by Asakura Shoten), and sections 81 to 85 of "Pesticide Handbook 1981 Edition" (published by Japan Plant Protection Association). It is a known compound in items 176-180. As disclosed in these documents, Captan is suitable for spraying against diseases of vegetables, fruit trees, and flowers and is also used for seed disinfection. Difortan is also suitable for controlling a wide range of diseases on fruit trees and vegetables by spraying. On the other hand, the triazole derivative represented by the general formula () is a novel compound discovered by the present inventors, as described as an agricultural and horticultural fungicide in Japanese Patent Application No. 56-163409. . The soil disease control agent of the present invention exhibits remarkable effects in controlling major soil diseases including Fusarium disease due to the synergistic effect of the contained active ingredients. Therefore, in order to obtain the same effect as each single agent application, the amount of control agent is reduced because it is effective at a lower concentration. In addition, captan and difortan have problems in terms of their efficacy, but the soil disease control agent of the present invention can not only overcome this drawback, but also provide stable effects due to synergistic effects, and can be applied in various situations. It has the advantage of being wider. The main diseases that can be expected to be controlled by the soil disease control agent of the present invention are seedling damping-off of cucumbers, hawthorns, eggplants, green peppers, watermelons, daikon radish, spinach, beets, etc., cucumber vine splitting disease, and tomato wilt. and hemi-wilt, cabbage;
Turnip, rapeseed and Chinese cabbage clubroot, watermelon acute wilt, radish fissure browning, radish and strawberry wilt, konnyaku root rot, butterbur and soybean white silk disease, ginger powdery scab , late blight of green peppers, damping-off blight of cucumbers,
It shows remarkable control effects against root rot of Japanese ginger, black bruise of potato, root rot of pea, etc., and no phytotoxicity is observed in any of the crops. Typical triazole derivatives that can be used in the present invention are illustrated below. In addition, compound No. is also referred to in the Examples and Test Examples below. Compound 1 4-chlorobenzyl N-(2,4-dichlorophenyl)-2-(1,2,4-triazole-1
-yl) ethanethioimidate Compound 2 3,4-dichlorobenzyl N-(2,4-dichlorophenyl)-2-(1,2,4-triazol-1-yl)ethanethioimidate Compound 3 2,4-dichlorobenzyl N-(2,4-dichlorophenyl)-2-(1,2,4-triazol-1-yl)ethanethioimidate Compound 4 2,4-dichlorobenzyl N-(4-chloro-2-trifluoromethylphenyl)-2-(1,
2,4-triazol-1-yl)ethanethioimidate Compound 5 4-chlorobenzyl N-(2-chloro-4-
fluorophenyl)-2-(1,2,4-triazol-1-yl)ethanethioimidate The blending ratio of the active ingredients in the present invention is 1 part by weight of one of the triazole derivatives of the present invention to 0.1 to 100 parts of captan or difortan.
Although it is appropriate to mix 100% of the total amount, the blending ratio can be changed as appropriate depending on the conditions at the time of application and the status of disease occurrence. A more preferred ratio is 1 part of the triazole derivative to 1 to 10 parts of captan or difortan. Furthermore, the soil disease control agent of the present invention has extremely low toxicity for human storage, and can be used to treat crops during the growing season. In order to fully demonstrate the excellent effects of the present invention as a soil disease control agent, the compound of the present invention is formulated into emulsions, flowables (sols), wettable powders, granules, etc., and used. It is better to do so.
Regarding the timing of use, soil treatment before sowing is common, but in the present invention, treatment during the growing season is also possible, and there is no need for degassing work, and crop seedlings can be planted at an appropriate time. The soil disease control agent of the present invention can also be used in combination or in combination with other known fungicides, insecticides, herbicides, or growth regulators. Next, examples of the present invention will be shown. Example 1 Wettable powder Compound 2 10 parts (parts by weight; the same applies hereinafter), 10 parts of captan, 5 parts of white carbon, 5 parts of alkylbenzene sulfonate, and 70 parts of diatomaceous earth were placed in a ribbon mixer and mixed well, and then added to an atomizer. Thoroughly crush the mixture using a ribbon mixer and mix again using a ribbon mixer to obtain a wettable powder containing 20% of the active ingredient. When using this hydrating agent to control cucumber vine disease, for example, dilute this hydrating agent, use an appropriate application tool, and apply water to cucumbers during the growing season from before sowing or transplanting. It can be effectively controlled by diluting it 200 to 5000 times and applying it to the soil surface at a rate of 1 to 5 per ^square meter. Example 2 Powder 1 part of Compound 1, 1 part of Captan, 3 parts of white carbon, 0.5 part of PAP (physical property improver) and 94.5 parts of diatomaceous earth were mixed in a ribbon mixer, and the mixture was thoroughly mixed with an admizer. Mix thoroughly again using a ribbon mixer to obtain a powder containing 2% of the active ingredient. This powder can be used as an active ingredient during the growing season from before sowing or transplanting using an appropriate spraying device.
By spraying 0.05 to 20 kg per 10 ares on the soil surface and mixing well with the topsoil, it can prevent beet seedling blight, wheat snow rot, rice seedling blight, cucumber damping off, etc. It can be effectively controlled. Example 3 Sol agent 5 parts of Compound 3, 5 parts of difortan (particle size of both compounds is 10 μ or less), 2 parts of lauryl sulfate, 2 parts of sodium alkylnaphthalene sulfonate, 1 part of hydroxypropyl cellulose, and water. Mix 75 parts uniformly to make a sol containing 10% of the active ingredient. Dilute this sol with water 200 to 5000 times and use it for 1 hour during the growing season from before sowing or transplanting of crops.
Irrigation to the soil surface at a rate of 1 to 5 per ^m2 will effectively control cucumber vine split disease, beet seedling damping-off, wheat snow rot, rice seedling damping-off, cucumber damping-off late blight, etc. I can do it. Next, the soil disease control effect of the soil disease control agent of the present invention will be explained using test examples. Test Example 1 Effect test on control of cucumber vine split disease In a field in a plastic greenhouse where cucumber vine split disease occurs frequently, the fungus Fusarium oxysporum fulma cucumerinum (Fusarium oxysporum) was used to further accelerate the disease.
Using a soil bran mixed medium culture of oxysporum ^f . 3 days after vaccination,
A hydrating agent prepared according to Example 1 was diluted with water,
The soil surface was irrigated with water at a rate of 3 ^/ m2. One day after chemical irrigation, 100 seeds of cucumber (variety: Sagami Hanshiro) were sown per plot, and after 30 days, the number of seedlings withering away was investigated, and the control value (%) was calculated using the following formula. This test was conducted in triplicate in 0.5 m ² per drug area, and the average control value (%) was determined. The results are shown in Table 1. Control value (%) = (1 - Seedling dieback rate in chemical treated area / Seedling dieback rate in non-chemical treated area) x 100

【table】

[Table] Test example 2 Pea root rot control effect test Peas were cultivated in a clay pot with a diameter of 14 cm filled with black volcanic ash soil according to the conventional method (variety: Shirahime pea)
When the plant height was 5 cm, a hydrating powder prepared according to Example 1 was diluted with water and watered onto the soil surface at a rate of 3 parts per 1 m ² . Then, 10 days after drug treatment,
Zoospores of the pea root rot fungus (Aphanomyces euteiches) were inoculated at a rate of approximately 100,000 per pot. Two weeks after inoculation, the peas were removed from the pot, the roots were washed with water,
The symptoms of the disease were investigated, and the severity of the disease was calculated using the following formula. Based on this disease severity, the control value (%) was calculated using the following formula. This test was conducted in 3 pots per district, and the average control value (%)
I asked for The results are shown in Table 2. Disease severity = Σ (number of individuals by severity x index by severity) / 4 × index of number of surveyed individuals 0...No disease onset 1...Roots are partially browned, waterlogged 2...Most of the roots are Water-soaked condition 3...Roots and hypocotyl parts are water-soaked 4...Roots rot and fall off, damping, and withering control value (%) = [1 - disease severity in treated area/ disease severity in untreated area ]×100

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【table】

Claims (1)

[Claims] 1. General formula (wherein, X represents up to two identical or different halogen atoms or lower haloalkyl groups, and Y
indicates up to two halogen atoms. ) and N-(trichloromethylthio)-4-cyclohexene-1,
2-dicarboximide or N-(1,1,2,
A soil disease control agent characterized by containing a mixture with 2-tetrachloroethylthio)-4-cyclohexene-1,2-dicarboximide as an active ingredient.