JPH04261106A - Fungicide for agricultural and horticultural use - Google Patents

Abstract

PURPOSE:To provide a fungicide effective against fungi having acquired resistance to benzimidazole compound. CONSTITUTION:The objective fungicide for agricultural and horticultural use contains (A) one or more compounds (benzimidazole compound) selected from among methyl 1-(n-butylcarbamoyl)-2-benzimidazole carbamate of formula I, methyl 2-benzimidazole carbamate of formula II, 2-(4-thiazolyl)benzimidazole of formula III and 1,2-bis(3-methoxycarbonyl-2-thioureide)benzene of formula IV and (B) pent-4-enyl-N-furfuryl-N-imidazol-1-ylcarbonyl-DL-homoalaninate of formula V as active components.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agricultural and horticultural fungicide for controlling plant pathogenic bacteria that cause great damage to various crops such as rice, vegetables, and fruit trees. That is,
The present invention provides an agricultural and horticultural fungicide that can be effectively used for controlling plant diseases in the fields of agriculture and horticulture.

0002

[Prior Art] One of the active ingredients of the agricultural and horticultural fungicide of the present invention, 1-(n-butylcarbamoyl)-2-benzimidazole carbamate (hereinafter referred to as "benomyl"),
Methyl 2-benzimidazole carbamate (hereinafter “M
BC"), 2-(4-thiazolyl)benzimidazole (hereinafter referred to as "TBZ") and 1,2-bis(
3-Methoxycarbonyl-2-thioureido)benzene (hereinafter referred to as "thiophanate methyl") is a compound known as an agricultural and horticultural fungicide, and has been used to treat vegetables, vegetables, etc.
Some of these compounds are used as spray agents to control various diseases of fruit trees and cereals, and as seed disinfectants. These drugs have a wide spectrum of control activity;
It also has the excellent property of causing little phytotoxicity to various crops [Japanese Patent Publication No. 45-25720,
Publication No. 5-11319, Japanese Patent Publication No. 42-23274, Japanese Patent Publication No. 45-19078, "Pesticide Handbook, 1989 Edition" (Japan Plant Protection Association, published November 20, 1989, pp. 174-179) Page] However, due to their effectiveness, these drugs have been used repeatedly over a long period of time, and as a result, resistant bacteria that have acquired resistance to these drugs have appeared, and powdery mildew of vegetables that were previously effective It is difficult to control gray mold, beet brown spot, and eye spot disease of wheat.

On the other hand, pent-4-enyl-N-furfuryl-N- is the other active ingredient of the agricultural and horticultural fungicide of the present invention.
Imidazol-1-ylcarbonyl-DL-homoalaninate (hereinafter referred to as "compound (1)") is a compound known as an agricultural and horticultural fungicide, for example,
Publication No. 60572 shows that it is highly effective as a seed disinfectant against bakanae disease of rice seeds, sesame leaf blight, blast disease, and spotted leaf disease of wheat, and as a foliage spray agent for powdery mildew of various crops and citrus. It has been disclosed that it is effective against green mold, blue mold, and powdery mildew of apples. However, in order to obtain a practical effect on controlling powdery mildew and gray mold on various crops, it is recommended to spray high-concentration chemical solutions or spray multiple times to ensure safety and prevent chemical damage to crops. required.

0004

[Problem to be solved by the invention] From this situation,
It is highly effective against powdery mildew, gray mold, and beet brown spot, which are resistant to the above-mentioned known benzimidazole drugs, at a low dose, just like the conventional susceptible bacteria. It is desired to develop a new fungicide that exhibits a high control effect against anthracnose in various crops, which is a common problem, even with a smaller dose and even when therapeutically sprayed. In other words, there is a need to provide agricultural and horticultural fungicides that are effective against these diseases, do not cause chemical damage to various crops, have low toxicity to humans, livestock, and fish and shellfish, and have little impact on the environment. It is.

[0005]

[Means for Solving the Problems] The present inventors have made extensive studies to solve these problems. As a result, among many drugs, especially the above-mentioned two different types of compounds, namely compound (1) and one or more compounds selected from benzimidazole drugs, are mixed to treat agricultural crops and When we investigated the control effect by spraying it on flower petals, we found that it was highly effective against gray mold and beet brown spot on vegetables, where resistant bacteria have appeared, at a low dose, similar to that on susceptible bacteria. The present invention was completed based on the discovery that they act synergistically and exhibit excellent effects in controlling anthracnose and strawberry anthracnose.

Compound (1) is disclosed in Japanese Patent Application Laid-Open No. 60-26057.
It can be easily produced according to the method described in Publication No. 2.

Compound (1) is a compound represented by the following chemical structural formula.

[0008]

[Chemical formula 1] Also, benomyl of the above-mentioned benzimidazole drugs, M
Each of BC, TBZ and thiophanate methyl is a compound represented by the following chemical structural formula.

[0009]

embedded image As can be seen from the above chemical structure, thiophanate methyl is not a compound having a benzimidazole ring, but due to the similarity in its chemical structure, it will be treated as a benzimidazole compound in this specification for convenience.

The compound (1) and the benzimidazole drug of the present invention act as a fungicidal ingredient for agriculture and horticulture. The agricultural and horticultural fungicide of the present invention, which is made by using these in combination, can prevent powdery mildew of various crops, which is difficult to control due to the emergence of resistant bacteria.
It also acts effectively against gray mold, beet brown spot, and rice blight, and shows a synergistic control effect, especially against cyclamen anthracnose and strawberry anthracnose.

[0011]

[Example] (Method for formulating a fungicide for agricultural and horticultural use) To produce the fungicide for agricultural and horticultural use of the present invention, the active ingredient of the present invention and appropriate carriers, adjuvants, etc. are blended, and a conventional method is used. Wettable powders, emulsions, sol (flowable), powders, DL type powders,
It may be formulated into granules, fine granules, etc.

[0012] The content of the active ingredient in these preparations is in the range of 10 to 80% in the case of wettable powders, emulsions, and sol preparations;
In the case of DL type powders, granules, and fine granules, the content can be in the range of 30 to 70%. As the carrier that can be used in the above, any solid or liquid carrier commonly used in agricultural and horticultural fungicides can be used, and the carrier is not limited to a specific carrier. For example, solid carriers such as clay, talc, bentonite, kaolin, diatomaceous earth, silica, and sucrose, or benzene, xylene, toluene, kerosene, alcohols (methanol, ethanol, isopropanol, n-butanol, etc.), ketones (acetone, Liquid carriers such as methyl ethyl ketone, cyclohexanone) are used. These can be formulated with appropriate amounts of surfactants and other auxiliary agents, such as stabilizers, spreaders, etc., and used.

[0013] The blending ratio of the active ingredients in the present invention is 0.1 to 4.0% of the compound (1) to a part of the mixture of benomyl, MBC, TBZ, or thiophanate methyl or more. It is appropriate to mix it in the ratio of 1 part. However, the blending ratio can be changed as appropriate depending on the conditions at the time of application. In addition, other fungicides, insecticides, plant growth regulators, etc. can also be mixed and used.

Next, examples of the present invention will be shown. In the examples, all parts are by weight.

Example 1 (hydrating powder) 20 parts of benomyl, 20 parts of compound (1), 20 parts of white carbon, 3 parts of sodium lauryl sulfate,
2 parts of calcium ligninsulfonate and 35 parts of clay are mixed and thoroughly ground to obtain a wettable powder.

Example 2 (Wettable powder) 20 parts of TBZ, 10 parts of compound (1), 10 parts of white carbon, 5 parts of sodium alkylbenzenesulfonate, and 55 parts of clay are mixed and ground to obtain a wettable powder.

Example 3 (hydrating agent) 50 parts of thiophanate methyl, 5 parts of compound (1),
5 parts of white carbon, 3 parts of polyoxyethylene nonylphenol ether, 2 parts of sodium naphthalene sulfonate, and 35 parts of clay are mixed and thoroughly ground to obtain a wettable powder.

Example 4 (flowable agent) 45 parts of water,
Add 1 part of polyoxyethylene nonylphenyl ether and 4 parts of sodium lignin sulfonate, stir well, then add 20 parts of compound (1) and 20 parts of MBC, mix and disperse uniformly using a homomixer, and then add 2 parts of sodium lignin sulfonate. % xanthan gum aqueous solution and stirred to obtain a flowable agent.

Example 5 (hydrating powder) Part of the benomyl used was replaced with TBZ,
That is, 20 parts of benomyl is mixed with 10 parts of benomyl and TBZ.
A wettable powder was obtained by repeating the same operation according to the recipe of Example 1 except that the amount was changed to 10 parts.

Example 6 (hydrating powder) Part of the benomyl used was replaced with MBC,
That is, 20 parts of benomyl is mixed with 10 parts of benomyl and MBC.
A wettable powder was obtained by repeating the same operation according to the recipe of Example 1 except that the amount was changed to 10 parts.

Example 7 (Wettable powder) Part of the benomyl used was replaced with thiophanate methyl, that is, 20 parts of benomyl was replaced with 1 part of benomyl.
A wettable powder was obtained by repeating the same operation according to the recipe of Example 1 except that the amount of thiophanate methyl was changed to 0 part and 20 parts.

Example 8 (hydrating agent) A part of the TBZ used was replaced with MBC, that is, 20 parts of TBZ was replaced with 10 parts of TBZ and 1 part of MBC.
A wettable powder was obtained by repeating the same operation according to the recipe of Example 3 except that the amount was changed to 0 parts.

The method of using the agricultural and horticultural fungicide of the present invention is generally as follows. When used as a foliar spray, it is diluted 200 to 2000 times with water and sprayed in the range of 100 to 400 liters per 10 ares using an appropriate spraying device. On the other hand, when using it as a seed disinfectant, dilute it 10 to 500 times with water and soak the rice seeds in a solution 1 to 2 times the volume of the seed rice for 10 minutes to 48 hours, or dilute it with a solution 5 to 10 times the volume of the rice seed. An amount equivalent to 3% of the weight of the rice seeds is treated using a special spraying device, or in the case of a hydrating agent, the rice seeds are thoroughly coated with a hydrating agent equivalent to 0.1 to 1% by weight of the rice seeds.

[0024]

[Effect of the invention] When the agricultural and horticultural fungicide of the present invention is used,
The following effects are brought about.

First, compounds (
1) and benzimidazole fungicides act synergistically and exhibit a synergistic control effect, especially against cyclamen anthracnose, strawberry anthracnose, and gray mold on cucumbers, tomatoes, eggplants, strawberries, and citrus. It is highly effective in controlling powdery mildew of cucumbers, melons, and watermelons, beet brown spot, eye spot disease of wheat, bakanae disease of rice, sesame leaf blight, and rice blast.

Secondly, since the agricultural and horticultural fungicides of the present invention have such an excellent synergistic control effect, the amount of the fungicides used can be reduced to, for example, half of the amount used when each agent is used alone. A sufficient control effect can be obtained even if the amount is reduced to one-fifth from the original amount, and the drug amount can be reduced.

[0027] Particularly, against the botrytis fungi of cucumbers and tomatoes that are resistant to benzimidazole drugs such as benomyl and thiophanate methyl, powdery mildew, beet brown spot fungi, and rice bakanae fungi, the bacteria that are susceptible to each of them are tested. It has a control effect equal to or greater than that of the case.

Thirdly, since the agricultural and horticultural fungicide of the present invention has the effect of reducing the dose, it does not cause any phytotoxicity to various crops. Next, the pesticidal effect of the agricultural and horticultural fungicide of the present invention will be shown using test examples.

Test Example 1 Effect on controlling cyclamen anthracnose disease: 1 dose per pot was placed in a pot with a diameter of 15 cm in a greenhouse.
A predetermined diluted solution of a flowable agent prepared according to Example 4 was added to cyclamen seedlings (variety: Schubert) that had been planted and whose flower buds were extracted at a predetermined concentration on a turntable at 150 ml per 3 pots.
Sprayed with hand spray in ml. One day after chemical spraying (preventive spraying) or 5 days before chemical spraying (therapeutic spraying), conidia of cyclamen anthracnose fungus (Colletotricum. SP), which had been isolated from the diseased strain and cultured in PSA medium, were suspended. The whole plant was inoculated with this solution. Afterwards, they were covered with a vinyl sheet at night to accelerate the onset of the disease. 12 days after inoculation, 15 leaves per plant were investigated according to the following investigation criteria, the disease severity was calculated using the following formula, and the control value (%) was calculated using the following formula from comparison with the unsprayed area.

Survey standard disease index (severity of disease onset) 0: No disease onset 1: Disease onset on less than 10% of the leaf area 2: Disease onset on 10% or more to less than 25% of the leaf area 3: Disease onset from 25% or more to 50% of the leaf area Disease onset is less than 4: leaf area is 50
% or more to less than 75% infected 5: More than 75% of the leaf area is infected

[Math 1] The degree of occurrence of drug damage was indicated by the following index.

[0031] Drug damage index 0: None, 1: Low, 2: Medium, 3: High.
4: The results are shown in Table 1.

[0032]

[Table 1] Test Example 2 Cucumber Gray Mold Control Efficacy Test Cucumber seedlings (variety: Sagami Hanjiro) were planted in a single row with a spacing of 30 cm and a ridge width of 60 cm in a field in a plastic greenhouse using a conventional method. The test plots consisted of three consecutive plots with six plants per plot. The chemical was sprayed using a small shoulder sprayer at a rate of 250 liters per 10 ares of a diluted solution of the wettable powder prepared according to Example 1 four times every 7 days from the initial onset of gray mold on cucumbers. Spread.

[0033] Disease onset investigation is carried out 4 times in total every 7 days after each spraying, healthy fruits and diseased fruits are picked, the number of fruits picked in each survey is summed to obtain the total number of fruits picked, and the number of diseased fruits is summed to obtain the total number of fruits picked. It was defined as the number of diseased fruits. The disease incidence rate (%) was determined from the total number of diseased fruits relative to the total number of fruits picked, and the control value (%) was calculated using the following formula.

[0034]

[Math 2] Investigation of drug damage was conducted according to Test 1.

[0035] After the final survey of this test, we investigated the ratio of susceptible strains to resistant strains of cucumber gray mold fungi that occurred in the test fields to benomyl, and as a result, the ratio of susceptible strains to resistant strains was 6:4. Separated by . The results are shown in Table 2.

[0036]

[Table 2] Test Example 3 Effect on controlling beet brown spot disease Using beets (cultivar: Monohill) at the 6-leaf stage, the area of 1 plot was 5 m2, and the test was conducted in triplicate.

For inoculation of diseased bacteria, diseased leaves from a field where benzimidazole-based chemicals were continuously sprayed were shredded and inoculated over the entire surface of the test field on June 25th. Chemical spraying will begin from July 10th.
Spraying was performed a total of three times at four-day intervals. 1 in each area 20 days after final spraying
Regarding 0 plants, the degree of onset of beet brown spot disease was investigated according to the following disease index, and the disease severity was determined by the following formula. Based on this, the control value (%) was determined by comparing with the non-sprayed area.

Disease index (severity of disease onset) 0: No lesions 1: Disease occurs on less than 10% of the leaf area 2: Disease occurs on 10% or more of the leaf area but less than 40% 3: Disease occurs on 40% or more of the leaf area and less than 70% Disease onset 4: More than 70% of the leaf area is infected

[Equation 3] The investigation of drug damage was conducted according to Test 1. The results are in Table 3
Shown below.

[0039]

[Table 3] Test Example 4 Seed disinfection effect test on paddy infected with Inabaka Nae bacterium (disinfection by seed dipping method) Test seed Paddy Benomyl-resistant Inabaka Nae bacterium and sensitive Inabaka Nae bacterium cultured in steam-sterilized rice straw medium ( Gibberella fujikuroi
was made into a spore suspension and sprayed and inoculated to rice (variety: Nipponbare) at the flowering stage twice each to obtain rice grains infected with the Inabaka Nae disease fungus (two types: rice infected with the resistant bacteria and rice infected with the susceptible bacteria).

Seed Disinfection Method The rice grains infected with Inakanae disease fungus obtained by the above method were added to a diluted solution with a predetermined concentration of each chemical solution prepared according to the wettable powder of Example 3, at a ratio (V/V) of the rice grains to the drug solution. The samples were immersed at a ratio of 1:1 at 20° C. for 24 hours. The next day, throw away the chemical solution, add new tap water at a ratio of 1:2 (V/V) to the rice seed, and incubate at 20°C for 30 minutes.
The seeds were soaked for days. After that, germination treatment was carried out at 30℃ for 24 hours,
5g per section in Kumiai granular soil (1 section 180cm2)
Seed each. After budding treatment at 32°C for 2 days, they were transferred to a glass greenhouse and cultivated.

[0041] To investigate the onset of disease, 30 days after sowing, the number of infected seedlings that showed symptoms of rice baka seedling disease such as elongation and withering and the number of healthy seedlings were investigated (the total number of seedlings per plot was 350 on average). The seedling rate (%) was determined. From this, the seed disinfection rate (%) was calculated in comparison with the diseased seedling rate (%) in the untreated plot, as shown by the following formula. Regarding phytotoxicity, germination rate, growth level, etc. were observed and expressed using the phytotoxicity index below.

[0042]

[Formula 4] Drug damage index 0 = no drug damage, 1 = small, 2 = medium, 3 = high,
4 = Jinmoto test was conducted in 1 treatment and 3 plots, average seed disinfection rate (%)
I asked for The results are shown in Table 4.

[0043]

[Table 4]

Claims (1)

[Claims] Claim 1: Methyl 1-(n-butylcarbamoyl)-2-benzimidazole carbamate, methyl 2-
one or more compounds selected from benzimidazole carbamate, 2-(4-thiazolyl)benzimidazole and 1,2-bis(3-methoxycarbonyl-2-thiourido)benzene and pent-4-enyl-N-furfuryl An agricultural and horticultural fungicide containing -N-imidazol-1-ylcarbonyl-DL-homoalaninate as an active ingredient.