JPH0959111A - Microbicide for agriculture and horticulture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a microbicide for agriculture and horticulture, especially useful as a seed disinfectant against Gibberella fujikuroi by adding a specific carboxylic acid to an albocycline compound which has been difficult in the practical use as a microbicide for agriculture and horticulture. SOLUTION: This microbicide for agriculture and horticulture is prepared by adding pyridazine-3-carboxylic acid or its salt to at least one microbicidal active ingredient selected from albocycline of the formula and its analogues. The total content of both the compounds is 0.1-10wt.% in the cases of a water- dispersible powder, an emulsifiable concentrate, a sol, an oil solution, and a liquid formulation, 0.1-3wt.% in the cases of a dust formulation, a DL dust formulation, a fine particle formulation and a coarse particle formulation, and 0.1-10wt.% in the case of a granular formulation. The microbicide for the agriculture and the horticulture exhibits a wholly synergistic control effect because the pyridazine-3-carboxylic acid compound can synergistically act on the control action of the compound of the formula against various plant diseases.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an agricultural and horticultural fungicide containing arbocycline or an analog thereof and pyridazine-3-carboxylic acid or a salt thereof, and particularly to a seed disinfectant for rice sprouting disease. Is.

[0002]

2. Description of the Related Art Arbocycline, which is a bactericidal active ingredient of an agricultural and horticultural fungicide of the present invention, has antibacterial activity against certain bacteria and fungi, and its analog is arbocyclin M1.
~ M9, OH-3984K1, OH-3984K2 are known [[The ・
Journal of Antibiotics, "20 volumes, N
o. 5, pp. 261 to 266 (1967); ibid., 27, No. 10, 1187.
P. To p. 1197 (1984); ibid., 37, No. 10, p. 1187 (1984)
); 46, No. 10, 1520, 1526 (1993)]. Further, JP-A-5-279205 describes that arbocycline has activity against rice blast disease.

Further, the chemical synthesis method of pyridazine-3-carboxylic acid, which is the other component to be incorporated in the agricultural and horticultural germicide of the present invention, is described in "Berichte", Vol. 32, p. 408 (1899).
It is publicly known. However, it is not known that pyridazine-3-carboxylic acid has a bactericidal action against plant pathogens.

[0004]

[Problems to be Solved by the Invention] Arbocycline
Use alone is not completely satisfactory for controlling rice blast and the like. In addition, as shown in the test examples below, it shows almost no control effect against rice scab seedling disease, cucumber wilt disease, and the like. Therefore, it was previously considered difficult to put albocyclin into practical use as an agricultural and horticultural fungicide.

On the other hand, until now, various compounds have been put to practical use as agents for controlling plant diseases such as rice sprouting disease. However, some of these practical plant disease control agents are insufficient in terms of safety for humans and crops, and some cannot exert a sufficient control effect due to the occurrence of drug-resistant bacteria.

An object of the present invention is to provide a novel agricultural / horticultural fungicide containing arbocycline or its analog as an active ingredient.

[0007]

[Means for Solving the Problems] The present inventors have investigated various compounds in order to provide a fungicide for agricultural and horticultural purposes that meets the above object. As a result, at least one compound selected from arbocycline and its analogs,
By using together with pyridazine-3-carboxylic acid,
It has been found that it exerts an excellent control effect against various plant diseases such as rice scabbed seedling disease and is highly safe for crops and humans.

Therefore, the gist of the present invention is to include at least one compound selected from arbocycline and its analogs as a bactericidal active ingredient, to which pyridazine-3-carboxylic acid or a salt thereof is added. It is an agricultural and horticultural fungicide characterized by being

Next, the agricultural / horticultural germicide of the present invention will be specifically described. Arbocycline, which is a bactericidal active ingredient contained in the agricultural and horticultural germicide of the present invention, has the following chemical structural formula:
(I): Having.

As an analog of arbocyclin that can be used in the present invention, a product having a structure similar to arbocyclin produced by an arbocyclin-producing bacterium, for example, arbocyclin M-1 (8,9-epoxy compound); M -2 (12
-Hydroxy form); M-3 (11-hydroxy, 2,3-dihydro form); M-4 (18-hydroxy form); M-5 (11-hydroxy form); M-6 (10-hydroxy, 2) , 3-dihydro form); M-7 (11-hydroxy form); M-8 (2,3-dihydro, 12-hydroxy, γ-lactone form); OH-3984K
1; OH-3984K2; and synthetic compounds chemically derived from arbocyclin or its analogs.

Arbocycline and its analogs (hereinafter, generically referred to as "compound A" unless otherwise specified) can be produced by the known methods described in the above-mentioned documents. Compound A used in the present invention
As the above, arbocycline itself is particularly preferable.

Arbocycline is a novel microorganism found by the present inventors, Streptomyces bruneogriseus MJ492-77F1 strain (this strain was applied for deposit at the Institute of Biotechnology, Institute of Industrial Technology, 1994). December 12 FE
It can be produced by a method of culturing RMP-14698) and collecting the culture, for example, as illustrated in Reference Example 1 below. The mycological properties of the MJ492-77F1 strain are described in detail in the specification of Japanese Patent Application No. 7-216895 filed by the present applicant.

In the fungicide according to the present invention, the compound A
Acts as a bactericidal active ingredient against plant pathogenic fungi, but when used alone, it shows almost no control effect against plant diseases such as rice seedling disease and cucumber wilt disease.

The other component, pyridazine-3-carboxylic acid or its salt (hereinafter referred to as "compound B"), which is the other component to be incorporated into the fungicide of the present invention, is described in the above-mentioned literature and some other literatures. It can be produced by the method described in. As the salt of pyridazine-3-carboxylic acid, ammonium,
Examples include sodium, potassium or calcium salts.

Compound B itself, which is incorporated into the bactericidal agent of the present invention, has almost no bactericidal activity and acts on Compound A as a bactericidal effect enhancer. The bactericide of the present invention can exert an excellent control effect against plant diseases in the field of agriculture and horticulture, for example, rice scabbed seedling disease, cucumber vine split disease, etc., by the synergistic effect of both components.

The compound A, which is an active ingredient in the bactericide of the present invention, and the compound B compounded therein are mixed in a proportion of 0.1 to 10 parts by weight of compound B to 1 part by weight of compound A.
It is suitable to mix in a ratio of 0.5 to 2 parts. However, the blending ratio can be appropriately changed according to the conditions at the time of application.

The agricultural and horticultural fungicides according to the present invention can be formulated as described below. That is, in order to produce the agricultural and horticultural fungicide of the present invention, the compound A and the compound B used in the present invention are mixed as they are, or an appropriate carrier and an agricultural chemical auxiliary agent are additionally mixed and mixed by a conventional method. , Wettable powder, emulsion, liquid, sol (flowable), oil, DL (driftless type) powder, fine granule, granule, tablet, spray, smoke agent and the like.

The content of the total amount of compound A and compound B in these preparations can be appropriately changed depending on the conditions such as the form of the preparation and the application method. In the case of wettable powders, emulsions, sol agents, oil agents and liquid agents, the sum of Compound A and Compound B is
In the range of 0.1-10% (weight%, the same applies below), powder,
In the case of DL powder, fine granule and coarse powder, it can be blended in the range of 0.1 to 3%, and in the case of granule, it can be blended in the range of 0.1 to 10%.

Further, the agricultural chemical auxiliary agent is used for the purpose of improving the control effect, stabilization and dispersibility of the agricultural and horticultural germicide. Examples of such auxiliary agents include carriers (diluents), spreading agents, emulsifiers, wetting agents, dispersing agents, disintegrating agents and the like. The carrier may be either solid or liquid as long as it is commonly used for agricultural and horticultural agents, and is not limited to a particular carrier.

For example, as the solid carrier, mineral powder (kaolin, bentonite, clay, montmorillonite, talc, vermiculite, gypsum, calcium carbonate, white carbon, silica sand, ammonium sulfate, urea, etc.), vegetable powder (starch, crystalline cellulose) Etc.), polymer compounds (petroleum resins, etc.), alumina, silicates, sugar polymers and the like.

As the liquid carrier, water, alcohols (methanol, ethanol, n-propanol, ethylene glycol, glycerin, etc.), ethers (tetrahydrofuran, etc.), ketones (methyl ethyl ketone, cyclohexanone, etc.), esters, nitriles. , Sulfoxides (such as dimethyl sulfoxide), alcohol ethers (such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether), aliphatic or alicyclic hydrocarbons (such as cyclohexane), industrial gasoline (such as solvent naphtha), And petroleum fraction etc. are mentioned.

When formulating emulsions, wettable powders, flowable agents (sols), etc., a surfactant (or emulsifier) is added for the purpose of emulsification, dispersion, solubilization, wetting, foaming, lubrication, spreading, etc. Can be blended. Examples of such a surfactant include nonionic surfactants (polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, sorbitan alkyl ester, etc.); anionic surfactant (alkylbenzene sulfonate , Alkyl sulfosuccinate, alkyl sulphate, polyoxyethylene alkyl sulphate, aryl sulphonate), cationic surfactants (alkyl amines (lauryl amine, stearyl trimethyl ammonium chloride, alkyl dimethyl benzyl ammonium chloride, etc.), polyoxyethylene Alkylamines, etc.], amphoteric surfactants (carboxylic acid (betaine type), sulfate ester salts, etc.), but of course only those exemplified Not be construed as being limited.

Examples of the spreading agent include polyoxyethylene nonylphenyl ether and polyoxyethylene lauryl ether. Examples of the wetting agent include polyoxyethylene nonylphenyl ether and dialkyl sulfosuccinate. Examples of the fixing agent include carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA). Examples of the disintegrant include sodium lignin sulfonate and sodium lauryl sulfate. In addition to these, various auxiliary agents such as gum arabic, gelatin, casein, sodium alginate, tragacanth gum, and xanthan gum can be used.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Next, examples will be given which exemplify the composition examples of the agricultural / horticultural germicide of the present invention. However, the compound A and the compound B contained in the fungicide of the present invention, that is, the types of two components, the mixing ratio, the addition amount, the types of the carrier and the auxiliary agent and the addition amounts thereof are limited to the following examples. It is not something that will be done.

In the examples, all "parts" are parts by weight, and% means% by weight. Example 1 (powder) 1 part of compound A, 1 part of compound B, 1 part of PAP (physical property improver) and 97 parts of clay were uniformly mixed and pulverized,
A dust containing 2% in total of compounds A and B is obtained.

Example 2 (wettable powder) 15 parts of compound A, 15 parts of compound B, 3 parts of calcium alkylbenzene sulfonate, 5 parts of polyoxyethylene nonylphenyl ether and 62 parts of clay were uniformly mixed,
Grind to give a wettable powder containing a total of 30% of compounds A and B.

Example 3 (Emulsion) Compound A 15 parts, Compound B 15 parts, methyl ethyl ketone 4
0 parts and polyoxyethylene nonyl phenyl ether
If 30 parts are mixed and dissolved, the total amount of compounds A and B is 30
% To obtain an emulsion.

Example 4 (Granule) 2.5 parts of Compound A, 2.5 parts of Compound B, 1.5 parts of lauryl sulfate, 1.5 parts of calcium lignin sulfonate, 25 parts of bentonite and 67 parts of white carbon were uniformly mixed and mixed with 15 parts of water. Parts are added, and the mixture is kneaded in a kneader to be granulated, and dried in a fluidized drier to obtain a granule containing 5% of the compounds A and B in total.

Example 5 (sol agent) Compound A (20 parts ) , compound B (20 parts), lauryl sulfate (2 parts), sodium alkylnaphthalenesulfonate (2 parts), hydroxypropyl cellulose (1 part) and water (55 parts) were uniformly mixed to give compound (A). And a sol containing 40% of B in total is obtained.

The agricultural and horticultural fungicides of the present invention include, in addition to the compounds A and B described above, fungicides, insecticides, herbicides, acaricides, nematicides, fertilizers, soil conditioners and the like. Can be blended. Then, by mixing them, the applicability of the disinfectant of the present invention (applicable disease, method of use, time of use, etc.) can be expanded, and in some cases, synergistic control effect by synergistic action of each active ingredient. Can be expected.

The method of applying the agricultural and horticultural germicide of the present invention is generally as follows. That is, the application rate varies depending on various factors, for example, target disease, occurrence state, weather, dosage form, application method, application location, application time, but generally 0.5 to 5 kg per 10 are for powders and granules, It is preferably sprayed in the range of 1 to 3 kg using a suitable sprayer. When using it as a foliar spray, use an emulsion or wettable powder 20 times.
Dilute with water from 0 to 2000 times and spray in an amount of 100 to 400 liters, preferably 100 to 200 liters per 10 are using a suitable sprayer.

To use the disinfectant of the present invention as a seed disinfectant, a general method for using a seed disinfectant may be used. That is, a wettable powder containing the two components of the present invention,
Emulsions, sol agents (suspension agents, flowable agents) are diluted in water to have an active ingredient concentration of 50 to 5000 ppm, preferably 500 to 2000 ppm.
As seed rice in this chemical solution for 10 to 60 minutes (short time immersion), or for 24 to 48 hours (long time immersion), or powdered wettable powder is applied to the surface of the seed rice. It can be applied by such methods.

Next, test examples of antibacterial activity of the bactericide of the present invention will be shown. Test Example 1 (antibacterial activity test) 20 ml of sterilized potato-dextrose agar medium was dispensed,
Each of the solidified 9 cm petri dishes was inoculated with the following two types of plant pathogenic fungi and cultured at 27 ° C. for 14 days to form spores well.

5 ml of sterilized water was added to the spore-formed medium in the petri dish, the spores were scraped off, and filtered with triple gauze. The number of spores in the obtained spore suspension was adjusted by diluting with sterilized water so that the number of spores was 10 per thomas grass.
Separately, the potato dextrose agar medium, which was dispensed in 200 ml portions, was melted by heating and then cooled to 47 ° C. To the chilled medium, 1 ml of the spore suspension prepared above was added and mixed well, and the mixture was dispensed into a petri dish to give an assay plate.

A methanol solution containing 1000 ppm of compound A (arbocycline), a methanol solution containing 1000 ppm of compound B (pyridazine-3-carboxylic acid), 1000 ppm of compound A and 1000 ppm of compound B. A methanol solution and a methanol solution were prepared. A paper disk was impregnated with 40 μl of each of these three methanol solutions and air dried. The paper disk containing the compound A alone, the paper disk containing the compound B alone, and the paper disk containing both the compounds A and B thus prepared were placed on an assay plate and incubated at 27 ° C. for 3 days. did. Then, the diameter of the inhibition circle on the surface of the medium around the paper disk was measured. The results are shown in Table 1.

[0036]

Test Example 2 (Seed germicidal effect test for controlling rice scab seedling disease) A concentrated spore suspension of rice scab seedling fungus (Jibiberella fujikuroi) was spray-inoculated at the flowering stage of rice (cultivar: Niigata early). The paddy infected with the rice scab seedling fungus thus obtained was used as a test paddy. Then, Arbocycline was added as Compound A, pyridazine-3-carboxylic acid was added as Compound B, and the mixture was dissolved in distilled water as it was to prepare a diluted chemical solution having a predetermined concentration.

Paddy rice seedling disease-infected paddy rice was soaked and sterilized in this chemical solution at 20 ° C. for 24 hours at a volume ratio (v / v) of seed paddy and chemical solution of 1: 1. Sterilized rice after sterilization is soaked in water at 20 ℃ for 3 days, and then drained at 30 ℃.
Sprouted for 24 hours. Then, the seed rice in the shape of pigeon chest was sown on Kumiai granular soil (made by Kureha Chemical Industry Co., Ltd.) according to a conventional box raising method, and thereafter, it was cultivated and managed in a glass greenhouse.

The disease onset was investigated 25 days after sowing (four-leaf stage) by examining the number of diseased and healthy seedlings that showed stubborn and dead rice seedling disease symptoms (about 150 seedlings per ward). The diseased seedling rate (%) was obtained by the formula (1) and the control value (%) was calculated from this. Regarding the phytotoxicity to rice, the degree of growth and the emergence rate were observed and displayed based on the following criteria for the phytotoxicity survey index. The results are summarized in Table 2.

Survey index of drug damage 5: severe, 4: severe; 3: large, 2: slight, 1: slight,
0: None

This test is carried out under the control of 1 ward and 3 stations, and the following calculation formula is used.
The average control value (%) was calculated from (2). Table 2 shows the results.

[0042]

[0043]

Reference Example 1 Production of Arbocycline Streptomyces bruneoglyceuus MJ492-77F1 strain (F
ERM P-14698) is a medium having the composition described below [glycerin 2%, dextrin 2%, yeast extract 0.3%, bactosoyton.
1%, ammonium sulfate 0.2%, calcium carbonate 0.2%
The water was inoculated into 10 liters (each of which was dispensed in 90 500-ml rotary flasks, 110 ml each), and the mixture was cultured at 27 ° C. for 7 days.

Methanol (3 liters) was added to the obtained culture, and the mixture was stirred and then centrifuged to separate into cells and a filtrate. The cells were extracted by immersing them in 2 liters of methanol. The methanol extract of the cells and the culture filtrate were combined and concentrated to 1 liter under reduced pressure to remove methanol. The aqueous solution obtained as a residue was adjusted to pH 3.0, extracted with 500 ml of ethyl acetate three times, and concentrated to dryness under reduced pressure. 3.83 g of the ethyl acetate-soluble neutral fraction obtained by treating the ethyl acetate-extracted fraction with an aqueous sodium hydrogencarbonate solution according to a conventional method was applied to a silica gel 7734 (manufactured by Merck) column for column chromatography.

First, elution was carried out with n-hexane and then with ethyl acetate-n-hexane while the concentration of ethyl acetate was increased successively, the main antibacterial activity was observed in the 25% ethyl acetate-n-hexane elution fraction. It was This fraction was sequentially subjected to precise fractional purification by the following three types of column chromatography. First, column chromatography was performed on silica gel 9385 (manufactured by Merck) with a developing solvent of chloroform-methanol system and then with n-hexane-ethyl acetate system, and finally, column chromatography of Sephadex LH20 (developing solvent: n-hexane). -Ethyl acetate-methanol = 3: 1: 1) to purely isolate 513 mg of arbocycline as a colorless oil.

[0047]

When the agricultural and horticultural fungicide of the present invention is used,
Regarding the control action of the compound A against various plant diseases, the compound B can act as a synergist and shows a synergistic control action as a whole. In particular, it shows a high control effect against rice scab seedling disease, cucumber wilt disease and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor St. Sato 200, Higashidahara, Hadano City, Kanagawa 96 (72) Inventor, Seiichi Kutsuma 1-5-9, Tsumadahigashi, Atsugi, Kanagawa Prefecture-901 (72) Inventor, Kazuo Kajikawa 4-11-26 Sanamibara-shi, Kanagawa Kotobuki House 102-11 (72) Inventor Tomio Takeuchi 5-11-11 Higashigotanda, Shinagawa-ku, Tokyo Nyufuji Mansion 701 (72) Inventor Masa Hamada Shinjuku, Tokyo No. 405, Hidewa Residence No. 26, 1F, Naito-cho, Tokyo

Claims (1)

[Claims] 1. Agricultural and horticultural production comprising at least one compound selected from arbocycline or an analog thereof as a bactericidal active ingredient, and pyridazine-3-carboxylic acid or a salt thereof being added thereto. Disinfectant.