JP2008024682A - Preventive agent against plant anthracnose and preventive method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a preventive agent for plant anthracnose, exerting excellent preventive effect for not only plant anthracnose having sensitivity to conventional sterilizers of benzimidazole-based sterilizers and strobilurin-based sterilizers but also plant anthracnose having resistance to the benzimidazole-based sterilizers and the strobilurin-based sterilizers. <P>SOLUTION: The preventive agent for plant anthracnose, containing a melanin biosynthesis inhibitor as a bactericidal ingredient is effective for not only sensitive strains but also resistant strains to benzimidazole-based sterilizers and/or strobilurin-based sterilizers. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plant anthracnose control agent. More specifically, the present invention relates to a plant anthracnose controlling agent containing a melanin biosynthesis inhibitor as a bactericidal component, and a method for controlling the same.

  Plant anthracnose is a disease that occurs in major cultivars such as cereals, vegetables and fruits, and is a serious problem in general agriculture because cultivars suffer serious damage. Plant anthracnose occurs throughout the cultivation process, and infected strains and disease residues in soil are the source of anthracnose transmission, so the cultivars are affected by a wide range of infection routes. It has become.

  In addition, the infectious strain does not immediately develop when the environment at the time of invasion of the spore is in a low temperature and dry state, and then develops only when it becomes a high temperature and humidity state. Is difficult to discover. Therefore, in order to prevent the anthracnose disease of the cultivars, it is important to be able to control the anthracnose fungi from the cultivars efficiently.

  Further, there are many species of plant anthracnose pathogens, and the species of the pathogen varies depending on each host plant. For example, cucumber anthracnose Colletotrichum lagenarium, tea anthracnose Colletotrichum theaesinensis, radish anthracnose Colletotrichum higginsianum, bean anthracnose Colletotrichum lindemuthianum, soybean anthracnose Colletotrichum truncatum, strawberry anthracnose Gromellaella cinghum Exists. Many chemical synthetic fungicides such as benzimidazole and strobilurin are used to control plant anthracnose.

  However, it becomes a problem because resistance to the fungicide of the anthracnose fungus develops by continuously using the same strain of fungicide to the cultivated plant. For example, the emergence of a strain resistant to anthrax anthracnose fungus to benomyl, which is the benzimidazole fungicide (see Non-patent Document 1), and the emergence of a strain resistant to anthrax anthracnose fungus to azoxystrobin, the strobilurin fungicide (non-patent Reference 2) has been reported.

  Here, the melanin biosynthesis inhibitor is demonstrated as a matter relevant to this invention.

  Melanin biosynthesis inhibitors such as fusalide, phenoxanyl, diclocimet, and pyrokilone are known to inhibit melanin biosynthesis of rice blast fungus, and are used as agricultural fungicides, especially as rice blast control agents. For example, fusaride is used as an agricultural fungicide (see Patent Document 1), phenoxanil is used as a fungicide (see Patent Document 2), diclosimet is used as a plant disease control agent (see Patent Document 3), and pyroxylone is used to treat plant diseases. As a composition (see Patent Document 4).

  And although the control effect with respect to the rice blast of the said melanin biosynthesis inhibitor has been reported, it has not been reported about the control effect regarding various fungicide-resistant bacteria about other plant disease fungi.

Japanese Patent Publication No. 44-32592. Japanese Patent Laid-Open No. 63-132867. JP-A-2-76846. JP-A-49-41539. Masayuki Oga, Proceedings of the 7th Symposium on Bactericide Resistant Bacteria, 48-56 (1997) Atsushi Inada, Akiko Furuta, Junichiro Yamaguchi, Kyushu Okinawa Agricultural Research Summary, 27-28 (2003)

  Therefore, the present invention provides a plant anthracnose control agent that exhibits an excellent control effect not only against anthrax bacteria having susceptibility to existing fungicides but also against anthracnose fungi having resistance to the fungicides. The main purpose is to do.

  In order to achieve the object, the present inventors searched for various compounds and performed various evaluations on them. As a result, the melanin biosynthesis inhibitor has a controlling effect not only against anthrax which is a sensitive strain of the benzimidazole fungicide and / or strobilurin fungicide but also against anthrax which is a resistant strain. I found it.

  Conventionally, the melanin biosynthesis inhibitor only exerts a control effect on rice blast, and the control effect of various fungicides used for other plant diseases other than rice blast has been known to date. It wasn't. On the other hand, in this invention, it discovered newly that the said melanin biosynthesis inhibitor exhibited the control effect which was excellent also with respect to the anthrax bacterium provided with the tolerance with respect to the said fungicide.

  Therefore, the present invention contains a melanin biosynthesis inhibitor as a bactericidal component, and is effective against not only sensitive strains but also resistant strains of benzimidazole fungicides and / or strobilurin fungicides. Provide a control agent. By using the melanin biosynthesis inhibitor as an active ingredient, anthrax with resistance to the fungicide can be effectively controlled.

No particular limitation is imposed on the type of "benzimidazole fungicide" in the present invention, for example, benomyl (Benomyl: Formula (in 5), R ¹ is (butylamino) carbonyl, R ² represents a methoxy carbonyl amino.) Cypentazole (cypendazole: in formula (5), R ¹ represents ((5-cyanopentyl) amino) carbonyl, R ² represents methoxycarbonylamino), carbendazim (carbendazim: in formula (5), R ¹ represents Hydrogen, R ² represents methoxycarbonylamino, also referred to as MBC), thiabendazole (thiabendazole: in formula (5), R ¹ represents hydrogen, R ² represents 4-thiazolyl), fuberidazole (fuberidazole: formula (5 in), it shows the ^{R 1} is hydrogen, ^{R 2} is 2-furanyl), di meth polybenzazole (dimetbenzazole:. formula In 5), ^{R 1} is hydrogen, ^{R 2} represents a 3,5-dimethyl -1H- pyrazol-1-yl.), And the like.

  Further, the type of the “strovirlin-based fungicide” in the present invention is not particularly limited, and examples thereof include azoxystrobin (formula (6)), metminostrobin (formula (7)), and pyraclostrobin. (Pyraclostrobin: Formula (8)), Cresoxim-methyl (Formula (9)), Trifloxystrobin (Formula (10)), Picoxystrobin (picoxystrobin: Formula (11)), etc. Can be mentioned.

  In the present invention, the “sensitive strain” for the drug refers to a strain having the property of preventing the growth of the strain at a normal effective concentration of the drug. And the "resistant strain" with respect to the said drug means the strain by which the sensitivity of the said drug fell with respect to the wild-type strain group, may be natural resistance, and acquired resistance may be sufficient as it.

Next, in this invention, the plant anthracnose control agent containing the fusalide (phthalide) shown by Formula (1) as said melanin biosynthesis inhibitor is provided. The phthalide is a so-called 4,5,6,7-tetrachlorofusalide having the chemical formula C ₈ H ₂ Cl ₄ O ₂ . Further, the method for synthesizing the fusalide used in the present invention is not particularly limited.

Subsequently, the present invention provides a plant anthracnose control agent containing phenoxanil represented by the formula (2) as the melanin biosynthesis inhibitor. Phenoxanil is a so-called N- (1-cyano-1,2-dimethylpropyl) -2- (2,4-dichlorophenoxy) propionamide having the chemical formula C ₁₅ H ₁₈ Cl ₂ N ₂ O ₂ . That is. The optical purity of phenoxanyl used in the present invention is not limited, and may be, for example, a mixture of optical isomers. Further, the method for synthesizing the phenoxanyl used in the present invention is not particularly limited.

Furthermore, the present invention provides a plant anthracnose control agent containing diclocymet represented by the formula (3) as the melanin biosynthesis inhibitor. Diclocymet is so-called 2-cyano-N- [1- (2,4-dichlorophenyl) ethyl] -3,3-dimethylbutyramide having the chemical formula C ₁₅ H ₁₈ Cl ₂ N ₂ O. And the optical purity of the diclosimet used by this invention is not limited, For example, the mixture of an optical isomer may be sufficient. Further, the method for synthesizing the diclocimet used in the present invention is not particularly limited.

And in this invention, the anthrax control agent of a plant containing the pyroquilon (pyroquilon) shown by Formula (4) as said melanin biosynthesis inhibitor is provided. Pyroquilon is a so-called 1,2,5,6-tetrahydropyrrolo [3,2,1-ij] quinolin-4-one having the chemical formula C ₁₁ N ₁₁ NO. In addition, the method for synthesizing the pyroxylone used in the present invention is not particularly limited.

  Subsequently, in the present invention, a melanin biosynthesis inhibitor is used as a bactericidal component for anthrax of a plant which is a resistant strain as well as a sensitive strain of a benzimidazole fungicide and / or a strobilurin fungicide. Provide a method for controlling anthrax. Thereby, anthrax can be effectively controlled even against the anthracnose fungus having improved resistance to the fungicide.

  The plant anthrax control agent of the present invention exhibits an excellent control effect not only against sensitive strains of benzimidazole fungicides and strobilurin fungicides, but also against resistant anthrax fungi.

  The anthrax control agent according to the present invention is not limited to the use of the active compound alone, and may be used, for example, dissolved or dispersed in a suitable liquid carrier, or mixed with a powder carrier or adsorbed thereto. It is also possible to use a mixture of a plurality of carriers. Furthermore, a suspending agent, an emulsifier, an oil agent, a spreading agent, a penetrating agent, a wetting agent, a stabilizer and the like may be added and used as a preparation such as a wettable powder, an emulsion, an oil agent, or a powder. Thereby, a control effect can be improved more.

  When the anthrax control agent according to the present invention is used as an agricultural and horticultural fungicide and mixed with a carrier, the liquid carrier preferably has a mixing ratio of 0.1% to 0.1% by weight (carrier / active compound). It is desirable that it is 80%. When a solid carrier is used, kaolin, attapulgite, bentonite, acid clay, borophyllite, talc, diatomaceous earth, calcite, walnut powder, urea, ammonium sulfate, synthetic silicon hydroxide, etc. can be used. By controlling the active compound and the solid carrier mixed or adsorbed on the solid carrier, the control effect can be further improved.

  In addition, when a liquid carrier is used, aromatic hydrocarbon compounds (benzene, toluene, xylene, methylnaphthalene, etc.), alcohols (isopropanol, ethylene glycol, Cellsolve (registered trademark), etc.), ketone compounds (acetone, cyclohexanone, isophorone) Etc.), vegetable oils (soybean oil, cottonseed oil, etc.), acid amide compounds (dimethylformamide, etc.), dimethyl sulfoxide, acetonitrile, etc. can be used. By spraying the active compound in a state dissolved or dispersed in the liquid carrier, the control effect can be further improved.

  Furthermore, in this invention, the adjuvant for formulation can be added to the said active compound, and it can also formulate and use for dosage forms, such as a wettable powder, a powder agent, and a flowable. The formulation adjuvant used in the present invention is not particularly limited, but it is preferable to use a surfactant, a wetting agent, a sticking agent, a thickener, a stabilizer and the like.

  In the present invention, as the surfactant used for emulsification, dispersion, wet spreading, penetration, solubilization, etc., for example, an anionic surfactant or a nonionic surfactant can be used. Examples of the anionic surfactant include alkyl sulfates, alkyl sulfonates, aryl sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkyl aryl ether phosphates, naphthalene sulfonate formaldehyde condensates, polycarboxylic acids Type polymer can be used.

  As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene polyoxypropylene block copolymer, sorbitan fatty acid ester and the like can be used.

  Furthermore, lignin sulfonate, alginate, polyvinyl alcohol, gum arabic, carboxymethyl cellulose (CMC), acidic isopropyl phosphate (PAP), xanthan gum and the like can be used as other adjuvants for preparations.

  The anthracnose control agent according to the present invention may be sprayed as appropriate by diluting the active compound alone or the preparation containing the active compound with water or the like to an appropriate concentration, or directly as a powder or the like. You can also Further, the anthracnose control agent according to the present invention is appropriately mixed with other fungicides, insecticides, acaricides, herbicides, plant growth regulators, fertilizers, etc., unless the desired anthracnose control effect is diminished. Alternatively, it can be used as a mixture.

  The bactericides that can be used in the present invention are not particularly limited, and examples thereof include copper bactericides (inorganic copper, organic copper, nonylphenyl ether sulfonate copper, etc.), inorganic sulfur bactericides, and organic sulfur bactericides (manneb, manzeb, ambam). , Propineb, thiuram, etc.), organophosphorus fungicides (fosetyl, tolcrofosmethyl, etc.), melanin biosynthesis inhibitors (fusalide, tricyclazole, pyrokilone, carpropamide, diclocimet, phenoxanyl, etc.), benzimidazole fungicides (thiophanate methyl, benomyl, Dietophenecarb, etc.), dicarboximide agents (iprodione, procymidone, etc.), acid amide fungicides (mepronil, flutolanil, boscalid, flumetopyl, tifluzamide, metalaxyl, etc.), sterol biosynthesis inhibitors (triflumizole, Conazole, ipconazole, metconazole, epoxiconazole, etc.), strobilurin fungicides (azoxystrobin, cresoxime methyl, trifloxystrobin, etc.), anilinopyrimidine fungicides (mepanipyrim, cyprodinil, etc.), antibacterial agents (oxolinic acid) , Teclophthalam, etc.), antibiotic fungicides (kasugamycin, polyoxin, streptomycin, etc.), probenazole, ferrimzone, tetrachloroisophthalonitrile (TPN), fludioxonil, iminoctazine acetate, cyazofamide, cyflufenamide and the like.

  The insecticide that can be used in the present invention is not particularly limited. For example, organophosphorus insecticides (fenitrothion, malathion, acephate, diazinon (registered trademark), etc.), carbamate insecticides (benfuracarb, mesomil, carbosulfan, etc.) , Pyrethroid insecticides (alleslin, permethrin, fenvalerate, etofenprox, silafluophene, etc.), nereistoxin insecticides (cartap, thiocyclam, etc.), neonicotinoid insecticides (imidacloprid (registered trademark), acetamiprid, thiamethoxam , Dinotefuran, etc.), IGR agents (diflubenzuron, cyromazine, etc.), fipronil, emamectin benzoate, pyridalyl, propylene glycol monofatty acid ester, BT agent and the like can be used.

  The said acaricide which can be mixed in this invention is not specifically limited, For example, bifenazate, milbemectin, etoxazole, etc. can be used.

  The herbicides that can be used in the present invention are not particularly limited. For example, phenoxy acid herbicides (2,4-D, chromeprop, fluazifop, etc.), carbamate herbicides (bencho curve, molinate, pyributycarb (registered trademark), etc.) , Acid amide herbicides (pretilachlor, diflufenican, mefenacet, cavenstrol, ashram, etc.), urea herbicides (Dimron, isouron, etc.), sulfonylurea herbicides (imazosulfuron, thifensulfuron methyl, nicosulfuron, halosulfuron) Methyl), triazine herbicides (atrazine, cimethrin, simazine, triadifram, etc.), diazine herbicides (bentazone, bromacil, etc.), diazole herbicides (pyrazolate, oxadiazone, etc.), bipyridylium Herbicides (paraquat (registered trademark), etc.), dinitroaniline herbicides (trifluralin, pendimethalin, oryzalin, etc.), aromatic carboxylic acid herbicides (fentrazamide (registered trademark), imazapyr, etc.), pyrimidyloxybenzoic acid herbicides Agents (bispyribac sodium salt, etc.), fatty acid herbicides (tetrapion, etc.), amino acid herbicides (glyphosate, glufosinate, etc.), nitrile herbicides (chlorothiamid, etc.), cyclohexanedione herbicides (cetoxydim, cretodim, etc.) Phenylphthalimide herbicides (chlorophthalim, etc.), butamifos, pentoxazone, benzobicyclone, etc. can be used.

  The plant growth regulator that can be used in the present invention is not particularly limited, and for example, uniconazole P, daminogit, paraffin, wax, benzylaminopurine and the like can be used.

  In addition, when anthrax that has developed resistance to a benzimidazole fungicide or a strobilurin fungicide has a certain resistance to another drug of the same strain having a chemical structure similar to that of the fungicide (cross resistance) However, the anthrax control agent according to the present invention can exert an effect of controlling the anthrax fungus having the cross resistance.

  The plant anthracnose controlling agent according to the present invention can be used to control a wide range of plant anthracnose, for example, cucurbit anthracnose Colletotrichum lagenarium, tea anthracnose Colletotrichum theaesinensis, radish anthracnose Colletotrichum higginsianum, bean anthracnose Colletotrichum lindemuthianum, soybean anthrax Colletotrichum truncatum, strawberry anthracnose Gromerella cingulata, western buckwheat anthracnose Colletotrichum graminicola, mango anthracnose Colletotrichum gleosporioides, citrus anthracnose Colletotrichum gloeosporioides It can be used against Glomerella anthracnose fungi and can be used against anthrax caused by pathogenic fungi of the same, genus or closely related to these plants.

  In Example 1, the effect of fusaride on anthracnose was examined using as an index the control effect on cucumber anthracnose caused by Colletorichum lagenarium in which many benzimidazole-resistant bacteria are generated. The experimental procedure was performed as follows.

<Treatment Zone 1>
Dissolve 5 mg of fusalide (manufactured by Kureha Co., Ltd.) in 1.25 mL of acetone (manufactured by SIGMA), add an appropriate amount of a spreader mainly composed of nonionic surfactant polyoxyethylene nonylphenyl ether, An aqueous solution of fusaride acetone was prepared by adding pure water so that the amount was 12.5 mL. The concentration of the active ingredient in the aqueous solution of fusaride acetone was 400 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha on the cucumber plant at the 1-leaf stage.

<Treatment Zone 2>
A total of 20 mg pure water and a surfactant are added to 5 mg of fusaride to prepare a wettable powder having an active ingredient concentration of 20%, and pure water is added thereto so that the final liquid amount becomes 12.5 mL. Thus, a diluted solution of fusalide wettable powder was prepared. Thereby, the active ingredient density | concentration of the fusalide wettable powder became 400 ppm, and this was sprayed with the chemical | medical solution to the 1st leaf stage cucumber plant body in the ratio of 1000 L / ha.

<Treatment Zone 3>
A fusalide powder was prepared by mixing 0.2 g of fusalide and 7.8 g of fine mineral powder and formulating it in the form of a powder with an active ingredient concentration of 2.5%. Then, the fusalide powder was dusted onto the 1-leaf cucumber plant at a rate of 80 kg / ha.

<Evaluation procedure>
Colletorichum lagenarium spore suspension prepared to be 5 × 10 ⁵ cells / mL with pure water 4 hours after the chemical spraying (see treatment zones 1 and 2) and dusting treatment (see treatment zone 3) The liquid was thoroughly sprayed on the cucumber plant. And the said cucumber plant body was hold | maintained for 24 hours with the wet box of temperature 25 degreeC. Then, it moved to the artificial weather apparatus maintained at the temperature of 25 degreeC and the humidity of 80%, and the driving | operation set to become 12 hours each day and night was performed for 5 days. And the control value was evaluated based on the following formula on the basis of the effect of the chemical | medical agent with respect to an untreated section. Table 1 shows the results.

  As a result, as shown in Table 1, it was found that fusaride exerts a high control effect against cucumber anthracnose even in various pharmaceutical forms such as an aqueous acetone solution, a wettable powder, and a powder.

  In Example 2, the effect of phenoxanil on anthrax was examined using cucumber anthrax as an index. The experimental procedure was performed as follows.

<Treatment Zone 1>
2.5 mg of phenoxanyl (Wako Pure Chemical Industries, Ltd.) is dissolved in 1.25 mL of acetone, an appropriate amount of a spreading agent mainly composed of nonionic surfactant polyoxyethylene nonylphenyl ether is added, and the final liquid amount is 12 A phenoxanylacetone aqueous solution was prepared by adding pure water to 5 mL. The concentration of the active ingredient in the aqueous phenoxanylacetone solution was 200 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha onto the 1-leaf stage cucumber plant.

<Treatment Zone 2>
Dissolve 1.25 mg of phenoxanyl in 1.25 mL of acetone, add an appropriate amount of a spreading agent based on the nonionic surfactant polyoxyethylene nonylphenyl ether, and add pure liquid so that the final liquid volume is 12.5 mL. An aqueous phenoxanylacetone solution was prepared by adding water. The concentration of the active ingredient in the aqueous phenoxanylacetone solution was 100 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha onto the 1-leaf stage cucumber plant.

<Control Zone>
A suitable amount of a spreading agent mainly composed of a nonionic surfactant polyoxyethylene nonylphenyl ether is added to 1.25 mL of acetone, and pure water is added thereto so that the final liquid amount becomes 12.5 mL, and a spray liquid is added. Was prepared. And this spraying liquid was sprayed to the 1st leaf stage cucumber plant body in the ratio of 1000 L / ha.

<Evaluation procedure>
About the inoculation to the cucumber to the cucumber anthracnose fungus Colletotrichum lagenarium spore suspension sprayed with the chemical solution (see treatment zones 1 and 2) and the spray solution (see control zone), subsequent treatment and evaluation method of the control value Was carried out in the same manner as in Example 1. Table 2 shows the results.

  As a result, as shown in Table 2, it was found that phenoxanil exerts a high control effect against cucumber anthrax.

  In Example 3, the effect of pyrokilone and diclosimet on anthrax was examined using cucumber anthrax as an index. The experimental procedure was performed as follows.

<Treatment Zone 1>
Pyroquinone (trade name “Kola Top Jumbo (registered trademark)”, extracted from Syngenta) 2.5 mg is dissolved in 1.25 mL of acetone, and the main component is nonionic surfactant polyoxyethylene nonylphenyl ether. An appropriate amount of a spreading agent was added, and pure water was added so that the final liquid amount was 12.5 mL, thereby preparing an aqueous pyroxylone acetone solution. The active ingredient concentration of the aqueous solution of pyroxylone acetone was 200 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha onto the 1-leaf stage cucumber plant.

<Treatment Zone 2>
Dissolve 2.5 mg of diclocimet (synthesized in Kureha Co., Ltd.) in 1.25 mL of acetone, and add an appropriate amount of a spreading agent mainly composed of nonionic surfactant polyoxyethylene nonylphenyl ether. Then, pure water was added so that the final liquid amount was 12.5 mL to prepare a diclosimet acetone aqueous solution. The concentration of the active ingredient in the diclosimet acetone aqueous solution was 200 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha on the 1-leaf stage cucumber plant.

<Control Zone>
A suitable amount of a spreading agent mainly composed of a nonionic surfactant polyoxyethylene nonylphenyl ether is added to 1.25 mL of acetone, and pure water is added thereto so that the final liquid amount becomes 12.5 mL, and a spray liquid is added. Was prepared. And this spraying liquid was sprayed to the 1st leaf stage cucumber plant body in the ratio of 1000 L / ha.

<Evaluation procedure>
About the inoculation to the cucumber to the cucumber anthracnose fungus Colletotrichum lagenarium spore suspension sprayed with the chemical solution (see treatment zones 1 and 2) and the spray solution (see control zone), subsequent treatment and evaluation method of the control value Was carried out in the same manner as in Example 1. Table 3 shows the results.

  As a result, as shown in Table 3, it was found that pyroxylone and diclocimet exert a controlling effect against cucumber anthrax.

  In Example 4, the fusaride control effect was evaluated for each of the cucumber anthracnose fungus Colletorichum lagenarium that is resistant to benzimidazole and the cucurbit anthracnose fungus Colletorichum lagenarium that is sensitive to benzimidazole.

<Treatment Zone 1>
Dissolve 2.5 mg of fusalide in 1.25 mL of acetone, add an appropriate amount of a spreading agent mainly composed of nonionic surfactant polyoxyethylene nonylphenyl ether, and add pure liquid so that the final liquid volume becomes 12.5 mL. An aqueous solution of fusaride acetone was prepared by adding water. The active ingredient in the aqueous solution of fusaride acetone was 200 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha on the 1-leaf cucumber plant.

<Treatment Zone 2>
A 1000-fold diluted solution of thiophanate methyl wettable powder (active ingredient concentration 40%, trade name “Top Gin M Sol” manufactured by Nippon Soda Co., Ltd.) was sprayed onto a 1-leaf cucumber plant at a rate of 1000 L / ha.

<Control Zone>
A suitable amount of a spreading agent mainly composed of a nonionic surfactant polyoxyethylene nonylphenyl ether is added to 1.25 mL of acetone, and pure water is added thereto so that the final liquid amount becomes 12.5 mL, and a spray liquid is added. Was prepared. The spray solution was sprayed on the cucumber plant of the first leaf stage.

<Evaluation procedure>
Colletorichum lagenarium spore suspension prepared to be 5 × 10 ⁵ cells / mL with pure water 4 hours after the drug solution (see treatment groups 1 and 2) and the spray solution (see control group) Was thoroughly sprayed on the cucumber plants. And the said cucumber plant body was hold | maintained for 24 hours with the wet box of temperature 25 degreeC. Then, it moved to the artificial weather apparatus maintained at the temperature of 25 degreeC and the humidity of 80%, and the driving | operation set to become 12 hours each day and night was performed for 5 days. This operation was performed for cucumber anthracnose fungus (Sensitive) having sensitivity to benzimidazole and cucurbit anthracnose fungus (Resistant) having resistance to benzimidazole, respectively. For these evaluation methods, the severity of disease was evaluated in 6 stages, and the control value was also evaluated in the same manner as in Example 1. Table 4 shows the results.

  As a result, as shown in Table 4, fusalide exerts a high control effect not only on cucumber anthracnose fungi that are sensitive to benzimidazole but also on cucumber anthracnose fungus that is resistant to benzimidazole. Indicated.

  In Example 5, the control effect of fusaride, pyroxylon, diclocimet, and phenoxanil on each of the cucumber anthracnose fungus Colletorichum lagenarium resistant to benzimidazole and the cucurbit anthracnose fungus Colletorichum lagenarium sensitive to benzimidazole. Evaluated.

<Treatment Zone 1>
Dissolve 2.5 mg of fusaride in 1.25 mL of acetone, add an appropriate amount of a spreading agent mainly composed of nonionic surfactant polyoxyethylene nonylphenyl ether, and add pure liquid so that the final liquid volume is 12.5 mL. An aqueous solution of fusaride acetone was prepared by adding water. The concentration of the active ingredient in the aqueous solution of fusaride acetone was 200 ppm, and this was sprayed onto the cucumber plant of 1 leaf stage at a rate of 1000 L / ha.

<Treatment Zone 2>
An aqueous solution of pyroxylone acetone was prepared by the same procedure as in the treatment group 1 using pyrokilone instead of the fusalide in the treatment group 1. The active ingredient of the aqueous solution of pyroxylone acetone was 200 ppm, and this was sprayed with a chemical solution at a rate of 1000 L / ha on the cucumber plant at the 1-leaf stage.

<Treatment Zone 3>
A diclocimet acetone aqueous solution was prepared by the same procedure as in the treatment section 1 using diclocimet instead of the fusalide in the treatment section 1. The active ingredient of the diclocimet acetone aqueous solution was 200 ppm, and this was sprayed with a chemical solution onto the 1-leaf stage cucumber plant at a rate of 1000 L / ha.

<Treatment Zone 4>
A phenoxanylacetone aqueous solution was prepared by the same procedure as in the treatment group 1 using phenoxanyl instead of the fusalide in the treatment group 1. The active ingredient of the phenoxanylacetone aqueous solution was 200 ppm, and this was sprayed with a chemical solution onto a 1-leaf cucumber plant at a rate of 1000 L / ha.

<Treatment Zone 5>
A 1000-fold diluted solution of thiophanate methyl wettable powder (active ingredient concentration 40%) was sprayed on the 1-leaf cucumber plant at a rate of 1000 L / ha.

<Control Zone>
A suitable amount of a spreading agent mainly composed of a nonionic surfactant polyoxyethylene nonylphenyl ether is added to 1.25 mL of acetone, and pure water is added thereto so that the final liquid amount becomes 12.5 mL, and a spray liquid is added. Was prepared. The spray solution was sprayed on the 1-leaf stage cucumber plant at a rate of 1000 L / ha.

<Evaluation procedure>
Inoculation of cucumber into the cucumber suspension of Colletotrichum lagenarium spore suspension sprayed with the chemical solution (see treatment areas 1, 2, 3, 4 and 5) and the spray solution (see control area), subsequent treatment and The evaluation method of the control effect was performed in the same manner as in Example 4. Experiments and evaluations were carried out on a cucumber anthracnose fungus (Sensitive) having sensitivity to benzimidazole and an urinary anthracnose fungus (Resistant) having resistance to benzimidazole. Table 5 shows the results.

  As a result, as shown in Table 5, the melanin biosynthesis inhibitors fusaride, pyrokilone, diclocimet, and phenoxanil are not only resistant to benzimidazole but also resistant to benzimidazole. It has been shown that the cucumber anthracnose fungus having a control effect is exerted.

  The plant anthracnose controlling agent according to the present invention can exert a stable anthracnose controlling effect regardless of the presence or absence of a fungicide resistant strain, particularly in the field of agriculture and horticulture.

Claims (6)

  A plant anthrax control agent which contains a melanin biosynthesis inhibitor as a bactericidal component and is effective not only for sensitive strains of benzimidazole fungicides and / or strobilurin fungicides but also for resistant strains. The said melanin biosynthesis inhibitor contains the fusalide (phthalide) shown by following formula (1), The anthrax control agent of the plant of Claim 1 characterized by the above-mentioned.
2. The plant anthracnose control agent according to claim 1, wherein the melanin biosynthesis inhibitor contains fenoxanil represented by the following formula (2).
2. The plant anthracnose control agent according to claim 1, wherein the melanin biosynthesis inhibitor contains diclocymet represented by the following formula (3).
2. The plant anthracnose controlling agent according to claim 1, wherein the melanin biosynthesis inhibitor contains pyroquilon represented by the following formula (4).
  A method for controlling plant anthracnose using a melanin biosynthesis inhibitor as a bactericidal component against a plant anthracnose fungus that is not only a susceptible strain of a benzimidazole fungicide and / or a strobilurin fungicide.