WO2019172268A1

WO2019172268A1 - Plant disease control agent

Info

Publication number: WO2019172268A1
Application number: PCT/JP2019/008681
Authority: WO
Inventors: 久笑山口; 河岸　洋和; 宰熏崔; 田中　薫
Original assignee: 国立大学法人静岡大学; 石原産業株式会社
Priority date: 2018-03-05
Filing date: 2019-03-05
Publication date: 2019-09-12
Also published as: JP2021073167A

Abstract

A plant disease can be controlled by applying at least one compound selected from the group consisting of 2-azahypoxanthine, 2-aza-8-oxohypoxanthine and imidazole-4-carboxyamide to a plant.

Description

Plant disease control agent

The present invention relates to a plant disease control agent and a method for controlling plant diseases.

In parks and golf courses, it is known that lawns grow thicker in the shape of rings and sometimes grow slowly and die, and later mushrooms are generated. This phenomenon is called “fairy ring”. 2-azahypoxanthine (hereinafter abbreviated as AHX) that promotes turf growth was found from the walnut swordfish that forms the fairy ring, and imidazole-4-carboxyamide (hereinafter abbreviated as ICA) that suppresses turf growth. ) Was also found. Furthermore, it was also found that when AHX is taken into plants, it becomes 2-aza-8-oxohypoxanthine (hereinafter abbreviated as AOH). These compounds are also called fairy compounds.

Japanese Patent No. 4565018 Japanese Patent No. 5915982 International Publication No. 2016/136508

As described above, the fairy compound was known to have a plant growth regulating action, but other actions were not known.

As a result of further research by the present inventors, it was found that the fairy compound has a plant disease control action, and the present invention was completed. That is, the present invention provides a plant disease control agent comprising at least one compound selected from the group consisting of AHX, AOH and ICA. The present invention further provides a method for controlling plant diseases, which comprises applying at least one compound selected from the group consisting of AHX, AOH and ICA to plants.

It is possible to control plant diseases by applying to a plant at least one compound selected from the group consisting of AHX, AOH and ICA.

The plant disease control agent according to the present invention contains at least one compound selected from the group consisting of 2-azahypoxanthine, 2-aza-8-oxohypoxanthine and imidazole-4-carboxamide.

AHX, AOH and ICA can be produced by known methods (for example, methods described in Patent Documents 1 to 3 and Non-Patent Document 1).

The target plant may be a seed plant, fern plant or moss plant, the seed plant may be a gymnosperm or angiosperm, and the angiosperm may be a monocotyledonous plant or a dicotyledonous plant. The seed plant also includes a plant that propagates without forming seeds, such as a vegetative plant that propagates through bulbs or tubers. From a commercial point of view, it is preferable to target vegetables and florets.

Specific examples of such plants include: Brassicaceae, Eggplant, Compositae, Cucurbitaceae, Apiaceae, Gramineae, Rosaceae, Lilyaceae, Orchidaceae, Clamaceae, Leguminosae, Legumes, Leek, Examples include plants such as aceae, convolvulaceae, red crustaceae, grapes, citrus, oysters, camellia, oleaceae, mallow, ginger, ginger, rhododendron, pineapple. Among these, from the point that the disease control effect by AHX, AOH and ICA is remarkable, it is preferably a plant of Brassicaceae, Solanum, or Asteraceae. Examples of cruciferous plants include Komatsuna, Chingensai, turnip, cauliflower, cabbage, radish, Chinese cabbage, broccoli and the like. Examples of solanaceous plants include tomato, tobacco, pepper, potato, pepper, eggplant, paprika, pepper and the like. Examples of the Asteraceae plants include lettuce, artichoke, burdock, garlic, chrysanthemum and sunflower. Examples of cucurbitaceae plants include pumpkin, cucumber, watermelon, and melon. Examples of celery family plants include celery, celery, carrot and parsley. Examples of gramineous plants include rice, barley, wheat, sugar cane, and corn. Examples of plants of the Rosaceae family include strawberry, rose, apple, pear, peach, loquat and almond. Examples of liliaceae plants include asparagus, tulips, and lilies. Orchids of the orchid family, cymbidium and the like. A daffodil etc. are mentioned as a plant of the Amaryllidaceae. Cyclamen etc. are mentioned as a plant of a primrose family. Examples of leguminous plants include soybeans, kidney beans and azuki bean. Examples of leeks include leek, leek, rakkyo and garlic. Buckwheat etc. are mentioned as a plant of the aceae family. Sweet potato etc. are mentioned as a plant of the convolvulaceae family. Examples of the plant of the family Rabbitaceae include spinach and sugar beet. Grapes etc. are mentioned as a plant of the vine department. Citrus plants include citrus, lemon, orange and the like. Oysters and the like can be mentioned as plants of the family Oysteraceae. Examples of camellia plants include tea. Olive plant, jasmine, etc. are mentioned as a plant of the oleaceae family. Examples of mallows include cotton, cacao and okra. A banana etc. are mentioned as a plant of a Musaceae family. Examples of ginger family plants include ginger and the like. Examples of Rubiaceae plants include coffee trees. Examples of pineapple plants include pineapple and bromeliad.

The target plant organ is not particularly limited and may be any of roots, stems, leaves, flowers, fruits, reproductive organs, and seeds.

The pathogens of diseases that can be controlled by AHX, AOH and ICA may be any of phytopathogenic bacteria, viruses and filamentous fungi, but AHX, AOH and ICA have a remarkable control effect on bacteria. Examples of phytopathogenic bacteria include Pectobacterium spp. (For example, Pectobacterium carotovorum and the like), Dickeya spp. (For example, Dickeya dadantii and the like), Ralstonia spp. (For example, Ralstonia 等 solanacearum and the like)), Agrobacterium （spp. ), Pseudomonas spp. (Eg, Pseudomonas fluorescens, P.syringae pv. Maculicola, P.syringae pv. Tomato, etc.), Xanthomonas spp. (Eg, Xanthomonas campestris 例えば pv. Campestris, X.oryzae pv.pporywinia, etc.) (For example, Erwinia amylovora, E. rhapontici, etc.), Burkholderia 例えば spp. (Eg, Burkholderia glumae, B. plantarii, etc.), Clavibacter spp. (Eg, Clavibacter michiganensis subsp. Michiganensis, etc.), Streptomyces spp.

The plant disease control agent may contain known additives for pharmaceutical preparations in addition to AHX, AOH and ICA. Examples of such formulation additives include excipients, emulsifiers, wetting agents and the like. In addition, the dosage form of the plant disease control agent is not particularly limited. For example, emulsion, wettable powder, aqueous solvent, liquid agent, granule, powder, microcapsule, fumigant, smoke agent, aerosol, flowable agent, paste agent , Tablets, coating agents, microdispersing agents, oils, and complex fertilizers, and can be appropriately selected by the user according to the target plant, its organ, purpose, and the like. The plant disease control agent of such a dosage form can be produced by a known method.

AHX, AOH, and ICA can be applied to plants by the same method as known plant disease control agents, for example, spraying, spraying, applying, and injecting directly to plant organs, and to soil You may mix and irrigate mixing, irrigation, and hydroponics nutrient solution.

The application concentration of AHX, AOH, and ICA varies depending on the type and organ of the target plant, the dosage form of the plant disease control agent, the application method, and the application amount, but in the case of foliage treatment, it is usually 0.01 ppm to 40,000 ppm. In the case of soil treatment, it is usually from 1 to 4,000 kg / ha, preferably from 1 to 400 kg / ha. In the case of seed treatment, it is preferably from 0.1 ppm to 4,000 ppm, more preferably from 1 ppm to 1,000 ppm. The amount is usually 0.1 to 40,000 g, preferably 1 to 4,000 g, more preferably 10 to 1,000 g per 100 kg of seeds. When AHX, AOH and ICA are injected into a plant, the concentration of AHX, AOH and ICA is preferably 0.1 to 10 mM. When AHX, AOH and ICA are mixed in a culture medium for hydroponics, the concentration of AHX, AOH and ICA in the culture medium is preferably 50 to 150 μM.

The mechanism by which AHX, AOH, and ICA control plant diseases is not limited to a specific theory, but may be due to pathogen growth inhibition and / or that induces defense response gene expression in plants. In particular, AHX is superior to the disease resistance inducer, acibenzoral-S-methyl (ASM), in its penetration into plants, and induces the expression of defense response genes at an earlier stage, thereby enabling faster priming. It is thought to bring about an effect.

Some of the preferred embodiments of the present invention are illustrated below but are not intended to limit the present invention.
[1] A plant disease control agent comprising at least one compound selected from the group consisting of AHX, AOH and ICA.
[2] A fungicide containing at least one compound selected from the group consisting of AHX, AOH and ICA.
[3] A plant disease control agent comprising AHX.
[4] A plant disease control agent containing AOH.
[5] A plant disease control agent containing ICA.
[6] A disinfectant containing AHX.
[7] A disinfectant containing AOH.
[8] A disinfectant containing ICA.
[9] A method for controlling plant diseases, comprising applying at least one compound selected from the group consisting of AHX, AOH and ICA to plants.
[10] A method for controlling plant diseases, which comprises applying AHX to a plant.
[11] A method for controlling plant diseases, wherein AOH is applied to plants.
[12] A method for controlling plant diseases, wherein ICA is applied to plants.
[13] A method for sterilization using at least one compound selected from the group consisting of AHX, AOH and ICA.
[14] A method of sterilization using AHX.
[15] A method of sterilization using AOH.
[16] A method of sterilization using ICA.
[17] The method for controlling plant diseases according to [9] above, wherein at least one compound selected from the group consisting of AHX, AOH and ICA is injected into a plant in a 0.1 to 10 mM aqueous solution.
[18] The method for controlling plant diseases according to the above [9], wherein the plant is hydroponically cultivated with 50 to 150 μM culture solution of at least one compound selected from the group consisting of AHX, AOH and ICA.
[19] The method for controlling plant diseases according to [17] or [18] above, wherein the compound is AHX.
[20] The method for controlling plant diseases according to [17] or [18] above, wherein the compound is AOH.
[21] The plant disease control method according to the above [17] or [18], wherein the compound is ICA.
In the above-mentioned embodiment, “bactericidal agent” and “method for sterilizing” are not only forms in which the fairy compound is applied directly to the plant, but, for example, before sowing plant seeds or transplanting plant seedlings, Including a form in which a fairy compound is applied to the soil in which the rice is cultivated.

Experimental Example 1A: Inoculation experiment with Chingensai (examination of pretreatment effect)
10 μL of distilled water or a fairy compound (5 mM AHX, AOH, or 0.5 mM ICA) was injected into the leaf axis of the chingensai. Three hours later, 10 μL of a suspension (OD ₆₀₀ = 0.3) of a soft rot fungus Pectobacterium carotovorum subsp. Carotovorum (hereinafter abbreviated as Pcc) was inoculated into the same part of the shaft. After 24 hours, the chin-thorn rhinoceros was observed and the length of the lesion site was measured. The average was 9.3 cm in the chin-gensai treated with distilled water, whereas the average 7.3 cm in the chin-gensai treated with AHX and The average was reduced to 4.6 cm, and the progression of disease symptoms was suppressed to about 50 to 70% when distilled water as a control was injected, and about 30 to 60% in the area calculation of the lesion site. Moreover, the same disease suppression effect was confirmed also in the ICA treatment section. When a similar experiment was performed using a known resistance inducer used for controlling plant diseases, the suppression rate was 40 to 80%, which was considered to have the same effect. From the above results, the disease suppression effect of the fairy compound was confirmed.

Experimental Example 1B: Inoculation experiment with Chingensai (examination of simultaneous treatment effect)
Distilled water or a fairy compound (5 mM AHX) was injected into the shaft of the Chingensai leaf, and immediately after that, a suspension of Pcc (OD ₆₀₀ = 0.3) was injected into the same part of the shaft. After 24 hours, the chin-thorn rhinoceros was observed and the length of the lesion was measured. As a result, the average was 8.9 cm in the chin-gensai treated with distilled water, whereas the average was 3.7 cm in the chin-gensai treated with AHX. The extension was suppressed to about 45% in the case of injecting distilled water as a control group, and similarly to about 44% in the area calculation of the lesion site. From the above results, the disease suppression effect of the fairy compound was confirmed. When similar experiments were performed using known resistance inducers used for plant disease control, the effect of simultaneous treatment was not confirmed, and the fairy compound is excellent in migration and penetrability, and can quickly control plant disease. It was thought to be effective.

Experimental Example 2: Inoculation Experiment with Tobacco 10 μL of distilled water or a fairy compound (0.5-5 mM AHX or AOH) was injected into tobacco (bright yellow species) leaves. Three hours later, 10 μL of a Pcc suspension (OD ₆₀₀ = 0.3) was inoculated into the same part of the leaf. After 5 hours, the tobacco leaves were observed and the number of Pcc bacteria in the tobacco leaves was measured. In the tobacco treated with distilled water, the decay progressed, whereas in the tobacco treated with AHX or AOH, the decay was suppressed. Moreover, the number of Pcc bacteria in tobacco treated with AHX or AOH was less than the number of Pcc bacteria in tobacco treated with distilled water. From the above results, the effect of inhibiting the growth of bacteria by the fairy compound was confirmed, and the effect of suppressing disease was confirmed.

Experimental Example 3: Komatsuna Inoculation Experiment Komatsuna was hydroponically cultivated with a culture solution containing or not containing a fairy compound (AHX or AOH) (added to the culture solution to 100 μM). Komatsuna leaves were inoculated with 10 μL of a Pcc suspension (OD ₆₀₀ = 0.3). After 5 hours, Komatsuna leaves were observed, and the number of Pcc bacteria in Komatsuna leaves was measured. Komatsuna cultivated under conditions that did not contain fairy compounds progressed in spoilage, whereas Komatsuna cultivated under conditions that contained fairy compounds suppressed rot. Moreover, the number of Pcc bacteria in Komatsuna cultivated under conditions containing a fairy compound was smaller than the number of Pcc bacteria in Komatsuna cultivated under conditions not containing a fairy compound. From the above results, the disease suppression effect of the fairy compound was confirmed.

Experimental Example 4A: Inoculation Experiment with Salad Vegetables Experiments similar to Experimental Example 3 were performed using lettuce (salad vegetables) instead of Komatsuna. In the case of salad vegetables cultivated under the condition not containing AHX, the rot progressed, whereas in the salad vegetables cultivated under the condition containing AHX, the rot was suppressed. From the above results, the disease suppression effect of the fairy compound was confirmed.

Experimental Example 4B: Inoculation experiment with salad vegetables 10 μL of distilled water or a fairy compound (5 mM AHX) was injected into the leaves of salad vegetables. Three hours later, 10 μL of Pcc suspension (OD ₆₀₀ = 0.3) was inoculated at the same site. After 24 hours, the salad vegetables were observed and the size of the lesion site was measured. As a result, the rot symptoms in the salad vegetables treated with AHX were suppressed (reduced) compared to the case of injecting distilled water as a control.

Experiment 5: Growth inhibition experiment against tomato bacterial wilt fungus A potato sucrose agar medium (PSA medium) containing a fairy compound (AHX or ICA) was poured into a petri dish with a diameter of 9 cm, and a suspension of tomato bacterial wilt fungus (Ralstonia solanacearum) 100 μL of (OD ₆₀₀ = 0.01) was applied and cultured at 30 ° C. in the dark for 3 days to evaluate the degree of bacterial growth. The evaluation was performed in four stages (++, ++, +, and −) from “equivalent to no drug treatment group” to “no growth”. Kanamycin was used as a positive subject.

As is clear from the results shown in Table 1, the growth inhibitory effect of the fairy compound against tomato bacterial wilt was confirmed.

Experimental Example 6: Experiment for measuring expression level of defense response gene 10 μL of distilled water or fairy compound (5 mM AHX) was injected into tobacco (bright yellow species) leaves. Three hours later, 10 μL of a Pcc suspension (OD ₆₀₀ = 0.3) was inoculated into the same part of the leaf. The inoculated site was excised after 1, 3 and 5 hours, RNA was extracted by a conventional method, and the expression level of the defense response gene rbohD was measured by semi-quantitative RT-PCR, electrophoresis, and real-time PCR. As a control gene, the constant expression gene EF-1α was used. Similarly, the expression levels of the defense response genes Acc oxidase and HSR201 were measured by real-time PCR. EF-1α or β-actin was used as a control gene. Table 2 shows rbohD, Table 3 shows Acc oxidase, Table 4 shows HSR201, Table 5 shows PR1a, Table 6 shows PR3, Table 7 shows RbohB, and Table 8 shows the rate of increase in SIPK expression. The numerical value of the increase rate was calculated by dividing the value of the expression level at the time of AHX treatment by the value of the expression level by the distilled water treatment as a control group. In the table, “nt” means not tested.

From the above results, it was confirmed that the expression level of the defense response gene was increased by the fairy compound, and it was shown that resistance to the disease was induced.

Example 7: Inoculation experiment with hydroponics Chingensai 3 days after sowing, Chingensai was hydroponically cultivated for 12 days. Fairy compound (AHX) was added to the culture solution so as to be 100 μM. In the control group, AHX was not added. Two days later, 10 μL of Pcc suspension (OD ₆₀₀ = 0.3) was injected and inoculated on the axis of the leaf of a plover. 24 hours later, the length of the lesion was measured and the length of the lesion was measured. As a result, it was 4.4 cm on average in the control group, whereas it was reduced to an average of 2.1 cm in the chestnut that was cultivated in the culture solution added with AHX. The average area of the lesion site was 72% of the control group. From the above results, the disease suppression effect of the fairy compound was confirmed.

Example 8: Inoculation experiment with hydroponic tomatoes Tomatoes were cultivated by hydroponic cultivation with a culture solution containing or not containing a fairy compound (AHX, AOH or ICA) in the tomato. Tomato leaves were inoculated with 10 μL of a suspension (OD ₆₀₀ = 0.3) of tomato (Pseudomonas syringae pv. Tomato; Pst). One day later, the number of Pst bacteria in tomato leaves was measured. The number of Pst bacteria in tomatoes grown under conditions containing fairy compounds was less than the number of Pst bacteria in tomatoes grown under conditions not containing fairy compounds. Similarly, Pst (OD ₆₀₀ = 0.3) was spray-inoculated on the leaf of tomato that was hydroponically cultivated. Two days after Pst inoculation, the number of lesions (number of black spots) was counted. The number of black spots was about 210 in the control group DDW treatment group, 92 in the AHX treatment group, 147 in AOH, and 83 in ICA. When the number of black spots per unit area was calculated, it was significantly reduced by about 50% in the AHX, AOH, and ICA treatment groups compared to the DDW treatment group. From the above results, the disease suppression effect of the fairy compound was confirmed.

Example 9: Inoculation experiment with hydroponics Chingensai 3 days after sowing, Chingensai was hydroponically cultivated for 12 days. Fairy compound (AHX) was added to the culture solution so as to be 100 μM. In the control group, AHX was not added. Two days later, 10 μL of a suspension (OD ₆₀₀ = 0.3) of soft rot bacteria (Dickeya dadantii) was injected and inoculated on the axis of the leaf of a plover. After 24 hours, the chin-thorn rhinoceros was observed and the length of the lesion site was measured. The average length was 3.2 cm in the control group, while that in the chin-grown rhinoceros cultivated in the culture solution added with AHX was reduced to an average of 2.0 cm. The average area of the lesion site was 50% of the control group. From the above results, the disease suppression effect of the fairy compound was confirmed.

Example 10: Growth inhibition experiment against various phytopathogenic bacteria 20 μL of bacterial suspension (OD ₆₀₀ = 0.001) in 3 mL of LB (tryptone, yeast extract, NaCl) liquid medium containing fairy compound (AHX or ICA) After dropping and shaking culture in the dark at 28 ° C. and 150 rpm for a predetermined time (cultivation time: 67 hours for tomato bacterial wilt fungus and black cabbage fungus, 16 hours for cabbage soft rot fungus and black cabbage fungus), spectrophotometer The turbidity OD ₆₀₀ of the culture was measured. The growth inhibition rate relative to the untreated group was calculated and evaluated in 4 stages (++, ++, + and −) from the degree of inhibition. Chloramphenicol was used as a positive control.
Growth inhibition rate = 100- _{(OD 600} of the _{OD 600} / non-treated area of the treated area) × 100
Evaluation criteria =
-: Growth inhibition rate for the untreated group is 90% or more +: Growth inhibition rate for the untreated group is 50% or more and lower than 90% ++: Growth inhibition rate for the untreated group is 30% or more and lower than 50% ++ : Growth inhibition rate for untreated areas is lower than 30%

In Table 9, Rs is tomato bacterial rot (Ralstonia solanacearum), Psm is Chinese cabbage black spot bacterial bacterium (Pseudomonas syringae pv. Maculicola), Pcc is Chinese cabbage soft rot fungus, and Xcc is Chinese cabbage black rot fungus (Xanthomonas campestris pv. Campestris). Represents. n. t. Means not tested.

As is clear from the results shown in Table 9, it was confirmed that the fairy compound exhibits a growth inhibitory effect against a plurality of phytopathogenic bacteria.

Example 10: Comparison experiment 1 between ASM and fairy compounds
Experiments comparing the disease resistance inducer ASM and fairy compounds were performed as follows. ASM is known to act between salicylic acid and the NPR1 protein on the systemic acquired resistance (SAR) signaling system, and functions to replace the role of salicylic acid.
Distilled water or 10 μL of fairy compound (5 mM AHX) was injected into the shaft of the chingensai or was sprayed with ASM (0.5 g / L). Twenty-four hours later, 10 μL of a Pcc suspension (10 ⁸ cfu / mL) was injected into the same part of the shaft and allowed to stand under high humidity. After 24 hours, chingensai was observed and the length of the lesion site was measured. In the AHX-treated group and ASM-treated group, the progression of disease symptoms was suppressed as compared with the control group.
In addition, the expression of defense response genes rbohD and PR1a at 1, 3 and 5 hours after Pcc inoculation was examined using tobacco (Nicotiana benthamiana species) in the same manner as in Example 6. The results are shown in Table 10 and Table 11. In the AHX-treated group, the expression level of PR1a gene expression related to the initial defense response was higher than that in the ASM-treated group, and a tendency for high expression to be sustained was observed.

Example 11: Comparison experiment 2 between ASM and fairy compounds
Distilled water or 10 μL of fairy compound (5 mM AHX) was injected into the shaft of the chingensai or was sprayed with ASM (0.5 g / L). Immediately after that, 10 μL of a Pcc suspension (10 ⁸ cfu / mL) was injected into the same part of the shaft, and allowed to stand under high humidity. After 24 hours, the phlegm was observed and the length of the lesion was measured. In the AHX-treated group, the progression of disease symptoms was suppressed compared to the control group, whereas in the ASM-treated group, the inhibitory effect was observed. There wasn't.
In addition, the fairy compound was treated with tobacco (Nicotiana benthamiana species) in the same manner as in Example 6, and immediately after that, Pcc was inoculated, and Pc inoculation 0.5, 1 and 3 hours after the protective response The expression of genes rbohB, HSR201 and SIPK was examined. The results are shown in Tables 12-14. In the AHX-treated group, the expression level of the defense response gene tended to increase from an early stage as compared with the ASM-treated group.

Example 12: Experiment for measuring expression level of defense response gene 100 μL of distilled water or fairy compound (5 mM AHX) was injected into tobacco (Nicotiana benthamiana species) leaves. Three hours later, 10 μL of a Pcc suspension (10 ⁸ cfu / mL) was injected into the same part of the leaf, and allowed to stand under high humidity. In the same manner as in Example 6, the expression of the defense response gene rbohD was examined 5 minutes before, 5 minutes and 30 minutes after the inoculation of Pcc. The results are shown in Table 15. In the AHX-treated group, it was found that the increase in the expression level of the rbohD gene involved in the production of reactive oxygen species started before Pcc inoculation. This suggests a priming state in preparation for the pathogen response.

Example 13: Inoculation experiment with hydroponics Chingensai 3 days after sowing, Chingensai was hydroponically cultivated for 12 days. A fairy compound (ICA) was added to the culture solution to a concentration of 100 μM. In the control group, ICA was not added. Seven days later, 10 μL of a Pcc suspension (OD ₆₀₀ = 0.3) was injected and inoculated on the axis of the leaf of a plover. 24 hours later, the length of the lesion was measured and the length of the lesion was measured. As a result, it was 6.8 cm on average in the control group, whereas it was reduced to 4.3 cm on average in Chingsai that was cultivated in the culture solution added with AHX. The average area of the lesion site was 73.7% of the control group. From the above results, the disease suppression effect of the fairy compound was confirmed.

Claims

A plant disease control agent comprising at least one compound selected from the group consisting of 2-azahypoxanthine, 2-aza-8-oxohypoxanthine and imidazole-4-carboxamide.
The plant disease control agent according to claim 1, comprising 2-azahypoxanthine.
The plant disease control agent according to claim 1, comprising 2-aza-8-oxohypoxanthine.
The plant disease control agent according to claim 1, comprising imidazole-4-carboxyamide.
A method for controlling plant diseases, which comprises applying to a plant at least one compound selected from the group consisting of 2-azahypoxanthine, 2-aza-8-oxohypoxanthine and imidazole-4-carboxamide.
6. The method for controlling plant diseases according to claim 5, wherein 2-azahypoxanthine is applied to plants.
The method for controlling plant diseases according to claim 5, wherein 2-aza-8-oxohypoxanthine is applied to plants.
The method for controlling plant diseases according to claim 5, wherein imidazole-4-carboxamide is applied to plants.