JP7572251B2 - Control agent for bacterial diseases of agricultural and horticultural plants - Google Patents

Description

The present invention relates to a control agent and a control method for bacterial diseases of agricultural and horticultural plants. More specifically, the present invention relates to a control agent and a control method that can preventively or therapeutically reduce diseases of agricultural and horticultural plants caused by bacteria.

Agricultural and horticultural plants, such as agricultural produce, can suffer from diseases caused by pests. These pests can be classified into mold (fungi, filamentous fungi), bacteria, viruses, insect pests, etc.

Examples of diseases caused by mold growth include powdery mildew, gray mold, and downy mildew. Mold fungi themselves are naturally found in soil and are necessary microorganisms, but if they grow too much they can cause disease. Fungicides or fungicides are used to prevent diseases caused by mold.

On the other hand, examples of diseases caused by bacterial infection include yellowing disease, wilt disease, necrotic mosaic disease, bacterial wilt, soft rot, halo blight, and brown stripe disease. Bacteria cannot invade vegetables on their own, and are said to be transmitted by insects such as stink bugs, aphids, and whiteflies. It is also said that bacteria carried by rain or wind can enter wounds in horticultural plants and cause infection.
Bactericides are used to control diseases caused by bacteria. However, fungicides or fungicides used to control diseases caused by mold are often said to be ineffective or only weakly effective in controlling diseases caused by bacteria or viruses due to differences in cell structure.

There are not many types of bactericides, and there is a need to develop agents to control diseases caused by bacteria.
For example, Patent Document 1 discloses an insecticidal, acaricidal, nematocidal, molluscicidal, fungicidal or bactericidal composition containing a first active ingredient compound I and a second active ingredient compound II. Patent Document 1 discloses a number of compounds as the second active ingredient compound II. It shows picarbutrazox as an example of an active ingredient group L among the second active ingredient compounds II. However, Patent Document 1 does not disclose the meaning of the active ingredient group L, and does not teach whether picarbutrazox itself has a bactericidal (bactericidal) effect.

Picarburazox is a known fungicide. Although the mechanism of action of picarbutrazox is unknown, it is believed to exert its fungicidal effect by inhibiting hyphae growth.
For example, Patent Document 2 discloses a tetrazoyloxime derivative and an agricultural chemical containing the same as an active ingredient. Patent Document 2 discloses many examples of tetrazoyloxime derivatives. One of them is shown to be picarbutrazox (compound number (13)-8). According to Patent Document 2, picarbutrazox appears to have a control effect against grape downy mildew (filamentous fungus) and tomato Phytophthora infestans (filamentous fungus).

Non-patent literature 1 and 2 state that picarbutrazox shows excellent efficacy against diseases caused by oomycetes. Oomycetes are a group of fungi that produce oospores by sexual reproduction using archegonia and antheridia, and appear to include the orders Chytridales, Saprolegnia, Sclerotiales, and Commelinoides.

WO2016/002790A JP 2003-137875 A

Kobori et al., "The Road to Picarburazox," Agricultural Chemicals Age, No. 199 (2018), pp. 14-19 Kuwahara, "Characteristics of the Fungicide Picarburazox," Plant Protection, Vol. 72, No. 3 (2018), p. 138

The objective of the present invention is to provide a control agent and a control method that can preventively or therapeutically reduce diseases of agricultural and horticultural plants caused by bacteria.

As a result of our investigations to solve the above problems, we have completed the present invention, which includes the following aspects:

[1] An agent for controlling bacterial diseases of agricultural and horticultural plants, comprising picarbutrazox.
[2] A method for controlling a bacterial disease in an agricultural or horticultural plant, comprising applying the control agent according to [1].
[3] A control agent for bacterial diseases of Chinese cabbage or turfgrass, which contains picarbutrazox.
[4] A control agent for at least one bacterial disease selected from the group consisting of soft rot, halo blight and brown stripe, which contains picarbutrazox.

The control agent of the present invention has the effect of preventively or therapeutically reducing diseases of horticultural plants caused by bacteria. According to the control method of the present invention, diseases of horticultural plants caused by bacteria can be preventively or therapeutically reduced. Note that "can preventively reduce" means that when the control agent of the present invention is applied to an agricultural or horticultural plant before it is infected with bacteria, even if the plant is subsequently infected with bacteria, the disease caused by the bacteria can be reduced. "Can be therapeutically reduced" means that when the control agent of the present invention is applied to an agricultural or horticultural plant that has already been infected with bacteria, the disease caused by the bacteria can be reduced or the progression of the disease can be delayed.

The control agent of the present invention contains picarbutrazox.
Picarbtrazox is a compound represented by formula (I) (tert-butyl (6-{[(Z)-(1-methyl-1H-5-tetrazolyl)(phenyl)methylene]aminooxymethyl}-2-pyridyl)carbamate [CAS number 500207-04-5]).
Picarbutrazox is usually provided as a white crystalline powder. Examples of products containing picarubutrazox include Quintect (registered trademark) water dispersible granule (20% content, manufactured by Nippon Soda Co., Ltd.), Pisiloc (registered trademark) flowable (5% content, manufactured by Nippon Soda Co., Ltd.), and Naefine (registered trademark) dust (0.7% content, manufactured by Nippon Soda Co., Ltd.).

The control agent of the present invention may be the active ingredient of picarubutrazox itself or a formulation using the active ingredient of picarubutrazox, or it may be a product provided containing picarubutrazox or a formulation using the product.

The formulation can be in any form that is commonly used for agricultural and horticultural chemicals. Examples of formulations include dusts (DP, Dustable Powder), wattable powders (WP, Wattable Powder), emulsifiable concentrates (EC, Emulsifiable Concentrates), flowables (FL, Flowable), suspension concentrates (SC, Suspension Concentrates), water soluble powders (SP, Water Soluble Powder), water dispersible granules (WG, Water Dispersible Granules), tablets (Tablets), granules (GR, Granules), SE (Suspo Emulsions), OD (Oil Dispersions), and EW (Emulsion oil in water).

The formulation is not particularly limited by the technique or procedure, and can be carried out by known techniques and procedures.
In the formulation, secondary formulation materials such as carriers, solvents, adjuvants, and additives; and other agricultural and horticultural ingredients such as fungicides, insecticides, miticides, nematicides, soil pesticides, anthelmintics, herbicides, plant growth regulators, and fertilizers may be contained in the formulation.

There are no particular limitations on the carriers, solvents, and auxiliary agents that may be included in the formulation, so long as they do not impede the objectives of the present invention. Specific examples of carriers and auxiliary agents are those listed in WO03/016303A and described in the present specification. As the solvent, water or an organic solvent may be used. There are no particular limitations on the mass of the carrier or auxiliary agent when included in the formulation, so long as they do not impede the objectives of the present invention.

Examples of additives that can be included in the formulation include surfactants, dispersants, antioxidants, colorants, lubricants, UV absorbers, antistatic agents, preservatives, pH adjusters, defoamers, specific gravity adjusters, drift inhibitors, blending improvers, moisturizers, spreaders, adhesives, chelating agents, and fragrances. Specific examples of surfactants are those listed in WO2019/221089A and described in the present specification. There are no particular limitations on the mass of each additive when included in the formulation, as long as it does not impede the objectives of the present invention.

There are no particular limitations on the fungicides, insecticides, acaricides, nematicides, soil pesticides, anthelmintics, herbicides, plant growth regulators and fertilizers that may be contained in the formulation, so long as they do not impede the object of the present invention. The mass of these substances when contained in the formulation is not particularly limited, but is preferably 1/1000 to 1000/1, more preferably 1/100 to 100/1, relative to the mass of picarubutrazox.
Specific examples of fungicides, insecticides, acaricides, nematicides and soil pesticides are as described herein with reference to those listed in WO2009/119072A. Specific examples of herbicides (herbicidal active ingredients) are as described herein with reference to those listed in WO2019/221089A.

The method for controlling bacterial diseases in agricultural and horticultural plants of the present invention includes applying the control agent of the present invention. The target of application is a plant body (leaves, stems, stalks, flowers, buds, fruits, seeds, sprouts, roots, tubers, tuberous roots, shoots, cuttings, etc.), soil, or hydroponic land, etc.

In the method of controlling bacterial diseases in agricultural and horticultural plants of the present invention, the control agent of the present invention may be applied as is or may be applied after diluting with water or the like, depending on the formulation. In the method of controlling bacterial diseases in agricultural and horticultural plants of the present invention, the control agent of the present invention may be applied in combination or in mixture with other agricultural and horticultural agents.

In the case of wettable powders, emulsifiable concentrates, or flowable preparations, they can be diluted with water to a desired concentration and applied in the form of a suspension or emulsion.
In the case of granules or dust, they can be applied as they are. Granules or dusts can be preferably used for seed treatment, foliage application, soil application or water surface application.

The control agent of the present invention may be applied to the cultivation soil before or after planting the plants.

The control agent of the present invention can be applied to soil or water surface so that the amount of picabutrazox is 0.1 g or more per hectare.

Seed treatment with the control agent of the present invention can be carried out so that the amount of Picarburazox is 0.1 g or more per 100 kg of seed weight. Seed treatment can be carried out, for example, by coating or dusting the seeds or tubers with the control agent of the present invention, or by immersing the seeds or tubers in the control agent of the present invention. A method of immersing the roots of plant seedlings in the control agent of the present invention can also be adopted.

Foliage treatment with the control agent of the present invention can be carried out so that the amount of picabutrazox is 0.1 g or more per hectare.

The control agent of the present invention can be sprayed using a spray gun, a chemical applicator, an unmanned aerial vehicle (drone, radio-controlled helicopter, radio-controlled airplane, etc.), a manned aerial vehicle (helicopter, light aircraft, etc.), a blower (blower, etc.), etc. The amount of the control agent of the present invention to be sprayed can be set appropriately depending on weather conditions, application time, application method, application equipment, etc., and can be set, for example, to an amount of picarubutrazox of preferably 1 to 500,000 g, more preferably 10 to 100,000 g, and even more preferably 100 to 10,000 g per 10 ares.

Examples of bacterial diseases that can be controlled by the control agent and control method of the present invention include:
Bacterial wilt disease caused by bacterial wilt bacteria (Ralstonia solanacearum, etc.) (tomato, strawberry, turnip, pumpkin, cucumber, perilla, potato, chrysanthemum, radish, chili pepper, eggplant, bell pepper, etc.)
Soft rot caused by rod-shaped bacteria (Erwinia carotovora subsp. carotovora, Pectobacterium carotovorum, etc.) (turnip, cabbage, cucumber, taro, potato, celery, radish, onion, pepper, tomato, eggplant, Chinese chive, carrot, Chinese cabbage, parsley, bell pepper, broccoli, scallion, lettuce, etc.)
Scab (potato) caused by actinomycetes (e.g., Streptomyces spp.);
Brown stripe disease (rice, turfgrass, etc.) caused by bacteria (Acidovorax avenae subsp. avenae, etc.)
Halo blight (turfgrass, etc.) caused by halo blight bacteria (Pseudomonas syringae pv. Atropurprea, etc.),
Leaf burn (such as on beans) caused by rod-shaped bacteria (such as Xanthomonas axonopodis pv. Glycines)
Bacterial leaf blight (turfgrass, etc.) caused by bacteria (Xanthomonas campestris pv. graminis = Xanthomonas translucens, etc.)
Sheath rot [sheath brown spot] (turfgrass, etc.) caused by bacteria (Pseudomonas fuscovaginae, etc.)
Brown stripe disease (turfgrass, etc.) caused by bacteria (Acidovolax avenae supsp. Avenae, etc.)
Bacterial foot blight (Bacterial foot blight) caused by bacteria (Burkholderia plantarii, etc.) (turfgrass, etc.)
Leaf chlorosis [milky leaf] caused by bacteria (lawn grass, etc.)
Bacterial spot disease (cucumber, soybean, lettuce, pepper, etc.) caused by rod-shaped bacteria (Pseudomonas syringae pv. lachrymans, etc.)
The plants in parentheses are examples of the target agricultural and horticultural plants.

The agricultural and horticultural plants that can be targeted by the control agent and control method of the present invention are not particularly limited as long as they are capable of developing diseases caused by bacteria. For example,
Plants of the Solanaceae family, such as tomato (Solanum lycopersicum), eggplant (Solanum melongena), potato (Solanum tuberosum), pepper (Capsicum annuum), and sweet pepper;
Plants of the Brassicaceae family, such as radish (Raphanus sativus), Chinese cabbage (Brassica rapa var. pekinensis), cabbage (Brassica oleracea var. capitata), turnip (Brassica rapa var. glabra), broccoli (Brassica oleracea var. italica), Japanese mustard spinach (Brassica rapa var. perviridis), and cauliflower (Brassica oleracea var. botrytis);
Plants of the Cucurbitaceae family, such as cucumber (Cucumis sativus L.), pumpkin (Cucurbita), watermelon, and zucchini;
Plants of the Fabaceae family (Fabaceae syn. Leguminosae), such as soybean (Glycine max), dry beans, and kidney beans;
Plants of the Rosaceae family, such as apples, pears, peaches, roses, and strawberries;
Plants of the Lamiaceae family, such as Perilla frutescens var. crispa;
Plants of the Asteraceae family (Asterales), such as Glebionis coronaria, Lactuca sativa, C. morifolium, and H. annuus;
Plants of the Araceae family, such as taro (Colocasia esculenta (L.) Schott);
Plants of the Apiaceae family, such as celery (Apium graveolens var. dulce), carrot (Daucus carota subsp. sativus), parsley (Petroselinum crispum), and honeywort (Cryptotaenia canadensis);
Plants of the Amaryllidaceae family, such as onion (Allium cepa), leek (Allium fistulosum L), Chinese chive (Allium tuberosum), scallion (Allium chinense), and scallion (Allium cepa var. proliferum);
Plants of the Malvaceae family, such as okra (Abelmoschus esculentus);
Asparagaceae plants, such as Asparagus;
Plants of the Amaranthaceae family, such as sugar beet (Beta vulgaris ssp. vulgaris) and spinach;
Plants of the Zingiberaceae family, such as ginger and myoga;
Plants of the Rutaceae family, such as Unshu mandarin oranges;
Plants of the Vitaceae family, such as grapes;
Plants of the Musaceae family, such as bananas;
Plants of the Ebenaceae family, such as persimmons;
Plants of the Gramineae family, such as oats (Avena sativa), pearl barley (Coix lacryma-jobi var. ma-yuen), orchard grass (Dactylis glomerata), barley (Hordeum vulgare), rice (Oryza sativa), timothy (Phleum pratense), sugarcane (Saccharum officinarum), rye (Secale cereale), foxtail millet (Setaria italica), bread wheat (Triticum aestivum), corn (Zea mays), and turfgrass (Zoysia spp.);
Some examples include:
The agricultural and horticultural plants that can be targeted by the control agent and control method of the present invention may be improved varieties or varieties of these plants, cultivated varieties, and even mutants, hybrids, and genetically modified organisms (GMOs).

The present invention will be explained in more detail below with reference to test examples. However, the present invention is not limited to these.

The bacteria used in this test example are as follows:
Bacteria 1: Pectobacterium carotovorum (soft rot fungus)
Bacteria 2: Pseudomonas syringae
Bacteria 3: Acidovorax avenae (brown streak fungus)

Test Example 1 (Evaluation test of Chinese cabbage soft rot)
A commercially available Pisiloc flowable (containing 5% picarbutorazox, manufactured by Nippon Soda Co., Ltd.) was diluted 1000 times with water to prepare drug solution 1.
In the greenhouse, 14 Chinese cabbage plants (variety: Musou) were transplanted per plot (4.2 ^m2 ). Six plots were set up with 0.5 m between each plot. Three of the six plots were test plots (plots 1 to 3) and the remaining three plots were untreated plots (plots 4 to 6).
The test plots were sprayed with 833 ml of solution 1 per plot. Nothing was done to the untreated plots.
Four days after spraying of Chemical Solution 1, two diseased Chinese cabbage pieces (Chinese cabbage sprayed with Bacteria 1 and cut into pieces of about 5 cm square) were placed on both ends of each plot.
Seven days after the spraying of Chemical Solution 1, 1000 ml of a suspension of Bacteria 1 at 1000 cells/ml was sprayed on each of the test plot and the untreated plot.
Eight days after spraying of Chemical Solution 1, the number of plants was counted using the following evaluation indexes. The average disease severity was calculated from the number of plants in the three plots using formula (A). The control value was calculated using formula (B).
The results are shown in Table 1. It can be seen that the control agent of the present invention has an effect of preventively reducing soft rot of Chinese cabbage.

Average disease severity [%] = (number of stocks with index 1 x 1 + number of stocks with index 2 x 2 + number of stocks with index 3 x 3)
/ (Number of stocks surveyed x 3) x 100 (A)

Control value [%] = 100 - [(average disease severity in the test area)
/ (average disease severity in untreated plots) × 100) (B)

Evaluation index for Chinese cabbage soft rot:
Index 0: No lesions Index 1: Only some of the outer leaves are affected Index 2: Some of the outer leaves and head leaves are affected Index 3: Most of the head leaves are affected or more damaged

Test Example 2 (Pot evaluation test for turf grass blight)
A commercially available Quintect water dispersible granule (containing 20% picarbutrazox, manufactured by Nippon Soda Co., Ltd.) was diluted 200 times with water to prepare drug solution 2.
Turfgrass (variety: bentgrass, 18 days after sowing) was transplanted into a pot (length 7 cm x width 7 cm x height 3 cm). Four of these were prepared and placed in a greenhouse. Two of the four were test pots (pots 1 and 2) and the remaining two were untreated pots (pots 3 and 4).
Using scissors to which 100,000,000 bacteria/ml (hawt blight fungus) had been attached, the grass in each pot was cut so that the grass was about 1 cm long, and the bacteria was attached to the grass. Each pot was covered with a vinyl sheet.
After two days had passed, the two test pots were placed in a 1 ^m2 frame (1 m long and 1 m wide), and 200 ml of Chemical Solution 2 was sprayed uniformly within the frame. Nothing was done to the untreated pots.
Seven days after the application of Chemical Solution 2, the number of lesions having a maximum length of 2 mm or more was counted (hereinafter, this count number is referred to as the number of diseased individuals). The control value was calculated using formula (C).
The results are shown in Table 2. It is clear that the control agent of the present invention has an effect of curatively reducing hay blight.

Control value [%] = 100 - [(number of diseased individuals in test pots)
/ (number of diseased plants in untreated pots)] × 100 (C)

Test Example 3 (Pot evaluation test for turfgrass brown stripe disease)
The control value was calculated in the same manner as in Test Example 1, except that Bacterium 3 (Brown Stripe Fungus) was used instead of Bacterium 2 (Halophyllum rot fungus).
The results are shown in Table 3. It is clear that the control agent of the present invention has an effect of curatively reducing turf brown stripe disease.

Test Example 4 (Field evaluation test of turfgrass brown stripe disease)
A commercially available Quintect water dispersible granule (containing 20% picarbutrazox, manufactured by Nippon Soda Co., Ltd.) was diluted 1000 times with water to prepare chemical solution 3.
A turfgrass field (bentgrass variety) was divided into six plots, each 1 m x 1 m in size. Of the six plots, three were test plots (plots 1 to 3) and the remaining three were untreated plots (plots 4 to 6).
500 ml of solution 3 was sprayed onto each test plot.
One day after spraying of the chemical solution 3, the turfgrass was cut with a lawnmower to a height of 4 mm across each plot. Next, three inoculation plots measuring 20 cm x 20 cm were set up in each of plots 1 to 6. 20 ml of a suspension of bacteria 3 (brown stripe fungus) at 10,000,000 cells/ml was uniformly sprayed onto each inoculation plot to inoculate the turfgrass with bacteria 3. The inoculation plots were covered with white cheesecloth (white light-shielding net or sunshade net) and left for two days.
Eleven days after spraying, the area of browned areas (symptoms of brown stripe disease [leaves turn brown along the veins]) that occurred in each section was measured, and the percentage of the area of browned areas in one section was calculated. This value is called the diseased area rate (%). The control value was calculated using formula (D).
The results are shown in Table 4. It is clear that the control agent of the present invention has an effect of preventively reducing turf brown stripe.

Control value [%] = 100 - [(disease area rate in the test area)
/ (Disease area rate in untreated plot)] × 100 (D)

As described above, it can be seen that the control agent of the present invention has the effect of preventively or therapeutically reducing bacterial diseases in agricultural and horticultural plants, and that the control method of the present invention can preventively or therapeutically reduce bacterial diseases in agricultural and horticultural plants.

Claims (4)

A control agent for halo blight in horticultural plants containing picarbutrazox. Contains picarbutrazox,
does not contain any of imidacloprid and its salts, triflumizole and its salts, spinosad and its salts, hydroxyisoxazole and its salts, thiophanate methyl and its salts, tricyclazole and its salts, clothianidin and its salts, benomyl and its salts, acetamiprid and its salts, picoxystrobin, flutolanil, isoprothiolane and basic copper sulfate,
An agent for controlling at least one bacterial disease selected from the group consisting of soft rot, halo blight and brown stripe in agricultural and horticultural plants. A method for controlling halo blight, comprising applying the control agent according to claim 1 to an agricultural or horticultural plant. A method for controlling at least one bacterial disease selected from the group consisting of soft rot, halo blight and brown stripe, which comprises applying the control agent according to claim 2 to agricultural and horticultural plants.