JPH07233020A - Agent for controlling eleocharis kuroguwai and method for controlling the same - Google Patents

Abstract

PURPOSE:To provide a strain selected from Epicoccosorus nematosporus JTK-003, etc., exhibiting a high controlling effect against Eleocharis kuroguwai, capable of withering not only stems and leave but also subterranean stems, and extremely useful on industry. CONSTITUTION:A herbicide containing as an active ingredient a strain which belongs to the genus Epicoccosorus nematosporus selected from the group of Epicoccosorus nematosporus JTK-003 strain (FERM BP-4906), Epicoccosorus nematosporus JTK-028 strain (FERM BP-4907), Epicoccosorus nematosporus JTK-028 strain (FERM BP-4907), Epicoccosorus nematosporus JTK-029 strain (FERM BP-4908), Epicoccosorus nematosporus JTK-030 strain (FERM BP-4909), and Epicoccosorus nematosporus JTK-035 strain (FERM BP-4477) is sprayed on Eleocharis kuroguwai to control the Eleocharis kuroguwai. The herbicide is compounded with a microorganism which belongs to the Epicoccosorus nematosporus having an Eleocharis kuroguwai-controlling ability and a water-soluble viscous compound to obtain a herbicide composition for controlling the Eleocharis kuroguwai.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel strain belonging to the genus Epicoccocorus and a method for controlling kurogwai using the strain, and a herbicidal composition for kurogwai containing a viscous water-soluble compound and a microorganism belonging to the genus Epicoccocora. Regarding things.

[0002]

BACKGROUND OF THE INVENTION Paddy field weeds, kurogwai, are very difficult to control because they continue to grow for a long period of time after puddling and form many tubers in the autumn and become the source of the next year. For this reason, conventional chemical pesticides have not been able to achieve satisfactory control effects.

In recent years, due to the problem of environmental pollution due to heavy use of chemical pesticides, it has been desired to develop a weed control agent which does not rely on chemical pesticides and a method of using the same. As a method for controlling kurogwai without using chemical pesticides, for example, Japanese Patent Publication No. 59-59
The method described in Japanese Patent No. 084 is known. This method
This is a method of inoculating spores (conidia) of a strain belonging to Hyphomycetes to cause kurogwai, and thereby controlling kurogwai. It should be noted that the strain belonging to Hyphomycetes and the epicoccocorus nematosporus of the present invention are the same genus species.

[0004]

However, since the strains described in the above publications have low pathogenicity, a large amount of spores are required to obtain a sufficient control effect. Therefore, there is a problem that the production cost of the required medium and the like becomes high and the amount of the applied drug also becomes large. The object of the present invention is to solve the problem with conventional Krogwai control means using a microorganism belonging to the genus Epicoccocorus, specifically, a strain having a higher Krogwai control effect than a known strain, and belonging to the genus Epicoccocorus An object of the present invention is to provide a composition that enhances the effect of controlling kurogwai of microorganisms.

[0005]

[Means for Solving the Problems] The inventors of the present invention have made extensive studies in order to solve the above problems, and as a result, among microorganisms belonging to the genus Epicoccocora, have a much higher Krogwai control effect than known strains. Succeeded in isolating the strain. Further, they have found that water-soluble compounds having viscosity significantly enhance the Krogwai control effect of microorganisms belonging to the genus Epicoccocora, and completed the present invention.

That is, the present invention relates to the Epicoccus soras nematosporus JTK-003 strain, the epicoccus soras nematosporus JTK-028 strain, the epicoccus soras nematosporus JTK-029 strain, the epicoccus soras nematosporus JTK-030 strain, and the epicoccus soras.
It is a strain belonging to the genus Epicoccocorus having a Krogwai control ability, which is selected from the group consisting of Nematosporus K-035 strain. Further, the present invention is a method for controlling kulogwai, which comprises applying a herbicide containing the above strain as an active ingredient to kulogwai.

Further, the present invention is a herbicidal composition for kurogwai, which contains a microorganism belonging to the genus Epicoccocorus having an ability to control kurogwai and a water-soluble compound having viscosity. Here, the above strains can be used as the microorganisms belonging to the genus Epicoccocora that have the ability to control kurogwai. Further, as the water-soluble compounds having viscosity, gum arabic, okra extract, carob bean gum, gati gum, soluble starch, guar gum, corn steep liquor, corn starch, troll aoi, potato starch, pectin, moroheiya,
At least one selected from the group consisting of alginic acid, carrageenan, agar, xanthan gum, pullulan, curdlan, yeast extract, dextran, alginate, sodium carboxymethylcellulose, glycerin, D-sorbit, polyacrylate, polyethylene glycol, and methylcellulose. One kind can be used.

The present invention will be described in detail below. The present inventors collected diseased kurogwai from all over Japan, and isolated pathogenic bacteria belonging to the genus Epicoccus solas from the lesions. Then, the isolated pathogenic fungus is inoculated into a healthy kurogwai, and from among them, the JTK-003 strain, J
TK-028 strain, JTK-029 strain, JTK-030 strain
Strain and K-035 strain were selected. The mycological properties of these strains are as follows.

(1) Conidia The size of conidia of the strain is as follows. K-035 strain: 55-75 μm × 3.8-4.5 μm JTK-003 strain: 50-80 μm × 3.0-5.0 μm
m JTK-028 strain: 44-72 μm × 3.0-5.0 μm
m JTK-029 strain: 23-60 μm × 3.0-5.0 μm
m JTK-030 strain: 50-70 μm × 3.0-5.0 μm
m In addition, the conidia of all the strains are nematodes or crescents from the curved shape of a single vesicle, and the color is colorless.

(2) Shape of colonies On potato-sucrose agar medium, spherical and fleshy conidial masses were formed in the center of the colonies of all strains, and spherical and dark brown structures were formed in the periphery. Covered with white aerial hyphae. Later, a flesh-colored conidial mass is formed on the peripheral black-brown structure.

(3) Culture characteristics Strains belonging to the known genus Epicoccocora (FERM P-10000) precultured on potato sucrose agar medium
Strain), JTK-003 strain, JTK-028 strain, J strain
The TK-029 strain, JTK-030 strain, and K-035 strain microflora were cut into a cylindrical shape having a diameter of 5 mm with a sterilized cork borer, and this section was cut into oatmeal agar medium (OM
A), oatmeal sucrose agar (OMSA), cornmeal agar (CMA), lima bean agar (LB)
A), potato sucrose agar medium (PDA), V-8 juice agar medium (V8A), or Tuapeck-Dox agar medium (Czapek-Dox). After culturing at 25 ° C. for 6 days, the diameter of each flora was measured. Each test was repeated 3 times and the average is shown in the table.

[0012]

[Table 1] The unit of numerical values in the table is millimeter.

The above-mentioned mycological properties are referred to as "agriculture and horticulture".
A comparative study was carried out with the mycological properties of Epicoccocorus nematosporus described in Vol. 63, No. 6 (1988), p. 63. As a result of the examination, since the morphology of the conidia of both is the same, the above JTK-003 strain and JTK-028
Strain, JTK-029 strain, JTK-030 strain, and K-0
All of the 35 strains were identified as strains belonging to Epicoccosora nematosporus.

These strains were distributed to the Institute of Biotechnology, Institute of Industrial Science and Technology, and JTK-003 strain was FER.
As M BP-4906 (deposit date December 5, 1994), JTK-028 strain is FERM BP-4907 (deposit date December 5, 1994), and JTK-029 strain is F
As ERM BP-4908 (deposit date December 5, 1994), JTK-030 strain is FERM BP-4909.
(Deposit date December 5, 1994), K-035 strain is F
ERM BP-4477 (Deposit date November 25, 1993)
Sun) as a deposit.

When the microorganism of the present invention is not used with water-soluble compounds having viscosity, the above-mentioned JTK-003 is used.
Strain, JTK-028 strain, JTK-029 strain, JTK-0
The strains are limited to 30 strains and K-035 strains, but when used together with water-soluble compounds having viscosity, the strains are not limited to the above-mentioned strains, and any strains belonging to the genus Epicoccocorus and having a Krogwai control ability can be used. It may be one.

No special method is required for culturing the microorganism belonging to the genus Epicococcus, and a usual method for culturing the microorganism can be used. As the medium, both synthetic medium and natural medium can be used as long as they appropriately contain assimilable carbon sources, nitrogen sources, inorganic substances and necessary growth promoting substances. Specific examples of the medium include oatmeal agar medium, oatmeal sucrose agar medium, cornmeal agar medium, lima bean agar medium, potato sucrose agar medium, V-8 juice agar medium, Tuapeck-Dox agar medium and the like. In culturing, the temperature is 15 to 33 ° C., preferably 23 to 25 ° C., p
It is desirable to maintain H at 3-10, preferably 5-7. When culturing is carried out under the above conditions for about 3 to 14 days, a sufficient amount of spores are formed on the surface of the medium.

The composition of the present invention uses microbial cells, preferably spores produced by microorganisms.
Spores can be collected by pouring sterile water onto the medium and scraping the surface of the medium with a brush. By this method, about 1 × 10 ⁷ to 1 × 10 ⁹ per plate having a diameter of 9 cm
Individual spores can be obtained.

The viscous water-soluble compounds include, for example, gum arabic, okra extract, carob bean gum, ghatti gum, soluble starch, guar gum, corn steep liquor, corn starch, troll aoi, potato starch, pectin, and moroheiya extract. Plant-derived, alginic acid, carrageenan, agar-derived seaweed-derived, xanthan gum, pullulan, curdlan, yeast extract, dextran-derived microorganisms, sodium alginate and calcium alginate alginates, carboxymethylcellulose sodium , Polyglycerin, D-sorbit, polyacrylic acid salts such as sodium polyacrylate, synthetic compounds such as polyethylene glycol and methyl cellulose can be used. All of these substances enhance the Krogwai control effect of microorganisms belonging to the genus Epicoccocorus,
In particular, the sodium or calcium salt of alginic acid, yeast extract, soluble starch, agar, glycerin, xanthan gum, D-sorbit, corn starch, potato starch, the potentiating effect of potato, further agar or D-sorbit of the potentiating effect. Especially strong. In the composition of the present invention, these water-soluble compounds having viscosity can be used alone, or a plurality of substances can be used in combination.

The composition ratio between the microorganism and the water-soluble compound in the composition varies greatly depending on whether spores are used as the microorganism or the bacterium itself, and the spores vary depending on the kind of the water-soluble compound used. In the case of using, the microbial spores are 10 ⁵ to ¹⁰ 10 in 1 L of the composition,
The water-soluble compounds are preferably prepared so as to have a weight of 0.5 to 100 g.

When the composition of the present invention is used as a herbicide, it is usually used by suspending the composition in water. At this time, a surfactant and a mineral powder can be added if necessary. The concentration of the microorganism in the suspended state is preferably 10 ² to 10 ⁷ spores / ml. Further, the concentration of the water-soluble compounds is 0.01 to 20% by weight, preferably 1 to 10 in the yeast extract.
% By weight, 0.01-20% by weight for soluble starch, preferably 5-15% by weight, 0.001-1% by weight for agar or sodium alginate, preferably 0.05-
0.5% by weight, 0.01 to 20% by weight of glycerin,
It is preferably 0.5 to 5% by weight, and xanthan gum has a density of 0.
001 to 1% by weight, preferably 0.01 to 0.1% by weight, D-sorbit is 0.01 to 20% by weight, preferably 1 to 20% by weight, corn starch is 0.0.
1 to 10% by weight, preferably 0.1 to 1% by weight, and potato starch is 0.01 to 10% by weight, preferably 0.1 to 10% by weight.
1% by weight is desirable.

When the composition of the present invention is applied to an actual field, the amount of spores of the microorganism is 10 ⁷ to 10 ⁷ fields.
Sprinkle 10 ¹² water-soluble compounds to 0.1 to 20 kg. The composition of the present invention is targeted for weeding of kurogwai and its related species. Examples of the closely related species of kurogwai mentioned here include Inu firefly, Hime firefly, Taiwan yamai, and the like.

[0022]

【Example】

[Example 1] Measurement of Klogwai control effect of strains belonging to the genus Epicoccocorus JTK-003, J of the present invention by the method described below.
TK-028 strain, JTK-029 strain, JTK-030 strain
Strains, and the strain K-035 and the strain described in Japanese Examined Patent Publication No. 5-59084 (deposition number FERM P-10000) were examined for their ability to control Klogwai. 10,000 with paddy soil
Kuroguy was grown in a greenhouse for about 1 month in a pot of 1 are and used for a control effect test. The strain of the present invention and F
Each of the ERM P-10000 strains was cultured on a potato sucrose agar medium for 2 weeks to form spores. The spores were suspended in sterilized water, adjusted to the concentrations shown in the table, and used as the inoculum.

This spore suspension was spray-inoculated into Klogwai with 3 ml of spore suspension per pot using a sprayer, and then placed in a moist chamber kept at 25 ° C. and 100% humidity for 24 hours. Three pots were inoculated for each treatment area. Then, it was placed in a greenhouse at 28 ° C during the day and 25 ° C at night, and 4 weeks later, the control effect was examined. The control effect was determined by measuring the degree of disease on each inoculated foliage. The degree of disease is 0 asymptomatic,
When the ratio of lesion length to Kurowai stem and leaf length is less than 25% 1, 25% to less than 50% 2, 50% to less than 75% 3, 75% to less than 100% 4, complete foliage death It is the average value of the inoculated foliage in one pot where 5 is 5.

[0024]

[Table 2] The degree of disease is the average value of 3 pots.

All strains were FERM P-10000.
The control effect was higher than that of the strain. Taking the K-035 strain as an example, 10 ⁵ spores of this strain and FERM P
Since the control effect of 10 ⁷ spores / ml of -10000 strain is almost the same, it is possible to reduce the required number of spores to about 1/100 by using this strain. In other words, the K-035 strain is about 100 times more virulent than the FERM P-10000 strain.

[Example 2] Measurement of Krogwai control effect of a herbicidal composition containing a microorganism belonging to the genus Epicoccocorthus (1) Preparation of microbial spores Epicoccocorus nematosporus K on PDA medium
When the −035 strain was transplanted and allowed to stand at 25 ° C. under a bright condition for about 10 days, a large amount of spores were formed on the surface of the medium. Sterile water was poured onto this medium, and the surface of the medium was scraped off with a brush to collect spores. Spores are approximately 1 × 10 ⁸ to 1 ×
About 10 ⁹ could be collected.

(2) Krogwai Control Effect Test Combining Bacteria and Water-Soluble Compounds Three Krogwai were grown in 1 / 10,000 are pots filled with paddy soil, and the control effect test was conducted after one month had passed. Using. The spores recovered by the above method were suspended in a water-soluble compound solution adjusted to a desired concentration. The spore concentration of the microorganism was adjusted to 1 × 10 ⁶ cells / ml. This spore suspension was sprayed with a sprayer to the extent that Klogwai was evenly and uniformly wet, and then placed in a moist chamber kept at 25 ° C. and 100% humidity for 24 hours. After that, 30 ° C during the day, 25 ° C at night,
It was placed in a greenhouse with a humidity of 60% for 2 weeks. The types and concentrations of the water-soluble compounds used are as follows.

─────────────────────────────── Water-soluble compounds Concentration (wt%) ─────── ──────────────────────── Sodium alginate (Junsei Kagaku Co., Ltd.) 0.1 Yeast extract (DIFCO LABORATORIES) 5 Soluble starch (DIFCO LABORATORIES) 10 Agar (DIFCO LABORATORIES) 0.1 Glycerin (Wako Pure Chemical Industries, Ltd.) 1 Xanthan gum (SIGMA CHEMICAL CO.) 0.05 D-Sorbit (Niken Chemical Co., Ltd.) 10 Corn starch (Junsei Kagaku Co., Ltd.) 0.5 Potato starch (Wako Pure Chemical Industries, Ltd.) 0.5 ────────────────────────────────

2 after inoculating Kurogui with the microorganism
The control effect was determined after a week. The control effect of the drug was judged by investigating the degree of disease on the Kurowai stems and leaves and calculating the average value (repeated 4 times). The degree of severity is 0 for no disease, 1 for the proportion of lesion length to Kurowai stem and leaf length of less than 25%, 2 for 25% or more and less than 50%, 2, 50% or more for 75%
Less than was 3 and 75% or more and less than 100 was 4 and 5 was the case where the entire foliage was completely dead. When water-soluble compounds were added to the microorganism, the control group (K-03
A control effect higher than that of the 5 strains only) was obtained.

────────────────────── Water-soluble compounds Control effect ───────────────────── ─ Sodium alginate 1.4 Yeast extract 1.3 Soluble starch 1.5 Agar 2.9 Glycerin 1.6 Xanthan gum 1.1 D-Sorbit 2.2 Corn corn starch 1.7 Potato starch 1.5 Control (K- 035 bacteria only) 0.8 ─────────────────────

[0031]

【Example of use】

(Liquid preparation 1) A preserved epiconococcus nematosporus K-035 conidial concentrate was diluted and 2 × 10 ⁸ conidia and 0.2 agar were added to 200 ml of water.
Grams were suspended and a spore suspension was prepared. This spore suspension was uniformly sprayed on a field with an area of 1 m ² where crocodile grows. When the field was observed 4 weeks later, most of the crocodile disease was sick, and a considerable part of them were already dead.

(Liquid preparation 2) A preconserved conidial concentrate of Epicoccus soras nematosporus K-035 was diluted and 2 × 10 ⁸ conidia and 20 ml of D-sorbit were suspended in 180 ml of water. To prepare a spore suspension. Area 1 where this spore suspension grows
It was evenly applied to the m ² field. When the field was observed 4 weeks later, most of the crocodile disease was sick, and a considerable part of them were already dead.

(Wettable powder) 2 × 10 ⁸ dry conidia of Epicoccus soras nematosporus K-035 which had been powdered and stored in advance were resuspended in 200 ml of water, and 0.2 g of sodium alginate was further added. And spore suspension was prepared. This spore suspension was uniformly sprayed on a field with an area of 1 m ² where crocodile grows. When the field was observed 4 weeks later, most of the crocodile disease was sick, and a considerable part of them were already dead.

[0034]

INDUSTRIAL APPLICABILITY The strain belonging to the genus Epicoccocorus of the present invention is highly industrially useful because it shows a higher control effect against Kurowai and can kill not only the foliage but also the rhizome as compared with the conventionally known strains. Is. Also,
INDUSTRIAL APPLICABILITY The herbicidal composition of the present invention not only enhances the control effect of microorganisms belonging to the genus Epicoccocorus, but also brings about a suitable effect with respect to the time of expression of the control effect. That is, it takes at least about 3 weeks after inoculation of the strains belonging to the genus Epicoccus solas until the Krogwai controlling effect is exhibited,
The combined use with a water-soluble compound having viscosity can accelerate the development of the Kokuwai control effect. Also,
Since microorganisms are used, there is no need to worry about environmental pollution due to residual chemicals. Furthermore, when used in combination with water-soluble compounds, when used as liquids, wettable powders, etc., the dispersibility and suspension of bacteria will be reduced. It also has the effect of being maintained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mine Fujimori 6-2 Umegaoka, Aoba-ku, Yokohama-shi, Kanagawa Japan Tobacco Inc. Plant Development Laboratory Yokohama Center

Claims (6)

[Claims] 1. An Epococco soras nematosporus ( Ep
icoccosorus nematosporus ) JTK-003 strain, epicoccocorus nematosporus JTK-028 strain, epicoccocorus nematosporus JTK-029 strain, epicoccocorus nematosporus JTK-030 strain, and epicoccocorus nematosporus group No. 5 strain No. 0-3 selected from epicoccus soras nematosporus K-03. A strain belonging to the genus Epicoccocorus having. 2. A method for controlling kulogwai, which comprises applying a herbicide containing the strain according to claim 1 as an active ingredient to kulogwai. 3. A herbicidal composition for Kulogwai, which contains a microorganism belonging to the genus Epicoccocorus having kurogowai control ability and a water-soluble compound having viscosity. 4. Microorganisms belonging to the genus Epicoccocorus that have the ability to control kurogwai are epicoccus soras nematosporus JTK-003 strain, epicoccus soras nematosporus JTK-028 strain, epicoccosora nematosporus JTK-029 strain, epicoccus soras J and nematosporus J nematosporus T. The herbicidal composition for kurogowai according to claim 3, which is a strain selected from the group consisting of Epicoccus soras nematosporus K-035 strain. 5. The viscous water-soluble compounds are gum arabic, okra extract, carob bean gum, gati gum, soluble starch, guar gum, corn steep liquor, corn starch, troll aoi, potato starch, pectin, morohaya, alginic acid, carrageenan, Agar, xanthan gum, pullulan, curdlan, yeast extract, dextran, alginate,
Carboxymethylcellulose sodium, glycerin,
It is at least 1 sort (s) selected from the group which consists of D-sorbit, polyacrylate, polyethyleneglycol, and methylcellulose, It is characterized by the above-mentioned.
The herbicidal composition for Kulogwai as described. 6. The viscous water-soluble compound is at least one selected from the group consisting of alginate, yeast extract, soluble starch, agar, glycerin, xanthan gum, D-sorbit, corn starch, and potato starch. The herbicidal composition for kurogwai according to claim 3 or 4, wherein