JPH0912417A - Herbicidal composition and weed controlling method using the composition - Google Patents

Abstract

PURPOSE: To obtain a herbicidal composition produced by using a specific microorganism having weed-controlling action in combination with a specific herbicidal substance and capable of efficiently and quickly exterminating harmful weeds such as water chestnut which decreases the yield of crops. CONSTITUTION: This agent contains a microorganism belonging to the genus Epicoccosorus and having weed controlling action in combination with a sulfonylurea-type herbicidal substance. The microorganism is preferably those belonging to Epicoccosorus nematosporus, especially preferably Epicoccosorus nematosporus JTK-003 (FERM BP-4906), Epicoccosorus nematosporus JTK-028 (FERM BP-4907), etc. The sulfonylurea-type herbicidal substance is preferably a compound of formula I (R1 is group of formula II, formula III, etc.; R2 is group of formula IV, etc.). The concentration of the conidiospore of the microorganism is preferably 10<2> to 10<8> /mL and that of the sulfonylurea-type herbicidal substance is preferably 0.00001-1wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for efficiently and quickly controlling strong damaging weeds such as kurogwai, which causes a decrease in the yield of cultivated crops.

[0002]

_2. Description of the Related Art As a basic skeleton, --SO ₂ NHCONH--
The development of a sulfonylurea herbicide containing a compound having the following as an active ingredient was started by DuPont (Patent No. US-
5071469), it exhibits a high level of herbicidal activity even in a very small amount, is effective in both soil treatment and foliar treatment, has a wide range of herbicidal species, and controls most weeds except for Nobie, and is particularly effective for broadleaf weeds. That it has selectivity to gramineous crops, has a long duration of weed control,
It has excellent characteristics such as extremely low toxicity.

However, in the case of sulfonylurea herbicides, it may not be possible to obtain the desired herbicidal effect from the viewpoint of crop cultivation with respect to cultivated kurogwai, firefly, such as the firefly, etc. . In other words, when the sulfonylurea herbicide is applied to the well-grown Kurogwai, the growth is stopped, but the grass is not killed but remains.

On the other hand, in recent years, due to the problem of environmental pollution due to heavy use of chemical pesticides, development of a weed control agent which does not rely on chemical pesticides and a method of using the same has been desired. As a method for controlling kurogwai without using chemical pesticides, for example, Japanese Patent Publication No. 59-59
No. 084 is known. This method
A control method by inoculating spores (conidia) of a strain of a new genus of the class of Hyhomycetes isolated from diseased stems of Krogwai into Krogwai, causing the Krogwai to become diseased, thereby suppressing the growth and fertility of the Krogwai. is there. The strain of a new genus of the class Hyhomomycetes is the same genus as Epicoccosulus nematosporus of the present invention (Agriculture and Horticulture, Vol. 63, No. 6, No. 6, 1988).
3).

However, these controlling methods generally use a microorganism belonging to Epicoccocora nematosporus alone, and it took a long time for the controlling effect against Klogwai to be exhibited, and the controlling effect was not satisfactory. .

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems relating to weed control, and an object of the present invention is to provide a more effective means for controlling weeds. It is in.

[0007]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have applied microorganisms belonging to Epicoccus soras nematosporus and sulfonylurea herbicides, etc. to weeds. By doing so, they found that the control effect against weeds was synergistically improved, and the present invention was completed.

That is, the first aspect of the present invention is a herbicidal composition comprising a microorganism belonging to the genus Epicoccocora and having a weed control ability, and a sulfonylurea herbicidal substance as active ingredients. A second aspect of the present invention is a method of controlling weeds, which comprises applying the above-described herbicidal composition to weeds.

[0009] A third aspect of the present invention is that a weed which belongs to the genus Epicoccocorus and which contains, as an active ingredient, a microorganism having weed control ability, and a sulfonylurea herbicide are applied to the weed. It is a control method. Less than,
The present invention will be described in detail. First, the herbicidal composition of the present invention will be described.

In the present invention, "Epicococcolas genus"
Is the summary of proceedings of the meeting of the Japanese Society for Plant Pathology, page 27 (19
March 15, 1988) and "Agriculture and Horticulture" Vol. 63, No. 6 (1988), p. 63, Epicoccosorus.
Means "genus" including nematosporus gen. et sp. nov. The microorganism used in the present invention is not particularly limited as long as it is a microorganism belonging to the genus Epicoccocorus and having weed control ability, but a preferable strain is Epicoccoccus
Nematosporus JTK-003 strain, epicoccus soras
Nematosporus JTK-028 strain, Epicoccus soras
Nematosporus JTK-029 strain, Epicoccus soras
Examples thereof include Nematosporus JTK-030 strain and Epicoccus soras Nematosporus K-035 strain.

[0011] These strains have been deposited with the National Institute of Bioscience and Biotechnology at the National Institute of Advanced Industrial Science and Technology under the following numbers. Epicoccosolus nematosporus JTK-0
The deposit number of the 03 strains is FERM BP-4906 (Original deposit date January 1994
February 5), Epicococsolus nematosporus JTK
-028 strain is FERM BP-4907 (Original deposit date December 5, 1994)
Sun), Epicococsolus nematosporus JTK-02
Nine strains are FERM BP-4908 (originally deposited on December 5, 1994), and Epicoccosolus nematosporus JTK-030 strain is FE
RM BP-4909 (Deposited on December 5, 1994), Epicoccoculus nematosporus K-035 strain was FERM BP-4477
(Original deposit date: November 25, 1993).

These strains were isolated from diseased weeds, and their mycological properties are as follows. It is an aerobic bacterium, and on a potato sucrose agar medium, forms a spherical, flesh-colored conidium mass at the center of the colony and forms a spherical, black-brown structure at the periphery. Later, a flesh-colored conidium mass is formed on the peripheral black-brown structure. Also, white aerial hyphae may be seen. Conidia (conidia) are nematodes or crescents from the curved shape of a single cell, and are colorless. The size of conidia is around 23-80 × 3-5 μm.

[0013] Epicoccosorus that are listed in the above-mentioned result in the "agriculture and horticulture," Vol. 63, No. 6 (1988), page 63, and the Phytopathological Society of Japan, Abstracts for the Annual Meeting Proceedings 27, pp. (March 15, 1988 issue) As a result of comparison and examination with the mycological properties of nematosporus gen. et sp. nov., the shape of the colony and the morphology of conidia were the same.
It was identified as nematosporus.

For culturing the above-mentioned strain, it is not necessary to use a special method, and the same method as a known strain belonging to the genus Epicoccocora can be used. As the medium, any synthetic medium or natural medium can be used as long as the medium appropriately contains assimilable carbon sources, nitrogen sources, inorganic substances, and necessary growth promoting substances. Specific examples of the medium include an oatmeal sucrose agar medium, an oatmeal agar medium, a potato sucrose agar medium, a V-8 juice agar medium, a Tupec-Docs agar medium, and the like. During culturing, the temperature is preferably 15 to 33 ° C, preferably
It is desirable to maintain the pH at 23-25 ° C and the pH at 3-10, preferably 5-7. When culture is performed for about 3 to 14 days under the above conditions, a sufficient amount of conidia is formed on the surface of the medium.

When this strain is used in a herbicidal composition,
Microbial cells can be used, but preferably, conidia produced by the present strain are used. Conidia can be collected by pouring sterile water onto the microbiota and scraping the surface of the medium with a brush. By this method, 1 × 10 ⁷ to 10 ⁹ conidia can be obtained per petri dish having a diameter of 9 cm. In the present invention, both the above-mentioned microorganism and the "sulfonylurea herbicidal substance" are used as active ingredients. Here, "sulfonylurea herbicides material" generally refers to a compound that is an active ingredient of herbicides are referred to as sulfonylurea herbicides, have -SO ₂ -NHCONH- as a basic skeleton, and A compound having weed control ability. Specific examples thereof include bensulfuron-methyl, chlorimuron, metsulfuron-methyl, cinosulfuron, flazasulfuron, imazosulfuron, nicosulfuron, primisulfuron, pyrazosulfuron-ethyl, thifensulfuron-methyl, tribenuron and the like. Examples of preferable compounds include compounds represented by the following formula (I).

R ₁ —SO ₂ NHCONH—R ₂ (I) Here, R ₁ is the following formula (II), formula (III), formula (I
V), formula (V), formula (VI) or formula (VII), or derivatives thereof.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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In the formula, R ₂ represents formula (VIII) or formula (IX), or a derivative thereof.

[0024]

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[0025]

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Among the above compounds, bensulfuron-methyl represented by the following formula (X) (chemical name: methyl = α-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate)

[0027]

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Pyrazosulfuron ethyl represented by the following formula (XI) (chemical name: ethyl = 5- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -1-)
Methylpyrazole-4-carboxylate)

[0029]

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Imazosulfuron (chemical name: 1- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -3- (4,6 dimethoxypyrimidine-2-) represented by the following formula (XII) Ill) urea)

[0031]

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Examples of particularly preferable compounds are:
The commercially available herbicides containing bensulfuron-methyl include Wolf Granule 17, Wolf Granule 25, Wolface Granule 17, Wolface Granule 25, Wolface 1 kg Granule 75, Wolface 1 Kilo granules 51, Zark granules 25, Zark 1 kg granules 75, Fujigrass, Kusamet, Wihope, Push, Zark D, Gorvo (above "sold by DuPont Japan") can be mentioned, and the above-mentioned Pyrazos Commercially available herbicides containing luflon ethyl include Sirius granules, Agreen wettable powder, Act granules, Act 1 kilo granules, riser granules 15, riser granules 20, riser 1 kilo granules 20, riser 1kg granules 15, bellows granules, contract granules, calcorn granules, potenza, spark star (above "Sales of Nissan Kagaku") Bets can be, as a commercial herbicide containing imazosulfuron, takeoff granules, Shibataito (or "sold by Takeda Chemical Industries"), go-ahead granules,
Examples include Hayate granules, battle granules, and award flowables.

When the herbicidal composition of the present invention is used as a herbicide, conidia of microorganisms and a sulfonylurea herbicidal substance are usually used by suspending them in water. At this time, the concentration of conidia is 10 ² to 10 ⁸ / ml, preferably 10 ⁴ to 10 ⁴ / ml.
It is appropriate to use 10 ⁷ cells / ml. The concentration of the sulfonylurea herbicidal substance varies depending on the type of substance used, but is 0.00001 to 1% by weight, preferably 0.001%.
It is suitable to be 1 to 0.1% by weight. The plants for which the herbicidal composition of the present invention is a control target, kurogwai,
Examples include firefly, water lily, sea urchin, sea urchin, monarch, eel, cypress, cypress, etc.,
Among these, it is particularly effective for Kokuwai. As a spraying time of the herbicidal composition of the present invention, for example, in the case of controlling kurogwai, the period before germination to the flouring period is preferable, and the period from immediately after germination to midgrowth is particularly preferable. The application amount of the herbicidal composition of the present invention in the field is not particularly limited as long as it can effectively control weeds, but conidia is 10 ⁸ to 10 ⁸ per 10 ares.
^{About 11 to} 10 sulfonylurea herbicidal substances are preferably sprayed at about 0.2 to 10 g.

Next, the weed control method of the present invention will be described. There are two methods for controlling weeds of the present invention.
One is a method of formulating the above herbicidal composition and spraying it onto weeds. The other one is a method in which both a separately prepared herbicide containing a microorganism belonging to the genus Epicoccocora as an active ingredient, a sulfonylurea herbicide, and the like are applied to weeds. In the latter method, the order of application of the two herbicides is not particularly limited, but it is preferable to apply them simultaneously.

[0035]

【Example】

[Example 1] Measurement of Kurogui control effect (1) Preparation of microbial spores Epicoccocorus nematosporus K on PDA medium
When the −035 strain was transplanted and allowed to stand under light conditions at 25 ° C. for about 7 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. 1 x 10 spores
^{About 8} to 1 × 10 ⁹ pieces could be collected. (2) Krogwai control effect test by combining fungus and sulfonylurea herbicide 10000 filled with paddy soil
Kuroguy was grown in a pot of 1 / A and the thing which passed for 14 days was used for the control effect test. The spores recovered by the above method were suspended in sterile water to prepare a spore suspension. The spore concentration in the spore suspension was adjusted to 1 × 10 ⁶ / ml.

This spore suspension was sprayed using a sprayer to the extent that Klogwai was evenly and evenly wetted, and at the same time, each of the sulfonylurea herbicides was added in an amount of 3 per 1 pot.
0 mg was applied. After application, apply Kurogui at 25 ℃, 100
It was placed in a humidity chamber kept at% humidity for 24 hours. Then, it was further placed in a greenhouse at 25 ° C. for 2 weeks. Two weeks after the application of the microorganism and the sulfonylurea herbicide, the control effect was evaluated. The control effect of the drug was judged by investigating the degree of mortality of kurogwai and calculating the average value (3 repetitions).

The degree of death was evaluated on a scale of 6 with 0 being healthy and 5 being the case where the entire foliage was completely dead. When treated with a sulfonylurea herbicide in combination with the microorganism,
As shown in the table below, a higher control rate was obtained than the control effects of the K-035 strain alone and the sulfonylurea herbicide only. ──────────────────────── Control method Control index ────────────────────── ── Wolface 0.17 Wolface + K-035 bacteria 2.84 Sirius 0.93 Sirius + K-035 bacteria 3.04 Takeoff 0.60 Takeoff + K-035 bacteria 2.55 K-035 bacteria 0.67 ──────────────────────── As described above, it has a sulfonylurea herbicide and a microorganism belonging to Epicoccocorus nematosporus or a component of the microorganism. When the herbicide was applied, a much higher control effect was obtained.

That is, when a sulfonylurea herbicide and a microorganism belonging to Epicoccocora nematosporus or a herbicide containing the microorganism as a component are used in combination, the control effect is shorter than that when applied individually. Appearance and remarkably high control effect are obtained. [Example 1 of use] A preconserved epicoccocorus nematosporus K-035 conidium concentrated solution was diluted, and 200 mL of water contained 2 × 10 ⁸ conidia and Sirius granules (containing 0.07% of pyrazosulfuron-ethyl). ) Was suspended for 3 g to prepare a spore suspension.

This spore suspension was uniformly sprayed on a field with an area of 1 m ² where kurogwai grew. When the field was observed 4 weeks later, most of the crocodile were infected,
Some of them were already dead. USE EXAMPLE 2 Dry conidia 2 × 1 of Epicoccus soras nematosporus K-035 which had been pulverized and stored in advance.
0 ⁸ was resuspended in water 200 ml, and further 3 g added Sirius granules were prepared spore suspension.

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 were infected,
Some of them were already dead.

[0042]

EFFECTS OF THE INVENTION By using a microorganism belonging to the genus Epicoccocorus in combination with a sulfonylurea herbicidal substance, it is possible to effectively control strong weeds such as kurogwai in a short period of time.

Claims (6)

[Claims] 1. A herbicidal composition comprising a microorganism belonging to the genus Epicoccocorus and having a weed control ability, and a sulfonylurea herbicidal substance as active ingredients. 2. The herbicidal composition according to claim 1, wherein the microorganism that belongs to the genus Epicoccocorus and has the ability to control weeds is a microorganism that belongs to Epicoccosora nematosporus. 3. The microorganism belonging to Epicoccosus nematosporus, wherein the microorganism belonging to Epicoccosus nematosporus JT is used.
K-003 strain, Epicococsolus nematosporus JT
K-028 strain, Epicococsolus nematosporus JT
K-029 strain, Epicococsolus nematosporus JT
At least one selected from the group consisting of strain K-030 and strain Epicoccosolus nematosporus K-035;
The herbicidal composition according to claim 2, which is a strain. 4. A sulfonylurea herbicidal substance has the following formula (I) R ₁ -SO ₂ NHCONH-R ₂ (I) (wherein R ₁ is the following formula (II), formula (III), Expression (I
V), formula (V), formula (VI) or formula (VII), or a derivative thereof, wherein R ₂ is represented by the following formula (VIII):
Alternatively, it represents formula (IX), or a derivative thereof. ) A herbicidal composition according to claim 1, which is a compound represented by the formula (1). Embedded image Embedded image Embedded image Embedded image Embedded image [Chemical 6] Embedded image Embedded image 5. A method for controlling weeds, which comprises spraying the weeding composition according to any one of claims 1 to 4 on the weeds. 6. A method for controlling weeds, which comprises applying to a weed a herbicide which belongs to the genus Epicoccocora and which contains, as an active ingredient, a microorganism having a weed control ability, and a sulfonylurea herbicide.