JP2002363011A - Herbicidal composition for paddy field and method for controlling weed in paddy field - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a herbicidal composition for paddy fields having high safety for rice plants and high herbicidal efficacies on various species of weeds growing in the paddy fields. SOLUTION: The herbicidal composition for the paddy fields comprises a bentazon sodium salt and benzofenap as herbicidally active ingredients and has the high herbicidal efficacies on the various species of weeds due to excellent synergistic effects and the high safety for the rice plants at the same time. The method for controlling the weeds in the paddy fields with the composition is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a herbicide composition for paddy fields and a method for controlling weeds in paddy fields.

[0002]

2. Description of the Related Art At present, various herbicides have been developed and put into practical use as paddy herbicides. Recently, mixed herbicides having a broad herbicidal spectrum consisting of a plurality of herbicides, referred to as one-shot herbicides, have been widely used. However, these herbicides are also effective for perennial cyperaceae, Kurogwai and Kazuki-tsuri, which are difficult to control rice paddies, and Azena, Mizuoi, Inuhotarii, etc., which are resistant to sulfonylurea-based herbicides that have recently become a problem in Hokkaido and elsewhere. Is often insufficient. In particular, the effect of a single herbicide containing a sulfonylurea herbicide, which is widely used at present, cannot be said to be insufficient. In addition, the effect of annual weeds on eel and the like is not always sufficient. Therefore, there is a demand for the development of an effective herbicide that shows an excellent effect on these weeds, has high safety against rice, and has a lower environmental load than conventional herbicides, that is, a lower dose.

[0003]

DISCLOSURE OF THE INVENTION The present invention has a high level of safety in rice and is suitable for various kinds of weeds growing in paddy fields.
An object of the present invention is to provide a novel herbicidal composition for paddy fields showing a high herbicidal effect by an excellent synergistic action and a method for controlling weeds in paddy fields using the composition.

[0004]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, as an active ingredient of herbicide, 3-isopropyl-1H-2,1,3-benzothiadiazine. -4 (3H) -one = 2,2-dioxide =
Sodium salt (hereinafter referred to as bentazone sodium salt)
And 2- [4- (2,4-dichloro-m-toluoyl)-
1,3-dimethylpyrazol-5-yloxy] -4 ′
-The herbicidal composition for paddy fields of the present invention containing methyl acetophenone (hereinafter, referred to as benzophenap) exhibits a remarkably synergistic effect on various weeds growing in paddy fields, which cannot be expected by application of each active ingredient alone. As a result, they have found that these weeds can be controlled at a low dose and that they have high safety without causing any phytotoxicity to rice, and completed the present invention.

The above herbicide active ingredients are both known herbicide compounds, and are described in, for example, "Agricultural Chemical Handbook" 1998 edition (issued by the Japan Plant Protection Association on December 15, 1998) and are commercially available. ing.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the present invention, the composition of the present invention containing bentazone sodium salt and benzofenap as active ingredients of a herbicide has a high herbicidal effect on weeds growing in paddy fields. The product shows a strong herbicidal effect on weeds while maintaining high safety against rice.

[0007] The composition of the present invention usually contains an inert carrier, if necessary, a surfactant, and other pharmaceutical adjuvants, in addition to the herbicide active ingredients bentazone sodium salt and benzofenap. The composition of the present invention generally contains 0.1 to 60% by weight of a total amount of bentazone sodium salt and benzofenap. The content of bentazone sodium salt and benzofenap in the composition of the present invention is usually from 1: 0.03 to 1: 8, preferably from 1: 0.06 to 1: 4 in weight ratio.

Examples of the inert carrier include solid carriers such as talc, clay, bentonite, kaolin, diatomaceous earth, calcium carbonate and white carbon. Examples of the surfactant include alkyl sulfonates (eg, alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt), and alkyl naphthalene sulfonates (eg, sodium salt, Alkali metal salts such as potassium salts, alkaline earth metal salts such as calcium salts), lignin sulfonates (eg, alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts), alkylbenzene sulfones Acid salts (eg, alkali metal salts such as sodium salt and potassium salt, alkaline earth metal salts such as calcium salt), dialkyl sulfosuccinate, naphthalenesulfonic acid formalin condensate, polyoxyethylene alkylaryl phenyl ether sulfate, polyoxy Ethylenestyrylphenyl -Anionic surfactants such as tersulfate, higher fatty acid salts, polycarboxylic acid surfactants and salts thereof, polyoxyethylene alkyl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene ant Examples include nonionic surfactants such as a killed aryl ether, a polyoxyethylene sorbitan fatty acid ester, a polyoxyethylene polypropylene block polymer, and a polyoxyethylene alkyl ester. The inert carrier and the surfactant are usually present in the composition of the present invention in an amount of 5 parts each.
-99% by weight and 0.1-30% by weight. Other adjuvants for formulation include binders, disintegrants, spreading agents and the like, and specific examples include gum arabic, polyvinyl alcohol, sodium polyacrylate, sodium carboxymethylcellulose and the like.

The composition of the present invention can be in the form of granules, powders, wettable powders, flowables and the like, and is formulated by a usual method. The composition of the present invention preferably has the following composition of a water-diffusible composition. The water-diffusible composition is a granular composition containing a surfactant, a water-soluble carrier, and a water-soluble binder, in addition to the active ingredients bentazone sodium salt and benzofenap, and is usually the active ingredient. 0.1 to 60% by weight in total, a surfactant,
The water-soluble carrier and the water-soluble binder are contained in 0.1 to 30% by weight, 5 to 99% by weight and 1 to 30% by weight, respectively.
Specific examples of the surfactant include those described above. As the water-soluble carrier, for example, urea, ammonium sulfate,
Examples thereof include ammonium chloride, potassium chloride, sodium chloride, sodium sulfate, sucrose, and lactose. Examples of the water-soluble binder include carboxymethylcellulose salt (for example, sodium salt), polyacrylate (for example, sodium salt), polyvinyl alcohol, dextrin,
Binders known as film-forming elements, such as chitansan gum, modified starch, gum arabic, and alginates (eg, sodium salts). The water-diffusible composition,
The above components can be mixed, water can be added thereto, and the mixture can be granulated and dried by a conventional method.

[0010] The composition of the present invention is applied to paddy fields in the same manner as ordinary paddy field herbicides. For example, it is useful for controlling paddy weeds such as oak, azalea, takasaburo, inuhotarui, swordfish, kuroguwai, urikawa and omodaka. Used. The application rate of the composition of the present invention may vary depending on the content of the active herbicide used in the preparation, the weeds to be controlled, the occurrence of weeds, and weather conditions. 1g-60 per 10 ares
It is preferable to appropriately select from the range of 0 g, preferably 50 g to 250 g.

【Example】

The composition of the present invention will be described more specifically with reference to formulation examples and test examples, but the present invention is not limited to the following examples. In the following description, “parts” means parts by weight.

Formulation Example 1 Benzofenap 8 parts, white carbon 10 parts, sodium polyacrylate 1.5 parts, carboxylic acid type polymer activator 1 part, chitansan gum 0.5 parts and potassium chloride pulverized product 67.0 Mix the parts with a mixer. To this mixture, 11 parts of bentazone sodium salt, 1 part of dialkyl sulfosuccinate and 10 parts of water were added, and the mixture was kneaded well in a mortar. The mixture was extruded and granulated by a horizontal granulator equipped with a screen having a diameter of 1.2 mm. After sizing, 60 ~
Drying was performed by blowing hot air at 70 ° C. to obtain a granule as a diffusible composition in water.

Formulation Example 2 8 parts of benzofenap, 5 parts of white carbon, 30 parts of talc, 39 parts of clay and 3 parts of a surfactant (a mixture of dodecylbenzenesulfonate and phosphate) are mixed by a mixer. To this mixture was added bentazone sodium salt 11
Parts, 2 parts of polycarboxylic acid polymer activator, starch decomposed product 2
Of water and 17 parts of water, kneaded well in a mortar, extruded and granulated by a horizontal granulator equipped with a screen having a diameter of 1.2 mm, wet sized, and then dried with a fluidized bed dryer at 60 to 70 parts.
Drying was performed by blowing hot air at a temperature of ° C to obtain granules.

Formulation Example 3 In 63.9 parts of water, 11 parts of bentazone sodium salt, 8 parts of benzofenap, 2 parts of sodium ligninsulfonate,
Add 4 parts of ammonium polyoxyethylene alkylaryl ether sulfate, 0.5 part of polyoxyethylene alkylaryl ether, 0.1 part of chitansan gum, 0.5 part of bentonite, and 10 parts of ethylene glycol, mix with a high-speed stirrer, and pulverize with a wet pulverizer. Then, a flowable agent was obtained.

Next, the effects of the composition of the present invention will be specifically described with reference to test examples.

Test Example 1. Herbicidal effect test In a greenhouse (average temperature 25 ° C), 1/5000 are Wagner pots were filled with clay loam, and in a state of shallow water flooding, four Rhizogynium tubers were planted in each pot. On the 14th day after planting, the granules prepared according to Formulation Example 1 were treated while keeping the water depth at 5 to 6 cm. At the time of the treatment, the horned beetle was in the 4-5 leaf stage. On the 21st day after the treatment, the degree of the herbicidal effect was observed. The herbicidal effect was evaluated in% as follows. 100%: Complete withering 0%: No effect The results are shown in Table 1.

[0017] As can be seen from the above table, 80 g of benzofenap showed only a 20% herbicidal effect, and 80 g of bentazone sodium salt provided an insufficient control effect, whereas 10 g of benzofenap produced only an insufficient control effect. A total control of 40 g of bentazone sodium salt shows a complete control effect. That is, an excellent synergistic weeding effect is shown.

Test Example 2 Herbicidal effect and rice phytotoxicity test A paddy rice seedling (variety: Nipponbare) at the 2.2 leaf stage was transplanted to a paddy field (clay loam) with a spacing of 30 cm between rows and 20 cm between strains. After transplantation, 3.1 m ² (1.4 mx 2.2
m). In the frame, weed seeds such as oak, azalea, takasaburo, and firefly were sowed, and croquis tubers were planted, and the water depth was always kept at 5 to 6 cm.
On the 26th day after transplantation, the granules prepared according to Formulation Example 1 were uniformly treated by hand in a frame. Five days after the chemical treatment, the phytotoxicity of rice was observed, and 23 days later, the degree of herbicidal effect was observed. as a result,
Treatment with 1.0 kg per 10 ares (the active ingredient amount of bentazone sodium salt 110 g and benzofenap 80 g per 10 ares) showed an excellent control effect on all of the above weeds, and phytotoxicity to rice was observed. Did not.

[0019]

INDUSTRIAL APPLICABILITY The paddy field herbicide composition of the present invention containing bentazone sodium salt and benzofenap as active ingredients exhibits excellent synergistic effects on various weeds generated in paddy fields, and shows excellent effects on rice. It also has the characteristics of high safety and reduces the labor of farmers, and is useful as a paddy field herbicide.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Fumio Kage 4-2-1 Takashi, Takarazuka-shi, Hyogo F-Term in Agros Co., Ltd. 4H011 AB02 BA01 BA06 BB09 BB10 BC03 BC07 BC18 BC19 BC20 DA02 DA15 DC04 DC05 DC06 DC07 DC08 DD01 DF04 DF06 DH02 DH03 DH08 DH10 DH14

Claims (4)

[Claims] (1) 3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H) -one = 2,2-dioxide = sodium salt and 2- [4- (2,4-dichloro-
m-toluoyl) -1,3-dimethylpyrazole-5
And a herbicide composition for paddy fields, which comprises [Iloxy] -4'-methylacetophenone as an active ingredient. 2. A mixture of 3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H) -one = 2,2-dioxide = sodium salt and 2- [4- (2,4-dichloro-).
m-toluoyl) -1,3-dimethylpyrazole-5
2. The herbicidal composition for a paddy field according to claim 1, wherein the composition contains iloxy] -4'-methylacetophenone in a weight ratio of 1: 0.03 to 1: 8. (3) 3-isopropyl-1H-2,1,3-benzothiadiazin-4 (3H) -one = 2,2-dioxide = sodium salt and 2- [4- (2,4-dichloro-
m-toluoyl) -1,3-dimethylpyrazole-5
2. The herbicidal composition for a paddy field according to claim 1, wherein the composition contains iloxy] -4'-methylacetophenone in a weight ratio of 1: 0.06 to 1: 4. 4. A method for controlling weeds, wherein the herbicidal composition for paddy fields according to claim 1, 2 or 3 is applied to paddy fields.