JPS6251921B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel herbicidal composition containing a specific benzamide compound and 2-methylthio-4,6-bis(ethylamino)-s-triazine (hereinafter referred to as simetrine). The composition of the present invention has a wide range of herbicidal activity in rice cultivation under flooded conditions. Although cymetrine is already used as a herbicide, it alone is not sufficient to control a wide variety of weeds found in rice cultivation. Weeds that cannot be eradicated will grow without competing with the weeds killed by the application of simetrine, and will therefore rapidly reproduce, significantly reducing the effectiveness of its use.
In particular, large weeds such as grasshoppers and staghorn weeds exhibit vigorous growth, negating the value of symetrine treatment. As a result of various studies aimed at solving these problems, the present inventors discovered the unique action of simetrine and a specific benzamide compound, and completed the present invention. The present invention contains (A) and (B) as active ingredients, where (A) is of the formula (wherein R is n-C ₄ H ₉ O, C ₂ H ₅ OCH ₂ O or n-C ₄ H ₉ OCH ₂ O), (B) is simetrine, and this (A ) and (B)
A herbicidal composition characterized by containing: The benzamide compounds used as the active substance (A) include 4-n-n-butoxy-N-(2,3-dichlorophenyl)-benzamide (hereinafter referred to as benzamide-(1)), 4-ethoxymethoxy-N-
(2,3-dichlorophenyl)-benzamide (hereinafter referred to as benzamide-(2)), 4-n-n-butoxymethoxy-N-(2,3-dichlorophenyl)-benzamide (hereinafter referred to as benzamide-(3)), and the like. The weight ratio of the benzamide compound (A) to the cymetrine (B) in the composition of the present invention is preferably 5:1.
The range is from 1:1 to 3:1. To prepare the active substance according to the present invention, the blending ratio of each component (A) and (B) is generally 50 to 500 g, preferably 100 to 400 g, of the benzamide compound of (A) per 10 ares; More preferably, the amount is 150 to 300 g, and the amount of cymetrine (B) is generally 20 to 100 g, preferably 30 to 80 g, and even more preferably 45 to 60 g. To formulate the compositions of the invention, surfactants, which are emulsifiers and/or dispersants, are used, for example,
By mixing the active substances with liquid or solid diluents, they can be converted into preparations such as emulsions, wettable powders, granules, powders, suspensions, pastes. Moreover, when using water as an extender, an organic solvent is used as an auxiliary agent. Liquid diluents or carriers include aromatic hydrocarbons such as xylene, toluene, chlorinated aromatic hydrocarbons such as chlorobenzene, alcohols such as methanol and butanol, or dimethylformamide, dimethylsulfoxide, and isophorone. There are highly polar solvents such as As a solid diluent or carrier, kaolin,
Ground natural minerals such as bentonite, white carbon, and talc are used. Examples of emulsifiers include nonionic emulsifiers such as polyoxyethylene fatty acid esters and anionic emulsifiers such as alkylaryl sulfonates. Examples of dispersants include lignin and methylcellulose. The compositions according to the invention can also be used in admixture with other active substances. The formulations contain from 0.1 to 95% parts by weight of active substance, preferably from 1 to 95% parts by weight. The composition of the present invention can be applied over a wide range from the early to middle stages of rice cultivation under flooded conditions, and has a wide range of herbicidal activity, making it suitable for the comprehensive eradication of rice field weeds. It is possible to simultaneously eradicate or suppress paddy field weeds, including not only annual weeds but also perennial weeds such as firefly and water cypress, which are difficult to exterminate. Examples for the preparation of the agent of the present invention are shown below.
Note that "parts" means "parts by weight." Example 1 (Preparation of a hydrating powder) Benzamide (1) 50 parts simetrine 15 parts kaolin clay 30 parts Solpol 5039 (trademark of Toho Chemical Co., Ltd.) 5 parts were uniformly mixed and ground to obtain a hydrating powder of the present invention. Ta. Example 2 (Preparation of emulsion) Benzamide (2) 25 parts cymetrine 5 parts xylene 30 parts cyclohexanone 30 parts Solpol 800-A (trademark of Toho Chemical Co., Ltd.) 10 parts were uniformly mixed and dissolved to obtain an emulsion of the present invention. Ta. Example 3 (Preparation of granules) Benzamide (3) 7 parts Cymetrine 1.5 parts Bentonite 45 parts Talc 41.5 parts Sodium ligninsulfonate 5 parts were uniformly mixed and pulverized, water was added, kneaded, granulated and dried. Invention granules were obtained. The usefulness of the agent of the present invention will be explained below using test examples. Test Example 1 (Paddy field flooding treatment) Paddy soil was filled in a pot with a diameter of 11.5 cm and a depth of 10 cm, and after adding paddy soil mixed with various paddy weed seeds to the surface layer, fertilization was applied, water was added, and the soil was submerged. The water was set at 3 cm. Two paddy rice seedlings (variety: Nihonbare) at the 2.5-leaf stage were transplanted, and three tubers of Cyperus japonica per pot were embedded in the soil 1 cm from the surface layer. Ten days after transplanting paddy rice, a predetermined amount of the wettable powder of the present invention diluted with water was dropped into water. For comparison, a single drug was also treated in the same manner. On the 20th day after chemical treatment, the effects on various weeds and the presence or absence of chemical damage to paddy rice were investigated by observation. The results are shown in Table-1. The evaluation in the table is based on the following criteria. Herbicidal effect index Phytotoxicity index 5: Complete herbicidal effect -: Harmless 4: 80-99% herbicidal effect ±: Slight damage 3: 60-79% 〃 +: Slight damage 2: 40-59% 〃 〓: Moderate damage 1: 20-39% 〃 〓: Severe damage 0: 19% or less 〃 〓: Severe damage After adding paddy soil mixed with seeds of various paddy weeds, fertilization was applied, water was added, and the soil was plowed to a depth of 3 cm. Two paddy rice seedlings (variety: Nihonbare) at the 2.5-leaf stage were transplanted, and three tubers of Cyperus japonica per pot were embedded in the soil 1 cm from the surface layer. Thirteen days after transplanting paddy rice, a predetermined amount of the emulsion of the present invention diluted with water was dropped into water. For comparison, a single drug was also treated in the same way. On the 20th day after chemical treatment, the effects on various weeds and the presence or absence of chemical damage to paddy rice were investigated by observation. The results are shown in Table-2. The evaluation in the table is the same as the criteria of Test Example 1. Test Example 3 A 1/5000th Ahl Wagner pot was filled with paddy soil, and paddy soil mixed with various paddy weed seeds was added to the surface layer, fertilized, watered and plowed, and then flooded to a depth of 3 cm. Paddy rice seedlings at the 2.5 leaf stage (variety:
3 plants (2 plants per pot) were transplanted, and 3 tubers of Urikawa and Cyperus japonica were each embedded in the soil 1 cm from the surface layer, 3 tubes per pot. A predetermined amount of the granules of the present invention was applied 16 days after transplanting paddy rice. The investigation was conducted 30 days after chemical treatment by observing the effects on various weeds and the presence or absence of chemical damage to paddy rice. The results are shown in Table-3. Note that the evaluation in the table is the same as the criteria of Test Example 1.

【table】

【table】

[Table] As shown in Tables 1, 2, and 3, benzamide compounds exhibit high activity against noviidae, but are less effective against firefly and the like. The herbicidal effect of the composition of the present invention exceeds the sum of the individual activities, and it shows particularly high activity against perennial weeds such as firefly and cypress, which are difficult to eradicate.
Moreover, no chemical damage to paddy rice is observed.

Claims (1)

[Claims] 1 formula (wherein R is n-C ₄ H ₉ O, C ₂ H ₅ OCH ₂ O or n-C ₄ H ₉ OCH ₂ O) and 2-methylthio-4,6-bis(ethylamino) -s-triazine.