JPH0153641B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a herbicide composition for paddy fields. For details, refer to 3-[2-nitro-5-(2-chlor-4-
trifluoromethylphenoxy) - phenoxy]
-Tetrahydrofuran (hereinafter referred to as "Compound A") and α-(2-naphthoxy)-propionanilide (hereinafter referred to as "Compound B"), 4-(2,
4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yloxy-p-toluenesulfonate (hereinafter referred to as "Compound C"), 4-(2,
4-dichlorobenzoyl)-1,3-dimethyl-
The present invention relates to a herbicidal composition for rice fields, characterized in that it is a mixture of one or more compounds selected from the group of 5-phenacyloxypyrazoles (hereinafter referred to as "compound D"). In recent years, in addition to annual weeds such as field weeds, many types of perennial weeds have become a major problem in rice fields. It is thought that this is a result of prioritization because it is difficult to control these herbicides with currently used herbicides, but as a result, there is a strong desire to develop herbicides that have a wide herbicidal spectrum that includes these perennial weeds. . The present inventors have carried out intensive research with these points fully taken into consideration, and as a result, we have discovered that Compound A and Compound B,
The present invention was completed by discovering that a remarkable synergistic effect can be observed by using C or D in combination. This significant increase in herbicidal activity is simply not expected from the herbicidal activity of each compound. To explain the present invention in more detail, Compound A is described as a herbicide in JP-A No. 56-86179, and exhibits strong activity against Japanese millet, bulrush, snail, and cypress in rice fields. However, depending on the conditions, the herbicidal effect decreases and becomes insufficient for some types of weeds. Also, although no mention is made of the activity against grasshoppers, water cypers, etc., the herbicidal activity becomes weaker when the treatment time is delayed. On the other hand, compound B has physical constants mp127~128
℃, and its herbicidal spectrum in rice fields shows a herbicidal effect on broad-leaved weeds, including perennial weeds such as porridge and firefly. become weak. Compounds C and D are each
This compound is described in Japanese Patent Application Laid-open No. 50-126830 and Japanese Patent Application Laid-Open No. 54-41872, and has a herbicidal effect on annual weeds as well as perennial weeds in rice fields. However, as the weeds grow larger or the dosage is lowered, the effectiveness decreases, and the herbicidal effect against wildflowers and other weeds becomes insufficient. However,
When compound A is used in combination with compound B, C or D, these drawbacks of these compounds are clearly corrected, and not only the herbicidal power is enhanced, but the range of suitable use is widened, and the herbicidal spectrum is expanded. That is, the herbicidal composition of the present invention exhibits a strong herbicidal activity against all kinds of annual broad-leaved weeds such as Japanese wild grass, Japanese grasshopper, and perennial weeds such as Japanese grasshopper, Japanese cypress, Japanese cypress, and other perennial weeds. This is unexpected from the herbicidal activity of each compound, and shows a strong herbicidal activity that clearly exceeds the activity of each compound alone. Based on these new findings, the present inventors succeeded in creating a herbicide composition that has the extremely useful properties of being fully effective at a low dose and maintaining its efficacy for a long period of time. The present invention was completed. Furthermore, in order to make the herbicidal compositions according to the invention more potent, 1-(α,α-dimethylbenzyl)-3-(4-methylphenyl)urea, N
-(α,α-dimethylbenzyl)-α-bromo-
A three-way mixture with t-butylacetamide, N-(α,α-dimethylbenzyl)-2-chlorophenylacetamide, 2-methylthio-4,6-bis(ethylamino)-S-triazine, etc. is also an effective means. It is. The composition ratio of the herbicide composition of the present invention can be applied in a wide range, but desirably, each of Compounds B, C, and D is 2 to 2 parts by weight to 1 part by weight of Compound A.
It is preferable to mix in a proportion of 20 parts by weight. The herbicide composition of the present invention contains compounds A, B, C,
Although D may be used as is, it is usually processed into formulations such as granules, powders, emulsions, and wettable powders using auxiliary agents by mixing with various carriers or diluents. If you do so, you can get even better results. Commonly used solid or liquid carriers or diluents are used. Examples of solid carriers include talc, bentonite, clay, kaolin, diatomaceous earth, white carbon, vermiculite, slaked lime, silica sand, and ammonium sulfate. , urea, etc., or mixtures thereof; liquid carriers include alcohol, dioxane, acetone, cyclohexane, methylnaphthalene, dimethylformamide, etc., or mixtures thereof;
As adjuvants, surfactants such as alkyl sulfates, alkyl sulfonates, acetylene glycols, polyoxyethylene glycol ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene sorbitan monoalkylate, or carboxymethyl cellulose,
Various adjuvants such as sodium alginate, polyvinyl alcohol, and gum arabic are used. When using the mixed herbicide of the present invention in rice fields,
It can be used before or after transplanting paddy rice, and is preferably applied before or during the weed growth period. The application amount depends on weather conditions, soil type, formulation form,
Although it varies depending on the application time and application method, in general, in the case of flooded soil treatment, the amount of active ingredient (as a mixture) is 10 to 1000 g per 10 ares, preferably 10 to 500 g, most preferably 50 to 50 g. 500g is preferred. Next, the herbicide composition of the present invention will be explained in more detail in Examples (formulation examples and test examples).
All test compounds are indicated by the above abbreviations. In addition, "parts" in the formulation examples represent "parts by weight." Formulation Example 1 10 parts of Compound A, 20 parts of Compound C, 10 parts of white carbon, 55 parts of diatomaceous earth, 3 parts of sodium ligninsulfonate, and 2 parts of sodium dodecylbenzenesulfonate were ground and mixed to obtain a wettable powder. Formulation Example 2 2 parts of Compound A, 7 parts of Compound B, 70 parts of bentonite, 20 parts of talc, and 1 part of sodium ligninsulfonate were pulverized and mixed, water was added, the mixture was kneaded, and the mixture was granulated and dried to obtain granules. Formulation Example 3 2 parts of Compound A, 5 parts of Compound B, 2 parts of sodium ligninsulfonate, and 91 parts of clay were ground and mixed to obtain granules. Formulation example 4 Compound A 2 parts, Compound C 5 parts, Phenylcellosolve 2 parts, Xylene 91 parts, Solpol 355S
(Product name: Toho Chemical Emulsifier) 10 parts were mixed well to obtain an emulsion. Test Example 1 Soil was filled in a 1/5000 Earl Wagner pot, and seeds of Japanese cabbage and firefly were sown, and tubers of Urikawa and Japanese cypress were planted, and the pot was submerged in water. Two paddy rice seedlings (two-leaf stage) that had been raised in advance were transplanted to this and grown in a greenhouse. Three days after transplanting paddy rice, at the beginning of weed emergence, a predetermined amount of the test compound was submerged in water using a granule according to the method described in Formulation Example 2 above. One month after the treatment, the herbicidal effect on weeds and the degree of chemical damage to paddy rice were investigated, and the results shown in Table 1 were obtained. In this table, the degree of chemical damage to crops and the herbicidal effect on weeds are expressed in accordance with the following evaluation criteria by comparing with the air dry weight of untreated plots in the state of emergence or growth of crops or weeds. The test compounds were the aforementioned compounds A, B, C, and D, respectively, represented by A, B, C, and D.

【table】

[Table] Test Example 2 Soil was packed in a 1/5000 Earl Wagner pot, and seeds of Japanese cabbage and firefly were sown, and tubers of Urikawa and Japanese cypress were planted, and the pot was submerged in water. Two paddy rice seedlings (two-leaf stage) that had been raised in advance were transplanted to this and grown in a greenhouse. After transplanting paddy rice, when the Japanese millet is at the 1.0 leaf stage,
A predetermined amount of the supplied compound was submerged in water using a wettable powder according to the method described in Formulation Example 1 above. The wettable powder was diluted with water and treated in 5 ml per pot. 25 days after treatment, the herbicidal effect on weeds and the degree of chemical damage to paddy rice were investigated, and the results shown in Table 2 were obtained.
The investigation method was conducted in accordance with Test Example 1.

[Table] Test Example 3 Soil was filled in a 1/5000 Ahl Wagner pot, seeds of Japanese cabbage and firefly were sown, and tubers of Urikawa and Japanese cypress were planted, and the pot was submerged in water. Two paddy rice seedlings (two-leaf stage) that had been raised in advance were transplanted to this and grown in a greenhouse. After transplanting paddy rice, when the Japanese millet had 1.5 to 2 leaves, a predetermined amount of the test compound was submerged using a hydrating powder according to the method described in Formulation Example 1 above. The wettable powder was diluted with water and treated in 5 ml per pot. On the 25th day after treatment, the herbicidal effect on weeds and the degree of chemical damage to paddy rice were investigated, and the results shown in Table 3 were obtained. The investigation method was conducted according to Test Example 1.

【table】

Claims (1)

[Claims] 1 3-[2-nitro-5-(2-chloro-4-
trifluoromethylphenoxy) - phenoxy]
-Tetrahydrofuran and α-(2-naphthoxy)
-Propionanilide, 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazole-
5-yl-p-toluenesulfonate, 4-
(2,4-dichlorobenzoyl)-1,3-dimethyl-5-phenacyloxypyrazole; and one or more compounds selected from the group of phenacyloxypyrazoles. . 2 3-[2-nitro-5-(2-chlor-4-
trifluoromethylphenoxy) - phenoxy]
-Tetrahydrofuran and α-(2-naphthoxy)
- Propion anilide and 1:2 to 20 (weight ratio)
The herbicidal composition for paddy fields according to claim 1, which is mixed in a ratio of: 3 3-[2-nitro-5-(2-chlor-4-
trifluoromethylphenoxy) - phenoxy]
-Tetrahydrofuran and 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazole-5
-yl-p-toluenesulfonate at 1:2~
20 (weight ratio) of the herbicidal composition for paddy fields according to claim 1. 4 3-[2-nitro-5-(2-chlor-4-
trifluoromethylphenoxy) - phenoxy]
- Claims consisting of a mixture of tetrahydrofuran and 4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-phenacyloxypyrazole in a ratio of 1:2 to 20 (weight ratio) 2. The herbicide composition for paddy fields according to item 1.