JPH0329762B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to herbicidal compositions having a broad herbicidal spectrum. More specifically, 3-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran and the general formula [In the formula, X represents a hydrogen atom, and R represents a 4-methylanilino group, a 1-bromo-2-dimethylpropyl group, or a 2-chlorobenzyl group, respectively. ] N-(α,α-dimethylbenzyl) represented by
The present invention relates to a herbicidal composition characterized by being mixed with an amide derivative. Herbicides are essentially required to be effective against a wide variety of weeds. This is because if some weeds survive, they will grow larger and sometimes even take over, leading to a situation where the effectiveness of herbicides is halved. In recent years, it has become a well-known fact that the weed ecosystem itself has changed significantly due to the long-term use of limited herbicides. Regarding rice fields, the prioritization of perennial weeds, such as weeds, snails, cypresses, and black croakers, is seen as a problem, and there is a strong demand for the emergence of new herbicides. We focused on these points and as a result of repeated research, we created 3-[2-chloro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran (hereinafter referred to as "Compound A"). and a compound represented by the general formula (1) (hereinafter referred to as "compound B")
The present invention was completed based on the discovery that a mixture with a compound of the same type as the "Group" has extremely excellent properties. That is, a remarkable synergistic effect was observed in the mixture, which would not be expected by simply mixing Compound A and Compound B. Compound A is described as a herbicide in Japanese Unexamined Patent Publication No. 56-86179, and it is disclosed that it exhibits a high herbicidal effect on Japanese millet, firefly, Japanese cypress, and Japanese cypress in rice fields. However, if the treatment time is delayed or the dose is reduced, the activity against firefly etc. and the residual effect will decrease. In addition, its activity is insufficient against other perennial weeds such as turmeric, cypress, and black porgy. It is also known that compounds included in compound B group exhibit herbicidal activity. 1-(α,α-dimethylbenzyl)-3-(4-methylphenyl)urea (hereinafter referred to as “compound B-1”) was produced by
No. 48-35454, N-(α,α-dimethylbenzyl)-α-bromo-t-butylacetamide (hereinafter referred to as “compound B-2”) was disclosed in Japanese Patent Application Laid-open No. 55
-43014, N-(α,α-dimethylbenzyl)-2-chlorophenylacetamide (hereinafter referred to as “Compound B-3”) is
Publication No. 110655 describes each of them as herbicides, and they all have a common herbicidal effect on weeds of the Cyperaceae family. In particular, it is a well-known fact that Compound B-1 has already been widely used as a special medicine for firefly under the trade name of Chiyoron. However, all of these compounds have weak herbicidal effects against other weeds and are insufficient for practical use. The mixed use of Compound A and compounds included in Compound B group not only compensate for each other's shortcomings, but also clearly have a synergistic effect on Japanese millet, firefly, water snail, etc., and the acceptable range of treatment time is also different from the single use of both compounds. becomes unexpectedly large. The mixing ratio of compound A and compound B-1 to produce such a mixing effect can be applied in a wide range, but preferably compound A and compound B-1 are 1:1 to 10 (weight ratio), The mixing ratio of compound A and compound B-2 is preferably 1:0.5 to 5 (weight ratio), and the mixing ratio of compound A and compound B-3 is 1:0.5 to 10 (weight ratio). The mixed herbicide of the present invention may be prepared by using compound A and compound B as they are, but usually by mixing them with various carriers or diluents, and in some cases using adjuvants, by conventional methods. , granules, powders,
Even better results can be obtained if the compound is processed into a formulation such as an emulsion or a wettable powder. As the carrier or diluent, commonly used solid or liquid substances are used. Examples of solid carriers include talc, bentonite, clay, kaolin, diatomaceous earth, white carbon,
Examples of the liquid carrier include vermiculite, slaked lime, silica sand, ammonium sulfate, urea, etc., or mixtures thereof, and alcohol, dioxane, acetone, cyclohexanone, methylnaphthalene, dimethylformamide, etc., or mixtures thereof. As adjuvants, surfactants such as alkyl sulfates, alkyl sulfonates, polyoxyethylene glycol ethers, polyoxyethylene alkylaryl ethers, polyoxyethylene sorbitan monoalkylate, or carboxymethyl cellulose, sodium alginate, polyvinyl alcohol. , gum arabic, and various other adjuvants are used. When using the mixed herbicide of the present invention in paddy fields,
It can be applied before or after transplanting paddy rice, and it is preferable to apply it before or during the weed growth period. The most effective results can be obtained when applied during the early stages of paddy rice growth, when weed damage is greatest. 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 (total amount of both compounds) is 10 to 1.000 g per 10 ares.
is preferably 10 to 500g, most preferably 20 to 400g
g is preferred. Next, the mixed herbicide of the present invention will be explained in detail using Examples (formulation examples and test examples). All test compounds are indicated by the abbreviations listed above. Note that "parts" in the formulation examples represent "parts by weight." Formulation Example 1 20 parts of Compound A, 40 parts of Compound B-1, 10 parts of white carbon, 25 parts of diatomaceous earth, 3 parts of Sozo ligninsulfonic acid, and 2 parts of sodium dodecylbenzenesulfonate were ground and mixed to obtain a wettable powder. Formulation Example 2 20 parts of Compound A, 30 parts of Compound B-2, 10 parts of emulsifier Solpol 355S (trade name: manufactured by Toho Chemical) and 40 parts of xylene were thoroughly mixed to obtain an emulsion. Formulation Example 3 2 parts of Compound A, 3 parts of Compound B-3, 70 parts of bentonite, and 25 parts of talc were pulverized and mixed, water was added, the mixture was kneaded, and the mixture was granulated and dried to obtain granules. Formulation Example 4 1 part of Compound A, 3 parts of Compound B-2, 20 parts of bentonite, and 76 parts of clay were pulverized and mixed, water was added, the mixture was kneaded, and the mixture was granulated and dried to obtain granules. Formulation Example 5 1 part of Compound A, 3 parts of Compound B-1, 1 part of sodium ligninsulfonate, and 95 parts of clay were ground and mixed to obtain a powder. Test Example 1 A 1/5.000 Earl Wagner pot was filled with soil, and seeds of Japanese millet and firefly were sown, and tubers of Japanese cypress and Japanese blackberry 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. Ten days after transplanting paddy rice, at the peak of weed growth, a predetermined amount of the test compound was submerged in water using a granule according to the method described in Formulation Example 3 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 by comparing the state of emergence or growth of crops or weeds with the air dry weight of untreated plots according to the following evaluation criteria. The test compounds have the above abbreviations, compound A, B-1,
B-2 and B-3 are respectively [A], [B-1] and [B
-2] and [B-3]. In addition, as a reference example, methyl-N-(3,4-
dichlorophenyl) carbamate (C) and 3
-(3,4-dichlorophenyl)-1-methoxy-
The herbicidal effect of 1-methylurea (D) (a compound described in JP-A-56-86179 as being usable in combination with Compound A) and the herbicidal effect of a mixture of these and Compound A were shown.

[Table] The numbers in parentheses in the table are Colby (Weed, Volume 15, Volume 20)
This is the predicted weed suppression value (P _E ) of the herbicide composition calculated by the following formula of 1967, p. 22). P _E = P _A + P _B (10 - P _A )/10 (P _A , P _B : Weed suppression value when the dosage of each component present in the herbicide composition is applied as a single agent) Weed suppression value When the actual value is larger than the expected value (P _E ), it indicates that there is a synergistic effect.

【table】

[Table] Test Example 2 A 50cm x 50cm x 30cm height outdoor concrete pot with a bottom was filled with soil, seeds of Japanese millet and firefly were sown, and tubers of Japanese cypress and Japanese black lily were planted, and the pot was flooded. A predetermined amount of the test compound according to the growth stage of each weed shown in Table 2 was treated under water using a granule according to the method described in Formulation Example 3 above. One month after the treatment, the herbicidal effect on weeds was investigated, and the results shown in Table 2 were obtained. The herbicidal effect was evaluated using the method of Test Example 1.

【table】

【table】

Claims (1)

[Claims] 1 3-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran and the general formula [In the formula, X represents a hydrogen atom, and R represents a 4-methylanilino group, a 1-bromo-2,2-dimethylpropyl group, or a 2-chlorobenzyl group, respectively] N-[α, α- 1. A herbicide composition comprising a mixture of dimethylbenzyl)amide derivatives. 2 3-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran and 1-(α,α-dimethylbenzyl)-3-(4-methylphenyl)urea The herbicidal composition according to claim 1, which is obtained by mixing the following in a ratio of 1:1 to 10 (weight ratio). 3 3-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran and N-(α,α-dimethylbenzyl)-α-bromo-1-butylacetamide The herbicidal composition according to claim 1, which is obtained by mixing the following in a ratio of 1:0.5 to 5 (weight ratio). 4 3-[2-nitro-5-(2-chloro-4-trifluoromethylphenoxy)-phenoxy]-tetrahydrofuran and N-(α,α-dimethylbenzyl)-2-chlorophenylacetamide in 1:
The herbicidal composition according to claim 1, which is mixed at a ratio of 0.5 to 10 (weight ratio).