JPS638303A - Herbicidal composition for paddy field - Google Patents

Abstract

PURPOSE:The titled composition, containing specific compounds in combination as an active ingredient, capable of exhibiting wide and improved herbicidal effect on annual and perennial weeds with a smaller amount of chemical than the independent chemical by synergistic action without giving phytotoxicity to paddy rice. CONSTITUTION:A herbicidal composition containing N-chloroacetyl-N-(2,6- diethylphenyl)glycine ethyl ester and 2-(2,4-dichloro-3-methylphenoxy) propionanilide and/or 4-(2,4-dichloro-3-methylbenzoyl)-1,3-dimethyl-5-(p-methylph- nenacyloxy)pyrazole as an active ingredient. The blending weight ratio of the compounds is 1:0.2-20 of the former to the latter by pts. EFFECT:The period of use can be selected in a wide period from transplanting of paddy rice to the peak growth period of weeds and the herbicidal effect sustains for a long period. The post-emergence of weeds is substantially inhibited up until the harvesting period of paddy rice.

Description

[Detailed description of the invention] Technical field The present invention relates to a herbicidal composition for paddy fields.

By using a combination of specific compounds, the herbicide composition of the present invention can be applied in the summer at any time from immediately after rice planting to the peak of weed emergence to achieve an appropriate control effect on a wide range of annual and perennial weed species. Background of the Invention At present, many herbicides have been put into practical use for use in paddy fields.
They are widely used as a single agent or as a mixture containing two or more components. However, although these agents are extremely effective against annual weeds, they are insufficiently effective against perennial weeds, and as a result, perennial weeds have been rapidly increasing in rice fields in Japan in recent years.

These perennial weeds are very difficult to control because they are numerous in variety, highly prolific, and last for a long period of time. Although various herbicides have been sprayed repeatedly, the current situation is that sufficient effects have not been obtained.

Further, repeated application of such herbicides not only increases the labor burden, but also causes concerns about undesirable effects on the environment, such as accumulation in soil 1, lakes, marshes, and rivers due to large amounts of herbicide components being dropped.

PRIOR ART The compounds used as active ingredients of the herbicidal composition of the present invention are known. For example, N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester (hereinafter sometimes abbreviated as compound A) is described in Japanese Patent Publication No. 178-1983, etc. Dichloro-
3-methylphenoxy)propionanilide (hereinafter sometimes abbreviated as compound B) is disclosed in Japanese Patent Application Laid-Open No. 17190-1983.
4-(2,4-'chloro-3-methylbenzoyl)-1,3-dimethyl-5-(p-methylphenacyloxy)pyrazole (hereinafter sometimes abbreviated as compound C) is disclosed in Japanese Unexamined Patent Publication No. 57-72903.

However, when each of these compounds is used alone, the types of weeds that can be controlled are limited and the efficacy is not sufficient. For example, Compound A is effective against annual weeds, but less effective against perennial weeds. Although Compound B and Compound C mainly show excellent effects on broad-leaved weeds, they have low effects on narrow-leaved weeds such as Japanese grasshopper, Japanese cypress, and black-leaved weed.

SUMMARY OF THE INVENTION The present inventors have investigated mixtures of various herbicides in order to solve the above-mentioned problems, and have found that the above-mentioned problems can be solved for the first time by the herbicidal composition of the present invention, which uses a combination of specific herbicides. This was confirmed and the present invention was completed.

That is, the present invention provides N-chloroacetyl-N-(2,6-
-) ethyl phenyl) glycine ethyl ester 2-(
2,4-dichloro-3-methylphenoxy)propionanilide and/or 4-(2,4-dichloro-3-methylbenzoyl)-1,3-dimethyl-5-(p-methylphenacyloxy)pyrazole An object of the present invention is to provide a herbicide composition for paddy fields, which is characterized by containing the present invention as an ingredient.

Effects of the Invention The herbicide composition of the present invention not only complements each other against weeds that are difficult to control using each of the active compounds alone, but also suppresses weeds with low weeds that cannot be controlled using each active compound alone. It has an appropriate weeding effect on a wide range of annual and perennial weeds in terms of quantity, and does not cause any chemical damage to paddy rice.

Moreover, the period of use can be arbitrarily selected within a wide period from immediately after transplanting paddy rice to the peak of weed growth. Furthermore, the herbicidal effect lasts for a long period of time, and virtually no weeds are allowed to emerge until the paddy rice harvest period.

These excellent effects clearly indicate the existence of a strong synergistic effect between the respective active ingredients contained in the composition of the present invention, which was completely unexpected and not seen in conventional mixtures. This shows the effect that is not possible.

Furthermore, since the composition of the present invention requires a significantly smaller amount of active ingredients to be applied than conventional herbicides, it is highly safe for the environment, crops, and users, and is a herbicide that meets the needs of the times. I can say that.

DETAILED DESCRIPTION OF THE INVENTION The herbicide composition for rice fields of the present invention exhibits a strong synergistic effect in a wide range of composition ratios.
,6-diethylphenyl)glycine ethyl ester (compound A) and 2-(2,4-dichloro-3-methylphenoxy)propionanilide (compound B) or when compound A to 4-(2, 4-dichloro-3-
methylbenzoyl) -1,3-dimethyl-5-(p-
When using a mixture of methylphenacyloxy)pyrazole (compound C), the mixing ratio of each active ingredient is 0.
．． The amount is 2 to 20 parts by weight. Preferably, the amount of Compound BO is 5 to 3 parts by weight or 2 to 10 parts by weight of Compound BO per 1 part by weight of Compound A.

When using a mixture of Compounds A, B71 and C as the herbicide composition of the present invention, the mixing ratio is (10 parts of Compound BO12 to 10 parts and 10 parts of Compound 01 to 1 part by weight of Compound A).
-20 parts, preferably 15-2 parts of Compound BO and 1 part of Compound C2-6.

The effective application rate of the composition of the present invention varies depending on the area to be controlled, the type of weed, the density of infestation, etc., but the amount of mixed active ingredients is 0.1 to 4 soils per ha, preferably 0.3 to 2 soils per hectare.
It's savings.

The timing of use of the herbicide of the present invention can be arbitrarily selected from a wide range from immediately after transplanting paddy rice to the peak of weed emergence (approximately 15 days after transplanting);
The best results can be obtained if the treatment is carried out on days (days).

When applying the composition of the present invention as a herbicide, a suitable carrier is generally used, such as a solid carrier such as clay, talc, bentonite, diatomaceous earth, etc., or a carrier such as water, alcohols (methanol, ethanol, etc.), aromatic hydrocarbons (benzene, etc.). , toluene, xylene, etc.), chlorinated hydrocarbons, ethers, ketones, esters, and acid amides (dimethylformamide, etc.) for convenience.

Furthermore, if desired, commonly used emulsifiers, dispersants, suspending agents, penetrating agents, spreading agents, stabilizers, etc. may be added to form any desired dosage form such as granules, emulsions, wettable powders, and sol preparations for practical use. However, preferably, it is easiest and most effective to spray the powder as granules using a rotary granulator, a power sprayer, etc. Further, if necessary, it may be used in combination with other various insecticides, fungicides, plant preparations, military agents, etc. during formulation or spraying.

In addition, especially in paddy fields where large amounts of perennial Cyperaceae weeds such as Cyperaceae and Cyperaceae occur, other herbicidally active compounds such as N-α,α-dimethylbenzyl −
Bromo-2-tert-butylacetamide, l-(α
, α-dimethylbenzyl)-3-p-tolylurea, 3
-Isopropyl-IH-2,1,3-benzothiacyanone-(4)-3H-one-2,2-dioxide and the like can be mixed and applied.

EXPERIMENTAL EXAMPLES The present invention will be explained in more detail with reference to formulation examples and test examples below. "Parts" used in the examples are by weight.

Formulation Example 1 (granules) 1 part of Compound A, 1 part of Compound B, 35 parts of bentonite, 59 parts of clay, 2 parts of sodium dodecylbenzenesulfonate and 2 parts of lignin sulfonate/sodium acid were mixed, pulverized and homogenized, and an appropriate amount Add water, knead, extrude and granulate.
The mixture was dried and sized to obtain granules.

Formulation example 2 (granules) 3 parts of compound 0 was used instead of 1 part of compound B, and 57 parts of clay was used instead of 59 parts of clay. Emulsion) 5 parts of Compound A, 88 parts of Compound, 8 parts of polyoxyethylene alkyl allyl ether, 9 parts of calcium dodecylbenzenesulfonate, 35 parts of xylene and 35 parts of cyclohexanone were mixed and homogenized to obtain an emulsion. Test Example 1 (by mixing) Paddy soil and chemical fertilizer were placed in a Wagner pot with an area of 20 G, and an appropriate amount of water was added and thoroughly stirred to form a paddy field.Additionally, paddy rice at the two-leaf stage, which had been grown in a greenhouse in advance, was added. Transplant 2 seedlings per pot,
A certain amount of firefly tubers and tubers of Urikawa and Cyperus japonica were sown. Five days after transplantation and seeding, a predetermined amount of the test compound was treated with granules (formulated according to Formulation Examples 1 and 2).

Thirty days after the chemical treatment, the herbicidal effect and the degree of chemical damage to paddy rice were investigated, and the results are shown in Tables 1 and 2. In addition, the herbicidal effect on each grass species and the degree of chemical damage to paddy rice are determined by numerical values in 6 stages from "O" to "5" and codes in 6 stages from "-" to "x" according to the following guidelines. expressed.

Table-1 *“Oza” = product name, Monsando Co., Ltd. Ributachlor 3
．． A mixed herbicide containing 5% and Mitsui Toatsu Kagaku Mutsunaproani IJdoor% as active ingredients. It can be seen that various weeds can be controlled with low doses. In addition, the amount of active ingredient applied per unit area is less than half that of general commercially available agents, and the purpose can be fully achieved.

Test Example 2 (Effect of extending the period of use by mixing) Pots prepared in the same manner as Test Example 1 except that the weed species were 2 grass species, wild grass and firefly, were treated with each drug (granules) over a period of time. 40 days after the pot preparation, the herbicidal effect was determined using the same criteria as Test Example 1. The results are shown in Tables 3 and 4.

(See margins below) These results show that the active ingredients of the composition of the present invention act synergistically to significantly extend the weeding period.

The excellent synergistic effect between the active compounds brought about by the present invention is already clear from the results of Test Examples 1 and 2, but the interaction will be explained in more detail using representative plants.

Colby's calculation formula is usually used as a method for testing the interaction between two types of active compounds. That is, where, X: herbicidal effect (%) when compound m cape/ha
If the expected herbicidal effect (2) or actually measured herbicidal effect (%) exceeds E, it means that the composition has a synergistic effect, and if it is less than E, it means that the composition has an antagonistic effect. The interaction test of the herbicide composition for paddy fields of the present invention and its results are shown below in Test Examples 3 and 4 and Tables 5 and 6.

Test example 3 (test of interaction between compound A and compound B) side f
Paddy soil mixed with an appropriate amount of chemical fertilizer is placed in a 200 t, nl, 13 cm deep plastic container, water is added and stirred to form a water-mixed state. Ten tubers of Urikawa were embedded in each pot and grown in a greenhouse while maintaining a water depth of 3 ctn. Nine days after seeding, a predetermined amount of the test compound was treated in the same manner as in Test Example 1. After 30 days of chemical treatment, the remaining above-ground parts of the weeds were cut and collected, the fresh weight was measured, and the weeding rate (%) compared to the untreated area was calculated. Table 5 shows the results.

(Leaving space below) Table 5 Test Example 4 (Analysis of interaction between Compound A and Compound C) The same procedure as Test %J3 was carried out, except that tubers of Cyperus spp. The results of the tests conducted are shown in Table 6.

(The following is a blank space) Table 6 From the above results, it can be seen that the herbicidal activity of the herbicide composition of the present invention is clearly due to the synergistic effect between the respective active compounds.

Finally, Test Row 5 and Table 7 show test results in which the herbicide composition of the present invention was actually applied to a paddy field to determine its practicality.

Test Example 5 (Field Test) A paddy field that had been planted according to normal farming methods was tested using a ridge sheet (manufactured by Shin-Etsu F-Higaku: trade name "Azenami").
The plots were divided into 10rrX (4m x 2.sm) plots, and each drug was treated using granules on the 8th day after rice planting. Thereafter, 40 days after the chemical treatment, the herbicidal effect and paddy rice damage were determined using the same criteria as in Test Example 1 while performing normal management. The results are shown in Table 7.

It should be noted that all weeds in the ponds where the wildflower seeds were sown were naturally occurring.

Table 7 *Shoron MJ = trade name, mixed herbicide containing MO manufactured by Mitsui Toatsu Chemical Co., Ltd. and Daimeron manufactured by Showa Denko Co., Ltd. as active ingredients.

As shown by the results of Test Examples 1 to 5, the herbicide composition of the present invention can effectively control various weeds with a low chemical composition unprecedented for conventional herbicides, and can be used as a material for agricultural cooperatives. It is extremely useful as a

Claims (1)

[Claims] (1) N-chloroacetyl-N-(2,6-diethylphenyl)glycine ethyl ester and 2-(2,4-dichloro-3-methylphenoxy)propionanilide and/or 4-(2,4-dichloro -3-Methylbenzoyl)-1,3-dimethyl-5-(p-methylphenacyloxy)pyrazole as an active ingredient.