JPH05320011A - Herbicide for paddy field - Google Patents

Abstract

(57) [Summary] [Object] The present invention aims to provide a novel herbicide for paddy fields. [Structure] 1- (α, α-dimethylbenzyl) -3-
(2'-chlorobenzyl) urea (Compound A), methyl-α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate (Compound B), N-[(4,6 -Dimethoxypyrimidin-2-yl) aminocarbonyl] -4-ethoxycarbonyl-1
-Methyl-5-pyrazole sulfonamide (Compound C)
And at least one selected from N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N '-(4,6-dimethoxy-2-pyrimidinyl) urea (Compound D). A herbicide for paddy fields consisting of a compound. [Effect] The paddy field herbicide of the present invention has a broad herbicidal spectrum by mixing two kinds of herbicides having different actions, and is extremely effective against many paddy field weeds including annual weeds and perennial weeds. It shows a high herbicidal effect, and the phytotoxicity of paddy rice compounds B, C and D is greatly reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a herbicide, especially a herbicide for paddy fields.

[0002]

2. Description of the Related Art Although many herbicides, especially herbicides for paddy fields, have been developed, a herbicide with low phytotoxicity and high selectivity is desired. Especially in paddy fields, various weeds from the first year to the perennial are generated and grown for a long period from the transplanting period to the growing period of paddy rice, so that a herbicide having a wide herbicidal spectrum and a wide range of treatment application period is required.

By the way, in recent years, 1- (α, α-dimethylbenzyl) -3- (2'-chlorobenzyl) urea (hereinafter referred to as compound A), methyl-α- (4,6-dimethoxypyrimidin-2-ylcarbamoyl) Sulfamoyl) -o
-Toluate (hereinafter referred to as Compound B), N-[(4,6
-Dimethoxypyrimidin-2-yl) aminocarbonyl] -4-ethoxycarbonyl-1-methyl-5-pyrazolesulfonamide (hereinafter referred to as compound C) and N
-(2-chloroimidazo [1,2-a] pyridine-3-
Ilsulfonyl) -N '-(4,6-dimethoxy-2-
Pyrimidinyl) urea (hereinafter referred to as compound D) has also been proposed as a herbicide that meets the above-mentioned demand (Japanese Patent Laid-Open Nos. 60-172910, 57-112379, 5).
9-122488 and 64-38091).

[0004]

However, the herbicides containing the above-mentioned compounds have high potency and can achieve the purpose of weeding by using a small amount thereof, but these herbicides, particularly those containing the compounds of B, C and D as described above. For example, when it is used under the condition of poor growth of paddy rice, phytotoxicity which cannot be put to practical use is observed. Especially in paddy fields, the problem of phytotoxicity on paddy rice is important because weeding takes a long time.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a herbicide for paddy fields, which does not cause phytotoxicity selectively to the paddy rice and has a wider herbicide spectrum and a wider application period. .. Therefore, the present invention provides compound A
There is provided a herbicide comprising at least one compound selected from the group consisting of compound B, compound C and compound D.

The chemical names and chemical formulas of Compound A, Compound B, Compound C and Compound D of the present invention are shown below.

Compound A: 1- (α, α-dimethylbenzyl) -3- (2'-chlorobenzyl) urea

[Chemical 1]

Compound B: Methyl-α- (4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate

[Chemical 2]

Compound C: N-[(4,6-dimethoxypyrimidin-2-yl) aminocarbonyl] -4-ethoxycarbonyl-1-methyl-5-pyrazolesulfonamide

[Chemical 3]

Compound D: N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N '
-(4,6-Dimethoxy-2-pyrimidinyl) urea

[Chemical 4]

The herbicide of the present invention is used from 1
Not only annual weeds but also perennial weeds, especially firefly and Cyperus japonicum, have extremely high herbicidal effect, and do not cause phytotoxicity to rice. Even when the herbicide containing only the compound B, C or D has a phytotoxicity which is difficult to put into practical use under the bad growth condition of the paddy rice, the herbicide of the present invention ignores it for practical use. The drug damage can be greatly reduced to the extent possible. It is presumed that this is because Compound A has the effect of reducing the phytotoxicity of Compound B, C or D.

In the herbicide of the present invention, the compound A and the compound selected from the group consisting of the compounds B, C and D may be mixed at an arbitrary ratio, but the compound A and the compounds B and C are mixed.
And a compound selected from the group consisting of D and 4 by weight ratio.
It is preferable to mix so as to be 0: 1 to 5. Thus, the herbicide of the present invention may be applied in an amount of 50 to 300 g per 10 ares depending on the growing condition of paddy rice.

The herbicide of the present invention can be in the form of a formulation suitable for use like the conventionally known herbicide containing only the compound A, B, C or D. That is, the active ingredient compound A,
Compound B, compound C or compound D is mixed in the above-mentioned ratio, and these amounts are about 2 to 80% (% by weight) of the total amount of the preparation.
To be dissolved or dispersed in a liquid carrier or mixed with a solid carrier and further used as an emulsifier, spreading agent, dispersant, penetrant, etc. Add an auxiliary agent used for the purpose of improvement, etc., and use it by formulating it in the form of granules, tablets, wettable powders, emulsions, flowables, or a hand-throwing agent in which the above-mentioned preparation is wrapped in a water-soluble polymer film etc. You can

Liquid carriers used for formulation include alcohols such as methyl alcohol and ethyl alcohol, ketones such as acetone and methyl ethyl ketone, ethers such as dioxane and methyl cellosolve,
Aromatic hydrocarbons such as benzene and xylene, halogenated hydrocarbons such as carbon tetrachloride and methylene chloride, acid amides such as dimethylformamide, and esters such as ethyl acetate are suitable. One of these or Two
More than one seed is used.

As solid carriers, kaolin, bentonite, talc, potassium chloride, calcium carbonate, clay, shirasu balloon, perlite, vermiculite and other mineral powders, starch, cellulose, glucose,
Suitable are plant powders such as maltose, lactose, xanthan gum and guar gum, and polymer compounds such as polyvinyl chloride and petroleum resins, and one or two of these are suitable.
More than one seed is used.

Various types of surfactants can be used. For example, nonionic surfactants (polyoxyethylene alkyl allyl ether, polyoxyethylene octyl phenyl ether, etc.), cationic surfactants (alkyldimethylbenzyl ammonium chloride, alkylpyridinium chloride, etc.), anionic surfactants (lignin Sodium sulfonate, dialkylsulfosuccinate, etc.), amphoteric surfactants (alkyldimethylbetaine, dodecylaminoethylglycine, etc.) and the like. These surfactants may be used alone or in combination of two or more.

As auxiliary agents other than the above, casein, gelatin, albumin, glue, sodium alginate, carboxymethyl cellulose, methyl cellulose,
Hydroxyethyl cellulose, polyvinyl alcohol,
Polymer compounds such as sodium polyacrylate, sodium carbonate, sodium hydrogen carbonate, citric acid, malic acid,
Fumaric acid or the like can be used.

The above carriers, surfactants and auxiliaries are
In consideration of the dosage form of the preparation, the application scene, etc., they may be used alone or in combination depending on the purpose.

Next, the herbicide for paddy field of the present invention will be explained with reference to examples, but the present invention is not limited to these. However, in the examples, “part” means “part by weight”.

Example 1 Granules (3 kg / 10a treating agent) Compound A 4 parts, Compound B 0.17 parts, sodium lignin sulfonate 3 parts, bentonite 60 parts and talc 32.83 parts were mixed and pulverized, An appropriate amount of water was added and kneaded, and granulated by a usual method using a granulator to obtain a granule.

Example 2 Granules (1 kg / 10a treating agent) 15 parts of compound A, 0.21 part of compound C, 2 parts of polyvinyl alcohol and 82.79 parts of clay were mixed and pulverized, and then an appropriate amount of water was added. The mixture was kneaded and granulated by a usual method using a granulator to obtain granules.

Example 3 Granules (1 kg / 10a treatment agent) 15 parts of compound A, 1 part of compound D, 2 parts of polyvinyl alcohol and 82 parts of clay were mixed and pulverized, and then an appropriate amount of water was added to knead the mixture to prepare a mixture. Granulation was performed by a usual method using a granulator to obtain granules.

Example 4 Flowable Agent Compound A 30 parts, Compound C 2 parts, polyoxyethylene nonylphenyl ether 0.5 part, xanthan gum 0.2
Parts and 67.3 parts of water were stirred with a chemical stirrer to obtain a flowable agent.

[0024]

When two kinds of herbicides, compound A and one kind selected from compound B, compound C or compound D, are mixed and used, the following effects are brought about. That is, the drawbacks of using each component alone, such as chemical damage to paddy rice and weeds with low herbicidal effect, are compensated.

As described above, with respect to paddy rice, factors that affect the growth of paddy rice such as the growth state and transplantation depth of rice seedlings, the nature of soil in paddy fields, the condition of soil, temperature, water temperature, and sunshine are Under the bad growth condition, the compound B, the compound C, or the compound D is difficult to put into practical use.
Due to the phytotoxicity-reducing effect of, it is significantly reduced to a level that can be practically ignored.

On the other hand, the weeds to be controlled by the herbicide for paddy field of the present invention have a very wide range. For example, eel, azena,
Yearly broad-leaved weeds such as sweet pepper, abalone, red pepper, red-billed sardine, red-billed sardine, clovefish, scutellaria, scutellaria, hornbill, velvetleaf, sardine, sardine, velvetleaf, velvetgrass, etc. The family includes perennial weeds such as first-year weeds, Cyperus japonicus, pine nuts, kurogwai, and stigma, and grass weeds such as indigoe and tanubier. In addition, the paddy field herbicide of the present invention has a suitable period of use from before the emergence of weeds to the growing season (two-leaf stage in the rice ball), and only a 1-year-old weed from the pre-emergence to the growing season when mixed in small amounts. It also shows extremely high herbicidal effect against perennial weeds, especially firefly and cyperus.

Next, the usefulness of the paddy field herbicide of the present invention will be specifically described with reference to test examples. Test example 1. Paddy rice phytotoxicity test in pots Wagner pots with a size of 1/2000 are were filled with paddy field soil, and two 2-leaf stage paddy rice plants were transplanted as 2 strains per 2 strains. The implantation depth was 0.5 cm and 2 cm, and the submerged depth was 3 cm. Five days after transplanting the paddy rice, a predetermined amount of the granules prepared according to the above-mentioned example was sprayed on the soil surface. Paddy rice phytotoxicity was evaluated by cutting the above-ground part of transplanted paddy rice 30 days after spraying the drug, measuring the plant height (cm) and fresh weight (g), and comparing with the case of complete weeding by manual weeding. The results are shown in Table 1 (transplantation depth 0.5 cm) and Table 2 (transplantation depth 2 cm).

Test Example 2. Herbicidal effect test in pots Wagner pots with a size of 1/2000 are are filled with paddy soil, various seeds of rice, green onion, and firefly are sown on the soil surface layer, and tubers of Spodoptera litura are further sown. I filled four. The submerged depth was 3 cm. A predetermined amount of the granules prepared according to the above-mentioned example was sprayed on the soil surface at the initial stage of weed development and the 2nd leaf stage of Laminaria.

The herbicidal effect was evaluated by pulling out the weeds remaining 30 days after spraying the chemicals, measuring the fresh weight (g), and calculating the residual grass ratio with 100% as the untreated plot. The results are shown in Table 3.

Test Example 3. Herbicidal effect and phytotoxicity in the field
The test paddy field was divided into 1 m × 2 m (2 m ² ) and seeds of Taenia cinerea, Konagi and Firefly were sown on the soil surface layer, and tubers of Urikawa, Mizugaya-tsuri and Kurogwai were embedded respectively. In addition, 24 paddy rice plants at the 2-leaf stage were transplanted as 4 strains each. The submerged depth was 3 cm.

Four days after the transplantation of paddy rice (the initial stage of weed development) and 10 days after the transplantation (two leaves stage of Laminaria), a predetermined amount of the granules of the drug prepared according to the above-mentioned example was uniformly sprayed on the entire surface of the compartment.

The phytotoxicity of paddy rice was evaluated 40 days after the chemical treatment by cutting the above-ground part of the transplanted paddy, measuring the plant height (cm) and fresh weight (g), and comparing with the case of complete weeding by manual weeding.

The herbicidal effect was evaluated by extracting the residual weeds 40 days after the treatment with the chemicals, measuring the fresh weight (g), and calculating the residual grass ratio by setting the raw weight (g) as 100%.

The results are shown in Tables 4 and 5. Table 4 shows the data 4 days after the rice transplantation (the initial stage of weed development), and Table 5 shows the data 10 days after the rice transplantation (Tainubier 2 leaf stage).

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahide Onoue 2385 Toda, Atsugi-shi, Kanagawa Kitakogaku Atsugi Dormitory (72) Inventor Iwa Taketomi 450, Ojiri, Hadano, Kanagawa Prefecture (72) Inventor Shuji Goto Tokyo 2-10-1 Toranomon, Minato-ku, Nippon Mining Building DuPont Tower DuPont Japan Limited

Claims (1)

[Claims] 1. 1- (α, α-dimethylbenzyl) -3
-(2'-chlorobenzyl) urea and methyl-α-
(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl) -o-toluate, N-[(4,6
-Dimethoxypyrimidin-2-yl) aminocarbonyl] -4-ethoxycarbonyl-1-methyl-5-pyrazolesulfonamide and N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N ′
-A paddy field herbicide comprising at least one compound selected from (4,6-dimethoxy-2-pyrimidinyl) urea.