JP3083204B2 - Paddy herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to herbicides, especially to paddy field herbicides.

[0002]

2. Description of the Related Art Although many herbicides, particularly herbicides for paddy fields, have been developed, there is still a need for highly selective herbicides with little phytotoxicity. In particular, in a paddy field, various kinds of weeds from first-year to perennial are generated over a long period from the transplanting stage to the growing stage of rice, and grow. Therefore, there is a need for a herbicide having a wide range of herbicidal spectrum and treatment application period.

Recently, 1- (α, α-dimethylbenzyl) -3- (2′-chlorobenzyl) urea (hereinafter referred to as compound A), methyl-α- (4,6-dimethoxypyrimidin-2-ylcarbamoyl) Sulfamoyl) -o
-Toluato (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-
Ylsulfonyl) -N '-(4,6-dimethoxy-2-
Pyrimidinyl) urea (hereinafter referred to as compound D) has also been proposed as a herbicide that meets the above demands (JP-A-60-172910, JP-A-57-112379, JP-A-5-11379).
Nos. 9-122488 and 64-38091).

[0004]

However, herbicides containing the above-mentioned compounds have high potency and can achieve the purpose of herbicidal use with a small amount of use. However, these herbicides, in particular, the herbicides comprising the compounds of B, C and D described above. For example, when used under poor growing conditions of paddy rice, phytotoxicity that cannot be practically used is observed. Particularly in paddy fields, the need for weeding is long, so the problem of chemical damage to rice is important.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a herbicide for a paddy field which does not selectively cause phytotoxicity to paddy rice and has a wider herbicidal spectrum and a wider application period. . Accordingly, the present invention provides a compound A,
Provided is 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 structural 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

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

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

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

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[0011] The herbicide of the present invention has a growth period of 1
It exhibits an extremely high herbicidal effect on perennial weeds as well as perennial weeds, especially fireflies and sedges, and does not harm rice. In addition, even if the herbicide containing only compound B, C or D shows a phytotoxicity which is difficult to put to practical use under the condition of poor growth of paddy rice, the herbicide of the present invention is practically ignored. The phytotoxicity can be greatly reduced to the extent possible. This is presumably because compound A has an effect of reducing the phytotoxicity of compound B, C or D.

In the herbicide of the present invention, Compound A and a compound selected from the group consisting of Compounds B, C and D may be mixed in any ratio.
And a compound selected from the group consisting of
It is preferable to mix them so that the ratio becomes 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 the rice.

The herbicide of the present invention can be formed into a formulation suitable for use in the same manner as a conventionally known herbicide containing only compound A, B, C or D. That is, the compound A of the active ingredient,
Compound B, Compound C or Compound D are mixed in the ratio described above, and these amounts are about 2-80% (% by weight) of the total amount of the preparation.
Prepared in such a manner that it is dissolved or dispersed in a liquid carrier, or mixed with a solid carrier, and further used as an emulsifier, spreading agent, dispersant, penetrant, etc. To be used in the form of granules, tablets, wettable powders, emulsions, flowables or hand-throwing preparations packaged with a water-soluble polymer film, etc., with the addition of adjuvants used for the purpose of improvement, etc. Can be.

Liquid carriers used for the preparation 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. 2
More than seeds are used.

As the solid carrier, mineral powders such as kaolin, bentonite, talc, potassium chloride, calcium carbonate, clay, shirasu balloon, perlite, vermiculite, starch, cellulose, glucose,
Suitable are plant powders such as maltose, lactose, xanthan gum and guar gum, and high molecular compounds such as polyvinyl chloride and petroleum resin.
More than seeds are used.

Various types of surfactants can be used. For example, nonionic surfactants (polyoxyethylene alkyl allyl ether, polyoxyethylene octyl phenyl ether, etc.), cationic surfactants (alkyldimethylbenzylammonium chloride, alkylpyridinium chloride, etc.), anionic surfactants (lignin Sodium sulfonate, dialkyl sulfosuccinate, etc.) and amphoteric surfactants (alkyl dimethyl betaine, dodecylaminoethyl glycine, etc.). One or more of these surfactants are used.

Other adjuvants other than those described above include casein, gelatin, albumin, glue, sodium alginate, carboxymethylcellulose, methylcellulose,
Hydroxyethyl cellulose, polyvinyl alcohol,
High molecular compounds such as sodium polyacrylate, sodium carbonate, sodium hydrogen carbonate, citric acid, malic acid,
Fumaric acid and the like can be used.

The above-mentioned carrier, surfactant and adjuvant include:
It is used singly or in combination according to the purpose, taking into account the dosage form of the preparation, the application scene, and the like.

Next, the herbicide for paddy fields of the present invention will be described with reference to examples, but the present invention is not limited to these. However, in the examples, “parts” indicates “parts by weight”.

Example 1 Granules (3 kg / 10a treating agent) 4 parts of compound A, 0.17 part of compound B, 3 parts of sodium ligninsulfonate, 60 parts of bentonite and 32.83 parts of talc were mixed and ground. An appropriate amount of water was added and kneaded, and the mixture was granulated by a usual method using a granulator to obtain granules.

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 ground, and 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 treating 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 kneaded by adding an appropriate amount of water. Granulation was performed by a usual method using a granulator to obtain granules.

Example 4. 30 parts of flowable compound A, 2 parts of compound C, 0.5 parts of polyoxyethylene nonyl phenyl ether, 0.2 parts of xanthan gum
And 67.3 parts of water were stirred with a chemical stirrer to obtain a flowable agent.

[0024]

The following effects are obtained when two kinds of herbicides, compound A and one selected from compound B, compound C or compound D, are mixed and used. That is, the drawbacks caused when each component is used alone, such as damaging the paddy rice or having a weed with a low herbicidal effect, are compensated for.

As described above, with respect to rice, factors affecting the growth of the rice seedling, such as the growth condition and transplanting depth of the rice seedling, the properties of the soil in the paddy, the soil condition, temperature, water temperature, and sunshine, are considered. Under poor growth conditions, compound B, compound C or compound D, which is difficult to put into practical use, is compound A.
The phytotoxicity-reducing action of the present invention greatly reduces it to a negligible level for practical use.

On the other hand, the weeds to be controlled by the paddy field herbicide of the present invention are extremely wide-ranging. For example, eel, azalea,
Perennial broadleaf weeds such as Sawa Pepper, Abnome, Azeugashishi, Azemushiro, Choujitade, Himesohagi, Kikashigusa, Mizumatsuba, Mizohakobe, Hoshikusa, etc. Family weeds, perennial weeds such as sedge beetle, pine beetle, kuroguwai, koukiyara, etc., and gramineous weeds such as dog millet and sand millet. In addition, the herbicide for paddy fields of the present invention has a suitable useable period from before the emergence of weeds to the growing season (two-leaf stage in Tainubie). On the other hand, it exhibits an extremely high herbicidal effect against perennial weeds, especially fireflies and sedges.

Next, the usefulness of the paddy field herbicide of the present invention will be specifically described with reference to test examples. Test Example 1. Potato rice phytotoxicity test A paddle paddy soil was filled in a Wagner pot having a size of 1/2000 ares, and two rice plants at the two leaf stage were transplanted as two single plants. The implantation depth was 0.5 cm and 2 cm, and the flooding depth was 3 cm. Five days after transplanting the paddy rice, a predetermined amount of the granules prepared according to the above example was sprayed on the soil surface. The paddy rice phytotoxicity was evaluated 30 days after application of the chemical, by cutting the above-ground part of the transplanted paddy rice, measuring the plant height (cm) and fresh weight (g), and comparing with the case of the complete weeding plot by manual weeding. The results are shown in Table 1 (implantation depth 0.5 cm) and Table 2 (implantation depth 2 cm).

Test Example 2. Test of herbicidal effect in a pot A paddy field soil was filled in a Wagner pot having a size of 1/2000 ares, and various seeds such as foxtail, conger and firefly were sown on the soil surface layer. Were filled. The flooding depth was 3 cm. At the early stage of weed development and the two-leaf stage of Echinochloa, a predetermined amount of the granules prepared in accordance with the above Examples was sprayed on the soil surface.

The herbicidal effect was evaluated by extracting the remaining weeds 30 days after the application of the chemical, measuring the fresh weight (g), and calculating the residual herbage rate with that of the untreated plot as 100%. The results are shown in Table 3.

Test Example 3. Herbicidal effect and phytotoxicity in the field
The test paddy field was sectioned into 1 m × 2 m (2 m ² ), and various seeds of foxtail, conger and firefly were sown on the soil surface layer, and tubers of urikawa, mizuyayatsuri and kuroguwai were embedded respectively. Furthermore, 24 rice plants were transplanted as four single rice plants at the 2 leaf stage. The flooding depth was 3 cm.

At 4 days after the transplantation of the rice (at the beginning of the emergence of weeds) and at 10 days (at the 2 leaf stage of the rice flour), a predetermined amount of the drug granules prepared according to the above-described example was evenly applied to the entire area of the compartment.

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

The herbicidal effect was evaluated by extracting the weeds remaining 40 days after the chemical treatment, measuring the fresh weight (g), and setting the residual weight as 100% in the untreated plot to calculate the residual weed rate.

The results are shown in Tables 4 and 5. Table 4 shows data 4 days after rice transplantation (early stage of weed development), and Table 5 shows data 10 days after rice transplantation (two-leaf millet).

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Iwao Taketomi 450-114 Ojiri, Hadano-shi, Kanagawa (72) Inventor Shuji Goto 2-10-1, Toranomon, Minato-ku, Tokyo Nippon Mining Building Dupont Tower Dupont-J Examiner Kenji Hara within Japan Limited (56) References JP-A-60-172910 (JP, A) JP-A-61-145155 (JP, A) JP-A-61-112003 (JP, A) JP-A Sho 62 -265207 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A01N 47/28 A01N 47/36 101

Claims (1)

(57) [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 herbicide for paddy fields comprising at least one compound selected from-(4,6-dimethoxy-2-pyrimidinyl) urea.