JPH04173701A - Chemical injury-mitigative agent for paddy herbicide - Google Patents

Abstract

PURPOSE:To provide the title agent capable of mitigating the chemical injuries of paddy herbicides on paddy without impairing the excellent effects of said herbicides on weeds, containing a pyridyl phenylurea derivative as active ingredient. CONSTITUTION:The objective agent containing as active ingredient a pyridyl phenylurea derivative of the formula (R is H, halogen or lower alkyl). Water- surface treatment with its combined order with a paddy herbicide such as a sulfonylurea-based one during 1-15 days after paddy seedling transplantation which is corresponding to the period for applying said herbicide or during the time from germination to the fourth leaf stage for directly seeded paddy will mitigate the chemical injuries for said herbicide to such an extent as to be virtually negligible without impairing the inherent effects of said herbicide on paddy weeds.

Description

[Detailed description of the invention] l) Purpose of the invention Industrial applications TECHNICAL FIELD The present invention relates to a phytotoxicity reducer for herbicides for paddy rice.

More specifically, the present invention relates to a phytotoxicity reducer for herbicides for paddy rice, which contains as an active ingredient a pyridyl phenyl urea derivative represented by the following formula (I). Therefore, it is useful in the chemical industry and agriculture, especially in the field of pesticide manufacturing.

PRIOR ART Regarding the pyridylphenylurea derivatives which are the active ingredients of the present invention, the knowledge that N-7enyl-N'-(4-pyridylurea) derivatives have cynin activity is based on phytochemistry: Phytocbemi.
stry Vol. 17, pp. 1201-1207, 197
Known for 8 years. Furthermore, in JP-A-56-131506, N-(2-chloro-4-pyridyl)-urea derivatives exhibit cytokinin-like activities such as promoting cell division, cell elongation, and cell differentiation, and promote plant growth. It is described that it has uses as a plant growth regulator, such as increasing yields, inhibiting growth, and preventing aging. Among these, N-phenyl, N'-(2-chloro-4-pyridyl)urea,
It is also known that it is used as a plant growth regulator, such as on pages 398 and 541 of the "Pesticide Handbook 1989 Edition" (published by the Japan Plant Protection Association).

Also, in JP-A-1-151559, N-phenyl,
N'-(2-iodo-4-pyridyl)urea is N-(2
-Chloro-4-pyridyl)-urea derivatives have been described to exhibit similar cytokinin-like activity.

On the other hand, compounds have been proposed that reduce the phytotoxicity of useful cultivated plants without affecting the herbicidal action against harmful weeds. For example, the phytotoxicity of haloacetanilide-based and sulfonylurea-based herbicides to paddy rice, etc. is reduced by the use of phenyltriazine (JP-A-60-260502, JP-A-60-26050).
3), the phytotoxicity of sulfonylurea herbicides to paddy rice is 1-(α,σ-dimethylbenzyl)-3-p-
Tolylurea (Japanese Unexamined Patent Publication No. 303903/1983) can be reduced by the use of 7-enylpyrimidine (Japanese Unexamined Patent Publication No. 131702/1989), and the damage caused by haloacetanilide herbicides to various crops can be reduced by the use of 7-enylpyrimidine. Public bulletin) etc. are known.

However, until now, it has not been known that the compound of formula (I) described below of the present invention reduces the phytotoxicity of paddy rice caused by herbicides for paddy rice.

Problems to be Solved by the Invention Herbicides for paddy rice suppress the growth of paddy rice under conditions that are unfavorable to the growth of paddy rice, such as the transplanting depth of seedlings, properties of paddy soil, soil conditions, air temperature, water temperature, and sunlight. There are some substances that cause harmful effects that are difficult to put into practical use.

As mentioned above, phytotoxicity reducers have been developed for various herbicides, but these are not fully satisfactory. Therefore, the development of new drug-toxicity reducing agents is desired.

The present invention provides a novel phytotoxicity reducing agent for paddy rice herbicides that can reduce phytotoxicity to rice when used in paddy fields without impairing the excellent herbicidal effects of the various herbicides as described above. This is what we provide.

2) Means for Solving the Constituent Problems of the Invention In order to achieve the above object, the present inventors have intensively studied a large number of compounds. As a result, by incorporating a pyridyl phenyl urea derivative represented by the formula (wherein R represents a hydrogen atom, a halogen atom, or a lower alkyl group) into a rice herbicide and applying it to rice fields, the herbicide's excellent effects on weeds can be improved. It has been found that the herbicide damage to paddy rice can be reduced to a virtually negligible level without impairing the herbicide effect. That is, the present invention provides a weed killer for paddy rice characterized by containing a pyridyl phenyl urea derivative represented by the general formula (1) (wherein R represents a hydrogen atom, a halogen atom, or a lower alkyl group) as an active ingredient. Concerning safeners for drugs.

Specific examples of the pyridyl phenyl urea derivatives represented by the general formula (I) of the present invention are shown in Table 1.

1st Table 1 2 H187-189 2 3' H170-1713 4 H
164-165 4 4 2-CQ 171 5 4 2-1 181-1g3 In addition, compound No. is also referred to in the following examples and test examples.

Even when the compound of action formula (1) is applied alone to rice fields in an amount larger than the amount normally used as a herbicide, for example, 20,009 per 1O are, it does not show any herbicidal effect and does not cause phytotoxicity to paddy rice. do not have. However, when applied to paddy fields in combination with various herbicides as described below, it is possible to reduce the chemical damage to paddy rice that would otherwise occur if herbicides were used alone, without impairing the excellent herbicidal effects of these herbicides. , or lose it altogether. In this way, the compound of formula (1) is
Has a drug-damaging effect.

Example (Method of Formulation) When the compound of the formula (I) of the present invention is contained in a formulation together with a herbicide as a phytotoxicity reducer for a herbicide for paddy rice and treated in paddy fields, according to a conventional formulation, It can be prepared in an appropriate form such as an emulsion, an aqueous solution, a liquid, a flowable (sol), a granule, a fine granule, or a tablet.

The compounding ratio of the compound of formula (1) to the formulation amount of the rice herbicide is 0.1% to 5% for sulfonylurea herbicides and 0.1% to 5% for other herbicides in the case of granules.
In the case of irrigation agents, emulsions, and liquid preparations, it may be added in the range of 1% to 75% for any herbicide.

In order for the compound of formula (1) to be incorporated into a herbicide for paddy rice to exert a mitigating effect on paddy rice, the amount of application should be determined depending on the growth stage of the weed, the type of weed, the dosage form of the preparation, the application method, and the environmental conditions. Usually, formula (I)
The compound may be treated in an amount of active ingredient per 1O are of 3 g to 150 i+ in the case of sulfonylurea herbicides, and 3 g to 300 g in the case of other herbicides.

In addition, in order to effectively exert the effect of reducing the phytotoxicity of the paddy rice herbicide of the formula (I) compound on paddy rice, it is necessary to use it for 1 to 15 days after transplanting paddy rice seedlings, which corresponds to the period of use of the paddy rice herbicide, or for directly sowing paddy rice. Water surface treatment may be performed from the time of germination to the fourth leaf stage.

Specific examples of herbicides that can reduce only the chemical damage to paddy rice without adversely affecting the herbicidal effect on harmful weeds by incorporating the compound of formula (1) of the present invention are listed below.

Sulfonylurea herbicide (S-1) Methyl-2-(4,6-cymethoxypyrimidin-2-ylcarbamoylsulfamoyl)-ohruate (S-2) Ethyl-5-(3-(4 ,6-diftquinpyrimidin-2-yl)ureidosulfonyl)-1-methylbilaf-4-carboxylate (S-3) 3-(4,6-simethoxy1,3.
5-triazin-2-yl)-1-(2-(2-methoxyethquin)-phenylsulfonyl)urea (S-4) 2-chloro-3-(4,6-cymethoxypyrimidin-2-yl) Ureidosulfonylimidazolopyridine (S-5) 2-chloro-3-(4-methyl-6-
medoxypyrimidin-2-yl)ureidosulfonylimidazolopyrimidine (S-6) 2-bromo-3-(4,6-cymethoxypyrimidin-2-yl)ureidosulfonylimidazolopyrimidine (S-7) 2 -Chloro-3-(4,6-dime]・
2-chloro-5-ethoxy/-3-(4
,6-dimethoxy/pyrimidin-2-yl)ureidosulfonylpyrrolopyridazine (T-1) N,N'-diisopropyl-6-methylthio-1,3,5-triazine-2,4-diyldiamine (T-2)N, N'-diethyl-6-methylthio-1
,3,5-triazine-2,4-diyldiamine (T-3) N-(1,2-dimethylpropyl)-N'-ethyl-6-methylthio-1,3,5-triazine-2,4-diyldiamine (A-1) N-butquinmethyl-2-chloro-2
1.3.4-oxadiazole-2(
3H)-onne2,2-dioquindoyl-paratoluenesulfomonyloxy/-pyrazoleruvirab-5-ylloki/)-14'-methylacetophenol)-pyrazoltyl or amide derivative mido derivative or amide derivative S Holamidothioate phosphorodithioate phosphorodithioate naphthoquinone (M-2) 3.7-Dichloro-8-calhoki.

-quinoline (1-3) S,S-dimethyl-2-(difluoromethyl)-4-(2-methylpropyl) -6-(+・lifluoromethyl)-3,5-pyridinecarbothioate (M -4) Exo-1-methyl-4-(1-methylethyl)-2-((2-methylphenyl)methquine)-7-oxabinclo(2,2,1)hebutane Next, examples of the present invention were show. In addition, all parts in the examples are parts by weight.

Example 1 Sulfonylurea herbicide (hydrated compound No. 50 parts, herbicide No. 5-15 parts,
5 parts of polyoxyethylene alkylaryl ether,
3 parts of carunium lignosulfonate and diatomaceous earth
37 parts were mixed and thoroughly ground to obtain an irrigation agent containing 5% of the active ingredient.

Example 2 Sulfonylurea herbicide (granules) compound N
3 parts of O2 compound, 1 part of herbicide NoS-20, 1 part of lauryl sulfate, 1 part of carunium ligninsulfonate, 64.9 parts of bentonite and clay, and water
After adding 15 parts and kneading with a kneader, granulate with a granulator,
Dry in a fluidized fluid dryer to obtain granules containing 01% of the active ingredient.

Example 3 Sulfonylurea herbicide (granules) compound N
15 parts of water was added to 2 parts of ol compound, 2 parts of herbicide NoS-30, 1 part of lauryl sulfate, 1 part of cal/um lignin sulfonate, 30 parts of bentonite, and 65.8 parts of clay, and kneaded with a kneader. Thereafter, the mixture is granulated using a granulator and dried using a fluidized fluidized dryer to obtain granules containing 0.2% of the active ingredient.

Example 4 Amide herbicide (granules) Compound Nol 2 parts, herbicide No A-1
Add 15 parts of water to 2.5 parts, 1 part of lauryl sulfate, 1 part of carunium lignosulfonate, 30 parts of bentonite, and 63.5 parts of white clay, knead with a kneader, and then granulate with a granulator. The mixture is dried in a fluidized fluid dryer to obtain granules containing 2.5% of the active ingredient.

Effects of the Invention The herbicide for paddy rice containing the herbicide for paddy rice containing the phytotoxicity reducer of the present invention can be used for 1 to 15 days after transplanting paddy rice seedlings, which corresponds to the treatment period of the herbicide for paddy rice, or at the time of germination of directly sown paddy rice. to 4th
If used on the water surface during the leaf stage, the herbicide will exert a selective chemical damage-reducing effect on paddy rice without impairing its original herbicidal effect on paddy field weeds.

What is particularly noteworthy is that, as shown in the test example below, sulfonylurea herbicides were used alone from 1 day after transplanting paddy rice seedlings to I
If used within 10 days, or within 11 to 15 days after transplanting paddy rice, where phytotoxicity is relatively unlikely to occur, phytotoxicity due to growth inhibition may occur if used under high temperature conditions, or if a small amount of compound of formula (I) is used. 1 day after transplanting paddy rice by adding
Even when used within 15 days, the herbicidal effect is not reduced, and the damage caused to paddy rice by these sulfonylurea herbicides can be reduced to a completely negligible extent. In addition, herbicides other than sulfonylurea NOA 1% herbicide NoA-
2. Herbicides such as Herbicide No M-3 and Herbicide NoM-4 may cause growth-suppressing phytotoxicity when paddy rice is transplanted to a shallow depth; however, a small amount of the compound of formula (1) should be added. As a result, the phytotoxicity of these herbicides to paddy rice can be reduced.

Next, the usefulness of the phytotoxicity reducing agent for the herbicide for paddy rice of the present invention will be explained using test examples.

Paddy soil is filled into a 115,000-are container, water is added, and chemical fertilizer (N/P: K=1
7:17:17) After mixing 3i+ and puddling, paddy rice seedlings (variety: Nipponbare) in the second leaf stage were transplanted. Subsequent management was carried out in a glass greenhouse at 17°C to 28°C, and an irrigation agent prepared according to Example 1 was diluted with water to a predetermined dose and dropped into the fifth white of the rice after transplanting. . On the 21st day after the chemical treatment, the drying chamber for the stems, leaves and roots of the paddy rice was measured, and the ratio (%) to the untreated area was determined.

Note that this test was conducted in triplicate for each drug and each group.

The results are shown in Table 2.

Table 2 Test Example 2 Test for phytotoxicity on paddy rice (high temperature conditions, transplanted at 1150
Paddy soil is filled into a 0.00 are-sized Wakufurubo/L, and water is added to apply chemical fertilizer (NP: K = 17: 1).
7: After mixing 3 g of 17) and performing plowing, the second.
Paddy rice seedlings (variety Nipponbare) at the 5-leaf stage were transplanted. Subsequent management was carried out in an artificial climate room. In other words, 1 after transplanting paddy rice
From day 1 to day 1, the temperature was maintained at 15°C at night and 25°C during day, and on the 11th day after transplanting the paddy rice, a wettable powder prepared according to Example 1 of the pewter was added with water to a predetermined dose. It was diluted and added dropwise.

Thereafter, the plants were maintained under high-temperature conditions of 22°C at night and 32°C during day until the growth survey. Then, 21 days after the chemical treatment, the drying chamber of the pewter, stems, leaves, and roots of paddy rice was measured, and the ratio (%) to the untreated plot was determined.

This test was conducted three times per drug concentration section. The results are shown in Table 3. Zone I II+2 (l mXl+m) test zones were established. After that, seeds of Japanese millet, Japanese azalea, azalea, and firefly were planted, as well as tubers of Japanese cypress, black cypress, and urikawa, and five paddy rice seedlings in the second leaf stage were planted.
Plant 4 plants in 1 row at 20 crn intervals, 2 rows at a depth of 0.5-Icm (shallow planting), and similarly, 4 plants in 1 row, 2 rows at a depth of 2 cm (standard planting) The water depth was 4.
I entered the water so that I could become a cta. Five days after transplantation, a hydrating powder prepared according to Example 1 was diluted with water to a predetermined amount, and the solution was dropped. After 28 days of chemical treatment, the above-ground dry weight of 8 shallow-planted and 8 standard-planted paddy rice plants and all weeds growing in the plots were removed, the above-ground dry weight was determined, and the ratio (%) to the untreated plot was calculated. I asked for it.

Regarding the growth status of paddy rice in the control plot, Compound NO 1%, and Compound No. 2 test plot, various weeds that emerged were manually weeded as needed, and the rice plants from which the weeds had been eliminated were investigated.

Note that this test was conducted in duplicate per drug concentration group. The results are shown in Table 4.

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Claims (1)

[Claims] Contains a pyridyl phenyl urea derivative represented by the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R represents a hydrogen atom, a halogen atom, or a lower alkyl group) as an active ingredient. A phytotoxicity reducing agent for a herbicide for paddy rice, which is characterized by: