JPH0331204A - Herbicide composition for paddy field - Google Patents

Abstract

PURPOSE:To obtain the title compound effective and safe to a wide range of weeds in a growth period with a small amount of herbicide, comprising a pyrone-3-carboxamide derivative and 1(2-chlorobenzyl)-3-(alpha,alpha-dimethylbenzyl)urea as active ingredients. CONSTITUTION:A herbicide composition for paddy field comprising at least one pyrone-3-carboxamide derivative shown by the formula [R1 and R3 are the same or different lower alkyl, lower alkenyl or lower alkynyl; R2 is H, halogen, lower alkyl, lower alkoxy or H2 and R3 are bonded to form -(CH2)m- (m is 3 or 4); X is halogen, cyano, nitro, amino, lower alkyl or halogenated lower alkyl] and 1-(2-chlorobenzyl)-3-(alpha,alpha-dimethylbenzyl)urea as active ingredients. The blending ratio is the ratio of the former: the latter of 1:(0.5-30), preferably 1:(1-20) by weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel herbicide composition for paddy fields.

[Conventional technology and its problems]

Currently, many types of herbicides for agricultural use are on the market and are widely used. However, there are a wide variety of weeds in agricultural land, and it can be said that there is no single herbicide that satisfies the requirements of having a broad herbicidal spectrum and being completely free from chemical damage. Therefore, a method of using a mixture of two or more herbicides has been carried out in order to compensate for the drawbacks of each herbicide, and in particular, there are many types of herbicides used as herbicides for paddy fields.

However, in recent years, rice cultivation has become more mechanized, the transplanting period has been rapidly advanced, and the number of poorly maintained paddy fields due to labor shortages has increased, creating conditions more suitable for weeds to grow than ever before.

Therefore, it is no longer possible to expect a satisfactory herbicidal effect when using a single agent, or even when using a mixture as described above, unless it is repeatedly used several times in the same paddy field.
The use of such herbicides not only requires a great deal of labor, but also causes chemical damage and environmental pollution due to the use of large amounts.

[Means for Solving the Problems] The present invention was made in view of the above-mentioned problems of conventional herbicides, and the present inventors have achieved a method that completely exterminates all weed species with a single application. As a result of continuing to search for herbicides that cause extremely little chemical damage and low toxicity to humans and animals, we discovered that the above problems could be improved by blending and using two types of herbicides with different herbicidal actions in combination, and completed the present invention. It's arrived.

That is, the present invention provides the following general formula represents an alkoxy group, or R2 and R3 together represent -(C
)IZ), -(m is 3 or 4), χ is a halogen atom, a cyano group, a nitro group, an amino group, a lower alkyl group,
It means a halogenated lower alkyl group, hydroxy group, lower alkoxy group, aryloxy group, carboxyl group, or lower alkoxycarbonyl group. ] Pyrone-3-carboxamide derivative (hereinafter referred to as
A rice field characterized by containing at least one type of compound A) and 1-(2-chlorobenzyl)-3-(α,α-dimethylbenzyl)urea (hereinafter referred to as compound B) as active ingredients. The present invention provides a herbicide composition for use in pesticides.

Among the active ingredients of the herbicide composition of the present invention, compound A is
It is a well-known compound described in Japanese Patent Application Laid-Open No. 63-115878, and has a wide spectrum from grass weeds such as Japanese millet in rice fields to Cyperaceae weeds and broad-leaved weeds, but it does not grow well when used alone. It has the disadvantage that it is less effective against perennial weeds such as advanced firefly and cypress.

On the other hand, compound B is a known compound described in JP-A-60-172910, and is highly effective against weeds of the Cyperaceae family, including firefly and pineweed in rice fields.
When used alone, it has the disadvantage that it cannot be expected to be effective against broad-leaved weeds or weeds of the grass family, such as grass millet, which have advanced growth.

By using Compound A and Compound B, each of which has the above-mentioned drawbacks, in a mixture in an appropriate ratio, the present inventors compensate for the drawbacks of using each alone, and the herbicidal spectrum is expanded due to a significant synergistic effect. - By applying a small amount of the chemical from the early stage of growth to the growing season of annual to perennial weeds, and by spraying it multiple times, a high herbicidal effect can be maintained throughout the entire growing period of paddy rice, and excellent effects such as no chemical damage can be obtained. I found out the truth.

In other words, when Compound A and Compound B2 are mixed and used in an appropriate ratio, it can be expected to have a synergistic effect on Japanese millet and various broad-leaved weeds, and also be expected to have a stable effect on Cyperaceae weeds such as Cyperus and Cyperus, and is safe for paddy rice. Its properties are not impaired, and no problematic chemical damage occurs.

Compounds belonging to pyrone-3-carboxamide and having herbicidal activity are disclosed in the above-mentioned Japanese Patent Application Laid-open No. 63-115.
Although it is known from Publication No. 878 and the like, the herbicidal composition for rice fields shown in the present invention is a novel combination that has not been described in any literature, and of course there is no literature that mentions its unique herbicidal effect.

Examples of compounds are shown in Table-1. (Hereinafter, an example of Compound A is shown as Compound Nα in Table 1.) The unique herbicidal effect of the herbicide composition for rice fields of the present invention is due to the fact that Compound A and Compound B are blended in a fairly wide range of ratios. Although A:8 weight ratio is preferably 1:0.5 to 30, more preferably 1:
: range of 1 to 20.

Although the herbicidal composition of the present invention may be used as is, it is generally mixed with a solid carrier, liquid carrier, surfactant, or other formulation auxiliary to form an emulsion, wettable powder, suspension formulation, etc. Prepare and use.

In these preparations, the herbicide composition of the present invention is added to the total amount of active ingredients of Compound A and Compound B in wettable powders or suspensions.
0-80%, 2-10% for granules, 10-50 for emulsions
% (all % by weight).

Solid carriers used in formulation include fine powders or granules of kaolin, bentonite, clays, talc, diatomaceous earth, gicrite, zeolite, pyrophyllite, synthetic silicon oxide, calcium carbonate, etc. Liquid carriers include aromatic hydrocarbons such as xylene and methylnaphthalene, alcohols such as ethanol, isopropanol, ethylene glycol, and methyl cellosolve, ketones such as acetone, isophorone, and cyclohexanone, and vegetable oils such as soybean oil and cottonseed oil. , dimethylformamide, dimethylsulfoxide, acetonitrile, water, etc.

In addition, surfactants used for dispersion, emulsification, etc. include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene polyoxypropylene block polymer. nonionic surfactants such as, alkyl sulfate ester salts,
Examples include anionic surfactants such as alkyl sulfonates, alkylaryl sulfonates, and polyoxyethylene alkyl sulfate salts.

Formulation adjuvants include lignin sulfonates, alginates, polyacrylates, polyvinyl alcohol, vegetable gums, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), and the like.

Next, formulation examples using the herbicide composition of the present invention will be shown, but the present invention is not limited thereto. Note that parts indicate parts by weight.

Formulation example 1... Wettable powder Compound A-95 parts Compound 8 20 parts Talc 50 parts Bentonite
20 parts Tsurupol 5039 (Toho Kagaku type) 3 parts are ground and mixed to obtain a wettable powder.

Formulation Example 2 Granules Compound A-6 Compound B Talcum bentonite lignin sulfonate 0.5 parts 5 parts 60 parts 31.5 parts 3 parts The above ingredients were thoroughly ground and mixed, and water was added. The mixture is added, kneaded well, and granulated by a conventional method to obtain granules.

Formulation example 3 Suspension formulation Compound A-166 parts Compound 8 30 parts Ethylene glycol 2 parts Niercalgen CP-15-200 5 parts (Takemoto Yushi) 3 parts Nucalgen PS-P (Takemoto Yushi) Pronal 502 0. 5 parts (Toho Chemical Type) Xanthan gum 55.5 parts 0.15% aqueous solution The above ingredients are mixed well and wet-pulverized until the particle size is 5 microns or less to obtain a suspension preparation.

In the herbicide composition for paddy fields of the present invention formulated as described above, the wettable powder is usually diluted with water, and the granule and suspension formulations are used as they are by spraying on the soil or on the foliage and on the soil. .

In addition, the application amount of the above preparation varies depending on the mixing ratio of Compounds A and B, the formulation form, the type of target weed, growth conditions, weather conditions, etc., but usually the total amount of the active ingredients of Compound A and Compound B per 1 are. 1g to 80g, preferably 2g to s
It is og.

Furthermore, the herbicide composition for rice fields of the present invention can be used in combination with other insecticides, acaricides, nematicides, fungicides, herbicides, plant growth regulators, etc., as necessary. .

〔Example〕

Next, the usefulness of the present invention will be explained using Examples, but the present invention is not limited to these Examples.

Example 1 A 115,000-a Wagner pond was filled with paddy soil, and seeds of Japanese millet, Japanese grasshopper, Japanese cypress, firefly, and broad-leaved weeds (Azaena, Japanese sagebrush, and Japanese chickweed) and Pinus cabbage tubers were mixed in at a depth of 1 to 2 cm. After flooding and making it into a paddy field, we planted the tubers of Mizugaya spp.
．． Two plants (2 plants/plant) of paddy rice at the two-leaf stage were transplanted. still,
The warm water depth was set to 3C1.

Two days after transplanting paddy rice (weed initiation stage) and about 6 days after transplantation (first leaf stage of Japanese millet), Compound A and Compound B were mixed as shown in Tables 3 and 4 according to Formulation Example 1, and water was added. A predetermined amount of the chemical compound was dropped onto the flooded surface.

Thirty days after each chemical treatment, herbicidal effects and chemical damage were evaluated according to the criteria shown in Table 2.

Table 2 The evaluation results for the initial stage of weed emergence are shown in Table 3, and the evaluation results for the first leaf stage of Japanese millet are shown in Table 4.

Claims (1)

[Claims] 1 The following general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) [In the formula, R_1 and R_3 are the same or different and are a lower alkyl group, a lower alkenyl group, or a lower alkynyl group , R
_2 represents a hydrogen atom, a halogen atom, a lower alkyl group, or a lower alkoxy group, or R_2 and R_3 together represent -(CH_2)_m- (m is 3 or 4), and
means a halogen atom, cyano group, nitro group, amino group, lower alkyl group, halogenated lower alkyl group, hydroxy group, lower alkoxy group, aryloxy group, carboxyl group, or lower alkoxycarbonyl group. ] At least one pyrone-3-carboxamide derivative represented by and 1-(2-chlorobenzyl)-3-(α,
1. A herbicide composition for paddy fields, characterized by containing α-dimethylbenzyl)urea as an active ingredient.