JPH04334302A - Herbicidal drug for paddy field - Google Patents

Abstract

PURPOSE:To provide the subject herbicidal drug for paddy fields, suitable for paddy surface application before and after transplantation, capable of labor saving application without walking in the paddy field for application thereof or dispensing with a special applicator, showing a certain herbicidal effect and free from chemical injury to paddy rice. CONSTITUTION:A liquid prepared by dissolving or suspending an active herbicidal component and a surfactant in an organic solvent is put in a package made of a water-soluble polymer film such as polyvinly alcohol, carboxymethylcellulose, dextrin, hydroxymethyl-cellulose or gelatin to obtain the objective herbicidal drug for paddy field having a spherical shape such as soft capsule or a package shape such as a bag. The above-mentioned film of the above-mentioned drug is dissolved in the paddy water and the active component is simultaneously emulsified or suspended and uniformly dispersed therein by the surfactant. Since application can be carried out by throwing it from the levee side therefor, ready and labor saving application is possible. In addition, even in the case application after transplantation, there is no danger of contact chemical injury due to the organic solvent as the content is gradually released and diluted with water without direct contact with water rice.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicidal preparation for treating paddy fields.

0002

BACKGROUND OF THE INVENTION Granules and emulsions for spraying on water have generally been used as labor-saving herbicide formulations that can be easily applied to flooded rice fields.

However, granules generally contain active ingredients at a relatively low concentration of about 5 to 15%, and are pulverized together with inorganic carriers such as bentonite, clay, kaolin, and talc, and various auxiliaries and surfactants. , mixing, kneading, granulation, drying, and classification processes, so the manufacturing cost is high. Further, the amount of spraying is usually large, 3 to 4 kg per 10 ares, and if the amount of spraying is smaller than this, the effect tends to vary due to uneven spraying. Furthermore, it has the disadvantage that it requires manual spreading while walking within the field or requires a special spreader.

[0004] On the other hand, emulsions for water surface spraying require a smaller amount of spray per unit area than when spraying granules, but like granules, they require walking or a special sprayer to spread across the field. , it cannot necessarily be said that it is a labor-saving formulation form. Furthermore, when such an emulsion is sprayed after transplanting paddy rice seedlings, there is a drawback that the organic solvent in the formulation tends to cause chemical damage to the paddy rice.

[0005] In JP-A-60-61504 and JP-A-2-48505, polyvinyl alcohol and carboxymethyl cellulose are used for the purpose of improving the dusting that occurs when diluting a wettable powder for foliage spraying with water. A product in which a powdered hydrating agent is enclosed in a bag made of a water-soluble polymer film such as , dextrin, or hydroxymethyl cellulose has been disclosed, but no herbicide that can be applied directly to rice fields is known.

[0006]

[Problems to be Solved by the Invention] The present inventors have developed an object that is suitable for rice field treatment before and after rice planting in paddy fields, and eliminates the need to walk within the rice field or use a special spreader during spraying, and is labor-saving. The present invention was achieved through research into a herbicidal formulation for paddy fields that can be applied, has a reliable herbicidal effect, and has no risk of phytotoxicity to paddy rice.

[0007]

[Means for Solving the Problems] The present invention is a herbicidal preparation for rice fields, in which a liquid obtained by dissolving or suspending a herbicide active ingredient and a surfactant in an organic solvent is sealed in a water-soluble polymer film container.

[0008] In this preparation, the herbicide active ingredient is not necessarily limited to being dissolved in an organic solvent, but the herbicide active ingredient may be stably suspended and dispersed in the organic solvent in the form of fine particles. . This content has a property of immediately emulsifying or suspending and dispersing in rice field water when it comes into contact with water.

[0009] If the undiluted solution of this content is applied directly to paddy fields,
If it comes into contact with paddy rice, there is a risk of serious chemical damage to the paddy rice as mentioned above, but even if the preparation of the present invention is applied to the rice field after rice transplantation, the contents will not come into direct contact with the paddy rice. Since it is gradually released and diluted with water, there is no need to worry about contact damage caused by organic solvents. In the applied herbicidal preparation of the present invention, the film film gradually dissolves in the rice field water for a certain period of time after treatment, and the herbicide active ingredient contained therein is emulsified or suspended and dispersed in the rice field water or on the rice field surface. Demonstrates high weeding effect.

The shape of the herbicidal preparation for paddy fields of the present invention is usually 1.
It has a volume of about 0 to 100 cm3, and is spherical like a soft capsule or packed like a bag, and the active herbicide ingredient enclosed in a water-soluble polymer film container is uniformly dispersed in the water on the rice field. Therefore, when applying it, it is possible to throw it into the field from the ridge. The application quantity is
Various changes can be made depending on the type and content of the herbicide active ingredient. Although not particularly limited, 3 to 30 pieces, preferably 6 to 10 pieces per 10a paddy field is suitable. Therefore, there is no need to walk across the field when spraying.
Furthermore, it only takes a few minutes to spray on rice fields, making it a convenient and labor-saving formulation.

[0011] When the herbicide formulation of the present invention having a spherical or pack-like shape is applied to a rice field, the water-soluble polymer film is dissolved by the rice field water, and the herbicide active ingredient contained therein is emulsified or is suspended and dispersed evenly in the rice water. The time it takes for the film to dissolve in rice field water can be arbitrarily adjusted depending on the water-soluble polymer used, but desirably, the content is dissolved within 1 minute to 24 hours after dropping the formulation of the present invention into rice field water. It is important to select water-soluble polymers so that substances can be diffused.

The water-soluble polymer film that can be used is not particularly limited as long as it has the above-mentioned water solubility, is moldable, and can encapsulate the herbicide active ingredient, but for example, , polyvinyl alcohol, carboxymethylcellulose, dextrin, hydroxymethylcellulose, gelatin, and the like. Specifically, a film made of polyvinyl alcohol with a degree of polymerization of 500 to 2,500 and a degree of saponification of 82.0 mol% or more and a film thickness of 20 to 40 μm, such as Toslon ET-20 manufactured by Tokyo Cellophane Paper Co., Ltd. #30,
Examples include Toslon ET-20 #40.

[0013] The herbicide active ingredients used in the present invention include the following. In addition, the name in parentheses represents the common name or test name of the herbicide active ingredient. S-(α,α-dimethylbenzyl)piperidine-1-carbothioate (dimepiperate), S-(4-chlorobenzyl)N,N-diethyl-thiocarbamate (benthiocarb), S-ethyl N,N-hexa Methylene-thiocarbamate (
molinate), S-benzyl N-ethyl-N-(1
, 2-dimethylpropyl)thiocarbamate (esprocarb), 2-benzothiazol-2-yl-oxy-
N-methylacetanilide (mefenacet), 2-chloro-2',6'-diethyl-N-(2-propoxyethyl)acetanilide (pretilachlor), 2-chloro-N-(3-methoxy-2-thienyl)methyl- 2'
, 6'-diethylacetanilide (NSK-850),
3,7-dichloro-8-quinolinecarboxylic acid (quinclorac), 2,3-dihydro-3,3-
Dimethyl-5-benzofuranylethanesulfonate (benfuresate), 2-bromo-N-(α,α-dimethylbenzyl)-3,3-dimethylbutanamide (bromobutide), 2-(2,4-dichloro-3- methylphenoxy)propionanilide (clomeprop), 1-(2-
chlorobenzyl)-3-(α,α-dimethylbenzyl)
Uria (JC-940), methyl-α-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-ο-toluate (bensulfuron methyl).

The herbicidal preparation for rice fields of the present invention contains an alkylbenzenesulfonate, an alkylnaphthalenesulfonate, or a dialkylsulfosuccinate salt as a surfactant in order to emulsify or suspend and disperse the herbicide active ingredient in the rice field water. Anionic surfactants such as sorbitan fatty acid ester, polyoxyethylene (hereinafter referred to as POE) sorbitan fatty acid ester, POE alkyl ether, POE
Nonionic surfactants such as fatty acid ester, POE vegetable oil, POE alkylamine, POE fatty acid amide, POE alkyl phenylene ether, POE alkyl phenyl ether formaldehyde condensate, polyoxyalkylene styrylated phenyl ether, polyoxyethylene-polyoxypropylene block polymer, etc. One or two of the agents
More than one seed can be added. The blending amount thereof is 1 to 15% by weight of the contents.

Furthermore, the herbicidal preparation of the present invention may contain a thixotropic agent such as white carbon, synthetic smectite, or quaternary ammonium bentonite for the purpose of improving storage stability. The blending amount is 0.0% of the content.
It is 1 to 5% by weight.

The organic solvent in which the herbicide active ingredient and surfactant used in the present invention are dissolved or suspended is an aromatic solvent having 8 to 16 carbon atoms, such as xylene, Solveso 200 [Exxon Chemical Co., Ltd.] Solbeso 150
[manufactured by Exxon Chemical Co., Ltd.]; paraffinic hydrocarbon solvents having 9 to 17 carbon atoms, such as liquid paraffin and kerosene; or in addition to these solvents, vegetable oils such as soybean oil, olive oil, and rapeseed oil. One species or two or more species can be used.

Next, the method for producing the herbicidal preparation of the present invention will be explained. First, a surfactant and a herbicide active ingredient are dissolved in an organic solvent, and then other herbicide active ingredients that do not dissolve in the organic solvent and a thixotropic agent are added. This product is milled using a wet ball mill such as Dyno Mill KDL model (manufactured by WAB) or Sand Grinder SL model (manufactured by Igarashi Kikai Co., Ltd.) so that 90% or more of the active ingredients have a particle size of 10 μm or less, preferably 0.1 to 5 μm. The contents are obtained by wet milling until the average particle size falls within the range of . Subsequently, this product is filled and sealed in a container made of a water-soluble polymer film. Further, sealing may be performed if necessary, but either heat sealing or adhesive bonding is possible. The bag making and filling machine used for bag making and filling is, for example, automatic bag making and filling machine GP-1000B2 (manufactured by General Packer Co., Ltd.), TWX1 (manufactured by Tokyo Automatic Machinery Works Co., Ltd.), and the like.

[0018]

[Examples] The present invention will be explained in more detail with reference to Examples and Test Examples, but the present invention is not limited to these Examples.

Example 1 30% by weight of dimepiperate, 10% by weight of calcium dodecylbenzenesulfonate, polyoxyethylene tristyrylphenyl ether (having 12 EO units) 5
5% by weight of polyoxyethylene castor oil (with 40 EO units) and 48.5% by weight of xylene were stirred until a homogeneous solution was obtained. This material was then milled in a wet ball mill (Willy A. Bachofen
0.5% by weight of bensulfuron methyl and 1% by weight of white carbon (Nip Seal NS-T, manufactured by Nihon Silica Kogyo Co., Ltd.) were added.
Grinding was carried out for 2 hours at a rotation speed of 2300 rpm. The obtained suspension was passed through an automatic bag making and filling machine (GP, manufactured by General Packer Co., Ltd.) using a film of polyvinyl alcohol (saponification degree: 80%, polymerization degree: 2000) (Toslon ET-20#40, manufactured by Tokyo Cellophane Paper Co., Ltd.). -1000B2) was used to form and fill bags to obtain a preparation having a pack-like form. The volume of this was 60 ml.

Example 2 A homogeneous solution of dimepiperate and a surfactant similar to that in Example 1 was transferred to a wet ball mill (Dynomil, manufactured by WAB), and further mixed with 1% by weight of bensulfuron-methyl, 4% by weight of quinclorac, and white. A suspension was obtained in the same manner as in Example 1 by adding 1% by weight of carbon. This product was made into bags and filled with the same polyvinyl alcohol film as in Example 1 to obtain a preparation having a volume of 60 ml.

Example 3 25% by weight of dimepiperate, 7% of benfuresate, 10% by weight of calcium dodecylbenzenesulfonate, polyoxyethylene styrylphenyl ether (12 EO
units) 5% by weight, ethoxylated castor oil (40% by weight)
5% by weight of EO units) and 46% by weight of xylene were stirred until a homogeneous solution was obtained. Next, this material was transferred to a wet ball mill (Dyno Mill, manufactured by WAB), and 1% by weight of bensulfuron methyl and 1% by weight of white carbon were added to obtain a suspension in the same manner as in Example 1. This product was made into bags and filled with the same polyvinyl alcohol film as in Example 1 to obtain a preparation having a volume of 60 ml.

Comparative example 1 The suspension before bag making and filling in Example 1 was used as it was.

Test Example 1 A paddy field (Ami Town, Ibaraki Prefecture) that had been planted according to customary practices was
One section is 100m2 (10m x 1
0m). 10 germinated seeds each of Japanese grasshopper, Japanese grasshopper, and firefly were sown at diagonal points every 2 m from the center of each plot. (See Figure 1)
At the 1.5-leaf stage of wildflowers, one piece of the preparation of the present invention of Example 1 was dropped in the center of the plot. In addition, 60 ml of the suspension of Comparative Example 1
was sprayed dropwise while walking around the ward. Thirty days after spraying, the herbicidal effect and paddy rice damage at each location were observed and investigated. The results are shown in Tables 1 and 2. In addition, the herbicidal effect and paddy rice damage for each grass species in the table are shown in the range from "0" to "5", respectively.
” and 6 grades from “-” to “×”.
Expressed by stage code. ──────────────────
──────────
Weeding effect
Paddy rice chemical damage ────────────
────────────
Evaluation score Weeding rate (%)
Code Degree of drug damage
────────────────────────
─── 5
100 ×
Withering 4 80
More than 100 +++
Major damage 3 60 or more but less than 80 ++
Intermediate damage 2 40 or more
Less than 60 + Minor damage 1 20 or more 4
Less than 0 ± slight harm
0 to less than 20 - harmless
────────────────────
───────

[0024]

[Table 1]

[0025]

[Table 2]

Test Example 2 A paddy field (Ami Town, Ibaraki Prefecture) that had been planted according to customary practices was
One section is 100m2 (10m x 1
0m). Seven days after rice planting, the formulation of the present invention of Example 3 was dropped in the center of the plot. Drop 30
After 1 minute, 1 hour, 3 hours, 6 hours, and 24 hours, rice water was sampled from diagonal sampling points 2 m apart from the center (see Figure 1). Component concentrations were determined. The results are shown in Table 3.

[0027]

[Table 3]

[0028]

Effects of the Invention: As is clear from the above test examples, by applying only one formulation of the present invention to a rice field per 100 m2, a uniform herbicidal effect is achieved throughout the area, and the emulsion of the comparative example shows no chemical damage to paddy rice. It can be seen that the herbicidal preparation is very labor-saving compared to the case where the herbicidal agent is applied.

[Brief explanation of drawings]

FIG. 1 shows a map of the test field.

Claims (1)

[Claims] 1. A herbicidal preparation for paddy fields, comprising a solution in which a herbicide active ingredient and a surfactant are dissolved or suspended in an organic solvent and sealed in a water-soluble polymer film container.