JPH0640822A - Herbicidal capsule for direct sowing cultivation for direct application on water surface - Google Patents

Abstract

PURPOSE:To obtain a herbicidal capsule, applicable according to a simple method without entering paddy field in direct sowing of rice on flooded paddy field and enabling a herbicide to have a high level of selectivity and manifest herbicidal effects without causing phytotoxicity even by treatment from the time of germination of rice plant to the extremely initial period of growth. CONSTITUTION:The capsule for direct sowing cultivation for direct application on the water surface is obtained by including 2',3'-dichloro-4- ethoxymethoxybenzanilide and N-(2chloroimidazo[1,2-a]pyridin-3-ylsulfonyl-N '-(4,6-dimethoxy-2-pyrimidinyl)urea, blending an oily substance as a solvent or a dispersion medium therewith, further blending a surfactant as an emulsifying agent, a dispersing agent or a spreader and sealing the resultant oily formulation in a gelatin film improved in water solubility at low temperatures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a herbicidal capsule for flooded paddy fields and a method for applying the herbicide. More specifically, it relates to a herbicidal capsule for direct seeding cultivation applied directly to the water surface of a flooded paddy field and a method for applying the herbicidal capsule. .

[0002]

2. Description of the Related Art Conventionally, in the cultivation of paddy rice, it has been common in Japan to work in paddy fields under submerged water, and it is still ongoing. Since the paddy field under flooded water is soft on the ground, it is difficult to walk without covering it with muddy water, and the work there is inefficient and extremely laborious. On the other hand, in spraying pesticides, the presence of water helps spread the active ingredients of pesticides, so for pesticides other than foliar treatment agents, the method of directly applying granules to the water surface has the drawbacks of loss of active ingredients and high cost. Even if there is, it is the mainstream because it is easy to spray. Further, in the case of a liquid preparation, a method of dropping an emulsion or a flowable agent directly on the water surface may be used. Compared with the method of diluting in water and spraying, these methods have an advantage that the amount of spraying is 1/10 to 1/200 and almost no equipment is required. Therefore, it is considered to have spread in Japan, where small-scale paddy fields are the mainstream.

However, no matter which method is adopted, there is almost no method for spraying pesticides without entering the rice field at present, and the power of a large machine is used in a limited area or condition. It can only be sprayed. Moreover, in order to make this possible, there are major problems such as land readjustment and purchase of machinery, and it still takes time before it can be widely spread, and there are many cases where it cannot be anticipated.

[0004]

DISCLOSURE OF THE INVENTION When spraying even granules which are relatively easy to spray, it is necessary to enter a paddy field under flooding, which is a heavy labor and a large scale work. There is also a limit to spraying by machine. Recently, direct seeding cultivation has also become quite popular, and there is a possibility that it will spread rapidly in the future due to the global situation. In the case of direct sowing, there is no striation when spraying or sowing at a time when the rice is small and the striations cannot be discriminated. Therefore, the rice body is unnecessarily trampled, and it is required not to enter the rice field more than transplant cultivation.

On the other hand, the spraying of the undiluted solution of the liquid formulation has problems that it is difficult to reach the intended place, it adheres to clothes or the like, or when it comes into contact with the leaves of rice, it easily causes chemical damage such as leaf wilting. Furthermore, in the case of direct sowing, the herbicide is often treated from the time before germination of rice to the very early stage of growth, and there is no difference in growth from weeds. Therefore, it is of course necessary to select a drug with high selectivity. Therefore, more severe conditions are required, such as that there should be no shading after treatment.

[0006]

Means for Solving the Problems As a simple method for applying a herbicide, the inventors of the present invention can put the herbicide at almost a distant place almost to a target point if it has a certain size and weight. Focusing on the fact that if the content is an appropriate oily formulation, it shows good spreadability on the surface of water, and as a result of various studies on its low-temperature water solubility, strength, storability, etc. for the membrane substance for capsules, the present invention Has been completed.

In the present invention, 2 ', 3'-dichloro-4-ethoxymethoxybenzanilide and N- (2
-Chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N '-(4,6-dimethoxy-2-pyrimidinyl) urea, an oily substance is blended as a solvent or a dispersion medium, and an emulsifier is added. , 1 to 50 ml of an oily preparation obtained by blending a surfactant as a dispersant or a spreading agent,
A herbicidal capsule for direct seeding cultivation on water directly, which is encapsulated in a gelatin film having improved water solubility at low temperature, and a method for applying a herbicide using the herbicidal capsule for direct seeding cultivation directly on water. Is provided.

Since one capsule of the present invention exhibits a wide spread, it is sufficient to apply 10 capsules / 10a, and conversely, even if it is 100 capsules / 10a, the work is extremely simple. is there. However, it is preferably 20 because of the size, strength, uniformity of spreading, and simplicity of the capsule.
The application of about 50 pieces / 10a is preferable. The inputs should be scattered over the entire paddy field. After a few minutes to several tens of minutes, the capsules that have been thrown in will have their membranes collapsed and the contents will erupt, then initially spread rapidly over the surface of the water and gradually spread while emulsifying even in water. Then, it will be in the state of exerting the same effect as when applied to the entire paddy field. Further, since the variation in the content amount in one capsule can be kept within ± 5%, the input amount can be adjusted accurately. In addition, the amount of the active ingredient eluted is higher than that of granules, and a high effect is often obtained. Therefore, it is possible to reduce the dose of the active ingredient.

The present invention is intended for direct-seeding cultivation, and naturally it is necessary to select a safe drug for direct-seeding rice. Except for chemicals that are specifically required to attach and absorb foliage, other herbicides, plant growth regulators, insecticides, bactericides or their mixtures are added as necessary as long as they are safe for paddy rice. It is also possible. In that case, the physicochemical properties of the pesticide raw material do not matter, and the melting point
Regardless of solubility in water or oil, etc., each can be made into an appropriate oily preparation.

Examples of the solvent or dispersion medium used in the present invention include various organic solvents such as xylene, toluene, chlorobenzene, cyclohexane, cyclohexanone, various glycols, alcohols, and mainly dispersion mediums. Animal and vegetable oils such as soybean oil and cottonseed oil, machine oil, mineral oil such as paraffin oil,
It is not limited to these. The solvent and the dispersion medium are usually selected and used depending on the specific gravity, the viscosity adjustment, the compatibility with the surfactant and the like.

The surfactant used in the present invention includes:
There is no particular limitation as long as it is an anionic or nonionic surfactant, and examples thereof include anionic surfactants such as alkylaryl sulfonates, dialkyl sulfosuccinates, polyoxyethylene alkyl allyl ether sulphates, and alkylnaphthalene sulfonates. Examples include nonionic surfactants such as polyoxyethylene (hereinafter abbreviated as POE) alkyl allyl ether, POE styryl phenyl ether, POE alkyl ether, POE sorbitan alkylate, POE glycol, and polyoxyalkylene glycol. These may be used alone or as a mixture of several kinds, and any mixing ratio can be selected. In addition, as an auxiliary agent, a thickener, a suspension stabilizer, a decomposition inhibitor,
Antioxidants can also be added.

The membrane component of the capsule is often 20 ° C. or lower on a cloudy day when the water temperature in the paddy field is low, and it is necessary to rapidly disintegrate even at a low temperature. The capsule of the present invention has made this possible. This is one of the major characteristics. That is, the film component of an ordinary soft capsule is composed of a film base gelatin, a plasticizer glycerin, and D-sorbitol, to which a colorant, a preservative, and the like are added if necessary, and the capsule accounts for the total weight of the capsule. The film weight is 20 to 50%, and the film thickness is 0.1 to 0.4 mm. On the other hand, this capsule uses low molecular weight gelatin, which is more water-soluble than gelatin, water-soluble collagen, starch and other derivatives, cellulose, dextrin, carrageenan, gum arabic, guar gum, pectin, oligosaccharide, etc. as a membrane base. A part of gelatin is substituted to improve the water solubility of the film itself, the capsule film weight is 10 to 25% of the whole, and the film thickness is at least partially at 0.15 mm or less directly on the water surface. It is an applied capsule.

The composition of the capsule used in the present invention is gelatin, modified gelatin, water-soluble collagen, low-molecular gelatin, starch and other derivatives, cellulose, dextrin, carrageenan, gum arabic, guar gum,
Pectin, oligosaccharide, glycerin, D-sorbitol,
It is composed of sucrose, propylene glycol, polyethylene glycol, organic acid (citric acid, aspartic acid, succinic acid) and the like, but is not limited thereto.

The shape of the capsule is not particularly limited as long as it does not significantly impede ease of loading, storage, transportation and the like. Generally round, oval
Type and oblong type are preferred.

The capsule manufacturing method includes a liner method,
Or the Scherrer type rotary die automatic capsule filling method is general, but is not particularly limited to this,
A capsule manufacturing method such as a flat plate method or a dropping method may be used. When the present capsule is stored, it is desirable to avoid high temperature and high humidity and keep it at room temperature (30 ° C or lower) in a package that does not absorb moisture.

[0016]

EXAMPLES The effects of the present invention will now be described more specifically by way of examples, which should not be construed as limiting the present invention.
The formulation test example of the capsule was the formulation example, the physical property test example of the capsule was the test example, and the test example in the actual paddy field was the example. The herbicidal drug substances used in the present invention are shown in Table 1 together with the compound names and physical properties. The herbicides below are the compounds N in Table 1.
o. To use.

[0017]

[Table 1]

Formulation Example 1 [Parts all indicate parts by weight] Compound 1 15 parts Compound 2 0.9 parts Solvent / dispersion medium Soybean oil 73.6 parts Surfactant Solpol-3815 (Toho Chemical Industry) (Manufactured by Co., Ltd.) 10 parts-Auxiliary agent Amorphous silica 0.5 parts These are mixed and ground with a wet grinder to give compound 1 (15
%, An oily suspension containing 0.3% of compound 2 was obtained.

Further, this oily suspension was encapsulated by a rotary die method, and a film component-gelatin 80 parts, starch 20 parts, glycerin 40 parts, citric acid 2 parts Film thickness-average 0.15 mm, minimum 0.05 mm shape- A capsule of the present invention was obtained having a spherical content-10 ml weight-about 12 g. [Formulation No. C-
1]

Formulation Example 2 ・ Compound 1 15 parts ・ Compound 2 0.9 parts ・ Solvent / dispersion medium Soybean oil 73.6 parts ・ Surfactant Solpol-3815 (manufactured by Toho Chemical Industry Co., Ltd.) 10 parts ・ Auxiliary agent Amorphous silica 0.5 parts These are mixed and ground with a wet grinder to give compound 1
%, An oily suspension containing 0.3% of compound 2 was obtained.

Further, this oily suspension was encapsulated by a rotary die method to form a film component-30 parts gelatin, 70 parts modified gelatin, 60 parts glycerin, 1 part citric acid film thickness-average 0.25 mm, minimum 0.05 mm shape -Oval shaped contents-50 ml weight-about 55 g of the capsules of the invention are obtained. [Formulation No. C-
2)

Formulation Example 3 30 parts of Compound 1 1.8 parts of Compound 2 52.9 parts of solvent / dispersion soybean oil Surfactant Solpol-3896 (manufactured by Toho Chemical Industry Co., Ltd.) 15 parts Auxiliary Amorphous silica 0.3 parts These are mixed and ground with a wet grinder to give compound 1
%, An oily suspension containing 0.3% of compound 2 was obtained.

Further, this oily suspension was encapsulated by a rotary die method, and film components-gelatin 70 parts, glycerin 50 parts, low molecular weight gelatin 30 parts Film thickness-average 0.2 mm, minimum 0.1 mm shape-oval shape Content-20 ml Weight-about 24.0 g A capsule of the invention is obtained. [Formulation No. C-
3)

The above capsule formulation examples C-1 to C-3 are listed in Table 2.

[0025]

[Table 2]

Physical Property Test Test Example 1. Film strength test (drying condition) Each capsule was installed in a Kiya type hardness tester used for tablet hardness test, and the hardness at which the capsule bursts under pressure was measured as the breaking hardness to evaluate the capsule film strength. It was The results are shown in Table 3.

[0027]

[Table 3]

Test Example 2. Membrane disintegration rate test After the capsules were put into a water tank with water temperatures of 15 ° C and 25 ° C, the time until the disintegration contents were ejected was measured. The results are shown in Table 4.
(The numerical value is the average value of 5 rounded off.)

[0029]

[Table 4]

Test Example 3. Storage test Each was placed in 5 layers, placed in a dry state at 30 ° C., and after 3 months, each item was observed and investigated. The results are shown in Table 5.

[0031]

[Table 5]

Example 1. Spreading efficacy test 2m x 20m in paddy field seeded with Nobie and Firefly seeds
The unit capsules of the present invention were provided, and the capsule of the present invention was placed at one end of the endmost unit plot, and 20 days later, an investigation was conducted by observing each unit plot every 2 m from the position where the capsule was put. The control granules were compound 1 at 15% and compound 2 at 0.
Those containing 9% were evenly sown within the plot. The results are shown in Table 6. The evaluation criteria are as follows. 0: Same as no treatment 1: 20% control 2: 40% 3: 60% 4: 80% 5: Complete control

[0033]

[Table 6]

Example 2. Herbicide efficacy test A unit area of 10m x 20m was set up in the paddy field that had been drained after scavenging, and soil mixed with Nobie, Konagi, and Firefly seeds was put into every 2m of the area, and the adjacent surface was laid and the surface sprouted. I threw in rice. Submerged depth 4 cm after the surface has dried
Then, the capsules of the present invention were put into the plot at regular intervals 3 days after the casting, before the emergence of weeds, and 16 days after the casting, in the Novier 2.5 leaf stage. The same control granules as in Example 1 were used. After one month, each site was observed and investigated. The evaluation criteria of the effect are the same as in Example 1. The evaluation criteria of drug damage are as follows. 0: Same as untreated 1: 20% suppression of plant height or reduction in density (allowable limit of chemical damage) 2: 40% 3: 60% 4: 80% 5: Complete death results are shown in Table 7. The second place below the decimal point was rounded off.

[0035]

[Table 7]

Example 3. Direct sowing rice damage test Calcium peroxide preparation (containing 16% of calcium peroxide) was sprinkled on slightly sprouted seed fir so that the weight ratio of dry fir was twice, and after paddling, the paddy field dropped 10m x 20m.
The unit section was prepared, and 3 kg / 10a of dry fir weight was sown using a power atomizer. It was left for 2 days, and after the soil surface was dried, it was filled with water to make a submerged depth of 4 cm. After the movement of water stopped, the capsule of the present invention was put into the section at equal intervals. After 2 weeks, select 6 areas with an average area of 0.5 m x 0.5 m in each ward, and observe the germination number, seedling rate, weight, plant height and leaf age for each of the 6 areas. It was investigated and the degree of drug damage was measured. In addition, phytotoxicity evaluation was also carried out based on the phytotoxicity evaluation criteria similar to those in Example 2. The results are shown in Table 8.

[0037]

[Table 8]

[0038]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to spray a herbicide without entering a paddy field under flooding, which enables a herbicidal work in direct seeding cultivation, It can be further reduced or omitted. Further, since this herbicide has a high selectivity, it can be applied to submerged direct cultivation, which requires treatment from the early stage of rice germination to the very early growth stage. Further, the present capsule has sufficient strength and storability, and even after being put into a paddy field under flooded water, the film can be quickly dissolved to release the contents. Furthermore, the contents of the capsule spread rapidly over a wide area on the water surface, and then diffuse while emulsifying in water, which makes it easy to spray the herbicide and sufficiently exerts the effect. it can.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location // (A01N 47/36 37:38) (72) Inventor Takeo Mogi 45 Miyukigaoka, Tsukuba, Ibaraki Prefecture Tsuchiya Chemical Industry Co., Ltd. Tsukuba Research Institute (72) Inventor Yukihiko Inayoshi 45 Miyukigaoka, Tsukuba City, Ibaraki Prefecture Hodogaya Chemical Industry Co., Ltd. Tsukuba Research Institute (72) Inventor Masatsugu Kikuta Miyukigaoka, Tsukuba City, Ibaraki Prefecture 45 Hodogaya Kagaku Kogyo Co., Ltd. Tsukuba Research Laboratory (72) Inventor Ryozo Kubo 1-3-9 Higashishimbashi, Minato-ku, Tokyo Miyagi Kagaku Kogyo Co., Ltd. Tokyo Sales Office (72) Inventor Takayuki Fukasawa Anzuhara Shizuoka 603-6 Kitamatsuno, Fujikawa-cho, Gunma

Claims (2)

[Claims] 1. An active ingredient of 2 ', 3'-dichloro-
A solvent containing 4-ethoxymethoxybenzanilide and N- (2-chloroimidazo [1,2-a] pyridin-3-ylsulfonyl) -N '-(4,6-dimethoxy-2-pyrimidinyl) urea and a solvent. Alternatively, 1 to 50 ml of an oily preparation obtained by mixing an oily substance as a dispersion medium and a surfactant as an emulsifier, a dispersant, or a spreading agent is added to a gelatin film having improved water solubility at low temperature. A herbicidal capsule for direct sowing cultivation which is directly applied on the water surface, which is encapsulated. 2. A method for applying a herbicide which uses the herbicidal capsule for direct seeding on the water surface according to claim 1.