JPH08133914A - Improved agrochemical granule - Google Patents

Abstract

PURPOSE: To obtain an agrochemical granule capable of lightening of preventing phytotoxicity to rice plant so as to almost eliminate phytotoxicity without reducing controlling effect on rice plant which probenazole essentially has. CONSTITUTION: This agrochemical granule contains 3-allyloxy-1,2- benzointhiazole-1,1-dioxide (hereinafter probenazole) and alginic acid or its salt, preferably sodium salt. The amount of probenazole blended is preferably 0.5-70wt.% and that of alginic acid (salt) is 0.01-2.0 pts.wt., preferably 0.05-0.5 pt.wt. based on 1 pt.wt. of probenazole. Alginic acid (salt) mixed with probenazole acts as a phytotoxicity alleviating agent for lightening or completely preventing phytotoxicity of probenazole such as yellowing of leaves and delayed growth of rice plant as the active ingredient.

Description

Detailed Description of the Invention

[0001]

The present invention relates to 3-allyloxy-1,
2-Benzisothiazole-1,1-dioxide (hereinafter simply referred to as "provenazole") is contained as an active ingredient, but alginic acid or a salt thereof is added to reduce the phytotoxic effect of probenazole on paddy rice without impairing its bactericidal effect. The present invention relates to an improved pesticide granule characterized by:

[0002]

BACKGROUND OF THE INVENTION Alginic acid or its salt used as a phytotoxicity-reducing agent in the pesticide granules of the present invention is a major structural polysaccharide of brown algae, and also as a thickener in ice cream or in pharmaceuticals and cosmetics. It is used as an emulsifier, etc.

Further, alginic acid or a salt thereof is blended with N- (p-fluorophenyl) -2,3-dichloromaleimide, a fungicide for agricultural and horticultural use, as a phytotoxicity-reducing agent, and these are used together to prepare a wettable powder. , When this wettable powder is diluted with water and applied to crops of apple, mandarin orange, cucumber, tomato, soybean, adzuki bean, alginic acid or a salt thereof may reduce the phytotoxicity of these maleimide compounds on these crops. It is known (Japanese Patent Laid-Open No. 54-140727).

On the other hand, 3-allyloxy-1,2-benzisothiazole-1,1-dioxide, which is used as an active ingredient in the pesticide granules of the present invention, is known by the general name of probenazole, rice blast and rice white leaf withering. It is a known fungicide for controlling rice scab and rice blight. In order to control these diseases, probenazole is generally applied by water surface treatment, immersion of roots in a chemical solution, soil mixing or soil irrigation. In addition to these treatment methods, granules containing probenazole as an active ingredient are evenly dispersed from the seedlings of rice growing in a nursery box, and the granules adhering to the foliage are wiped off. It is also known to apply the probenazole to rice seedlings to control the above-mentioned rice diseases by the method of treating the seedlings in a nursery box by sufficiently irrigating the granules sprayed on the surface.

Although probenazole has an excellent control effect against the above-mentioned diseases, especially when it is applied by a nursery box treatment method, when the paddy rice seedlings at the time of treatment are weak or after transplanting the paddy rice seedlings. When the climatic conditions are poor, rice may suffer from phytotoxic effects such as yellowing of leaves or delay of growth at the early stage of growth after transplantation due to the action of probenazole. It is also observed that when the probenazole granules are applied by a method other than the above-mentioned seedling raising box treatment method, the phytotoxicity of probenazole may occur in the paddy rice under field cultivation.

[0006] Therefore, it is desired to develop a granule containing probenazole as an active ingredient, which can reduce or prevent phytotoxicity in transplanted rice without reducing the excellent control effect of probenazole originally.

[0007]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problem of phytotoxicity to paddy rice caused by probenazole granules, and a probenazole which meets the above-mentioned needs is used as an active ingredient. However, it is an object of the present invention to provide agricultural chemical granules with reduced phytotoxicity.

[0008]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve these problems. As a result, probenazole prepared by adding alginic acid or a salt thereof at an appropriate ratio to probenazole and adding a suitable auxiliary agent such as a carrier and auxiliary additive components to the mixture and granulating the mixture by a conventional method. It was found that the contained granules prevent or hinder the damage to paddy rice.

That is, the gist of the present invention is that
3-allyloxy-1,2-benzisothiazole-
A pesticide granule characterized by containing 1,1-dioxide and alginic acid or a salt thereof.

Next, the novel and improved pesticide granules of the present invention will be described in detail. The pesticide granule according to the present invention is an agricultural fungicide composition containing probenazole as an active ingredient, alginic acid or a salt thereof as a phytotoxicity-reducing agent, and formulated into a granule type. Alginic acid or a salt thereof is used as a safener in the present granule, and examples of the alginate include a sodium salt, a potassium salt, a magnesium salt, a calcium salt or an ammonium salt, but the safener is preferably the above. Alginic acid or sodium alginate. Hereinafter, the salt of alginic acid will be simply referred to as “alginic acid” unless otherwise specified.

In the probenazole-containing granules of the present invention, probenazole can be blended in a content of 0.5 to 70% (by weight). The amount of alginic acid added to this granule is 0.01 to 2.0 parts by weight, preferably 0.05 to 0.5 parts by weight, as alginic acid based on 1 part by weight of probenazole mixed in the preparation. When the added amount of alginic acid is less than 0.01 parts by weight as alginic acid with respect to 1 part by weight of probenazole, the obtained drug damage reducing effect is small, and the added amount of alginic acid exceeds 1.5 parts by weight as alginic acid with respect to 1 part by weight of probenazole. In this case, although a phytotoxicity-reducing effect on paddy rice can be obtained, the effect does not increase so much, so there is a problem in that even if an extra amount of alginic acid is added, it is not economical.

In the composition forming the granules of the present invention, there are usually used auxiliary agents such as a carrier for the active ingredient and a surfactant, a binder, a stabilizer, a physical property improver and an auxiliary additive ingredient. (Or) A coagulant and a coloring agent can be added. The surfactants used include nonionic surfactants, anionic surfactants and cationic surfactants commonly used in agricultural chemical formulations, and nonionic surfactants and anionic surfactants. Examples include mixed surfactants.

For example, as the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene styryl phenyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkylate,
Polyoxyethylene phenyl ether polymer, polyoxyethylene alkylene aryl phenyl ether,
Examples include polyoxyethylene alkylene glycol and polyoxyethylene polyoxypropylene block polymer. Examples of the anionic surfactant include lignin sulfonate, alkylaryl sulfonate dialkyl sulfosuccinate, polyoxyethylene alkyl aryl ether sulfate, alkyl naphthalene sulfonate, polyoxyethylene styryl phenyl ether sulfate and the like.

The binder which can be blended with the granules of the present invention is not particularly limited, but for example, polyvinyl alcohol,
Starch, dextrin, carboxymethyl cellulose, polyvinylpyrrolidone, sodium lignin sulfonate,
Examples include binders that are commonly used in pesticide granules, such as calcium lignin sulfonate.

Examples of the inert carrier which can be incorporated in the granules of the present invention include white carbon, clay, silica stone, talc, bentonite, calcium carbonate, pumice stone, diatomaceous earth, vermiculite and perlite.
These may be used as a mixture of two or more kinds.

To the granules of the present invention, in addition to the above auxiliary additives, one or more kinds of auxiliary agents such as stabilizers for agrochemical active ingredients, physical property improvers, and solidifying agents are added. May be.

When the pesticide granules of the present invention are applied by the nursery box treatment method, 1.0% to 60% of the 1.3-4 leaf-age rice seedlings being cultivated in the nursery box containing the nursery soil. %(weight)
Granules containing probenazole of 20 to 200 g per box are usually used in a nursery box (width 30 cm x length 60 cm x depth 3 cm).
Preferably, it is sprayed evenly in an amount of 30 to 80 g, and after removing the granules adhering to the foliage of the rice seedlings and transferring them to the surface of the seedling cultivating soil, the granules sprinkled on the surface of the seedling cultivating soil should be thoroughly applied. Irrigation is preferred.

In the pesticide granules of the present invention, alginic acid or a salt thereof is blended together with probenazole to reduce or completely prevent phytotoxicity such as yellowing and growth retardation of paddy rice leaves due to the active ingredient probenazole. To work.

The method for preparing the agricultural chemical granules of the present invention is not particularly limited. It can be prepared by a conventionally known general method for preparing pesticide granules, for example, a wet granulation method, a compression molding method, or an extrusion granulation method for the raw material composition used for preparing the granules. However, it is preferably prepared, for example, by the method comprising the following steps.

Step: A mixture of probenazole, alginic acid, a surfactant, a binder and a carrier and, if desired, other auxiliaries is mixed together with a hammer mill to obtain a solid powdery raw material composition. Step: An appropriate amount of water is added to the powdery raw material composition to prepare a water-containing mixture, which is put into a basket-type extrusion granulator and granulated to obtain a granular composition. Step: fluidizing and drying this granular composition, sieving the dried particles to obtain particles having a target particle size distribution, and sieving the desired size particles to the improved pesticide particles of the present invention. Use as an agent.

Next, the production examples of the pesticide granules of the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples. In the following examples, all "parts" mean parts by weight.

Example 1 Probenazole raw material 20.0 parts, alginic acid 2.0 parts, white carbon 2.0 parts, sodium lauryl sulfate 0.2 part, polyvinyl alcohol 2.0 parts, and clay 73.8 parts were mixed together with a hammer mill to obtain 100 parts of a uniform powder mixture. After obtaining, an appropriate amount of water was added thereto and kneaded well. The obtained kneaded product was granulated by a basket type extrusion granulator, fluidized and dried, and then sized by sieving to obtain an improved agricultural chemical granule of the present invention.

Examples 2-6 Instead of the alginic acid used in Example 1, sodium alginate, potassium alginate, magnesium alginate,
The manufacturing procedure of Example 1 was repeated with ammonium alginate or calcium alginate. Five kinds of pesticide granules similar to those in Example 1 were obtained.

Example 7 8.0 parts of probenazole drug substance, 2.0 parts of sodium alginate
Part, white carbon 2.0 parts, sodium lauryl sulfate
0.2 parts, 2.0 parts of sodium lignin sulfonate, 20.0 parts of bentonite and 65.8 parts of talc were mixed together with a hammer mill to obtain 100 parts of a uniform powder mixture. An appropriate amount of water was added to this and kneaded well. The obtained kneaded product was granulated by a basket type extrusion granulator, fluidized and dried, and then sized by sieving to obtain an improved agricultural chemical granule of the present invention.

Examples 8-12 Instead of the sodium alginate used in Example 7, alginic acid, potassium alginate, magnesium alginate,
The manufacturing procedure of Example 7 was repeated with ammonium alginate or calcium alginate. Five kinds of pesticide granules similar to those in Example 7 were obtained.

Next, the test examples have the effect of reducing or preventing the granules of the present invention when applied to rice seedlings during nursery, from developing the phytotoxicity of probenazole in rice after transplanting to paddy fields. Illustrate that.

Test Examples 1 to 10 Seedling box containing conventional soil for raising seedlings (width 30 cm x length 60 cm)
150 g of rice (variety: Asahi) that had been subjected to normal seed disinfection and preliminary measures was sown in each box (height x 3 cm). The seedling-growing box so seeded was allowed to stand for 2 days at 32 ° C. under high humidity conditions to allow the emergence of paddy. Then, the nursery box was transferred to a transparent acrylic resin greenhouse and the seedlings were grown and managed until transplantation for 20 days after sowing.

19 days after seeding (the day before transplantation), probenazole prepared as in Example 1 or 7 and used as an active ingredient
Alginic acid or sodium alginate 0.2%, 1.0%, 20.0% or as a safener containing 20% (by weight)
50 g of granules containing 30.0% (by weight) were evenly dispersed from the top of the seedlings in each nursery box (the amount of probenazole applied per box was 10 g). At this time, the granules adhering to the foliage of the seedlings were blown off to the surface of the soil by hand. Thereafter, 500 cc of water per box was irrigated from above the foliage. One day after applying this granule, 4 seedlings with the soil still attached to the root are taken out from the nursery box as 1 strain so that the granules attached to the soil do not fall off, and a Wagner pot with a size of 1/5000 ares. Were individually transplanted.

After transplanting, the rice in the pot was cultivated and managed under a flooded condition in a transparent acrylic resin greenhouse. During this cultivation, the length (cm) from the tip of the longest leaf of each strain to the root of the plant was measured as "plant height" from 7 to 28 days after transplantation. Also,
Twenty-eight days after transplantation, the number of stems (number) per strain and the fresh weight (g) of the above-ground part per strain were also examined. In addition, this test example 1
In -10, rice was cultivated in 5 Wagner pots per test plot, and the test was conducted in 5 consecutive cycles. The plant height, the number of stems, and the fresh weight were calculated as respective average values.

For comparison, granules prepared in the same manner as the granules used in the above test examples and containing probenazole but no phytotoxicity reducing agent were placed in a nursery box in the same manner as in the above test examples. A comparative test example was applied to seedlings and then transplanted and cultivated as in the above test examples. Further, a case where the above test example was repeated without applying probenazole granules was set as a control test example (untreated section). The test results obtained are summarized in Table 1 below.

[0031]

As can be seen from the results in Table 1 above, in Test Examples 1 to 10 using the granules of the present invention, the rice seedlings were examined 7 days, 14 days, 21 days and 28 days after transplanting. The growth status in terms of plant height, leaf age, and fresh weight was found to be almost the same as that of the control test example (untreated section), indicating that the rice did not show phytotoxicity due to growth failure. It was On the contrary,
In Comparative Test Example 1 in which probenazole granules containing no alginic acid or its Na salt were applied, Test Examples 1 to 10 of the present invention were carried out.
Also, it was confirmed that the growth condition of rice was clearly worse than that of the control test example, indicating that phytotoxicity occurred.

Test Examples 11 to 20 This example shows a test example for evaluating the presence or absence of phytotoxicity due to treatment with probenazole granules in field cultivation of rice and the effect of controlling leaf blast disease. The same seedling raising box as that used in Test Examples 1 to 10 was subjected to normal seed disinfection and preliminary measures (rice: variety:
150 g of paddy rice (Koshihikari) was sown. Then, test example 1
As in ~ 10, the emergence of paddy and the growth of seedlings were controlled in the nursery box.

20 days after seeding (the day before transplantation), Test Examples 1 to
10 kinds of granules according to the present invention containing probenazole and a safener as in the same manner as in 10, were respectively sprayed on the seedlings of the rice growing in the nursery box from the top of the foliage in the same manner as in Test Examples 1 to 10. Granules were applied (Test Examples 11 to 20). Furthermore, water was sufficiently irrigated in the same manner.

One day after the application of this granule, a test plot with an area of 60 m ² (2 m × 30 m) was prepared in a paddy field where blast disease occurs every year, and seedlings were transplanted to the paddy field by a rice transplanter.

14 days (2 weeks) and 28 days (4 weeks) after transplanting the paddy field
Weekly), the plant height (length from the tip of the longest leaf to the root of each plant, cm) and leaf age of 50 plants per test plot are investigated and the average value for each 50 plants is calculated. did. In addition, the phytotoxicity was determined to be "none", "minor", and "mild" in a consensus survey that comprehensively determines the yellowing of leaves and the growth status according to plant age and leaf age 14 and 28 days after transplantation. , "Heavy" was judged in four stages. The investigation of the blast disease targeted for leaf blast disease,
It was performed 45 and 60 days after transplanting the paddy field.

For the disease onset, 50 strains were arbitrarily selected from 3 sites in each test plot (150 strains in total for each plot), the degree of disease was investigated based on the following criteria, and rice treated with probenazole according to the following formula. The disease control level (%) of the test plot (treated) where the seedlings were transplanted was determined by comparing with the control test example (untreated plot).

Leaf blast survey standard index No lesions are found (healthy) 0 The number of lesions per strain is 1 to 3 The number of lesions per strain is 4 to 10 2 Many lesions are found in lower leaves However, there are few lesions on the uppermost leaf. 4 Multiple lesions are observed on the uppermost leaf. 5 Dead leaves are prominent along with Zuricomi with Zurikomi symptoms. 6

[0039]

For comparison, granules prepared in the same manner as the granules used in the above Test Examples 11 to 20 and containing probenazole but no phytotoxicity reducing agent were prepared in the same manner as in the above Test Examples. It was applied to the seedlings in the above, and then transplanting and cultivating rice was carried out in the same manner as in the above-mentioned test example, which was taken as a comparative test example. The case where the above test example was repeated without applying probenazole granules was designated as a control test example (untreated section). The test results obtained are summarized in Table 2 below.

[0041]

As can be seen from the results in Table 2, in Test Examples 11 to 20 using the granules of the present invention, the plant heights examined by 28 days after transplanting the rice into the paddy field and the growth status of the rice as observed by the leaf age were as follows. It was recognized that it was almost equivalent to that of the control test example (untreated section), and there was no or slight phytotoxicity, indicating that phytotoxicity such as growth disorder was not expressed or suppressed in rice. On the other hand, in Comparative Test Example 2 in which probenazole granules for comparison containing no alginic acid or its Na salt were applied, compared to Test Examples 11 to 20 of the present invention and Control Test Example It was recognized that the growth situation was clearly poor and the phytotoxicity was severe.

Further, Test Examples 11 to 11 to which the granules of the present invention were applied
In No. 20, it was confirmed that the development of leaf blast caused by natural infection could be completely controlled until 60 days after transplanting the paddy field. On the other hand, in the control test example (untreated section), the onset of leaf blast disease reached about 30% at 60 days after transplanting the paddy field.

Further, in place of alginic acid or its Na salt contained in the granules of the present invention used in Test Examples 1 to 10 or Test Examples 11 to 20, potassium alginate, magnesium salt, calcium salt or ammonium salt may be contained. Using the probenazole granules prepared as described above, Test Examples 1 to 10 or Test Example 11
Repeating ~ 20 test methods showed that similar test results as summarized in Table 1 or Table 2 were obtained.

[0045]

INDUSTRIAL APPLICABILITY When the novel pesticide granules of the present invention are applied, it is possible to reduce or prevent the phytotoxicity to paddy rice almost without relieving the original disease control effect of probenazole on rice. Therefore, since the pesticide granules of the present invention do not cause phytotoxicity in paddy rice after transplanting in paddy fields,
It can be safely used to control rice blast and other diseases.

Claims (1)

[Claims] 1. An agrochemical granule containing 3-allyloxy-1,2-benzisothiazole-1,1-dioxide and alginic acid or a salt thereof.