JPH06345609A - Disease injury controlling agent in zoisia japonica - Google Patents

Abstract

PURPOSE:To obtain a disease injury controlling agent, composed of an aqueous solution containing water-soluble chitosan powder mixed with a germicide and capable of manifesting excellent controlling effects on lawn disease injuries such as rhizoctonia large patch or fusarium patch and useful in Zoisia japonica. CONSTITUTION:The disease injury controlling agent useful in Zoisia japonica is obtained by dissolving raw material chitosan in a solution of an organic acid, preferably a solution of acetic, lactic or citric acid, then treating the prepared solution with acetone, an alcohol, etc., for about 16 hr, carrying out the dehydration, providing water-soluble chitosan powder and mixing the resultant water-soluble chitosan powder with a germicide. Low-molecular weight chitosan having <100000 molecular weight thereof and high-molecular weight chitosan having >=100000 molecular weight are fractionated for use as the raw material chitosan. The low-molecular weight chitosan can be mixed with the high-molecular weight chitosan for use. Well-known herbicides for the lawn registered as an agrichemical for use in golf courses, e.g. pencycuron, tolcofos- methyl, isoprothiolane or flutolanil wettable powder, mepronil and polyoxin are preferably used as the germicide.

Description

Detailed Description of the Invention

[0001]

This invention relates to Japanese turf (Zoisia).
Japonica), the purpose of which is to exert an excellent control effect against turf diseases such as Rhizoctonia large patch and spring baldness, which often occur in the grass, especially on fairways and greens of golf courses. Japanese turf that can do (Zoisia Japanese
It is to provide a disease controlling agent in a).

[0002]

Background of the Invention Examples of lawn vegetation in Japan include golf courses, soccer fields, athletic fields, parks, and stadiums, but the occurrence of disease is limited to golf courses and soccer fields. Has been. The reason for this is that in golf courses and soccer fields, the growth of grass is under severe conditions such as strong cutting and treading, and a high degree of homogeneity of the grass surface that is incomparable to other places is required. Are listed. In general, for disease control of agricultural crops, it is necessary to adopt a cultivation system that keeps the environment as less susceptible to disease as possible, but on golf courses and soccer fields, play conditions take precedence and environmental conditions for disease control are given priority. Improvements are said to be secondary. That is, strong grass mowing facilitates pathogen invasion and aids transmission, and the mow provides a hotbed for pathogen growth.

Most grasses grown on golf courses are Japanese bentgrass such as cold-grass-type bentgrass (Western grass), warm-season type Korai-shiba (Zoisia tenuifolia), and Noshiba. In both cases, the major diseases that occur are predominantly caused by soil-living filamentous fungi, most of which are caused by Rhizoctonia and Pythium.
An example of this is Rhizoctonia solani [AG-2-2 (I
V)] is the main causative agent of Rhizoctonia large patch (leaf rot), and Pythium periplocum is the main causative agent of Pythium bright. Among them, Rhizoctonia large patches are invaded by Japanese turf (Zoisia jaiba) such as Himekoishiba, Koraishiba, Noshiba.
limited to ponica), part of the Kanto region, Kansai area,
Outbreaks have been observed in northern Kyushu and Chushikoku, and it is considered to be one of the most seriously serious diseases in Japanese turf.

[0004]

2. Description of the Related Art As a countermeasure for disease of grass at a golf course,
Preventive spraying of pesticides is the mainstream. Examples of pesticides used include mepronil wettable powder (trade name: Basitac, Kumiai Chemical Co., Ltd.), tolclofos-methyl wettable powder (trade name: Grancer wettable powder, Sumitomo Chemical Co., Ltd.), penciclone hydrate Examples of disinfectants (trade name: MONSELEN, manufactured by Japan Bayer Agrochem), thiraum penciclone wettable powder (trade name: TIVIC wettable powder, manufactured by Japan Bayer Agrochem), etc. It was possible to control the above-mentioned diseases almost completely by applying it to

[0005]

However, since the range of application of pesticides on a golf course is tens of thousands of m ² , a method such as aerial spraying is adopted. However, environmental pollution due to aerial sprayed agricultural chemicals may occur. In recent years, it has become very problematic. In other words, pesticides that adhere to grass and soil are washed away by rainwater and flow out into the surrounding rivers, resulting in deterioration of tap water raw water or effects on fish.
The impact of the spread of pesticides in the atmosphere on the surrounding residents and the problem of residual toxicity to soil, etc. has been reported very widely in public opinion, and it seems that the use of pesticides itself is considered dangerous. Is becoming.

[0006] In the meantime, the global environmental protection problem has come to be regarded as important worldwide, and even in Japan, the Ministry of Health and Welfare has tentatively shown the permissible concentration in tap water for agricultural chemicals used in golf courses. The water quality target was announced, the Temporary Environment Agency announced a tentative guideline for pesticides used in golf courses, and a guideline for water discharged from golf courses.In addition, the Ministry of Agriculture, Forestry and Fisheries announced the appropriate use of pesticides in golf courses. With the announcement of guidelines for chemicals, thorough guidance is being given to use the minimum necessary pesticides safely and properly. In response to this, even in prefectures nationwide, guidance guidelines and guidance are announced for the purpose of preventing environmental pollution due to the use of pesticides at golf courses, and the use of pesticides at golf courses is optimized nationwide. It is like this.

In view of such circumstances, there is a problem in safety such as residual toxicity, and the use of pesticides which may harm human livestock and the surrounding environment and cause environmental pollution is reduced as much as possible. It is desired to create an excellent disease control agent that can effectively control diseases such as Rhizoctonia large patches and spring baldness that tend to occur on grass such as golf courses and soccer fields even if the use of pesticides is reduced. It was rare.

[0008]

The present invention is characterized by comprising an aqueous solution in which a chitosan water-soluble powder obtained by dissolving raw material chitosan in an organic acid solution and then dehydration treatment and a bactericide are mixed. Japanese Shiba (Zoisia Japan)
By providing the disease controlling agent in ica), the above-mentioned conventional problems are solved.

[0009]

[Function] An aqueous solution prepared by mixing a chitosan water-soluble powder and a bactericide is used as a Japanese turf (Zoisia) such as Koishiba, Noshiba, etc.
japonica), especially Rhizoctonia
For large patches, extremely high control effect equivalent to or higher than that of the bactericide alone can be obtained. Therefore, it can be effectively used as a Japanese turf disease control agent on a golf course, and the concentration of the pesticide sprayed on the golf course can be reduced.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, Japanese turf (Zois) according to the present invention will be described.
The composition of the disease controlling agent of ia japonica) will be described in detail. In the present invention, as one of the essential components, a chitosan water-soluble powder obtained by dissolving raw material chitosan in an organic acid solution and then dehydrating it is used. Chitosan is a deacetylated product of chitin [polysaccharide having a large number of N-acetyl-D-glucosamine residues bonded thereto] widely existing in the kingdoms of fungi, plants and animals. To prepare chitosan, first cut the shrimp or crab cuticle (shell) and the cell wall of microorganisms with a 2% alkaline solution (sodium hydroxide, etc.).
After deproteinization with, the product is dissolved in about 4% hydrochloric acid and decalcified to isolate chitin, and this chitin is then heated in a concentrated alkaline solution of about 50% to deacetylate the raw material chitosan. Can be obtained.

The molecular weight of the obtained raw material chitosan can be set to some extent depending on the conditions of hydrochloric acid treatment for the isolation of the raw material chitin and the deacetylation reaction conditions for the preparation of chitosan. That is, the decrease in the molecular weight of chitosan was moderated to some extent by carrying out the deacetylation reaction in a nitrogen atmosphere, and when an alkaline solution of the same concentration was used, it was better to treat it at a low temperature for a longer time at a higher temperature. Chitosan having a higher molecular weight than that obtained can be obtained.

In the present invention, the raw material chitosan obtained by the above-mentioned preparation method is suitably used without any particular limitation. Particularly, the low molecular weight chitosan having a molecular weight of less than 100,000 and the molecular weight of 100,000 or more are used. High molecular weight chitosan can also be used separately. Here, in particular, the reason for limiting the use of high molecular weight chitosan and low molecular weight chitosan, respectively, is that by using the raw material chitosan whose molecular weight is limited in this way, the damage caused to the Japanese turf is seriously affected by Rhizoctonia large patch. This is because it is based on the experimental knowledge of the present inventors that it is possible to almost completely control P. Also, the molecular weight
A mixture of a low molecular weight chitosan having a molecular weight of less than 100000 and a high molecular weight chitosan having a molecular weight of 100,000 or more can also be preferably used in the present invention. The mixing ratio is not particularly limited, but an equal mixture of low molecular weight chitosan and high molecular weight chitosan can be preferably used.

In the present invention, chitosan water-soluble powder obtained by dissolving the above-mentioned raw material chitosan in an organic acid solution and then dehydrating it is used as one of the essential components. Suitable examples of the organic acid used include acetic acid, lactic acid, citric acid and the like, but are not particularly limited. Although the conditions for dissolving the raw material chitosan in this organic acid solution vary depending on the type of organic acid used, for example, when lactic acid is used, about twice the volume of lactic acid (about 20% concentration) per 100 g of chitosan powder is used. The solution may be dissolved in) for 12 to 24 hours. After being dissolved in the organic acid solution, it is treated with acetone / alcohol or the like for about 16 hours for dehydration to obtain a chitosan water-soluble powder which is one of the essential components of the present invention.

In the present invention, a fungicide is also used as one of the essential components together with the above-mentioned chitosan water-soluble powder. Here, as the bactericide, any of the known bactericides for lawn that have been registered as pesticides used in golf courses is preferably used without particular limitation, and specifically, a penciclone agent, Known bactericidal agents for turf such as tolclofos-methyl agent, isoprothiolane / flutonyl wettable powder, mepronil agent and polyoxin agent are preferably used. In the present invention, chitosan water-soluble powder and a bactericide are mixed to prepare a disease control agent for Japanese turf. The application form is not particularly limited, but it is desirable from the viewpoint of use to apply the mixture in the form of an aqueous solution in which the mixture is dissolved in water. In the present invention, the chitosan water-soluble powder and the bactericide may be mixed in an amount of 10 to 10000 parts by weight, preferably 100 to 1000 parts by weight, with respect to 1 part by weight of the chitosan water-soluble powder. Is preferred. When an aqueous solution is used, 1 g of chitosan water-soluble powder may be dissolved in 100 liters of water before use. That is, in the case of the aqueous solution form, the concentration of the chitosan water-soluble powder in the aqueous solution is 0.01 to 0.0001%, more preferably about 0.001%, and the bactericide is appropriately selected and used. It may be mixed at a required concentration according to the above. Also, the method of applying such a controlling agent is not particularly limited, and spraying may be performed using a sprayer or the like.

[0015]

EXAMPLES Hereinafter, Japanese turf (Zoisia) according to the present invention will be described.
The effect of the disease control agent of Japonica) will be explained more clearly with reference to Examples. The present invention is not limited to the embodiments described below.

(Example 1) 100.8 g of lactic acid [purity 50%, Kenei Pharmaceutical Co., Ltd.] was diluted with 3 times the volume of water, and chitosan [manufactured by Sanei Industry Co., Ltd., molecular weight] was added to this lactic acid solution. 100000
Above] 100 g was dissolved. This solution is allowed to stand for 12 to 24 hours, and after the chitosan solution becomes gel-like, 250 to 260 cc of acetone (Yamada Yakuhin Co., Ltd.) is added to the gel chitosan solution, and after stirring, About 16-18
After leaving for a while, acetone and water in the supernatant were removed for dehydration, and after air-drying, a high molecular weight chitosan water-soluble powder was obtained.
This high molecular weight chitosan water-soluble powder was diluted 50,000 times with water to give a chitosan aqueous solution. Mepronil as a fungicide
A 75% wettable powder (trade name: Basitac wettable powder, manufactured by Kumiai Kagaku Co., Ltd.) was used in a 1000-fold dilution, and the chitosan aqueous solution was mixed in an equal amount to the diluted solution to prepare a disease control agent of Example 1. Was prepared.

(Example 2) 56 g of lactic acid [purity 90%, manufactured by Kenei Pharmaceutical Co., Ltd.] was diluted with 3 times the volume of water, and chitosan [manufactured by Sanei Industry Co., Ltd., molecular weight 30] was added to this lactic acid solution. 000 ~
Less than 100,000] 100 g was dissolved. Add this solution to 12
After leaving it to stand for -24 hours, the chitosan solution becomes gel-like, and then 2 to 3 times the volume of acetone [made by Yamada Yakuhin Co., Ltd.] of the gel-like chitosan solution is added, and after stirring,
After leaving it for 16 to 18 hours, the supernatant acetone and water were removed to perform dehydration, and after air-drying, a low-molecular weight chitosan water-soluble powder was obtained. This low molecular weight chitosan water-soluble powder was added to water for 50,0
The disease control agent of Example 2 was prepared by diluting with 00 times an aqueous chitosan solution and mixing it in the same amount with the same fungicide as in Example 1 [Mepronil 75% wettable powder (1000 times dilution)].

(Example 3) Example 3 similar to Example 1 except that a 1000-fold diluted solution of tolclofos-methyl wettable powder (trade name: Resolex wettable powder, manufactured by Agros Co., Ltd.) was used as a bactericide. Was prepared. (Example 4) As a bactericide, tolclofos-methyl wettable powder [trade name: Resolex wettable powder, manufactured by Agros Co., Ltd.]
Example 4 similar to Example 2 except that a 1000-fold dilution was used
Was prepared.

(Example 5) Diclomedine wettable powder as a bactericide [trade name: Monguard wettable powder, manufactured by Sankyo Pharmaceutical Co., Ltd.]
A disease controlling agent of Example 5 was prepared in the same manner as in Example 1 except that the 1000-fold diluted solution was used. (Example 6) Disease control of Example 6 similar to Example 2 except that a 1000-fold diluted solution of diclomedine wettable powder [trade name: Mongard wettable powder, manufactured by Sankyo Pharmaceutical Co., Ltd.] was used as a bactericide. The agent was prepared. (Example 7) Chitosan was prepared by diluting an equivalent mixture of the high molecular weight chitosan water-soluble powder prepared in Example 1 and the low molecular weight chitosan water-soluble powder prepared in Example 50,000 with water. An aqueous solution was mixed with the same fungicide as in Example 1 [Mepronil 75% wettable powder (1000-fold diluted solution)] in an equal amount to prepare the disease controlling agent of Example 7.

(Comparative Example 1) Mepronil 75% wettable powder [trade name: Basitac wettable powder, manufactured by Kumiai Chemical Co., Ltd.]
What was twice diluted was used as the disease controlling agent of Comparative Example 1. (Comparative Example 2) Torquelphos-methyl wettable powder (trade name: Resolex wettable powder, manufactured by Agros Co., Ltd.) diluted 500 times was used as the disease controlling agent of Comparative Example 2. (Comparative Example 3) Diclomedine wettable powder [trade name: Monguard wettable powder, manufactured by Sankyo Pharmaceutical Co., Ltd.] was diluted 500 times to obtain the disease controlling agent of Comparative Example 3.

[0021]

[Test example] Fairway [No1, No1] of Green Park Oyama Golf Club (altitude about 200m), Himi Town, Saihaku County, Tottori Prefecture
5 (Noshiba)], where 100 m ² (5 × 20 m) where Rhizoctonia large patches were remarkably observed in the spring was defined as one test group, and two test groups were tested in Example 1 above.
6 and disease control agent prepared in Comparative Examples 1 to 3 were sprayed by the power sprayer by 0.5 liters per 1 m ^2, respectively (Test Date: September 16, 1992). 49 days after spraying,
The number of lesions and lesion area in each test plot were investigated. As a control group, a disease-controlling agent-free section was set up, and the same control group was also investigated. The results are shown in Table 1.

[Table 1]

In the control group to which no disease controlling agent was applied, the occurrence of lesions was observed from the beginning of October, and the lesions were rapidly increased and expanded thereafter, but as is clear from the results in Table 1, It can be seen that in the test plots to which the disease control agents of Examples and Comparative Examples are sprayed, the number of lesions and the number of lesions are remarkably reduced as compared with the control plots. Furthermore, in the test plots to which the disease control agent of Example was sprayed, it was found that no lesions were observed at all, although the concentration of the disinfectant used was lower than that of the disease control agent of Comparative Example.

[0023]

As described above in detail, the present invention comprises an aqueous solution in which a chitosan water-soluble powder obtained by dissolving raw material chitosan in an organic acid solution and then dehydration treatment and a bactericide are mixed. Characteristic Japanese turf (Zoisia japo
nica) is a disease control agent, so it exerts an extremely excellent control effect against turf diseases such as Rhizoctonia large patches and spring baldness, which tend to occur frequently on turf vegetated in golf courses and soccer fields in Japan. It is possible to reduce the use concentration of fungicides (pesticides), which has been problematic for safety to rivers, human livestock, and soil, to less than half that of the conventional method, thus contributing to global environmental conservation. It is effective as a next-generation disease control agent that can contribute.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location (A01N 63/00 43:58)

Claims (4)

[Claims] 1. A Japanese turf (Zois), characterized in that a chitosan water-soluble powder obtained by dissolving raw material chitosan in an organic acid solution and then dehydration treatment is mixed with a bactericide.
ia japonica) disease control agent. 2. The molecular weight of the raw material chitosan is 10,000.
The low molecular weight chitosan water-soluble powder having a molecular weight of less than 0 is used, and the Japanese turf (Zoisia jap) according to claim 1.
onica) disease control agent. 3. The molecular weight of the raw material chitosan is 10,000.
The water-soluble powder of high molecular weight chitosan having a molecular weight of 0 or more is used, and the Japanese turf (Zoisia jap) according to claim 1.
onica) disease control agent. 4. The raw material chitosan has a molecular weight of 100,000.
It is a mixture of a low molecular weight chitosan having a molecular weight of less than 100 and a high molecular weight chitosan having a molecular weight of 100,000 or more, and the Japanese turf (Zoisia japonic) according to claim 1.
The disease controlling agent in a).