JPH0717806A - Exterminator for red rot disease - Google Patents

Abstract

PURPOSE:To obtain an exterminator for red rot disease capable of selectively exterminating red rot disease due to the genus Pythium of Phycomycetes which is parasitic on laver leaf body in culture of laver and not exerting a bad influence upon the laver leaf body as well as environmental pollution of sea and fishes and shellfishes. CONSTITUTION:This exterminator for red rot disease is characterized by including a fumaric acid monosodium salt and/or fumaric acid monopotassium salt and an organic carboxylic acid. The exterminator has effect of selectively exterminating pathogenic fungus by which red rot disease is produced or spread in culture of laver in a concentration and pH range of exterminator which does not exert a bad influence on laver leaf body ranging from young bud period to adult leaf period in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pest control agent for scab disease that occurs in Nori culture. Pythiu, a fungus that parasitizes Nori leaves in Nori culture
The present invention relates to a pest control agent for scab disease that selectively exterminates scab scab caused by genus m and has no adverse effects on the Nori leaf body and environmental pollution of the sea and fish and shellfish.

[0002]

2. Description of the Related Art Akagushi disease is a fungal Pythium
It is caused by the infestation of mold belonging to the genus, and the Nori thalli parasitized by this fungus frequently spreads in a short period of time, and the degree of spread is severe.

As a method for controlling diseases, for example, in Japanese Patent Application Laid-Open No. 48-336328, a method is used in which the antibacterial agent P-hydroxybenzoic acid and its ester are used in combination with a nonionic or anionic surfactant. However, it is necessary to immerse for 30 minutes to 5 hours so that the working efficiency is poor and it is not practical. JP-A-50-12142
No. 5, selected from the group consisting of saturated aliphatic monocarboxylic acids having 1 to 4 carbon atoms, saturated or unsaturated dicarboxylic acids having 2 to 4 carbon atoms, glycolic acid, lactic acid, tartaric acid, malic acid, citric acid. Also disclosed is an algicidal agent containing one or more organic carboxylic acids as an active ingredient. Also, JP-A-60-244245
The specification discloses an algae killing method in which a material to be treated is treated by immersing it in a treatment liquid in which fumaric acid in a saturated amount or more is present. When treating with an algicidal agent containing these organic carboxylic acids as active ingredients, the pH is usually preferably in the range of 2-3.
When the acid concentration becomes high, problems such as the leaf bodies of Nori die off. Particularly, during the treatment of the bud stage of Nori, the buds of Nori are killed in a low pH range and the productivity is deteriorated. Therefore p
Sufficient H management is required. As a means for solving this problem, Japanese Unexamined Patent Publication No. 60-244245 describes that the treatment solution can be adjusted at the larval stage by using, for example, sodium fumarate. In this way, the algaecides must be used properly according to the growth in the bud stage and the leaf stage of Nori. JP-A-62-190103 discloses
There is disclosed a repellent for algal fungi parasitic on flaxseed cells, which contains gluconic acid as an active ingredient, but the concentration used is in the range of 1 to 20% by weight, and gluconic acid is used at a high concentration, so that nori leaf bodies It is not practical because it may cause drug damage that kills cells.

Further, JP-A-1-2798055 discloses an algicidal agent containing a monosodium fumarate salt and / or a monopotassium fumarate salt as an active ingredient.

[0005]

[Problems to be Solved by the Invention] There are no effective repellents for scab disease at present, and commonly used repellents contain organic acids such as malic acid, citric acid and gluconic acid as active ingredients. It is carried out by a method of dipping or spraying in a treatment solution of 0.1 to 1% water or a seawater solution for 3 to 15 minutes.

However, when the scab disease is prevalent, the concentration of the pesticide containing the organic carboxylic acid is increased to obtain a low pH treatment liquid or the immersion time is lengthened. However, when such a method is adopted, there is a serious drawback that the laver leaves die.

The present inventors have the effect of selectively exterminating pathogenic fungi in which scab has been caused or spread in a short time within a pH range that does not adversely affect Nori leaf bodies from the embryonic stage to the adult stage. It has been found that the pest control agent of the invention is effective.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a pesticidal agent for scab disease, which comprises monosodium fumarate and / or monopotassium fumarate and an organic carboxylic acid.

The pesticide of the present invention is used in water or seawater at 0.05%.
It can be used by dissolving it in the range of wt% to 3.0 wt%, preferably 0.1 to 2.0 wt%.

If the concentration of the pesticide of the present invention is less than 0.05% by weight, the pesticidal effect is insufficient, and if it exceeds 3.0% by weight, it is economically undesirable.

The organic carboxylic acid of the present invention is selected from among the compounds recognized as food additives, which are compounds which decompose rapidly in seawater. As specific compounds, organic carboxylic acids such as lactic acid, tartaric acid, malic acid, citric acid, fumaric acid, succinic acid and gluconic acid can be used. These organic carboxylic acids may be used alone or in combination of two or more as an active ingredient.

The mixing ratio of the fumaric acid monosodium salt and / or fumaric acid monopotassium salt and the organic carboxylic acid of the present invention is 0.1 with respect to 1 of fumaric acid monosodium salt and / or fumaric acid monopotassium salt. It can be used in a weight ratio of 10 to 10, preferably 0.2 to 8.0.

The pesticide of the present invention can be used by dissolving it in water or seawater in advance. The pH of this treatment liquid is pH 2.2.
-3.5, preferably pH 2.5-3.5.

If the pH is less than 2.2, there is a risk that the laver itself will die. If the pH exceeds 3.5, the extermination effect will decrease.

The pesticide of the present invention is used by dissolving it in water or seawater in advance. When it is used by immersing the object to be treated, the immersion time is 1 to 30 minutes, preferably 3 to
It is in the range of 20 minutes.

If the immersion time is less than 1 minute, the exterminating effect will be insufficient. Immersion times of more than 30 minutes have the disadvantage of killing Nori leaf cells.

The pesticide of the present invention can also be treated by spraying it on the object to be treated.

The algae and bacteria repellent of the present invention may be used in combination with an emulsifier or the like in order to improve solubility and permeability. In addition, various nutrient salts and the like may be added for the purpose of improving the growth and quality of Nori. Examples of various additives used include sodium nitrate, sodium hydrogen phosphate, vitamin B ₁₂ and chelating agents.

[0019]

The present invention is for a short period of time by dipping or spraying the Nori leaf body in which the scab has been caused or spread in a low-concentration pesticide in a pH range where there is no adverse effect on the Nori leaf body during the larval stage to the adult stage. Can be selectively removed.

[0020]

EXAMPLES The embodiments of the present invention will be specifically described with reference to the following examples. The invention is not limited to these examples.

Example 1 Fumaric acid monosodium salt was dissolved in seawater to a concentration of 0.2% by weight and citric acid to a concentration of 0.2% by weight.
The pH of seawater was 2.8. 10 Nori leaf bodies infected with Pythium were infected with this pesticide solution.
Immersion was carried out for a minute, and extermination treatment was performed.

The treated Nori leaf bodies were washed with sterilized seawater to observe dead cells, and the cells were transferred to 300 ml beakers containing 200 ml of PES containing nutrient salt and cultured. The culture conditions were aeration culture at 15 ° C., 5000 Lx, and a 12-hour light-dark cycle. 1 is alive or dead
Cultured for a week and observed. The results are shown in Table 1.

Example 2 The procedure of Example 1 was repeated except that the fumaric acid monosodium salt was changed to fumaric acid monopotassium salt.
The results are shown in Table 1.

Example 3 The same process as in Example 1 was carried out except that the citric acid in Example 1 was changed to 0.2% by weight of malic acid. The results are shown in Table 1.

Example 4 The same procedure as in Example 1 was carried out except that the citric acid in Example 1 was changed to 0.2% by weight of gluconic acid. The results are shown in Table 1.

Example 5 The procedure of Example 1 was repeated except that the citric acid in Example 1 was changed to 0.2% by weight of succinic acid. The results are shown in Table 1.

Example 6 The same treatment as in Example 1 was carried out except that the citric acid in Example 1 was changed to 0.2% by weight of fumaric acid. The results are shown in Table 1.

Example 7 The same treatment as in Example 1 was carried out except that the citric acid in Example 1 was changed to 0.2% by weight of tartaric acid. The results are shown in Table 1.

Example 8 The same treatment as in Example 1 was carried out except that citric acid was changed to 0.2% by weight of lactic acid in Example 1. The results are shown in Table 1.

Example 9 Example 1 except that the fumaric acid monosodium salt was 0.4% by weight and the citric acid was 0.05% by weight in Example 1.
The same process was carried out. The results are shown in Table 1.

Example 10 Example 1 except that fumaric acid monosodium salt was 0.05% by weight and citric acid was 0.4% by weight in Example 1.
The same process was carried out. The results are shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that only 0.4% by weight of fumaric acid monosodium salt was used in Example 1. The results are shown in Table 1.

Comparative Example 2 The same treatment as in Example 1 was carried out except that only 0.4% by weight of citric acid was used in Example 1. The results are shown in Table 1.

Comparative Example 3 The same treatment as in Example 1 was carried out except that only 0.4% by weight of malic acid was used in Example 1. The results are shown in Table 1.

Comparative Example 4 The same treatment as in Example 1 was carried out except that only 0.4% by weight of gluconic acid was used in Example 1. The results are shown in Table 1.

Comparative Example 5 The same treatment as in Example 1 was carried out except that only 0.4% by weight of tartaric acid was used in Example 1. The results are shown in Table 1.

[0037]

[Table 1]

Example 11 0.2% by weight of fumaric acid monosodium salt and 0.2% by weight of citric acid were dissolved in seawater. The pH of this seawater was 2.8. 300 to 50 in this pesticide solution
0 cells of Nori bud and 20 cm of Nori adult leaf
Immersion treatment was performed for 30 minutes. Immediately after the treatment, the cells were washed with water to determine the relationship between the killing rate of Nori cells. The results are shown in Table 2.

Comparative Example 6 A 0.4 wt% citric acid solution (pH 2.2) was used instead of the fumaric acid monosodium salt and citric acid in Example 11.
Was treated in the same manner as in Example 11 except that was used.

COMPARATIVE EXAMPLE 7 A 0.4% by weight gluconic acid solution (pH 2.
The same treatment as in Example 11 was performed except that 3) was used. The results are shown in Table 2.

[0041]

[Table 2]

Example 12 In January 1993, a monosodium salt of fumaric acid was added at a concentration of 0.15% by weight at a Nori floating fishing ground in the Ariake district of Fukuoka Prefecture.
And citric acid was dissolved in seawater to a concentration of 0.10% by weight. This seawater had a pH of 3.0. A frozen net was developed in this seawater, and red rust spots were generated on the Nori adult leaf growing to 7 to 10 cm, and a test for exterminating the rot of the Nori net infected with the scab was performed.

Number of treated nets: 4, water temperature: 12 ° C., concentration: 0.25
When the extermination treatment was performed under the conditions of weight% and immersion time of 5 to 8 minutes, the scab was recovered. In addition, it was confirmed by microscopic observation that the fungus turned white after immersion. The condition of vegetative cells in the adult leaf of Nori was extremely healthy and no dead cells were observed.

Comparative Example 8 In Example 12, without using fumaric acid monosodium salt, the citric acid concentration was 0.15% by weight and malic acid was 0.10.
Only wt% was dissolved in seawater. The seawater had a pH of 2.3. A frozen net was developed in this seawater, and red rust spots were generated on the Nori adult leaf growing to 7 to 10 cm, and a test for exterminating the rot of the Nori net infected with the scab was performed.

Two processing nets, water temperature 12 ° C., concentration 0.25
When the extermination treatment was carried out under the conditions of weight% and immersion time of 10 to 13 minutes, the red rust spots of the scab disease were not discolored, and the scavenging disease control effect was not recognized. 15% of the vegetative cells of the adult Nori leaf were dead.

[0046]

In the examples and comparative examples, the akagushi disease-controlling agent containing fumaric acid monosodium salt and / or fumaric acid monopotassium salt and an organic carboxylic acid is
Conventionally, as compared to malic acid, citric acid gluconic acid, and tartaric acid, which are conventionally used as algae and bacterial pesticides, fumaric acid monosodium salt and / or fumaric acid monopotassium salt, or organic carboxylic acids, are used for laver leaves. It was confirmed that there was no adverse effect, the effect of exterminating scabs was high, and the subsequent growth was not promoted.

In the examples, the disinfectant containing fumaric acid monosodium salt and citric acid was found to be extremely safe for laver young leaves and adult laver leaves as compared with the use of citric acid and gluconic acid alone. It was

In the Examples and Comparative Examples, the exterminating agent containing monosodium fumarate and citric acid in an actual Nori fishing ground is extremely safe against young Nori leaves and Nori adult leaves, and is an exterminating agent for scabs. It was confirmed that the extermination effect was extremely high.

Claims (1)

[Claims] 1. A pest control agent for scab disease, which comprises monosodium fumarate and / or monopotassium fumarate and an organic carboxylic acid.