JP2000324967A - Disease elimination from cultivated laver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for exterminating mold fungi belonging to the genus Pyshium in a short time without impairing laver itself. SOLUTION: This method is to formulate an aqueous solution of acetic acid having a concentration of <=0.3 wt/wt.% with at least one kind selected from the group consisting of adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, formic acid, ketoglutaric acid, phytic acid, phosphoric acid, hydrochloric acid, tartaric acid, sulfuric acid, nitric acid, maleic acid, itaconic acid, propionic acid and butyric acid in such a way that the concentration of the latter acid in the aqueous solution is 0.01-0.3 wt/wt.% depending on required treating time, and to immerse cultivated laver in the above formulated solution or to scatter the above formulated solution to cultivated laver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling red rot fungi on cultured seaweed.

[0002]

2. Description of the Related Art In seaweed cultivation, a method of performing an acid treatment in order to exterminate algae, i.e., Aonori, Aosa, and diatom, has been adopted. If Aonori etc. are mixed in the product, the price of nori will decrease. Various acids such as hydrochloric acid, phosphoric acid, citric acid, malic acid and phytic acid are used as these acids. Citric acid is mainly used because it is recognized as a food additive and is inexpensive.

[0003] 1-2% of citric acid (pH about 2.0-2.
The processing of 5 to 10 minutes is performed in 2). In addition, an extermination effect against red rot has been recognized, and if the treatment is carried out at the above-mentioned concentration, it can be exterminated within 1 to 2 minutes. Therefore, the treatment is actually performed for 5 to 6 minutes.

[0004] The disease called red rot occurs rapidly when the laver foliage grows and finally can be harvested, spreads over all fishing grounds within a few days, and causes the foliate to die and flow. Therefore, the damage is enormous. The cause of the disease is said to be the parasites of the genus Pythium or related water molds, and these microorganisms grow mainly at temperatures around 15 ° C, and are said to be propagated by living organisms or organic matter produced by the death and decomposition of organisms, and probably by the presence of Amanori. It is thought that the presence of a large amount of fronds on the sea surface satisfies the conditions suitable for growth.

[0005] Red rot fungi proliferate in a mycelium within the parasite,
The parasite cells feed and grow, with vigorous hyphae forming a large number of zoospores at the end, and a large number of zoospores within the sac. When the sac matures, it ruptures and releases zoospores.The released zoospores swim in water and attach to new parasites.
It becomes hyphal again and immediately infests the parasite cells. The foliage that has been damaged by poisoning usually breaks off and falls, and is industrially said to be hundreds of times more damaging than what is directly damaged by fouling.

In Japanese Patent Publication No. 46-35873, P-
A method for controlling red blight of Amanori, which is applied with oxybenzoic acid or an ester thereof, has been proposed. This means that with the use of antibiotics and inverse soaps up to that point, they will kill all of them, including useful bacteria, but will not only have a low stopping power against mold and yeast, but will also be harmless to humans. Because it is not something.

Japanese Patent Application Laid-Open No. Sho 50-121425 discloses saturated fatty acid carboxylic acids having 1 to 4 carbon atoms, saturated or unsaturated carboxylic acids having 2 to 4 carbon atoms, glycolic acid, lactic acid, tartaric acid, malic acid and citric acid. Discloses a algicide containing one or more organic carboxylic acids selected from the group consisting of: It describes exclusively the algicidal action, but does not describe red rot fungi.

Japanese Patent Publication No. 60-13647 discloses citric acid containing 0.3 to 5.0% by weight and a pH of 1.0 to 6.
Nori cultivation by immersion in a treatment solution of No. 0 and control and prevention of diseases are described.

JP-B-60-13648 discloses a method of adding an inorganic acid such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid to adjust the pH to 1.
A seaweed cultivation method for controlling and preventing algae and diseases, which are 0 to 4.0, is described.

Japanese Patent Publication No. 60-21950 discloses a fertilizer for laver cultivation containing phytic acid or a salt thereof as an active ingredient, a preventive effect against red rot and a diatom control effect.

Japanese Unexamined Patent Publication No. 57-8722 discloses a nori cultivation method in which a nori net is treated with a treatment solution containing phosphoric acid or a salt thereof to remove and prevent diseases such as weeds and red rot. Has been started.

JP-A-60-87202 discloses a fungicide for marine bacteria of edible seaweeds containing adipic acid as an active ingredient.

Japanese Patent Application Laid-Open No. 60-244245 discloses an algicidal method in which fumaric acid is present in a saturating amount or more, and at least one of malic acid, citric acid, tartaric acid and succinic acid is used in combination. There is also a statement that it is good.

Japanese Unexamined Patent Publication No. Sho 60-248121 discloses that algae and arachnid fungi can be obtained by immersion in a treatment solution containing one or more of chloroacetic acid, dichloroacetic acid, trichloroacetic acid and the like consisting of a halogenated carboxylic acid. Nori cultivation methods for controlling sickness, redhead disease and the like have been disclosed.

Japanese Unexamined Patent Publication (Kokai) No. 62-21784 discloses a liquid fertilizer which is also used as an algicide for seaweed cultivation, comprising an acidic buffer containing dilute hydrochloric acid as a main component and nitrates, ammonium salts and phosphates.

Japanese Patent Application Laid-Open No. 62-190103 discloses an agent for controlling algal fungi of the genus Pythium and Olpidiopsis, which are pathogenic fungi of blight and arachnid disease, using gluconic acid as an organic component.

JP-A-1-279805 discloses an algae and bacteria control agent containing monosodium fumarate and / or monopotassium fumarate as an active ingredient.

JP-A-2-25404 discloses a pesticide containing fumaric acid and / or a fumarate salt and at least one member selected from the group consisting of sodium carbonate, sodium hydrogencarbonate, potassium carbonate and potassium hydrogencarbonate. A disinfectant for algae and bacteria which is dissolved in water or seawater to form monosodium fumarate and / or monopotassium fumarate is disclosed.

JP-A-2-291218 (Japanese Patent Publication No.
No. -47810) discloses an algicidal method in which an amount of fumaric acid exceeding a saturation amount is present in a state of being covered with a water-soluble coating means, and an object to be treated is immersed in the treatment solution. .

As will be described later, since the control of algae such as Aonori depends exclusively on the pH of the treatment solution, the above-mentioned known hydrochloric acid, phosphoric acid, phytic acid, tartaric acid, citric acid, malic acid, Any acid, such as succinic acid and gluconic acid, used alone or in combination, has a pH of about 9 and
It can be completely exterminated in 10 minutes.

However, since red rot fungi have a high infectivity when they occur, they must be treated quickly and completely killed. However, if the treatment is not performed at intervals of 2 to 6 days because infection from the sea occurs immediately, the seaweed will be destroyed.

The seaweed producer collects 100 to 200 sheets of seaweed net on average, and the current processing agent requires a processing time of at least 5 minutes. However, since it takes 8 hours or more, 30 to 40 sheets can be processed in one day. Therefore, as the spread of red rot becomes severe, it is impossible to control red rot fungi in time, and nori is no longer produced and production of nori ends. Therefore, development of a drug capable of eliminating red rot bacteria in a shorter time is desired.

[0023]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method capable of eliminating red rot bacteria in a short time without damaging the laver itself.

[0024]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the aqueous solution of acetic acid is highly impaired against laver, and over a certain concentration and for a certain treatment time, the laver is killed. On the other hand, below its concentration and processing time,
It is not used at all because it has no effect of controlling red rot bacteria and cannot be used as a red rot fungicide at all. However, the inventors have found that when this acetic acid is used in combination with adipic acid, lactic acid, phosphoric acid, etc., the bactericidal activity of the acid itself can be greatly increased, and therefore, the treatment can be performed at a low concentration for a short time, and the environmental pollution can be reduced. .

That is, according to the present invention, the concentration is 0.3 W / W%.
In the following acetic acid aqueous solution, adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, formic acid, ketoglutaric acid, phytic acid, phosphoric acid, hydrochloric acid, tartaric acid, sulfuric acid,
A concentration of at least one acid selected from the group consisting of nitric acid, maleic acid, itaconic acid, propionic acid and butyric acid in an aqueous solution having a concentration in the range of 0.01 to 0.3 W / W%, each corresponding to a required treatment time; And then immersing the cultured seaweed in the mixed liquid or spraying the solution on the cultured seaweed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As can be seen from Test Example 1, acetic acid has a high degree of damage to laver, so that nori is damaged and killed before red rot bacteria are eliminated. Therefore, acetic acid cannot be used alone as a pesticide for red rot. However, as shown in Test Example 2 and later, it was found that the combined use with other acids, such as phytic acid, lactic acid, and acetic acid, did not damage the laver and could significantly increase the bactericidal activity of the combined acid itself. Was.

At present, a mogboat has been developed and can be processed in a short time (1).
In some fishing grounds, the use of acetic acid and adipic acid, lactic acid, phosphoric acid, etc. can be used at a low concentration, and the amount of acid used can be reduced. When used on a boat, the use of inorganic acids such as hydrochloric acid and phosphoric acid requires a concentration of 2 to 8%. Therefore,
According to the present invention, the amount of acid used can be considerably reduced, and the burden of environmental pollution on the ocean can be reduced.

The pesticide of the present invention comprises ammonium nitrate, ammonium hydrochloride, monoammonium phosphate as a nitrogen source,
Mono-potassium phosphate, mono-sodium phosphate, inositol 6-phosphate and phosphoric acid can be used in combination as a phosphorus source such as urea, sodium nitrate and nitric acid. In particular, the combined use of phosphoric acid and phosphate can relieve the laver damage and produce soft laver with soft quality.

The pesticide of the present invention is used by immersing a nori culture net infected with red rot in the pesticide or by spraying the pesticide on the culture net. Thus, by bringing the nori leaf body infected with the disease into contact with the pesticide,
It does not damage nori and selectively removes pathogenic bacteria, adherent bacteria, diatoms and the like. Treat fish nets free of disease as a preventive measure.

[0030]

The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited to these examples. In the following test examples,
The mark indicates that there is no seaweed damage and completely eliminates red rot bacteria, and the mark △ indicates that there is no seaweed damage and significantly suppresses red rot bacteria. is there.
Other marks are comparative examples.

(Test Example 1) 0.00% of acetic acid (90%)
5,0.01,0.05,0.1,0.2,0.3W /
A seawater solution of W% is prepared, and each is fixed for a certain period of time (5 seconds, 10 seconds,
20 seconds, ... 60 seconds, 2 minutes, 3 minutes, 4 minutes, ... 10
Min) After immersing the red rot fungus-infected laver, wash with seawater,
The state two days after static culture was observed under a microscope, and the control effect of red rot bacteria and damage to laver were investigated. Table 1 shows the results.
Shown in

[0032]

[Table 1]

0.005%, 0.01%, 0.0% of acetic acid
5% and 0.1% cannot be used as a red rot control agent because they have no or no effect of controlling red rot even after soaking for 10 minutes. As described above, acetic acid alone cannot be used as a pesticide for red rot bacteria.

(Test Example 2) 0.01 W of acetic acid (90%)
/ W sea water solution, phytic acid (50%), phosphoric acid (75%)
%) Hydrochloric acid (36%), lactic acid (90%), formic acid (90%
%), Tartaric acid, sulfuric acid, nitric acid, maleic acid, malic acid, citric acid, gluconic acid, fumaric acid, ketoglutaric acid, adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, itaconic acid, propionic acid, butyric acid 0.01,0.05,0.1,0.2,0.3W respectively
Nori cultivation infected with red rot fungus from the adjusted liquid added so as to be 10%, 20 seconds,... 60 seconds, 90 seconds,
After immersion for 2 minutes, 3 minutes, 4 minutes... 10 minutes, the plate was washed with seawater, and after 2 days of standing culture, the state was observed under a microscope. The results are shown in Tables 2 to 5.

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

Test Example 3 0.05 W of acetic acid (90%)
/ W% seawater solution, phytic acid (50%), phosphoric acid (7%)
5%), hydrochloric acid (36%), lactic acid (90%), formic acid (90%)
%) Are 0.01, 0.05, 0.1, 0.2,
Nori leaf infected with red rot fungus was added to the adjusted solution added to 0.3 W / W% for 10 seconds, 20 seconds, ... 60 seconds,
After immersion for 90 seconds, 2 minutes, 3 minutes, 4 minutes,... 10 minutes, the plate was washed with seawater, and the state after 2 days of standing culture was observed under a microscope to examine the effect of controlling red rot bacteria. Table 6 shows the results.

[0040]

[Table 6]

Test Example 4 0.1 W / acetic acid (90%)
Phytic acid (50%), phosphoric acid (75%)
%), Hydrochloric acid (36%), lactic acid (90%), formic acid (90%
%), Tartaric acid, sulfuric acid, nitric acid, maleic acid, malic acid, citric acid, gluconic acid, fumaric acid, ketoglutaric acid, adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, itaconic acid, propionic acid, butyric acid 0.01, 0.05, 0.1, 0.2, 0.3 W /
Nori leaf infected with red rot fungus was added to the adjusted solution added so as to be W% for 10 seconds, 20 seconds, ... 60 seconds, 90 seconds, 2
After immersion for 10 minutes, 3 minutes, 4 minutes... 10 minutes, the plate was washed with seawater, and the state after 2 days of stationary culture was observed under a microscope to examine the effect of controlling red rot bacteria. Tables 7 to 10 show the results.

[0042]

[Table 7]

[0043]

[Table 8]

[0044]

[Table 9]

[0045]

[Table 10]

Test Example 5 0.2 W / acetic acid (90%)
Phytic acid (50%), phosphoric acid (75%)
%), Hydrochloric acid (36%), lactic acid (90%), formic acid (90%
%), Tartaric acid in 0.01, 0.05, 0.1,
Nori leaf infected with red rot fungus was added for 10 seconds, 20 seconds ... 6 to a modifier added to 0.2, 0.3 W / W%.
After soaking for 0 seconds, 90 seconds, 2 minutes, 3 minutes, 4 minutes, and 5 minutes, the cells were washed with seawater, and the state after 2 days of standing culture was observed under a microscope to examine the effect of controlling red rot bacteria. Table 11 shows the results.

[0047]

[Table 11]

Test Example 6 0.3 W / acetic acid (90%)
Phytic acid (50%), phosphoric acid (75%)
%), Hydrochloric acid (36%), lactic acid (90%), formic acid (90%
%), Tartaric acid, sulfuric acid, nitric acid, maleic acid, malic acid, citric acid, gluconic acid, fumaric acid, ketoglutaric acid, adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, itaconic acid, propionic acid, butyric acid, Are 0.01, 0.05, 0.1, 0.2 and 0.3 W, respectively.
/ W% of the nori leaf infected with the red rot fungus was added to the adjusted solution added for 10 seconds, 20 seconds ... 60 seconds, 90 seconds, 1
After immersion for 20 seconds, the plate was washed with seawater, and the state after 2 days of standing culture was observed under a microscope to examine the effect of controlling red rot bacteria. The results are shown in Tables 12 to 15.

[0049]

[Table 12]

[0050]

[Table 13]

[0051]

[Table 14]

[0052]

[Table 15]

(Test Example 7) (Comparative Example) Phytic acid (50%), phosphoric acid (75%),
Hydrochloric acid (36%), lactic acid (90%) formic acid (90%), tartaric acid, sulfuric acid, nitric acid, maleic acid, malic acid, citric acid, gluconic acid, fumaric acid, ketoglutaric acid, adipic acid, succinic acid, monochloroacetic acid, Dichloroacetic acid, trichloroacetic acid, itaconic acid, propionic acid,
Butyric acid 0.01, 0.05, 0.1, 0.2, 0.3 W /
After preparing a W% seawater solution and immersing the nori leaf infected with red rot fungus for a certain period of time, washing it with sea water, and observing the state after 2 days of standing culture under a microscope, the red rot fungus controlling effect is observed. investigated. The results are shown in Tables 16 to 19.

[0054]

[Table 16]

[0055]

[Table 17]

[0056]

[Table 18]

[0057]

[Table 19]

(Test Example 8) In the present invention, 0.01%, 0.05%, 0.1% of various acids used in combination with acetic acid.
%, 0.2%, 0.3%, the acetic acid concentration is 0%,
Tables 20 to 23 show the results of measuring the control time of the red rot fungus when the values were changed to 0.01%, 0.05%, 0.1%, and 0.3%. It is clear that the disinfection time is significantly reduced for the various acids compared to the absence of acetic acid.

[0059]

[Table 20]

[0060]

[Table 21]

[0061]

[Table 22]

[0062]

[Table 23]

(Test Example 8) A leaf rot infected with red rot fungi was added for 5 seconds, 10 seconds, 20 seconds... 60 seconds to a seawater solution of the following combination in which two or more acids were added to acetic acid (90%). , 90
After immersion treatment for 2 seconds and 120 seconds, wash with sea water
The state after a day was observed under a microscope, and the effect of controlling red rot bacteria was investigated. The combinations are shown in Table 24 below. Table 25 shows the effect of controlling red rot fungi.

[0064]

[Table 24]

[0065]

[Table 25]

[0066]

EFFECT OF THE INVENTION By itself, the degree of damage to laver is high,
Acetic acid, which cannot be used to control red rot bacteria, is used in combination with other acids such as adipic acid, succinic acid, lactic acid, phytic acid, phosphoric acid, etc. The red rot bacteria could be eliminated in a short time.
Since the amount of acid used can be significantly reduced, environmental pollution to the ocean can be significantly reduced.

Claims (1)

[Claims] 1. An aqueous acetic acid solution having a concentration of 0.3 W / W% or less is mixed with adipic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, formic acid, ketoglutaric acid, phytic acid, phosphoric acid, hydrochloric acid, tartaric acid, sulfuric acid, A concentration of at least one acid selected from the group consisting of nitric acid, maleic acid, itaconic acid, propionic acid and butyric acid in an aqueous solution having a concentration of 0.0
Cultured seaweed characterized by mixing at a concentration corresponding to the required treatment time in the range of 1 to 0.3 W / W%, and immersing the cultured seaweed in the mixed solution or spraying the solution on the cultured seaweed. How to get rid of the disease.