JPS6217963B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an algae control agent that controls harmful algae that are mixed into the artificial culture of nori filaments and leaves without causing any harm to nori. Nori is an important natural food and an indispensable food in Japan's diet, but due to improvements in cultivation technology, its production is now almost entirely dependent on artificial seedling collection. However, in the artificial collection of seaweed seedlings, other algae are always contaminated, which harms the growth of seaweed in the thallus and filament cultures of seaweed, so there is a strong desire to establish a method for controlling them. However, the inventors of the present invention have conducted intensive studies on agents that can control algae that contaminate the seaweed during artificial cultivation without causing any harm to the seaweed. We have completed the present invention by discovering that the algae selectively exhibits an extremely excellent control effect on algae without the need for additional algae. In general, the main types of algae that contaminate artificial cultivation of seaweed include green algae, diatoms, and blue-green algae, and although they are the same plants, there has not been as much research into controlling weeds on land. Phycology Volume 6 (1966
In addition to the report that germanium salts are effective against diatoms (2011), pages 1-12, there are only a few studies that have been conducted, and germanium salts are also ineffective against green algae and other algae, and there are other reports that germanium salts are effective against diatoms. The reality is that there are no effective algae control agents that are safe for practical use and harmless to seaweed, such as those considered to be highly toxic to humans and animals, or harmful to seaweed. The active ingredient N-phosphonomethylglycine in the present invention is a compound originally invented as a herbicide (Japanese Patent Publication No. 56-6401), and its feature is that by applying an effective amount to the living parts of a growing plant, It is a so-called non-selective herbicide that kills all plants. According to Japanese Patent Publication No. 56-6401, it is stated that N-phosphonomethylglycines are also effective against certain types of aquatic plants, but in that case, they can also be used directly on these aquatic plants in areas where aquatic plants are desired to be suppressed. A spraying method is used. In addition, the control of algae is unknown, and the effect on nori and the control effect on miscellaneous algae during the cultivation of nori have not been investigated at all.
The active ingredient N-phosphonomethylglycine of the present invention is a compound represented by the general formula (1), that is, a salt of N-phosphonomethylglycine.
- Alkali metal salts, ammonium salts and organic ammonium salts of phosphonomethylglycine are conveniently used. In addition, these compounds have low toxicity to humans and livestock, low toxicity to fish, and are quick to decompose in nature and are safe without fear of environmental pollution. The algae control agent for culturing seaweed of the present invention has the general formula (1) [In the formula, R is -OH, and OR ⁶ {In the formula, R ⁶ is an alkali metal, an alkaline earth metal, ammonium, or an organic ammonium (However, this ammonium salt is a lower alkylamine salt or a lower alkanolamine salt. ) and cations of mixtures of such salts, and R ¹ and R ² are each -OH, and OR ⁶ (R ^{6 is} selected from ^the group consisting of
and more than two of R ² are not −OR ⁶ ), or a strong acid salt of the compound of the above formula (wherein,
R, R ¹ and R ² are -OH, and this strong acid is
It has a pK of 2.5 or lower) as an active ingredient. Specific examples of the compounds are as follows. N-phosphonomethylglycine Sodium N-phosphonomethylglycinate Disodium N-phosphonomethylglycinate Trisodium N-phosphonomethylglycinate N-phosphonomethylglycine mono-ethanolamine salt N-phosphonomethylglycine mono -Ammonium salt Monohydrate calcium salt of N-phosphonomethylglycine Magnesium salt of N-phosphonomethylglycine Magnesium bis-(N-phosphonomethylglycinate) Potassium salt of N-phosphonomethylglycine N-phosphonomethyl Dimethylamine salt of glycine Dilithium salt of N-phosphonomethylglycine Mono(methylamine) salt of N-phosphonomethylglycine Mono(diisopropylamine) salt of N-phosphonomethylglycine Mono(diethanolamine) salt of N-phosphonomethylglycine ) salt Mono(triethylamine) salt of N-phosphonomethylglycine Bis(N-phosphonomethylglycine) hydrochloride hydrate Mono(isopropylamine) salt of N-phosphonomethylglycine Mono(n- butylamine) salts The N-phosphonomethylglycines mentioned above can be prepared by phosphonomethylation of glycine, preferably using chloromethylphosphonic acid. These can also be produced by adding phosphite to azomethine. For example, the reaction of ethylglycinate with formaldehyde and diethyl phosphite produces triethyl ester of N-phosphonomethylglycine.
Further, these compounds can be easily obtained by oxidizing the corresponding aminophosphinic acid compounds using mercuric chloride or other oxidizing agents. These N-phosphonomethylglycines are generally water-soluble granular or crystalline solid materials. The strong acids that form salts with the N-phosphonomethylglycine include those having a pK of 2.5 or less, such as hydrochloric acid, sulfuric acid, phosphoric acid, trifluoroacetic acid, and trichloroacetic acid. In some cases, these hydrochloric acids liberated are hemi-monosalts. That is, one molecule of acid can combine with two molecules of N-phosphonomethylglycine and contain water for hydration. The amide or ester of N-phosphonomethylglycine can be prepared by combining an acid halide dissolved in a solvent,
It can be produced by reaction with a suitable amine or alcohol in the presence of a hydrogen halide acceptor such as triethylamine, pyridine, etc., or by transesterification with the methyl ester of N-phosphonomethylglycine. Salts of N-phosphonomethylglycine are prepared by partially or completely neutralizing the above acid with a suitable base, basic carbonate, ammonia or organic amine. The present inventors continued their search for a selective algae control agent for artificial cultivation of nori, and found that N-phosphonomethylglycine, which was originally thought to kill all plants in a non-selective manner, was discovered. It was found that it is selectively safe for nori filaments and completely controls contaminated green algae and diatoms at low concentrations. In particular, during nori filament culture, for example, in shell filament culture or free filament culture, by adding a small amount of N-phosphonomethylglycine to the culture solution, green algae and diatoms can be completely exterminated, and even more No effect was observed on filamentous growth, sporangium formation, spore formation and maturation, and it was found to be extremely useful in terms of effectiveness and safety for nori. When operating according to the present invention, N-phosphonomethylglycines are added to the seawater to be treated at a predetermined concentration, for example, 25 ppm or more, but they may be used as they are, or with the addition of surfactants, etc. It can also be formulated into solutions, emulsions, wettable powders, etc., and then added. In addition, the algae control agent of the present invention may not only be used in combination with one or more other algae control agents, seawater disinfectants, vitamins and other nutrients, but also mixed preparations with these agents are also possible. In some cases, synergistic effects can also be expected. An algae control test example is shown below, and as is clear from the test results, the algae control agent containing the compound of the present invention has a remarkable algicidal effect on algae at low doses, and also on seaweed. has excellent selectivity without causing any drug damage even at high doses. Reference Example 1 A mixture consisting of about 50 parts of glycine, 92 parts of chloromethylphosphonic acid, 150 parts of 50% aqueous sodium hydroxide solution and 100 parts of water is introduced into a suitable reaction vessel and maintained at reflux temperature while , and another 50 parts of 50% aqueous sodium hydroxide solution were added. The pH of the reaction mixture was maintained at 10-12 by the addition rate of sodium hydroxide. After all of the caustic solution has been added, the reaction mixture is added for an additional 20
It was refluxed for an hour, cooled to room temperature and filtered. Approximately 160 parts of concentrated hydrochloric acid was then added and the mixture was filtered to obtain a clear solution in which N-phosphonomethylglycine was gradually precipitated. This material had a melting point of 230°C, with decomposition.
The elemental analysis values for C ₃ H ₈ NO ₅ P are as follows. Calculated values C 21.31, H 4.77, N 8.28 Actual values C 21.02, H 5.02, N 8.05 Reference example 2 A mixture consisting of about 17 parts of N-phosphonomethylglycine, 100 parts of water and 5.4 parts of sodium carbonate was dissolved in an appropriate amount. The mixture was placed in a reaction vessel and shaken at room temperature. After complete dissolution, as indicated by clearness of the reaction mixture, the reaction mixture was concentrated on a steam bath under reduced pressure. The residue was washed with hot methanol and then diethyl ether. The product thus obtained is N
- Monosodium salt of phosphonomethylglycine hemihydrate. The elemental analysis value as C ₃ H ₇ NO ₅ PNa1/2H ₂ O is as follows. Melting point: 200℃ (decomposition). Calculated value C 18.01, H 3.53 N 7.00 Actual value C 18.21, H 3.56 N 6.98 Reference example 3 About 170 parts of N-phosphonomethylglycine was added to a solution of 59.4 parts of isopropylamine dissolved in 15 parts of water, and This was placed in a suitable reaction vessel. The reaction mixture became clear within a short time, during which time the mixture was shaken. The resulting solution was then concentrated by heating to 100°C under reduced pressure. This residue is a viscous oil;
And from this a crystalline solid was obtained. This product is
It was a mono-isopropylamine salt of N-phosphonomethylglycine. Softening point 95℃. The elemental analysis value as C ₆ H ₁₇ N ₂ O ₅ P is as follows. Calculated value C 31.57, H 7.52 N 12.28 Actual value C 31.60, H 7.58 N 12.26 Example 1 (Efficacy test) (Reinforcement seawater SWM - modification liquid adjustment method)

【table】

[Table] Drug name Stock solution Concentration Mixing amount

Claims (1)

[Claims] 1 General formula (1) [In the formula, R is OH, and -OR ⁶ {In the formula, R ⁶ is an alkali metal, an alkaline earth metal, ammonium, or an organic ammonium (however, this ammonium salt is a lower alkylamine salt or a lower alkanolamine salt) and cations of mixtures of such salts}, and R ¹ and R ² are respectively -OH and -OR ⁶ (R ⁶ is (However, when R ⁶ is ammonium or organic ammonium, R, R ¹
and more than two of R ² are not −OR ⁶ )] or a strong acid salt of the compound of the above formula (wherein,
R, R ¹ and R ² are -OH, and this strong acid is
A control agent for harmful algae that occurs during the artificial cultivation of seaweed, which contains as an active ingredient (having a pK of 2.5 or lower).