JPS5938925B2 - Plant virus disease infection prevention composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an agricultural pharmaceutical composition, particularly an agent for preventing infection by a plant virus disease, which contains a biopolymer substance as a component.

It has been reported that various biopolymer substances such as alginic acid and casein derived from living organisms have plant disease control effects such as the effect of inhibiting virus infection.
mosaic.

Its use in agricultural chemicals has been reported as an inhibitor for plant virus infections such as virus (CMV).

(Japanese Society of Plant Pathology Bulletin 39 231.41155-16
1) However, because of its remarkable water compatibility and enormous viscosity when submerged in water, it is extremely difficult to dissolve it in water in a short period of time without causing joint powder.

Therefore, when dissolving it in water during use, it is necessary to heat and stir for a long time, which is inefficient and impractical.

In addition, this has resulted in insufficient medicinal efficacy, chemical damage, and clogging of spraying equipment.

Other problems when using sodium alginate as a main ingredient in agricultural chemicals include gelatinization caused by hard water and difficulty in mixing it with other chemicals.

Gelatinization caused by hard water is a gelatinization phenomenon that occurs when a chemical containing sodium alginate as its main ingredient is dissolved in highly hard water, and in extreme cases, it may become impossible to spray with normal spraying equipment.

This is said to be structural viscosity caused by Ca++ (calcium ions) in hard water even forming cross-linking bonds between different molecules.

Furthermore, if a drug containing sodium alginate as its main ingredient is mixed with other drugs, jelly formation or agglomeration may occur, and in severe cases it may become impossible to spray, or even if spraying is possible, the drug may not be able to demonstrate its original efficacy.

When used, this means that mixed spraying is not possible, which is inefficient and disadvantageous from the viewpoint of labor saving.

In order to improve these drawbacks, the addition of additives such as polymeric phosphates, polyacrylates, carboxymethyl cellulose salts, etc. has been proposed as a method for rapidly dissolving sodium alginate.

The present inventors have accomplished the present invention as a result of various studies aimed at developing a practical, non-polluting plant virus disease infection preventive agent using sodium alginate derived from a biopolymer.

Before explaining the present invention in detail, the properties of alginic acid used in the present invention will be briefly explained.

Alginic acid is derived from a polysaccharide contained in large quantities in brown algae such as Casino algae, and is a copolymer of D-mannuronic acid and L-guluronic acid.

Moreover, the average degree of polymerization is said to be between 250 and 900.

Alginic acid has remarkable water compatibility due to the hydrogen bonding of water to the carboxyl group and hydroxyl group of the pyranose ring, which is the basic skeleton, and becomes a viscous solution when added to water.

The viscosity of the solution is said to be related to the average degree of polymerization.

For example, the formula representing the relationship between the average degree of polymerization of sodium alginate and the viscosity when it is made into an aqueous solution is the Filitsupov (Ph
1lippoff) and Arrhenius (Arrh
According to Mr. Kasahara et al. (Industrial Chemistry Journal 61(5) 583), a viscosity formula of 200 centipoise (hereinafter abbreviated as cP) has been proposed in contrast to the results of measuring the degree of polymerization by osmotic pressure method.

) below the Ph1lilippof level.
f ), and for higher viscosities Arrhenius
ius ) is considered more appropriate.

The present inventors conducted various studies focusing on the viscosity of alginate, and discovered that a fast-soluble plant virus disease infection preventive composition can be obtained by using an ultra-low viscosity alginate.

The present inventors used various available alginates, that is, alginates having a viscosity of 30 to 1000 cP in a 1% by weight aqueous solution at 20°C, and obtained them either alone or in combination with an auxiliary agent having a foaming function. When an agricultural chemical composition is added to water, due to the high water compatibility and enormous viscosity of alginate, only the surface of the drug agglomerates stays in the water, resulting in a joint powder state, but the robustness of joint powder was found to be proportional to the viscosity of alginate, which is the main component.

That is, when alginate of 30 to 50 cP is used as a raw material, the joint powder is not strong and a homogeneous solution can be obtained by stirring for about 15 minutes.

However, stirring for 15 minutes is inefficient and impractical in use.

The present inventors decided to study alginates with even lower viscosity, but alginates with a viscosity of 30 cP or less are far from the original properties and uses of alginates. ℃2
~10 cP has a much lower viscosity than what is generally called alginate.

Since alginate with a weight of 30 cP or less cannot be synthesized by the conventional method of depolymerization by heating, the present inventors depolymerized the alginic acid to a predetermined degree of polymerization, and then returned it to the salt form. It was used in experiments by

The ultra-low viscosity alginate synthesized in this way alone,
Alternatively, if the raw material alginate has a viscosity of 30 to 10 cP and is added to water in combination with an auxiliary agent that has a foaming function, joint powder will remain as when using a material with a higher viscosity, but if the viscosity is less than 10 cP, The solubility was dramatically improved.

The solubility was lower than 10 cP, and the lower the viscosity, the better; however, considering various biological tests for plant viruses such as TMV and CMV, the lower limit is 2 cP, preferably 3 cP.

That is, in the present invention, the viscosity of a 1% by weight aqueous solution is 2 to 2 at 20°C.
This invention relates to a plant virus disease infection preventive agent whose main component is alginate having a concentration of 10 cP, and a plant virus disease infection preventive agent which is blended with an auxiliary agent having a foaming function in order to increase solubility.

To explain the present invention in detail, the alginate used in the present invention includes sodium alginate, potassium alginate, ammonium alginate, etc., and when adjusted to pH 5 to 7 with a 1% aqueous solution, the viscosity at 20 ° C. 2-10
As long as it is a cP alginate, any proportion of alginic acid carboxyl groups in the salt form can be used.

Further, as an auxiliary agent for improving solubility, a mixture of a carbonate and an organic acid is used, and the carbonate includes calcium carbonate, sodium bicarbonate, potassium bicarbonate, potassium carbonate, ammonium carbonate, and the like.

The role of carbonate is to react with other auxiliary organic acids to foam and disperse the main component, alginate, and also to act as an alkali source when the mesophase change of the main component, alginate, is low. There is.

Organic acids include citric acid, succinic acid, fumaric acid, lactic acid,
Higher fatty acids such as malic acid, maleic acid, phthalic acid, tartaric acid, acetic acid, or lauric acid are used.

The ratio of carbonate to organic acid must be changed depending on the degree and amount of neutralization of alginate, as carbonate may also be used to neutralize alginate if the degree of neutralization is low as mentioned above. It is necessary to make sure that when a 1% aqueous solution is finally made from the blended composition, the liquid properties of the solution will not have a negative effect on plants, and the amount is usually about 1% relative to the alginate. It is within 35% by weight, preferably within 25% by weight.

Furthermore, in the present invention, in addition to alginate, which is the main component, various biopolymer substances other than alginate that have the effect of inhibiting plant virus infection can be used in combination with the alginate used in the present invention. These include carrageenan, casein, α-globulin, β-glolin,
lactoglobulin, albumin, gluten, pectin,
Examples include starch, gelatin, xylose, arabinose, and salts thereof.

In addition, the amount is within 40% by weight based on the alginate,
Preferably it is within 20% by weight.

The plant virus disease infection preventive agent obtained according to the present invention can be used alone, but it is convenient in terms of handling etc. if it is supported on a carrier.

The carrier is preferably silica or a silica-containing substance, and specific examples include silica or clay minerals such as talc, clay, kaolin, and bentonite, diatomaceous earth, and white carbon, and the amount used is 5i02 based on the alginate. , 1 to 30% by weight is preferred.

Further, it is preferable to add a surfactant, since it is possible to obtain a drug with even better solubility and to increase the spreading effect when sprayed on plants.

The surfactant can be selected from a wide range of general nonionic and anionic surfactants, but it is desirable to have a high affinity for biopolymer substances, excellent wetting and dispersibility, and low toxicity. Specifically, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan dioleate, polyoxyethylene sorbitan monostearate, nonylphenol (polyoxyethylene) hexaphosphate sodium salt, lauryl (polyoxy ethylene) 4
Polyoxyethylene-based nonionic surfactants such as phosphate ester potassium salt, oleyl (polyoxyethylene) 7 phosphate ester sodium salt, and anionic surfactants such as higher alcohol sulfate ester salt are listed, and their usage amounts are listed. is 1 to 10% by weight based on the alginate.

As explained above, the low-viscosity alginate of the present invention can be used not only when used in combination with an auxiliary agent having a foaming function, but also when alginate alone is dissolved in water, the gelatinization phenomenon and There is no jelly formation or agglomeration when mixed with other chemicals, and it is easy to handle and wasteful when applied.
, economical.

The method of applying the plant virus disease infection preventive agent obtained according to the present invention is not particularly limited, and the usual method of applying this type of pesticide can be adopted.

For example, when applying the composition of the present invention shown in Example 1 below to control the tobacco mosaic virus disease in tobacco, for the purpose of controlling the tobacco mosaic virus disease in the transplantation stage, a chemical solution prepared by diluting the composition of the present invention 200 times with water is used at a rate of 1:1.
Spray over the entire tobacco seedling just before transplanting at a rate of 5-101/are.

After that, as the tobacco seedlings grow, they are heated to 10-15 o's depending on the size of the seedlings, just before the mulching stage, dog mulching stage, and budding stage.
It is common to spray chemicals up to J.

Next, the method of the present invention will be explained in more detail using production examples, working examples, and test examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Production Example (Production Method for Sodium Alginate) Sodium alginate of any viscosity used in the present invention was produced as follows.

Since the low-viscosity sodium alginate used in the present invention is not available and cannot be synthesized by depolymerization by heating, which is a conventional method for reducing the viscosity of sodium alginate, it is depolymerized in the form of alginic acid (acid Sodium alginate having various viscosities listed in Table 1 was synthesized by reducing the viscosity to a predetermined value (in which depolymerization occurs upon heating) and then returning it to soda salt.

Further, in order to keep the experimental conditions the same, the loss on drying was set to be in the range of 15 to 7%.

In addition, when the sodium alginate with 7 CP in the table was returned to soda salt, the degree of neutralization was not increased to 15%, but the degree of neutralization of the other sodium alginate was adjusted to 80% or more.

In addition, the degree of neutralization is the weight percent of the carboxyl group bonded to the pyranose ring, which is the basic skeleton of alginic acid, represented by the general formula (C5H704COOH)n, and is expressed as sodium carboxylate. It was measured according to the general test method "Analysis method of organic acid alkali salts".

Examples Sodium alginate with various viscosities and casein soda,
α-globulin, bicarbonate of soda, carbonate of soda, tartaric acid,
Malic acid, diatomaceous acid, white carphone, and Turupon T-80 (trademark) (polyoxyethylene sorbitan monooleate-based surfactant) as a surfactant were blended in the amount ratio (weight ratio) listed in Table 1, and each A composition was obtained.

Test Example 1 Potted tobacco seedlings (Nicotiiana glut)
inosa) 100 times the composition shown in Table 1, 20
Spray 0x and 400x diluted solutions (diluted with water and let stand for 5 minutes before use) with a spray gun and air dry.
Separately prepared TMV purification solution (2×10-7?/TL
1) inoculated by the conventional carborundum method, and about 1
Leave it alone for a week and develop local lesions ＼(1 local 1esio
n) was formed.

In the investigation, the number of local lesions formed was determined, and compared with that in the untreated area, the TMV lesion formation inhibition rate of each test chemical solution was determined.

The results are shown in Table 2, and it is clear that the comparative composition is inferior in medicinal efficacy to the composition of the present invention.

TMV-purified liquefied liquid MV-purified liquefied liquid was prepared by separating and purifying TMV from the sap of diseased leaves using an ultracentrifuge.

Table 2 also shows the results of spraying a 100-fold diluted solution of the composition shown in Table 4 on tobacco seedlings (Prite Yellow) and examining the chemical damage.

Test Example 2 The effect of the composition of the present invention on cucumber mosaic virus (CMV) was tested in the same manner as in Test Example 1 using cowpea seedlings (variety: Kurotane Sanshaku) as test plants.

The results are shown in Table 3. Test Example 3 The effects of some of the compounds shown in Table 1 were investigated using potted tobacco seedlings (variety: Bright Yellow and Xanthi).

The composition was diluted with water to make a 200-fold solution, left to stand for 5 minutes, and then sprayed all over the tobacco seedlings using a spray gun.

Maximum 5×5Cr on leaves of tobacco seedlings after air-drying of sprayed chemicals
TMV concentration 2X10' on IL leaf surface? The purified solution adjusted to /ml was inoculated.

In the investigation, strains with mosaic symptoms were investigated orally along with the diseased strains.

The results are shown in Table 4.

Test example 4 The solubility of the composition of the present invention in water was tested.

That is, put tap water in No. 21 into a beaker No. 31, then add 20 g of the drug composition, leave it for 2 minutes (conditions that facilitate the formation of joint powder), then start stirring, observe the state after 1 minute, and The time required for the solution to become completely clear without any powder or undissolved precipitate was measured.

The results are shown in Table 5.

Test Example 5 Changes in the viscosity of the solution were investigated when the solution was diluted by changing the hardness of the dilution water.

Dilute 1 g of the composition of the present invention with 200 ml of hard water of each hardness, stir for 30 minutes, and measure the viscosity of the solution at 20°C using a rotational viscometer (Vismetron VSA-L model manufactured by Shibaura System ■).
At the same time, a backpack-type spreader (Yokohama Ueki Co., Ltd. MA-
10 type) was used to examine the dispersibility.

The results are shown in Table 6.

Test example 6 The possibility of mixed use with various pesticides was investigated.

Two grams of the composition of the present invention and a predetermined amount of the pesticide to be mixed were weighed, diluted with 200 ml of tap water, stirred for 5 minutes, and the presence or absence of jelly formation and agglomeration of the solution was observed.

The results are shown in Table 7.

In addition, A, B, C, and D in Table 7 have the following meanings.

A: No jelly formation or agglomeration, B: Slightly jelly-formed and agglomerated.

C: Significant jelly formation and agglomeration.

D: Severely gelatinized and aggregated.

In addition, commercially available dog drugs are agricultural drugs containing the following compounds as main ingredients.

Commercial product A: Zinc ethylene bisdithiocarbamate 7
Commercial product containing 2%: 1,2-bis(3-methoxycarbonyl-2
Commercial product containing 70% of benzene (3-thioureido) C: Commercial product containing 1.5% of dimethyl dihydrurbethoxyethyl dithiophosphate Commercial product containing 2% of dimethyldithiophosphorylphenylacetate E: Dimethyl (3-methyl- Commercial product containing 50% of 4-nitrophenyl)thiophosphate: 0.0-diethyl-Q-3,5,6-to
Commercial product containing 50% trichloro-2-pyridine phosphorothioate: Methyl-1-(butylcarbamoyl)-2-
2 Commercially available product containing 50% benzimidazole carbamate: S-methyl-N-[(methylcarbamoyl)
Commercial product containing 45% oxycothioacetimidate: Commercial product containing 25% streptomycin sulfate: Commercial product containing 83% cupric hydroxide 27-

Claims (1)

[Scope of Claims] A plant virus disease infection preventive composition containing alginate as a main component and having a viscosity of 2 to 10 centipoise at 20°C in an 11% by weight aqueous solution. 2. The plant virus disease infection preventive composition according to claim 1, which comprises a carbonate and an organic acid. 3. The plant virus disease infection preventive composition according to claim 1, which contains a biopolymer substance other than alginate that has an effect of inhibiting plant virus infection, a carbonate, and an organic acid. 4. The plant virus disease infection preventive composition according to claim 1, which contains a biopolymer substance other than alginate that has an effect of inhibiting plant virus infection, a carbonate, an organic acid, and silica.