JPS5938924B2 - Plant virus disease infection prevention agent - 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 derived from living organisms, such as alginic acid and casein, have plant disease control effects, such as the effect of inhibiting virus infection. Its use in agricultural chemicals has been reported as an infection inhibitor for plant viruses such as mosaic virus (CMV).

(Japanese Society of Plant Pathology Bulletin 1231, 1155-161
) However, alginic acid is inconvenient to use because it does not dissolve in water, and sodium alginate has great water compatibility and enormous viscosity when submerged in water, so it cannot be dissolved in water in a short period of time to prevent joint powder from forming. It is extremely difficult to do so.

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

Furthermore, there have been other problems such as insufficient medicinal efficacy in use, causing chemical damage, and clogging of spraying equipment.

In order to improve these drawbacks, it has been proposed to rapidly dissolve sodium alginate by adding additives such as polymeric phosphates, polyacrylates, carboxymethyl cellulose salts, and the like.

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 alginate derived from a biopolymer.

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

Alginate is derived from polysaccharides that are abundantly contained in brown algae such as casino, and is a copolymer of D-manuronic acid and L-guluronic acid, and its average degree of polymerization is said to be between 250 and 900. Alginic acid and alginate are classified depending on whether the carboxyl group of the pyranose ring, which is the basic skeleton of the alginic acid, is a carboxylic acid or a carboxylate.

Both alginic acid and alginate have significant hydration properties due to hydrogen bonding of water to the carboxyl and hydroxyl groups of the pyranose ring, but alginic acid is insoluble in water, whereas the sodium, potassium and ammonium salts of alginic acid etc. dissolve in water to form a viscous solution.

Therefore, the present inventors focused on the difference in properties between alginic acid and alginate, and found that the carboxyl group bonded to the pyranose ring, which is the basic skeleton of alginic acid, expressed by the general formula (C5H704COOH)n, becomes a carboxylate type. When we examined the water solubility of each alginate either alone or uniformly mixed with an alkaline source commensurate with the neutralization level, we found that alginate with a degree of neutralization of 10 to 30% was soluble in water. It has been found that it has rapid solubility.

The degree of neutralization (%) in the present invention is expressed by the general formula (C3l(7
When only a of the alginic acids represented by 04COOH)n is in the salt form, it is expressed by the following formula.

[However, in the formula, M represents Na or NH4.

That is, the present invention provides a plant virus disease infection preventive agent containing alginate as a main component with a degree of neutralization of 10 to 30%, and a plant virus disease infection prevention agent containing an auxiliary agent having a foaming function to increase solubility. It concerns an anti-infective agent.

To explain the present invention in detail, the alginate used in the present invention includes sodium alginate, potassium alginate, ammonium alginate, etc., and the degree of neutralization thereof is 10.
~30%, preferably 10-20%.

A mixture of carbonate and organic acid is used as an adjuvant to improve solubility, and examples of the carbonate include calcium carbonate, sodium bicarbonate, soda carbonate, potassium bicarbonate, potassium carbonate, and ammonium carbonate. However, care must be taken when using calcium carbonate as the alginate may harden (gel).

The role of the carbonate used here is to react with the organic acid, which is another auxiliary agent, to foam and disperse the main component, alginate, and to have a low degree of neutralization of the main component, alginate. Therefore, it is also a source of alkali.

As the organic acid, higher fatty acids such as citric acid, conolilic acid, fumaric acid, lactic acid, 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 of neutralization and amount of alginate, since carbonate is also used for neutralizing alginate as mentioned above, and the final ratio is 1% in the blended composition. When making an aqueous solution, it is necessary to ensure that the liquid properties of the solution are such that they do not have a negative impact on plants.
Usually, the amount is within 35% by weight, preferably within 25% by weight of the alginate.

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-globulin, lactoglobulin, albumin, gluten, pectin, starch, gelatin, xylose, arabinose, and salts thereof.

In addition, the amount is within 40% by weight based on the alginate,
It is preferably 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.

As the carrier, silica or a silica-containing substance is preferable, 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 weight vertical--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.

Surfactants can generally be selected from a wide range of nonionic and anionic surfactants, but it is desirable to have a good affinity for biopolymer substances, excellent wetting and dispersibility, and low toxicity. , specifically polyoxyethylene sorbicun monolaurate, polyoxyethylene sorbicun monooleate, polyoxyethylene sorbicun dioleate, and polyoxyethylene sorbitan monostearate.

Nonylphenol (polyoxyethylene) 6 phosphate ester sodium salt, lauryl (polyoxyethylene)
4. Polyoxyethylene-based nonionic surfactants such as phosphate ester potassium salt, oleyl (polyoxine ethylene) 7. Polyoxyethylene-based nonionic surfactants such as phosphate ester sodium salt, and anionic surfactants such as higher alcohol hydrochloride ester salt are listed, and their use is The amount is 1 to 10% by weight, based on the alginate.

The plant virus disease infection preventive agent of the present invention has a neutralization degree of 10 to 30.
% of alginate alone, or an auxiliary agent with a foaming function is added to this, or these compounds are combined with a biopolymer substance other than alginate that has the effect of inhibiting plant virus infection, silica or a silica-containing substance, or an interface. It is commercialized by adding active agents and other ingredients.

As explained above, the degree of neutralization used in the present invention is 10 to 30%.
Alginate can be used not only when combined with an auxiliary agent that has a foaming function, but also when alginate is used alone, and even when an alkaline source suitable for neutralization is uniformly mixed with it and dissolved in water. , a homogeneous solution is obtained without generation of splinters or insoluble precipitates.

Furthermore, alginates with a high degree of neutralization can be added to water alone or in combination with the aforementioned adjuvants, due to their high water compatibility and water compatibility. Due to the enormous viscosity when moistened, dissolution stops with only the surface of the drug granules moistened with water, resulting in a joint powder state.

In addition, alginic acid with a low degree of neutralization, which is usually referred to as alginic acid, is added to water even if an alkali source is added that is commensurate with the neutralization amount of alginic acid.Alginic acid is insoluble in water and will precipitate, resulting in a neutralization reaction. The reaction time is slow, and stirring for 10 to 20 minutes is required to advance the reaction, which prevents cross-powdering, but is inefficient.

The application method of the plant virus disease infection preventive agent obtained by the present invention is not particularly limited (the usual application method for 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, the composition of the present invention is diluted 200 times with water and then added to
Spray over the entire tobacco seedling just before transplanting at a rate of 5 to IOJ per 0 are.

After that, as the tobacco seedlings grow, 100 to 150
It is common to spray up to 1 chemical solution.

Since the agent of the present invention can be easily dissolved uniformly in water, it is easy to handle during application and is economical without waste.

Next, the method of the present invention will be explained in more detail with reference to production examples, working examples, and test examples, but the present invention is not limited to the following examples, which do not go beyond the gist of the invention.

Production Example (Production method of sodium alginate) An alginate soda having an arbitrary degree of neutralization used in the present invention was produced as follows.

After dissolving commercially available sodium alginate for food additives (neutralization degree 88%) in water to make a homogeneous solution, while stirring vigorously,
Add a specified amount of diluted hydrochloric acid and leave at room temperature overnight.

Next, add a large amount of methanol and collect the precipitated gel by filtration.
After washing with methanol, drying is performed under reduced pressure at a temperature of 50° C. or lower.

In order to make the test conditions the same, each sodium alginate sample was adjusted to have a drying loss of 7 to 15%.

The degree of neutralization of the sodium alginate thus obtained was measured according to the Food Additives General Test Method "Determination of Organic Acid Alkaline Salts" to obtain alginate having the degree of neutralization described on page 1. .

For reference, the corresponding drying loss% and 1% aqueous solution were prepared and the pH was adjusted to 5 to 7.
The viscosity at °C is shown in Table 1.

Examples Sodium alginate with various degrees of neutralization, casein soda, α-globulin, sodium bicarbonate, soda carbonate, tartaric acid, phosphoric acid, diatomaceous earth, white carbon and as a surfactant Turpon T-80 (trademark) (oxyethylene sorbicun monooleate surfactant) was blended in the amount ratio (weight ratio) shown in Table 2 to obtain each composition.

Test Example 1 Potted tobacco seedlings (N1 cotiiana gluti)
nosa) 100 times the composition shown in Table 2, 20
Spray 0x and 400x diluted solutions (use after diluting and dissolving with water and leaving for 5 minutes) with a spray gun and air dry.
Separately prepared TMV purified solution [2×10”?/ml
! "J" was inoculated by the conventional carborundum method and left in a greenhouse for about one week to form local lesions.

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

The results are shown in Table 3, and it is clear that the comparative composition is inferior in medicinal efficacy to the composition of the present invention.

The TMV-purified liquid was prepared by separating and purifying TMV from the juice of TMV-purified diseased leaves using an ultracentrifuge.

Table 3 also shows the results of spraying a 100 times diluted solution of the composition shown in Table 2 on tobacco seedlings (bright yellow) and investigating 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 were as shown in Table 4. Test Example 3 The effects of some of the compounds shown in Table 2 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.

Spraying agent: After air-drying, a purified solution adjusted to a TMV concentration of 2 x 10-''g/ml was inoculated onto the largest 115 x 5 CrrL leaf surface of tobacco seedlings.

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

The results are shown in Table 5.

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

That is, put the tap water of No. 21 into the beaker of No. 31, then add the pharmaceutical composition 20'iI, leave it for 2 minutes (conditions that facilitate the formation of joint powder), then start stirring, observe the state after 1 minute, The time required for the solution to become completely clear without any splinters or insoluble precipitates was measured.

The results are shown in Table 6.

Claims (1)

[Scope of Claims] 1. A plant virus disease infection preventive agent containing alginate as a main component with a degree of neutralization of 10 to 30%. 2. The drug according to claim 1, which contains a carbonate and an organic acid. 3. The drug according to claim 1, which contains a biopolymer substance other than alginate that has the effect of inhibiting plant virus infection, a carbonate, and an organic acid. 4. The drug according to claim 1, which contains a biopolymer substance other than alginate that has the effect of inhibiting plant virus infection, carbonate, organic acid, and silica.