WO2023190668A1 - Method for producing aqueous solution to be applied to plants - Google Patents

Abstract

Provided is a simple, efficient and low-energy method for producing an aqueous solution to be applied to plants with the use of a plant as a starting material instead of using silicon dioxide contained in stones, gravel, sand, etc. as a starting material. More specifically, provided are: a method for producing an aqueous solution to be applied to plants which is obtained by extracting silicon compounds contained in rice husks with water, or an aqueous solution to be applied to plants containing a concentrated aqueous solution obtained by removing water from the aforesaid aqueous solution to be applied to plants, said method being characterized in that the rice husks are not burned in the presence of oxygen, a step for generating silicon dioxide is not performed, and the water-soluble silicon compounds contained in the rice husks are not carbonized but extracted, while maintaining the water solubility thereof, as the subject to be extracted; and an aqueous solution to be applied to plants produced by the production method.

Description

Method for producing plant-applied aqueous solution

The present invention relates to a method for producing a plant-imposed aqueous solution containing a silicon compound extracted by a specific method using rice husk as a raw material, and more specifically, a method for producing a water-soluble silicon compound contained in the rice husk using rice husk as an extraction target. The present invention relates to a method for producing a plant-applied aqueous solution containing a water-soluble silicon compound obtained by extracting the silicon compound while maintaining its water solubility.

It is known that rice husk contains many "silicon compounds having silicon element (Si) in the molecule."

Patent Document 1 describes a method for producing a fire-resistant heat insulating material, in which calcium silicate hydrate crystals obtained by suspending rice husk ash and lime raw materials in water and reacting them are molded and dried.
However, in Patent Document 1, white amorphous rice husk ash is obtained by heating rice husks in an oxidizing atmosphere to, for example, 600°C to burn and ash, which is used as a raw material (Patent Document 1 Claim 1, Example 1, etc.).

Furthermore, Patent Document 2 describes a method for producing amorphous silica in which rice husks are immersed in an aqueous solution containing an oxidizing substance, and then heated and oxidized in the presence of oxygen.
However, in Patent Document 2, rice husk is oxidized by heating in the presence of air to sufficiently reduce the organic material in the rice husk, and this is used as a raw material (Claim 9 of Patent Document 2, [0010] , [0016], [0020], etc.).

Patent Document 3 describes a mushroom mycelium growth promoter and fruiting body formation promoter whose active ingredient is an extract obtained by extracting rice husk with an aqueous solvent such as alcohol.
However, Patent Document 3 uses organic substances in rice husks to promote growth, etc., and does not focus on the element silicon (Si) at all, but actively extracts silicon (Si). It wasn't something to do. In other words, the invention was not aimed at obtaining a silicon compound.

Further, Patent Document 4 describes a method for producing a silicate having a specific molar ratio by reacting rice husk ash with a silicate precursor.
However, Patent Document 4 also uses rice husk ash as a raw material (claim 1 of Patent Document 4, etc.), and there is no mention of the technical concept of extracting water-soluble silicon compounds present in rice husks. There's no suggestion.

Patent Document 5 discloses that a raw material is produced by mixing silica ash obtained by burning rice husks so that the C/Si molar ratio is 0.2 or more and 2.0 or less, and the raw material is injected with an inert gas. A manufacturing method is described in which the raw material is heated by irradiation with microwaves in an atmosphere, and silica is reduced to obtain metallic silicon.
However, in Patent Document 5, silica ash obtained by burning rice husks is obtained and used as a raw material (Claim 1, [0050] Example 1, etc. of Patent Document 5).

On the other hand, silicon dioxide, which is a typical silicon compound on earth, exists mainly as quartz in rocks or gravel, and among them, large transparent crystals are called quartz, and sand-like ones are called silica sand. In other words, it is used as a raw material for various silicon (Si)-containing products (used for various purposes). Furthermore, quartz glass obtained by heating silicon dioxide at high temperature and once melting it is also used for various purposes.
Silicon (Si), which is used in electronic materials, is made from naturally occurring quartz or silica sand (the main component is SiO ₂ ), and when heated with coke, etc., a chemical reaction occurs: SiO ₂ +2C→Si+2CO It is obtained by
Furthermore, silicon-containing materials obtained by the chemical reaction: SiO ₂ +2NaOH→Na ₂ SiO ₃ +H ₂ O are used as water glass as raw materials for various products.

As described above, most silicon-containing materials are currently obtained by chemical or physical reactions on _SiO2 contained in natural rocks, gravel, and sand, and elemental silicon and silicon-containing materials are They are obtained by melting them and using the above reaction formula.
Moreover, a plant-applied aqueous solution obtained by dissolving a water-soluble silicon compound in water is also produced using silicon dioxide (SiO ₂ ) as a starting material.

In fact, with the exception of "Patent Document 3," which does not focus on silicon (Si) at all, most of the prior art methods first burn rice husks in the air and turn them into ash to release non-aqueous substances such as silicon dioxide (SiO ₂ ). As a natural inorganic substance, it is used as a manufacturing raw material.
In other words, in the conventional technology, the raw material rice husks are burned, There was no idea to extract silicon (Si) without destroying its form as a water-soluble substance originally contained in a plant-derived substance called rice husk.

On the other hand, in Patent Document 6, aiming at the effect of imparting silicon compounds to plants, metasilicate ions (SiO ₃ ^2- A method for producing cultivated plants is described in which a fertilizer containing .
However, the vitreous foam fired body to be added to the fertilizer is manufactured by using waste glass as a raw material, adding a foaming agent, and firing the mixture at a temperature above 750°C, which is the softening point of glass, preferably in the range of 840 to 980°C. It was not derived from plants, nor from grains or rice husks.

Patent Document 7 describes a liquid fertilizer for ornamental plants or trees containing a silicate such as potassium silicate.
Furthermore, Patent Document 8 describes the application of a mixture of fatty acids and silicates in a method for treating plants against diseases caused by specific bacteria or specific fungi.

However, Patent Document 7 and Patent Document 8 do not describe the raw material or origin of the silicate. It is presumed that it was manufactured using a general-purpose method, that is, using SiO ₂ contained in stones, gravel, and sand as a raw material.

In this way, most of the silicon compounds contained in plant disease prevention agents and fertilizer formulations are made from silicon dioxide and glass, and more broadly (if you go further) from stones, gravel, and sand. It was not derived from plants, rice husks or rice husks.

Japanese Patent Application Publication No. 58-041752 Special Publication No. 2004-527445 Japanese Patent Application Publication No. 2003-310051 Special table 2018-530512 publication Japanese Patent Application Publication No. 2020-090429 Japanese Patent Application Publication No. 2020-100524 Japanese Patent Application Publication No. 2020-132442 Special Publication No. 2022-509033

The present invention has been made in view of the above-mentioned background art, and an object of the present invention is to provide a simple, efficient, and low-energy method for producing a plant-applied aqueous solution containing silicon (Si). An object of the present invention is to provide a method for producing a plant-applied aqueous solution containing silicon (Si) without using silicon dioxide contained in rocks, gravel, sand, etc. as a raw material.

As a result of intensive studies to solve the above-mentioned problems, the present inventor discovered that by using rice husks as a raw material and using a specific method, an aqueous solution for plants can be obtained simply, efficiently, and with low energy, and that the aqueous solution can be used as a raw material. By doing so, they discovered that it is possible to produce a plant-imparting aqueous solution that has various beneficial effects on plants in a short process, and have completed the present invention.

That is, the present invention provides an aqueous plant-applied solution that contains a plant-applied aqueous solution obtained by extracting silicon compounds contained in rice husk with water, or a concentrated aqueous solution obtained by distilling water from the plant-applied aqueous solution. A method of manufacturing,
The water-soluble silicon compounds contained in the rice husks are extracted as extraction targets without burning the rice husks in the presence of oxygen, without performing a step of producing silicon dioxide, and without carbonizing the rice husks. The present invention provides a method for producing a plant-imparted aqueous solution, which is characterized in that extraction is performed while maintaining the following properties:

The present invention also provides the production of the plant-applied aqueous solution obtained by extracting the silicon (Si) element contained in the rice husk with water while maintaining the chemical structure of the water-soluble silicon compound contained in the rice husk. The present invention provides a method.

Further, the present invention provides the method for producing the plant-imposed aqueous solution, wherein the extraction target is the rice husk itself, which is neither rice husk ash nor smoky charcoal derived from the rice husk, or is obtained after the cuticle layer of the rice husk has been destroyed. It provides:

The present invention also provides a method for producing the above-mentioned plant-imparted aqueous solution, in which water-soluble silicon compounds already contained in rice husks are extracted with water at a temperature of 20°C or higher and 180°C or lower.

The present invention further provides a method for producing the plant-imparted aqueous solution, which removes lignin and/or coloring components or rice husk odor components contained in the rice husk after the extraction.

The present invention also provides a plant-applied aqueous solution produced by the above-described method for producing a plant-applied aqueous solution.

The present invention also provides the above-mentioned plant-applying aqueous solution for spraying onto the surface of leaves or stems of plants.

The present invention also provides the above-mentioned plant-imparting aqueous solution for promoting germination of vegetable seeds.

The present invention also provides the above-mentioned plant-imparting aqueous solution for improving the shelf life of vegetables, fruits, or flowers.

The present invention also provides the above-mentioned plant-imparting aqueous solution for enhancing the disease resistance of plants or the pest resistance of plants.

The present invention also provides the above-mentioned plant-imparting aqueous solution for increasing the yield of vegetables, fruits, or flowers.

According to the present invention, the above-mentioned problems and problems are solved, and the silicon (Si) element in the rice husk is extracted in the form of a water-soluble silicon compound contained in the rice husk while maintaining its water solubility. Furthermore, since the water-soluble silicon compounds already present in the rice husk are extracted into water while maintaining their chemical structure, the silicon (Si) element can be obtained efficiently and therefore at low cost.
In other words, compared to the conventional method of extracting silicon (Si) element in the form of silicon dioxide (SiO ₂ ) from stones, gravel, and sand, silicon (Si) element can be extracted using an extremely simple method, resulting in a significant cost reduction. become.
Since rice husk can be obtained as waste, it does not increase the cost of raw materials compared to stones, gravel, and sand such as quartz and silica sand.

Moreover, since the extracted form is not silicon dioxide (SiO ₂ ) but a water-soluble silicon compound (H ₂ SiO ₃ , H ₄ SiO ₄ , Si(OH) ₄ , condensates thereof, etc.), the water solubility is reduced. For the desired use as a plant-applied aqueous solution, it can be used almost as is, although it needs to be concentrated and diluted, so further cost reductions can be expected.

That is, the plant-imparted aqueous solution of the present invention is safe; cost reduction is possible because the plant-imparted aqueous solution extracted from rice husk with water can be used almost as is, that is, with the chemical structure contained in the natural product; It has the following effects.

Traditionally, technology has been developed to extract silicon (Si) from rice husks and change the chemical structure of the silicon (Si) element (containing compounds) into "elementary silicon or silicon-containing compounds" for various purposes and uses. There was a report.
In these methods, rice husks are first turned into rice husk ash or smoldering charcoal, that is, once in the form of silicon dioxide (SiO ₂ ), etc., and the silicon (Si) element is extracted from there (Patent Document 1, 2, 4, 5, etc.).

However, this is disadvantageous in terms of chemical energy, and in the end, silicon dioxide (SiO ₂ ) There is no difference from the conventional method of extracting (obtaining and manufacturing) elements, but rather the conventional method of burning rice husks in terms of the abundance of raw materials on earth and the ease of obtaining raw materials. is unilaterally disadvantageous.
In other words, in the currently known "method for obtaining silicon (Si) from rice husk," it is converted into a water-insoluble inorganic substance called silicon dioxide (SiO ₂ ) in the obtaining process, so quartz and silica sand are not used. This method is inferior to methods of obtaining silicon (Si) from "rocks, gravel, and sand" such as the above-mentioned methods.

Silicon (Si) elements are often used as inorganic substances, such as silicon wafers, high-purity semiconductor gases, and metal silicon nanoparticles, and for this purpose, it is sufficient to extract silicon (Si) elements. Therefore, in the past, when using rice husks as a raw material, it was considered that they were first burned to remove unnecessary organic matter.
In fact, when attempting to separate silicon (Si) from a substance or perform its qualitative or quantitative analysis, it is usually incinerated in a platinum crucible or heated at high temperatures using atomic absorption.

Therefore, it is thought that the idea of ``obtaining silicon (Si)-containing water in the form that it is contained in raw rice husks'' by extracting with water was difficult to come up (there were reasons that inhibited it).
Although silicic acid is water-soluble, it is not considered an "organic substance" (it is not an organic substance). Therefore, it is thought that the idea of organic chemical "extraction" did not occur to him. Therefore, it is thought that in the past, there was no idea (the idea did not arise) of mass producing silicon compounds by the water extraction method.

In plants, substances cannot be transported from roots to fruits unless the substances are water-soluble. Therefore, rice, wheat, etc. absorb water-soluble silicon compounds such as silicic acid (salts) from their roots to the rice husk, transport them, and accumulate them in the rice husk. Water-soluble silicon compounds such as silicic acid exist in an ionized state and are unstable, so rice, wheat, etc. are stabilized by incorporating them into the cuticle layer of rice.
On the other hand, to convert silicic acid into silicon dioxide, it is necessary to add energy to remove the hydroxyl groups and crystallize it. However, in plants such as rice and wheat, water-soluble silicon compounds are accumulated in the rice husk and then high energy is applied to produce water-insoluble forms (chemical structures) such as silicon dioxide (SiO ₂ ). There's no way he's doing it. In other words, the chemical structure sucked up from the roots should be maintained (retained) within the rice husk.

If so, we thought that it would be possible to extract the silicon compound with hot water, and when we actually tried it, we were successful, leading to the present invention. According to the present invention, a plant-applied aqueous solution containing a high concentration of silicon (Si) was unexpectedly easily obtained in large quantities by extraction with water.

Regarding the acquisition and use of silicon (Si), it is often treated as ``silicon dioxide (SiO <sub>2</sub> )'' rather than ``silicic acid'', and since the image of ``crystal'' has preceded it, stone ( Rice husk, which is inferior to quartz, etc.) and sand (silica sand, etc.), has been left unused or discarded. As mentioned above, there have been only some basic studies on methods for extracting from incinerated ash (rice husk ash) and methods for extracting using sodium hydroxide or calcium hydroxide.

Furthermore, if a water-soluble silicon compound is used as a raw material, compared to using silicon dioxide (SiO ₂ ) contained in stones or sand as a raw material, "various silicon compounds and elemental silicon" for subsequent use can be used in total. can be obtained at low cost.
In particular, silicon compounds with bonded hydroxyl groups can be made from minerals, but in order to do this, it is necessary to create a mine by cutting down a mountain, turn the resulting mineral into powder, and repeatedly refine it at high heat of over 2000 degrees Celsius. Because it has to be produced chemically through chemical processes, it is inefficient in terms of energy efficiency and is not suitable for the current era of recycling-based systems that aim to reduce energy loads.

In addition, if the production method of the present invention is used, that is, if the rice husk is extracted with water, the obtained product is water-soluble, so the desired plant-applied aqueous solution can be easily obtained by simply concentrating or diluting it. can be manufactured.
Originally, water-soluble silicon compounds are obtained from rice husks, which are "plant-derived" raw materials, so if you apply them to (cultivated) plants, etc., you will find that they have good absorbency and do not cause any harm to the plants. It should be a good match.

In addition, to protect the embryos (genes) of rice and wheat from the external environment, there is a rice husk, and the outermost layer of the rice husk is a cuticle layer. It is thought that it has the ability to protect against the external environment (pathogens, pests, etc.). The present invention utilizes the "ability of rice husk" as a plant-imparting liquid.

In addition, rather than ingesting silicon (Si) in the form of a poorly water-soluble substance such as silicon dioxide (SiO ₂ ), plants can consume silicon (Si) by using the "easily water-soluble silicon compound" dissolved in the plant-applied aqueous solution of the present invention. Needless to say, it is more effective to take it.
Furthermore, since the plant-applied aqueous solution of the present invention is derived from plants, it is highly safe and can be used with confidence, so it is suitable for cultivating vegetables, fruits, and flowers.

In many plants, silicic acid is absorbed through the leaves rather than through the roots. Therefore, when the plant-applied aqueous solution of the present invention is used for spraying on the surfaces of leaves or stems of plants, it exhibits remarkable effects.

When the plant-applied aqueous solution of the present invention was applied to vegetable seeds, it was effective in promoting germination and subsequent growth.
Furthermore, when the plant-applied aqueous solution of the present invention was applied to vegetables, fruits, or flowers, the shelf life was improved. In other words, they are less likely to rot, discolor, or wilt.

Furthermore, when given to plants that produce vegetables, fruits, and flowers, the disease resistance and pest resistance of the plants were enhanced. In particular, it prevented the spread of chlorotic disease, and was particularly effective against filamentous fungi. As a result, the yield of vegetables, fruits, or flowers increased.

Rice husks are produced in large quantities, and it is difficult to dispose of them as waste. The present invention not only has the above-mentioned excellent effects on plants, but also has excellent effects as waste treatment.
In addition, since rice husk, which is an extraction raw material, is easy to obtain and secure, and the raw material cost is low, the total manufacturing cost of the plant-imparted aqueous solution of the present invention can be kept low.

It is a photograph showing the germination status and the post-germination status of arugula seeds in Evaluation Example 5. (a) When germinated using tap water (b) When germinated using the plant-imparting aqueous solution of the present invention It is a bar graph showing the difference in the total mass of leaves and stems after germination when three types of water are used for germination of arugula seeds in Evaluation Example 5.

The present invention will be described below, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the technical idea.

[Method for producing plant-applied aqueous solution]
The method for producing a plant-applied aqueous solution of the present invention includes an aqueous silicon compound solution obtained by extracting silicon compounds contained in rice husks with water, or a concentrated aqueous solution obtained by distilling off water from the aqueous silicon compound solution. A manufacturing method comprising:
The water-soluble silicon compounds contained in the rice husks are extracted as extraction targets without burning the rice husks in the presence of oxygen, without performing a step of producing silicon dioxide, and without carbonizing the rice husks. It is characterized by extracting while maintaining the .

<Rice husk>
In the case of rice, the "rice husk" in the present invention may be the residue after removing brown rice (bran and white rice), that is, it may be after threshing and hulling, and the starting material (raw material) in the present invention is the rice husk. It may contain other things as long as it contains. Further, the rice husk is not limited to rice husk, but may be wheat husk such as barley or wheat.
Moreover, the rice husk is not limited to the husk of glutinous rice (glutinous rice), but may be the husk of glutinous rice (glutinous rice) or the like. Examples of the rice husk include rice husks of Japonica (Japanese-type rice), Indica (Indian-type rice), and Javanica (Java-type rice).

Rice husk consists of the outermost layer, the cuticula layer, and the inner layer of cellulose, hemicellulose, and lignin, and silicon (Si) is mainly contained in the cuticle layer.
In the present invention, the object to be immersed in water and heated may be the entire rice husk, or only the ``cuticular layer containing silicon compounds'' from which ``cellulose, hemicellulose, and lignin layers'' have been removed.・Since it is costly or difficult to remove the hemicellulose/lignin layer in advance, it is preferable to use the entire rice husk.

Rice husk may be crushed before extraction, but since silicon (Si) is mainly contained in the "surface layer of the cuticle layer", which is the outermost layer of rice husk, crushing is effective. However, considering the cost, it is preferable not to crush the rice husks.

<Contains an extracted silicon compound aqueous solution or a concentrated aqueous solution of the silicon compound aqueous solution>
The method for producing a plant-applied aqueous solution of the present invention contains an aqueous silicon compound solution obtained by extracting silicon compounds contained in rice husks with water, or a concentrated aqueous solution obtained by distilling off water from the aqueous silicon compound solution. let
Since "the silicon compound aqueous solution obtained by extracting the silicon compound contained in rice husk with water is contained", the aqueous solution is further diluted with water etc. to produce the plant-applied aqueous solution of the present invention. Good too. Alternatively, since "a concentrated aqueous solution obtained by distilling water off from the silicon compound aqueous solution is contained", the concentration of the "water-soluble silicon compound" in the plant-applied aqueous solution of the present invention does not have to be dissolved in water. For example, it may be anywhere from a concentrated solution (for example, the concentrated aqueous solution itself is used as the plant-applied aqueous solution of the present invention) to a dilute solution.

That is, the present invention is characterized in that an aqueous solution extracted from rice husks with water is used substantially as is, although a step of concentrating and diluting with water or the like may be added.
The aqueous solution itself extracted from the rice husks with water is used as the plant-applied aqueous solution without converting the rice husks into water-insoluble silicon compounds by ashing, carbonization, etc. Since "the aqueous solution itself is used as the plant-imparting aqueous solution", the chemical structure of the silicon compound that exhibits the water-solubility is not changed.
By doing so, costs can be reduced and the effects of the present invention described above can be achieved.

Further, in the present invention, it is preferable to obtain the silicon (Si) element contained in the rice husk by extracting it with water while maintaining the chemical structure of the water-soluble silicon compound contained in the rice husk.
It is preferable to extract the silicon compound with water without changing the chemical structure of the silicon compound that provides water solubility in the rice husk as a natural product.
By doing so, the "water solubility of silicon compounds in rice husk" can be utilized as it is in other "plants such as cultivated plants", and the above-described effects of the present invention can be achieved.

<Destruction of the cuticle layer>
In the present invention, it is also preferable to perform a treatment to destroy the cuticle layer containing silicon compounds prior to or during extraction from the rice husk, from the viewpoint of improving extraction efficiency.
That is, in the method for producing a plant-applied aqueous solution of the present invention, the extraction target is neither rice husk ash nor smoky charcoal derived from rice husk, but is the rice husk itself, or is obtained after the cuticle layer of the rice husk has been destroyed. preferable.

Furthermore, the above-mentioned "destruction of the cuticle layer of rice husk" is preferably caused by a protein that destroys the cuticle layer, and examples of the protein include, but are not limited to, proteins contained in pollen and proteins that cause diseases in plants. It is preferable to use a cuticle-degrading enzyme selected from the group consisting of proteins possessed by microorganisms.

Specifically, it is preferable to contact the rice husk and the protein in water prior to extraction, or to include the protein in the extraction water during extraction to bring the rice husk and the protein into contact.

<Removal of lignin etc.>
Lignin and/or coloring components or rice husk odor components (hereinafter abbreviated as "lignin etc.") contained in rice husk usually degrade the quality of the plant-applied aqueous solution of the present invention.
(1) Preliminary removal and then extraction using fresh water, or
(2) It is preferable to remove it from the plant-applied aqueous solution obtained by the production method of the present invention.

For (1) above, lignin is preliminarily dissolved by hydrolyzing lignin using acids such as sulfuric acid; solvents such as water, ethanol, and phenol; etc., by reducing the molecular weight of lignin and making it water-soluble. One example is removal.
It is also preferable to remove lignin in advance by lowering the molecular weight of lignin, making it water-soluble, etc. using hot water or steam at 80°C or higher, superheated steam at 100°C or higher, or high-pressure hot water at 100°C or higher. . In this case, since lignin etc. are extracted before the water-soluble silicon compound, it is preferable to first remove lignin etc. in advance and then extract using fresh water.

On the outside, rice husks have a cuticle layer that contains silicon compounds, enzymes such as cutinase, cutin (a polymer of unsaturated fatty acids), and wax (a water-insoluble fatty acid ester). It consists of a cuticle layer) and a ``cellulose, hemicellulose, and lignin layer'' that exists inside the cuticle layer. Furthermore, a bran layer and polished rice are present further inside the rice husk.

Silicon compounds are abundantly contained in the cuticle layer of rice husks, so they are preliminarily contained in the "cellulose/hemicellulose/lignin layer", "lignin and/or coloring components or rice husk odor components" (lignin, etc.), and/or It is also preferred that the silicon (Si)-free material is removed by a method other than combustion, and then the rice husks are extracted using fresh water.

As the method, in addition to the above-mentioned "removal by a method other than combustion", it is preferable to "remove by a method other than strong acid or strong alkali treatment".

In (1) above, the above substances including "lignin etc." are removed, but it also includes removing unnecessary organic substances contained in the cuticular layer such as enzymes such as cutinase, cutin, and wax. , it is preferable to remove it (if possible) unless it increases the cost.

The above (2) will be explained in detail later, but when water-soluble silicon compounds are extracted from rice husks with water using the production method of the present invention, the resulting plant-applied aqueous solution contains "lignin, etc." as mentioned above. Contains (organic) impurities, which must be removed.
Methods for removal include membrane separation, adsorption separation on activated carbon, etc., chromatographic separation using gel, etc., which will be described later.

In (2) above, ``lignin etc.'' are removed, but it also includes removing unnecessary organic substances contained in the cuticle layer such as enzymes such as cutinase, cutin, and wax, which increases costs. It is preferable to remove it if possible (if possible).

Although not limited, the above (2) is more preferable than the above (1) in terms of difficulty, cost, etc.

<Using silicon compounds in rice husks>
The present invention is a method for producing a plant-applied aqueous solution using silicon compounds in rice husks. Although it is characterized by extraction with water, it does not utilize the effects of water-soluble organic matter contained in rice husks.
In other words, the present invention is a method for producing a plant-applied aqueous solution that utilizes the effects of water-soluble silicon compounds contained in rice husks.

<Do not generate silicon dioxide (SiO ₂ )>
In the method for producing a plant-applied aqueous solution of the present invention, the rice husk is extracted as an extraction target without being burned in the presence of oxygen, without performing a step of producing silicon dioxide, and without being carbonized. It is essential to extract the water-soluble silicon compound while maintaining its water solubility.
The object to be extracted in the present invention is rice husk, which is neither rice husk ash nor smoky charcoal derived from rice husk.
As mentioned above, the present invention has discovered that silicon (Si) element can be obtained without burning rice husks, and furthermore, silicon (Si) element can be obtained more efficiently than when rice husks are burned. This was done after discovering what could be done.

Converting rice husks into silicon dioxide (SiO ₂ ) is disadvantageous compared to conventional methods that use silicon dioxide (SiO ₂ ) such as quartz or silica sand as a raw material. In other words, the advantages of rice husk over quartz and silica sand are not fully utilized.
Furthermore, producing silica (silicon dioxide (SiO ₂ )) by burning rice husks is disadvantageous in terms of the number of steps, energy, cost, and usage.

Once the rice husks are incinerated and carbonized, and the water-soluble silicon compounds in the rice husks are converted to SiO ₂ , the method becomes the same as the conventional method using quartz or silica sand, and does not exhibit the effects of the present invention.
Furthermore, if the rice husk is incinerated or carbonized, it may not be possible to completely remove the organic matter contained in the rice husk, and the ash and elemental carbon (C) may be extracted and removed from the organic matter. It may also interfere with.

<Extracting the silicon (Si) element in the rice husk with water at a temperature of 20°C or higher and 180°C or lower>
In the production method of the present invention, it is preferable to extract silicon compounds already contained in the rice husks using water at a temperature of 20° C. or higher and 180° C. or lower. Note that "water" here may be any liquid having a chemical formula of H ₂ O, and includes, for example, hot water, hot water, and the like.

The lower limit of the water temperature is preferably 40°C or higher, more preferably 60°C or higher, even more preferably 80°C or higher, and particularly preferably boiling water at 100°C under normal pressure. It is particularly preferable to use boiling water that is boiling at 100° C., since there is no need to control the temperature and extraction can be carried out stably at high temperatures.
If the temperature is too low, the yield of the plant-applied aqueous solution will drop, the silicon (Si) content will drop, the extraction time will take too long, the odor characteristic of rice husks will remain, and there will be coloration due to lignin in the rice husks, etc. There is.

On the other hand, the upper limit of the water temperature is preferably 180°C or lower, more preferably 150°C or lower, even more preferably 120°C or lower, and particularly preferably 100°C or lower. Water above 100°C is obtained by preventing boiling by applying pressure.

If the temperature is too high, the high temperature may be wasted; organic matter in the rice husks may be decomposed, making subsequent purification (removal of impurities from the obtained plant-applied aqueous solution) difficult. For example, the decomposition of cellulose in rice husks may be accelerated, making purification inefficient.
In addition, especially when the temperature is higher than 100°C, substances contained in the "cellulose/hemicellulose/lignin layer" such as lignin, coloring components or rice husk odor components, and the above-mentioned silicon (Si)-free (organic) substances, etc. Since it is relatively easier to extract than other silicon compounds, the concentration of (organic) impurities in the resulting plant-applied aqueous solution may increase.
Further, when the temperature exceeds 180° C., water becomes subcritical water, which promotes decomposition of organic matter in the rice husks and may make subsequent purification difficult.

<Water and extraction method>
The water (extracted water) used in the present invention is preferably neutral water. Here, "neutral" refers to a pH of 6 to 8. Preferably the pH is 6.5 to 7.5.
Although the presence of formulations in the water is not excluded, it is not particularly required (as it is unnecessary) and may increase costs. The compound includes, but is not particularly limited to, a pH adjuster; a compound that decomposes cuticle or cellulose; a compound that decomposes protein; and the like.

Additionally, if alkaline substances such as sodium hydroxide, calcium hydroxide, sodium (hydrogen) carbonate, and ammonia are blended in the extracted water, calcium silicate, sodium silicate, ammonium silicate, etc. are generated. In the present invention, since the solution is made entirely of plant-derived substances, it is particularly suitable as an aqueous solution for plants to be applied to cultivated plants.

There are various extraction methods other than water extraction, including steam distillation, organic solvent extraction, compression squeezing, extraction using superheated steam, (sub)critical extraction using carbon dioxide, and vacuum extraction (usually (below 100°C), water-soluble silicon compounds cannot be extracted properly, the silicon (Si) concentration in the resulting extract is low, the extraction time is long, the equipment is complicated (expensive), and the extraction efficiency is low. There are cases where it is bad.

<Extract into water in the form of water-soluble silicon compounds present in rice husk>
In the method for producing a plant-applied aqueous solution of the present invention, it is preferable that the silicon (Si) element in the extraction target is extracted into water in the form of a water-soluble silicon compound already present in the rice husk, which is the extraction target. "Already present in rice husk" means that it is present in raw or dried rice husk, and it can be burned, oxidized, or carbonized to produce silicon dioxide (SiO ₂ ), etc. This means that it does not become a water-insoluble compound.

Furthermore, it is preferable to extract the water-soluble silicon compounds contained in the rice husk while maintaining its original chemical structure without causing any chemical changes. It is preferable to produce the silicon compound while maintaining the chemical structure that makes the silicon compound water-soluble in the plant-applied aqueous solution.
When extracted in this way, wasteful energy such as combustion is not used; since the application is for a plant-supplemented aqueous solution that requires water solubility, the obtained extract (aqueous solution) may not be diluted or concentrated before use. Natural products can also be utilized and used as they are.
Substances that rice and wheat transport from their roots to the rice husk must be water-soluble because if they are in the form of granules or powder that are not dissolved in water, they cannot be transferred to the rice husk. Also, the silicon compounds stored in rice husks should be water-soluble. The present invention is characterized in that the water-soluble substance is extracted with water while maintaining its water solubility.

The chemical structure of the water-soluble silicic acid compound in the plant-applied aqueous solution of the present invention is not particularly limited.
The chemical structure and composition of the water-soluble silicon compounds already present in rice husks has not been completely specified, but at least they contain silicic acid (H ₂ SiO ₃ ) or silicate ions ( It has been confirmed that there is some SiO ₃ ^2- ), formally in the form of Si(OH) ₄ .

<Concentration of extracted water-soluble silicon compounds, blending ratio of rice husk and water>
Regarding the concentration of the water-soluble silicon compound in the present invention, it is preferable that the concentration of the water-soluble silicon compound is extracted to be 10 mass ppm or more in terms of silicon atom content, based on the entire plant-applied aqueous solution immediately after extraction.
Immediately after extraction, it is desirable to extract the amount to be more preferably 20 mass ppm or more, still more preferably 30 mass ppm or more, particularly preferably 45 mass ppm or more, and most preferably 60 mass ppm or more.
In the method for producing a plant-applied aqueous solution of the present invention, it is possible to extract the plant-applied aqueous solution to the above-mentioned mass ppm or more with respect to the entire plant-applied aqueous solution, and the later processing is easier when obtained at a high concentration. This is preferable because it is flexible and flexible.

There is no particular limitation on the upper limit as long as it can be extracted, but it is preferable to extract so that the content of silicon atoms is 2000 mass ppm or less in terms of the entire plant-applied aqueous solution immediately after extraction, and 1500 mass ppm or less. It is more preferable to extract so that the amount is less than ppm, and it is particularly preferable to extract so that the amount is less than 1000 ppm by mass.
If the above upper limit is too high, the extraction speed will decrease as the concentration increases in batch extraction; extraction is performed at high temperature to obtain high concentration, but the high temperature at that time may cause the rice husk to There are cases where hydrolysis of cellulose etc. is promoted and purification after extraction becomes difficult; cases where there is no need to increase the concentration to such a high level; etc.

In the present invention, rice husk is first immersed in water, and the mass ratio of "rice husk" and "water" at that time is such that water-soluble silicon compounds can be suitably extracted and the concentration as silicon (Si) There is no particular limitation as long as a plant-applied aqueous solution is obtained that is not too dilute, but water is preferably 5.0 to 1000 parts by mass, more preferably 10 to 700 parts by mass, and 20 to 1000 parts by mass per 1.0 parts by mass of rice husk. More preferably 500 parts by weight, particularly preferably 50 to 300 parts by weight.
When boiling water is used as water and the water is reduced by evaporation, the above range is the mass ratio of "rice husk" to "water" at the time of preparation or at the initial stage of extraction.

If there is too much water, the silicon (Si) concentration in the resulting plant-applied aqueous solution will be low; the volume will become too large, making subsequent handling such as concentration difficult; in the first place, this amount of water is not required. Water is wasted; equipment becomes unnecessarily large and costs increase; etc.

According to the present invention, even if the amount of water used as an extraction solvent is small or the extraction time is short, the extraction efficiency of silicon (Si) is extremely high. An aqueous solution can be produced.
If you want to obtain a highly concentrated plant-applied aqueous solution, you can concentrate by distilling off the water after extraction, but if you keep the above-mentioned "rice husk to water" mass ratio in the (more particularly) preferable range, An aqueous solution with a sufficiently high concentration can be obtained. The present invention is characterized in that an aqueous solution containing a high concentration of silicon compounds is obtained by extraction with water.

<Content of metasilicate ion (SiO ₃ ^2- )>
The water-soluble silicon compound contained in the plant-applied aqueous solution of the present invention contains many metasilicate ions.
Therefore, assuming that the above-described content in terms of silicon atoms is entirely contained in metasilicate ions (SiO ₃ ^2- ), in the present invention, metasilicate ions (SiO ₃ ^2- ) are contained in amounts of 54 mass ppm or more. An aqueous acid ion solution can be obtained.

The metasilicate ion (SiO ₃ ^2- ) contained in the plant-applied aqueous solution of the present invention is preferably 100 mass ppm or more (100 mass ppm or more can be obtained), and more preferably 150 mass ppm or more (150 mass ppm or more is obtained). 200 mass ppm or more is more preferable (200 mass ppm or more is obtained), and particularly preferably 250 mass ppm or more (250 mass ppm or more is obtained).

The upper limit of the content of silicon compounds in the plant-applied aqueous solution of the present invention converted into "silicon atom content" and the upper limit of the metasilicate ion (SiO ₃ ^2- ) contained in the plant-applied aqueous solution of the present invention is not particularly limited, but it will gel if it reaches a very high concentration. Therefore, the upper limit is the concentration at which gelation does not occur.

The method for quantifying silicon (Si) is not particularly limited, and any quantitative analysis method may be used. Alternatively, it may be quantified as metasilicate ion (SiO ₃ ^2- ) or the like and converted into the content ratio (mass ppm) of silicon (Si). Examples of such "methods for quantifying silicate ions (SiO ₃ ^2- )" include the molybdenum blue colorimetric method.
The value of the silicon (Si) content of the present invention is determined by quantifying silicate ions (SiO ₃ ^2- ) using a molybdenum blue colorimetric method and converting it into a silicon (Si) content ratio (mass ppm). The "silicon content" in the present invention is defined as the value obtained by such a method.

Although there are no limitations on such a device, specific examples include PackTest (registered trademark) (model: WAK-SiO ₂ ), manufactured by Kyoritsu Rikagaku Kenkyusho Co., Ltd., and the like.

<Removal of substances other than water-soluble silicon compounds>
The plant-applied aqueous solution of the present invention may contain substances other than water-soluble silicon compounds, such as lignin, cutinase, cutin, wax, cellulose, hemicellulose, starch, etc. in rice husks. Can be mentioned.

After the extraction, the plant-applied aqueous solution of the present invention preferably removes "lignin and/or coloring components or rice husk odor components" (lignin, etc.) contained in the rice husk. Note that this is described as (2) in the section <Removal of lignin, etc.> above.
If a plant-applied aqueous solution that has a smell is used, the smell may drift around the house, field, etc.

For their removal, filtration or membrane separation is preferred since it also removes water-insoluble substances from the plant-applied aqueous solution. Specifically, membrane separation using a UF membrane, MF membrane, etc. is preferable because the above-mentioned substances can be easily removed.
Preferred methods include adsorption separation on activated carbon, zeolite, etc., chromatographic separation using gel, and the like.

[Plant-applied aqueous solution]
The present invention also provides a plant-applied aqueous solution produced by the above-mentioned "method for producing a plant-applied aqueous solution."

The plant-applied aqueous solution obtained by the production method of the present invention contains silicon (Si) at least as metasilicate ion (SiO ₃ ^2- ), but it is either orthosilicate ion, metasilicate ion, or metasilicate ion. The details are not clear, such as whether it is disilicate ions, amorphous silica (SiO ₂ ), or whether they are mixed in small amounts, and there is no clear analysis of the silicon compounds contained in the cuticle layer of rice husks. .
Further, the aqueous solution may contain trace amounts of cellulose, hemicellulose, lignin, cutinase, cutin, wax, starch, coloring components, odor components, unpleasant taste components, and the like.

It is absolutely impossible to directly specify the form of such (water-soluble) silicon compounds and the form of "other contained substances" by component name, chemical structure, parameters, etc. , it is impossible or impractical to define them by chemical formulas, compositional formulas, parameters, content ratios, etc.

<Silicon (Si) concentration relative to the entire plant-applied aqueous solution>
<<Concentration as a product>>
By using the production method of the present invention, as described above, it is possible to extract silicon (Si) atoms to a content of 10 mass ppm or more in terms of silicon (Si) atom content. (When selling a plant-applied aqueous solution as an aqueous solution), it is preferable to concentrate or dilute the aqueous solution immediately after extraction to have a silicon (Si) atom content of 1.0 mass ppm or more and 2000 ppm or less.
In other words, in a preferred embodiment of the present invention, by adjusting the silicon (Si) concentration in the silicon compound aqueous solution or the concentrated aqueous solution, the content of silicon (Si) atoms can be increased with respect to the entire plant-applied aqueous solution. It is also a method for producing the above-mentioned plant-applied aqueous solution in which the amount is 1.0 mass ppm or more and 2,000 ppm or less in terms of the amount, and it is also the plant-applied aqueous solution produced by this manufacturing method.

More preferably 2.0 mass ppm or more and 1000 mass ppm or less, particularly preferably 3.0 mass ppm or more and 500 mass ppm or less.
If the concentration is too high, it may become difficult to manufacture or gel, and if the concentration is too low, it may be difficult to store. When the concentration is within the above range, it is possible to dilute the product with water during use, making it easier to handle the product and providing stability.

<<Concentration during use>>
When the plant-applied aqueous solution of the present invention is used, it is preferable that the silicon (Si) atom content is 0.1 mass ppm or more and 600 mass ppm or less when used. preferred for.
When obtained in high concentrations, it is preferred to dilute with water before use.

It is more preferably used in an amount of 0.3 mass ppm or more and 400 mass ppm or less, still more preferably 1.0 mass ppm or more and 200 mass ppm or less, particularly preferably 2.0 mass ppm or more and 100 mass ppm or less.
If the concentration is too high, it may be wasted, and if the concentration is too low, the effects described later on plants may not be exhibited.

<How to use the plant-applied aqueous solution and specific applications>
<<For spraying on the surface of leaves and stems>>
Silicon (Si) is more easily absorbed through leaves and stems than roots. Therefore, the aqueous solution applied to plants of the present invention is effective for spraying onto the surfaces of leaves and stems.
In other words, the present invention also provides the above-mentioned plant-applied aqueous solution for spraying onto the surfaces of leaves or stems of plants.

Foliar spraying makes the stems of cultivated plants flexible, making them less likely to break and becoming stronger.
When the stem becomes stronger, the number of fruits that can be supported increases in the case of vegetables and fruits, which increases the mass of the fruit. In the case of flowers, by making the stems stronger, the number and size of flowers can be increased.

Foliar spraying increases the effect of promoting photosynthesis, which is the basic metabolism of plants, allowing leaves to grow larger and increasing the amount of nutrients accumulated in fruits.
It is also effective in alleviating stress caused by metal ions such as aluminum ions in the soil, excessively applied chemical fertilizers, and the like.
Furthermore, it is resistant to high temperatures, relieves stress caused by strong ultraviolet rays caused by the ozone hole, etc., and stabilizes yields.
As described above, the plant-applied aqueous solution of the present invention is promising as a useful element that enhances the ability to adapt to the environment and as a material necessary for recycling agriculture.

<<For promoting germination of vegetable seeds>>
The plant-applied aqueous solution of the present invention is useful for promoting germination of vegetable seeds.
In fact, when leafy vegetable seeds were soaked in the aqueous solution for plants of the present invention and germinated, the germination period was shortened and the growth rate after germination was also fast.
It was suggested that the so-called germination stress was reduced by the plant-applied aqueous solution of the present invention.
Therefore, the present invention also provides the above-mentioned plant-imparting aqueous solution for promoting the germination of vegetable seeds.

<<For improving the shelf life of vegetables, fruits, or flowers>>
The plant-imparting aqueous solution of the present invention is useful for improving the shelf life of vegetables, fruits, or flowers.
When the plant-applied aqueous solution of the present invention was sprayed and applied to leaves or soil, silicic acid was accumulated in the pericarp of fruits and vegetables, and their shelf life was improved. Furthermore, even leafy vegetables have a longer shelf life due to the accumulation of silicic acid in the outer skin.
Therefore, the present invention also provides the above-mentioned plant-imparting aqueous solution for improving the shelf life of vegetables, fruits, or flowers.

<<For enhancing plant disease resistance or plant pest resistance>>
The plant-imparting aqueous solution of the present invention is useful for enhancing plant disease resistance or plant pest resistance.
When the plant-applied aqueous solution of the present invention is applied to plants, especially when sprayed on the leaf surface, silicic acid is accumulated in the outer skin of the plant, which prevents the invasion of hyphae such as plant pathogenic bacteria, thereby improving disease resistance.
It is particularly effective when the pathogen is a filamentous fungus, such as powdery mildew and rice blast. In fact, there is electron microscopy data showing that a protective wall of silicic acid is built around hyphae, preventing hyphae from entering.

In addition, by making the outer skin of the plant stronger, it is possible to reduce the damage caused by insects feeding on it and the damage caused by insects laying eggs on the leaf surface.
Therefore, the present invention also provides the above-mentioned plant-imparting aqueous solution for enhancing the disease resistance of plants or the pest resistance of plants.

<<For increasing the yield of vegetables, fruits or flowers>>
It exhibits the above-mentioned effects on vegetables, fruits, or flowers.
Therefore, the present invention also provides the above-mentioned plant-imparting aqueous solution for increasing the yield of vegetables, fruits, or flowers.

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples unless the gist thereof is exceeded.

Example 1
After washing 30 g of rice husk after threshing with pure water, it was immersed in 1000 mL of purified water in a heat-resistant glass bottle, and treated in an autoclave at 121° C. and 1.1 atm for 15 minutes.

When the obtained aqueous solution was quantified for silicate ions (SiO ₃ ^2- ) using PackTest (registered trademark) (manufactured by Kyoritsu Rikagaku Kenkyusho Co., Ltd., model: WAK-SiO ₂ ), the concentration was 200 mass ppm or more. showed that.
Using the fact that [silicate ion (SiO ₃ ²⁻ )]/[Si]=76/28=2.71, the concentration of silicon atoms was calculated to be 74 mass ppm or more.

Silicon compounds accumulated in the rice husks were eluted into water as silicate ions by treatment at 121° C. and 1.1 atm for 15 minutes to form an aqueous solution (extract).
This aqueous solution (extract) can be used as a plant-applied aqueous solution.
When the aqueous solution (extract) was examined for silicon, at least 70 mol% of silicon (Si) was silicate ion (SiO ₃ ^2- ).

Example 2
In Example 1, after autoclave treatment under the above conditions (after heat treatment under the same conditions), the resulting aqueous solution was extracted, new purified water was added thereto, and autoclave treatment under the same conditions (after heat treatment under the same conditions) was performed. ) was repeated four times.

Even after repeating the above treatment four times, the silicate ion (SiO ₃ ²⁻ ) concentration was 200 mass ppm or more. That is, even the fourth silicon compound aqueous solution after repeating the above treatment four times showed a silicon (Si) atom concentration of 74 mass ppm or more.

When the number of treatments is increased, "unnecessary compounds" such as lignin contained in the cuticle layer of rice husks are eluted into water, and when the treatment is repeated three times, for example, "unnecessary compounds" such as lignin are completely eluted into water. After repeating the process four times, the aqueous solution (extract liquid) became a colorless and transparent plant-applied aqueous solution.

Example 3
In Example 2, the first to third elutions of "unnecessary compounds such as lignin" were replaced with "121 ° C., 1.1 atm, 15 minutes" using an autoclave as described in Examples 1 and 2. The extraction was carried out at 98° C. and 1 atm (normal pressure) for 15 minutes using a general-purpose hot water extraction device designed to be used at normal pressure.
The fourth extraction was performed under the extraction conditions described in Examples 1 and 2: "121°C, 1.1 atm, 15 minutes." Other than that, the same procedure as in Example 1 was carried out.
Thereby, a colorless and transparent plant-applied aqueous solution was obtained.

Example 4
In Example 1, instead of using an autoclave and treating at 121°C and 1.1 atm for 15 minutes, a general-purpose hot water extraction device designed to be used at normal pressure was used to perform the treatment at 100°C and 1 atm. Hot water extraction was carried out for 15 minutes and 90 minutes, respectively (normal pressure).

The "aqueous solution containing a silicon compound" obtained above was subjected to quantitative determination of silicate ions (SiO ₃ ^2- ) using the same apparatus and method as in Example 1, and [silicate ions (SiO ₃ ^2- )] /[Si] = 76/28 = 2.71, and when converted into the silicon atom concentration, each was 20 mass ppm.

Example 5
A heat-resistant container was charged with 1000 mL of pure water and 5.0 g of rice husks and sealed. The mixture was placed in an autoclave and heated at 121° C. for 15 minutes, and the water-soluble silicon compound was extracted into water to obtain a plant-applied aqueous solution.

The concentration of silicon (Si) atoms in the obtained plant-applied aqueous solution was determined by the same method as in Example 1, and was found to be 500 mass ppm.

Example 6
1000 mL of water and 5.0 g of rice husks were put into a 2 L beaker, and after boiling at 100° C., the mixture was further boiled for 10 minutes to obtain a plant-applied aqueous solution.

The concentration of silicon (Si) atoms in the obtained plant-applied aqueous solution was determined by the same method as in Example 1, and was found to be 100 mass ppm.

Example 7
Rice husk suspension water having a concentration of [5.0 g of rice husks]/[1 L of water] was placed in a tubular heat exchanger heated to 80° C. with steam, and was allowed to pass through for 3 minutes.

The concentration of silicon (Si) atoms in the plant-applied aqueous solution obtained in the above extraction process was determined by the same method as in Example 1, and was found to be 80 mass ppm.

Example 8
Rice husk suspension water in which rice husks were suspended in water at a concentration of [5.0 g of rice husks]/[1 L of water] was placed in a hot water cooker, and the mixture was allowed to stand at 85° C. for 15 minutes.

The concentration of silicon (Si) atoms in the plant-applied aqueous solution obtained above was determined by the same method as in Example 1, and was found to be 80 mass ppm.

<Results of Examples 1 to 8>
From Examples 1 to 8, it was found that silicon (Si) atoms could be obtained at high concentrations at least at an industrial/mass production level. Naturally, in the case of incineration or carbonization, there are disadvantages such as a large number of steps and a waste of thermal energy.
Moreover, since it is used as an aqueous solution, the aqueous solution obtained by extraction can be diluted or concentrated, if necessary, to become a plant-applied aqueous solution, making it possible to further reduce the number of steps and reduce costs. It turned out to be extremely advantageous.

Evaluation example 1
The plant-applied aqueous solutions obtained in Examples 1 to 8 were adjusted to have a silicon (Si) atom content of 20 mass ppm, and applied to the leaves of various "plants that produce fruits and vegetables." It was sprayed once a day for a month.
As the stems bend and become stronger, the number of fruits increases, and the fruits become heavier (larger), which increases the yield.
It was suggested that foliar spraying promoted photosynthesis.

Evaluation example 2
The plant-applied aqueous solutions obtained in Examples 1 to 8 were adjusted to 20 mass ppm in terms of silicon (Si) atom content, and applied to tomato and strawberry leaves once a day for one month. It was spread all over.
Silicic acid accumulates in the skins of tomatoes and strawberries, making them last longer.
In addition, the accumulation of silicic acid in the outer skin prevents the invasion of plant pathogenic fungal hyphae, resulting in fewer diseases.

Evaluation example 3
The plant-applied aqueous solutions obtained in Examples 1 to 8 were applied to the leaves of various ``plants that produce fruits and vegetables'' and ``plants that provide various flowers,'' depending on the content of silicon (Si) atoms. The amount was adjusted to 20 mass ppm and sprayed once a day for one month.
By making the outer skin stronger, it was possible to reduce insect feeding damage and insect egg laying (and subsequent effects), increasing yields.

Evaluation example 4
In Evaluation Examples 1 to 3, the plant-applied aqueous solutions obtained in Examples 1 to 8 were adjusted to 5 mass ppm and 100 mass ppm in terms of silicon (Si) atom content. When evaluated in the same manner as in Examples 1 to 3, almost the same evaluation results as Evaluation Examples 1 to 3 were obtained.

Evaluation example 5
<Used for germination water of arugula seeds>
The plant-applied aqueous solutions prepared in Examples 6 to 8 were diluted with water to arugula seeds, which are germinated vegetables (a type of leafy vegetable). A "plant-applied aqueous solution of the present invention containing 50 mass ppm" was prepared.

The plant-applied aqueous solution of the present invention was used as water for germination, and the plants were allowed to germinate as shown in FIG. 1, and the total mass of leaves and stems was measured 10 days after germination.
As a result, in the plant-applied aqueous solution of the present invention, the "mass of leaves and stems" increased by 15% compared to purified water, and the "mass of leaves and stems" increased by 10% compared to tap water. (See Figure 2). In other words, there was a difference in mass after the same amount of time had passed after germination.

Also, the start of germination was early, but this may be due to the silicon compound in the plant-applied aqueous solution of the present invention reducing germination stress.

Evaluation example 6
<Sprayed on rose leaves>
The plant-applied aqueous solution prepared in Examples 6 to 8 is diluted with water to obtain "the plant-applied aqueous solution of the present invention containing 5 to 8 mass ppm of silicon (Si) atoms based on the entire obtained plant-applied aqueous solution." was prepared.

In winter, the temperature inside the greenhouse is high and the sunlight is weak, so only the flower branches of roses tend to elongate in search of light, often resulting in substandard flowers.
In winter, the roses grown in the greenhouse are filled with the above-mentioned "plant-applied aqueous solution adjusted to a concentration of 5 to 8 ppm by mass in terms of silicon (Si) atoms" using a vaporizer, and the leaves are Scattered on the surface.

As a result, the length was reduced. It was assumed that by spraying the plant-applied aqueous solution of the present invention on the leaves, the photosynthetic ability was increased and photosynthesis was carried out suitably even under weak light.
In addition, the rose buds became firmer, the leaves became more elastic, and the flowers lasted longer.

Evaluation example 7
<Sprayed on strawberry leaves>
The plant-applied aqueous solution prepared in Examples 6 to 8 was diluted with water to prepare "the plant-applied aqueous solution of the present invention containing 35 mass ppm of silicon (Si) atoms based on the entire obtained plant-applied aqueous solution". did.

When the above-mentioned plant application solution adjusted to a concentration of 35 mass ppm was sprayed on the leaves of strawberries, the size and rise of the leaves were improved, firmer leaves grew, and the size and color of the strawberries improved. Ta.

Evaluation example 8
<Used against filamentous fungi such as strawberry chlorosis>
The above-mentioned plant application solution adjusted to a concentration of 35 ppm by mass was applied to a strawberry strain infected with a filamentous fungus causing chlorotic disease (sprayed on the leaves).

As a result, although no improvement was observed in the affected area, no further progression of the disease was observed, and the newly sprouted axillary buds showed no symptoms of yellowing disease and grew normally.
It was suggested that the expansion of hyphae may have been controlled using silicon compounds.

Evaluation example 9
<Sprayed on the wave surface of Komatsuna>
The plant-applied aqueous solution prepared in Examples 6 to 8 was diluted with water to prepare "the plant-applied aqueous solution of the present invention containing 10 mass ppm of silicon (Si) atoms based on the entire obtained plant-applied aqueous solution". did.

When the above-mentioned "plant-applied aqueous solution adjusted to a concentration of 10 mass ppm" was sprayed on the leaves of Komatsuna, the size of the leaves increased by about 5 to 10 mm compared to those without the plant-applied aqueous solution. .
Furthermore, when leaves of Komatsuna were left in a refrigerator at 5° C. for 5 days, no wilting was observed in those using the plant-applied aqueous solution. In other words, as the leaves became stronger, the shelf life effect was improved.
Therefore, if the leaf growth rate is high and the leaves grow large, it can be expected that the time of shipping will be brought forward.

<Results of evaluation examples 1 to 9>
From Evaluation Examples 1 to 9, it was found that using the plant-applied aqueous solution of the present invention can improve the shelf life of vegetables, fruits, or flowers, and the plant-applied aqueous solution of the present invention is useful for improving the shelf life of vegetables, fruits, or flowers. I found out something.
It was also found that the disease resistance of plants or the pest resistance of plants could be enhanced, and the plant-imparting aqueous solution of the present invention was found to be useful for enhancing the disease resistance of plants or the pest resistance of plants.
It was also found that the yield of vegetables, fruits, or flowers could be increased, and the plant-imparting aqueous solution of the present invention was found to be useful for increasing the yield of vegetables, fruits, or flowers.

The method for producing a plant-applied aqueous solution of the present invention allows a high concentration of silicon compounds from a natural product called rice husk to be easily dissolved in water, and the resulting product is water-soluble.
Therefore, if it is applied to cultivated plants, the silicon (Si) element can be suitably incorporated into the plants.
Therefore, the present invention can be widely used in the field of agriculture, agriculture-related fields, the field of manufacturing, selling, and using general foods and health foods, the field of waste treatment, and the like.

Claims (15)

1. A method for producing a plant-imparted aqueous solution, which comprises a plant-imparted aqueous solution obtained by extracting silicon compounds contained in rice husks with water, or a concentrated aqueous solution obtained by distilling water off from the plant-imposed aqueous solution, ,
   The water-soluble silicon compounds contained in the rice husks are extracted as extraction targets without burning the rice husks in the presence of oxygen, without performing a step of producing silicon dioxide, and without carbonizing the rice husks. A method for producing a plant-imparted aqueous solution, which comprises extracting the plant-imparted aqueous solution while maintaining the
2. The method for producing a plant-applied aqueous solution according to claim 1, wherein the silicon (Si) element contained in rice husk is extracted with water while maintaining the chemical structure of the water-soluble silicon compound contained in rice husk. .
3. The plant-applied aqueous solution according to claim 1 or 2, wherein the extraction target is the rice husk itself, which is neither rice husk ash nor smoky charcoal derived from the rice husk, or after the cuticle layer of the rice husk has been destroyed. Production method.
4. The cuticle layer of the rice husk is destroyed by a cuticle-degrading enzyme selected from the group consisting of proteins contained in pollen and proteins possessed by microorganisms that cause disease in plants. 3. The method for producing a plant-applied aqueous solution according to claim 3.
5. The method for producing a plant-applied aqueous solution according to any one of claims 1 to 4, wherein the water-soluble silicon compound already contained in the rice husk is extracted with water at a temperature of 20°C or higher and 180°C or lower.
6. 2. The water-soluble silicon compound is extracted so that the concentration of the water-soluble silicon compound immediately after extraction is 10 mass ppm or more in terms of silicon (Si) atom content, based on the entire plant-applied aqueous solution immediately after extraction. A method for producing a plant-applied aqueous solution according to claim 5.
7. By adjusting the silicon (Si) concentration in the plant-applied aqueous solution or in the concentrated aqueous solution, the silicon (Si) atom content is 1.0 mass ppm or more in terms of the entire plant-applied aqueous solution. The method for producing a plant-applied aqueous solution according to any one of claims 1 to 6, wherein the amount is 2000 ppm or less.
8. Furthermore, after the extraction, lignin and/or a coloring component or a rice husk odor component contained in the rice husk is removed, the method for producing a plant-imposed aqueous solution according to any one of claims 1 to 7. .
9. A plant-applied aqueous solution produced by the method for producing a plant-applied aqueous solution according to any one of claims 1 to 8.
10. The plant-applied aqueous solution according to claim 9, which has a silicon (Si) atom content of 0.1 mass ppm or more and 600 mass ppm or less when used.
11. The plant-applied aqueous solution according to claim 9 or 10, which is for spraying onto the surface of leaves or stems of plants.
12. The plant-applied aqueous solution according to claim 9 or 10, which is for promoting germination of vegetable seeds.
13. The plant-applied aqueous solution according to claim 9 or 10, which is used to improve the shelf life of vegetables, fruits, or flowers.
14. The plant-imparting aqueous solution according to claim 9 or 10, which is for enhancing the disease resistance of plants or the pest resistance of plants.
15. The plant-imparting aqueous solution according to claim 9 or 10, which is used to increase the yield of vegetables, fruits, or flowers.

Images