JP2014018190A - Hydroponic culture method for fruit vegetables that bear plural fruits per root and fertilizer for hydroponic culture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydroponic culture method that enables mass production of fruit vegetables such as tomato having low potassium.SOLUTION: The method focuses on a finding that when a plant is provided with a sufficient fertilizer and a stem blooms a flower, the stem has accumulated sufficient nutrients. For example, when plural roots are hydroponically grown under the same culture conditions and one specified flower blooms, the time when one specified flower blooms among plural roots is determined as a reference point. A normal fertilizer containing at least three major fertilizer elements of nitrogen, phosphorous and potassium is provided before the reference point. After the reference point, a fertilizer composed of arbitrary elements where standard concentration of potassium, etc. is lower is provided. And fruits based on flowers that blooms after the reference point are harvested.

Description

  The present invention relates to a hydroponic cultivation method and a fertilizer for hydroponic cultivation of fruit vegetables that give a plurality of fruits to a specific strain.

In hydroponics, fertilizer elements that are harmful to the human body remain in fruit and vegetables, but especially for patients with kidney disease, residual potassium, which is one of the fertilizer elements, has become a problem. Yes. This is because patients with kidney disease cannot fully excrete potassium in the body because of impaired kidney function.
However, since potassium is one of the three major elements of fertilizer, using a fertilizer that is completely removed is not suitable because it significantly impairs the growth of fruits and vegetables.

  Therefore, as disclosed in Patent Document 1, it is considered to set a reference time in the growing stage of fruit vegetables and change the culture solution with the reference time as a boundary. That is, in the hydroponic cultivation method disclosed in Patent Document 1, a standard culture solution containing potassium at a standard concentration is used before and after the flowering or fertilization period, and after that standard. Uses a potassium-reduced culture solution in which the potassium concentration is lower than the standard concentration.

JP 2011-135797 A

In the conventional hydroponics method, the individual flowering seasons must be observed for their flowering or fermenting periods. However, even if the cultivation conditions are the same for fruit vegetables, the flowering period and the fermenting period vary depending on the strain, so it is virtually impossible to observe the flowering period or the fermenting period for each individual strain. .
Therefore, the conventional hydroponic cultivation method has a problem that the larger the number of strains, the worse the cultivation efficiency, which is not suitable for mass cultivation.
An object of the present invention is to provide a hydroponics method suitable for mass cultivation of fruit vegetables and a fertilizer used for hydroponics.

  In the hydroponic cultivation method of the first invention, a specific flower is flowered among one or a plurality of strains that are hydroponically cultivated under the same cultivation conditions such as the planting time, the type of fertilizer, or the local environment of cultivation. Fertilizer consisting of any fertilizer element with a standard concentration such as potassium reduced after the standard, using normal fertilizer containing at least nitrogen, phosphorus and potassium, which are at least three major elements of fertilizer. Is used. Furthermore, the fruit which set based on the specific flower which determines the said reference | standard, and the flower which opened after the said reference | standard is harvested as fruit vegetables.

The time when the flower blooms is confirmed by visual observation and includes not only a state where the flower is completely opened but also a state immediately before the flower is opened.
Further, if attention is paid to one strain, the flowers bloom in order from the bottom so-called close to the root, but any of these flowers may be determined as the standard flower. In this case, if the flower that bloomed before the reference flower is pruned, the fruit that has fruited based on the flower that bloomed after the reference can be easily identified. However, in the first invention, the pruning is not an absolute condition.

In addition, it is not necessarily limited which flower should be used as the standard. However, if a single strain is used as the standard, the flower that blooms first is the one that is based on the flower that first blooms near the root. It is efficient in that it can harvest all the fruits.
In addition, at the stage where the plant blooms the first flowers, nitrogen, phosphorus and potassium, which are the three major elements of fertilizer, are sufficiently stored in the stem. This can be accomplished while consuming the generated nitrogen, phosphorus and potassium.

In addition, the flower that should be the standard among one or more strains that are hydroponically cultivated under the same cultivation conditions, such as the planting time, the type of fertilizer, or the local environment of cultivation, is based on the flower that first bloomed. This makes management easier, including observation work.
In any case, the first invention is characterized in that the time when a specific flower blooms is used as a fertilizer conversion standard, and the fruit after the specific flower blooms is harvested.

The hydroponics method of 2nd invention has the characteristics in the point which uses the fertilizer which does not contain potassium substantially instead of the said normal fertilizer after the said reference | standard.
The third invention is characterized in that after the above standard, a fertilizer containing substantially no calcium and containing calcium, magnesium, phosphorus and nitrogen as main components is used.

The hydroponics method of 4th invention has the characteristics in the point which uses the fertilizer which does not contain potassium and sodium substantially but has calcium, magnesium, phosphorus, and nitrogen as a main component after the said reference | standard.
The hydroponics method of 5th invention has the characteristics in the point which made the pH value of the aqueous solution of the main component of the fertilizer used after the said reference | standard 5-5.

  The fertilizer for hydroponics of the sixth invention is substantially free of potassium and sodium, contains calcium, magnesium, phosphorus and nitrogen as main components, and the pH value of the aqueous solution of this main component is 5-9. It has the characteristics.

  According to the hydroponic cultivation method of the first invention, a specific flower is present in one or more strains that are hydroponically cultivated under the same cultivation conditions such as the planting time, the type of fertilizer, or the local environment of cultivation. After the flowering time is based on the time of flowering, for example, other strains that do not bloom can also be used as fertilizer conversion standards. Therefore, when hydroponically cultivating a large number of strains at the same time, it is possible to proceed with the change of fertilizers of other large-scale strains at a stretch only by using only one flower attached to a specific strain. Cultivation efficiency can be dramatically improved.

  Moreover, since the specific fruit which determines the conversion standard of a fertilizer and the fruit which grew on the flower which bloomed after that specific flower were harvested as fruit vegetables, a fruit with a high growth degree can be harvested. Because, at the stage where even one flower blooms, nitrogen, phosphorus and potassium, which are the three major elements of fertilizer, are sufficiently stored in the stem, the necessary fertilizer, for example, potassium, is somewhat insufficient. This is because even if you are doing it, it will not cause any trouble in producing fruit.

  In fact, the fruit that has been produced after blooming as described above is expected to grow sufficiently, and in the harvested fruits and vegetables, the residual amount of the fertilizer elements not included in the fertilizer given after the conversion standard is small. Become. Therefore, if potassium is not included in the fertilizer after the conversion standard, for example, low potassium fruit vegetables can be harvested.

  According to the hydroponics method of the second invention, after the conversion standard of fertilizers, fertilizers that do not substantially contain potassium are used instead of normal fertilizers, so that sufficient growth of fruit vegetables is realized. Fruits and vegetables with a small amount of potassium can be harvested.

  According to the hydroponic cultivation method of the third invention, after the fertilizer conversion standard, it contains substantially no potassium and fertilizers mainly composed of calcium, magnesium, phosphorus and nitrogen. While absorbing trace amounts of potassium, phosphorus and nitrogen remaining in the stem, it can grow by sufficiently absorbing magnesium and the like instead of potassium. As described above, fruit vegetables absorb only a small amount of potassium remaining in the stem, and the shortage is supplemented with magnesium or the like, so that low potassium fruit vegetables can be harvested.

  According to the hydroponic cultivation method of the fourth invention, after the fertilizer conversion standard, a fertilizer containing substantially no calcium and sodium but containing calcium, magnesium, phosphorus and nitrogen as main components is used after the standard. Therefore, fruit vegetables can grow by sufficiently absorbing magnesium and the like instead of potassium and sodium while absorbing trace amounts of potassium, sodium, phosphorus and nitrogen remaining in the stem. As described above, fruit vegetables absorb only a small amount of potassium and sodium remaining in the stem, and the shortage is supplemented with magnesium or the like, so that fruit vegetables with low potassium and low sodium can be harvested.

  According to the hydroponic cultivation method of the fifth invention, since the pH value of the aqueous solution of the main component of the fertilizer used after the fertilizer conversion standard is set to 5 to 9, the fertilizer used after this fertilizer conversion standard also has sufficient function as a fertilizer Can be kept in.

  According to the fertilizer for hydroponics of the sixth aspect of the invention, it contains substantially no potassium and sodium, and mainly contains calcium, magnesium, phosphorus and nitrogen, and the pH value of the aqueous solution of this main component is 5-9. Therefore, if this fertilizer is used after the fertilizer conversion standard of the first invention, fruit vegetables of low potassium and low sodium can be harvested.

It is explanatory drawing which showed the apparatus for hydroponics. It is the table | surface which showed the cultivation conditions of tomato. It is the figure which showed the number of days which gave the normal fertilizer, and the number of days which gave the invention fertilizer. It is the figure which showed the component of the hydroponic liquid using the invention fertilizer 1. FIG. It is the figure which showed the component of the hydroponic liquid using the invention fertilizer 2. FIG. It is the figure which showed the component of the hydroponic liquid using the invention fertilizer 3. FIG. It is the figure which showed the component of the hydroponic liquid using a normal fertilizer. It is the figure which showed the harvest condition by the 1st tomato cultivation. It is the figure which showed the harvest condition by the 2nd tomato cultivation. It is the figure which showed the cultivation conditions of cucumber. It is the figure which showed the harvest condition of a cucumber. It is the figure which showed the cultivation conditions of the strawberry. It is the figure which showed the harvest condition of the strawberry.

  FIG. 1 shows an apparatus for hydroponics. This apparatus includes three hydroponic containers 1 to 3, and these hydroponic containers 1 to 3 include a pump P that circulates water such as tap water. Between them, a circulation circuit is configured through a pipe. Therefore, when the pump P is driven to supply tap water, the tap water circulates from the hydroponic container 1 via the hydroponic container 2 and the hydroponic container 3. However, the apparatus for hydroponics is used with one hydroponic container or multiple stages depending on the purpose.

The hydroponic cultivation apparatus as described above sets the external environment to the same and hydroponically cultivates predetermined fruits and vegetables. At this time, one or a plurality of strains are simultaneously planted in the hydroponic container. . Even when one hydroponic container is used, a plurality of plants may be planted in the container.
Each hydroponic container made as described above is given the same amount of normal fertilizer containing nitrogen, phosphorus and potassium, which are the three major elements of fertilizer, until the first flower of the above-mentioned strain blooms. Cultivate. In addition, the hydroponic liquid using this normal fertilizer is a commonly used aqueous solution of fertilizer for hydroponic cultivation. As shown in FIG. 7, the stock solution contains the above nitrogen, phosphorus and potassium as main components. In the following, this is usually called fertilizer.

And, based on the time when the flower first bloomed in any one of the plants planted in the hydroponic container, the normal fertilizer is replaced with a fertilizer that does not contain, for example, potassium or sodium. ing.
And the biggest feature of this embodiment is that when a flower is first bloomed in any one of the plurality of strains in the hydroponic containers 1 to 3, even if the other strains are not yet bloomed. The point at that time was used as the fertilizer conversion standard.

The reason for making the fertilizer conversion standard when flowers bloom as described above was because of the following two discoveries by the applicant.
First, fruit vegetables grow while absorbing the nutrients stored in the stem, but the nutrients stored in the stem are stored enough until the flower blooms in the plant. It was discovered that even if there was a shortage, the fruits could be grown sufficiently by the nutrients stored in the stem.

  Second, in the case of multiple plants that are hydroponically cultivated under the same cultivation conditions, such as the time of planting, the type of fertilizer, or the local environment of cultivation, if any of the plants blooms, the flowers will bloom. Even if there are other strains that are not, enough nutrients are accumulated in the stems of those strains, and after that, even if there is a shortage of nutrients, they can grow well with the nutrients stored in the stems It is to have discovered.

The above principle can also be applied to the case where there is one strain to be hydroponically cultivated. In this case, when a flower blooms in one strain, it becomes the fertilizer conversion reference point.
In addition, in any case of one or a plurality of strains, it is not necessary to specify exactly the time when the flower first blooms. The flower that blooms second may be used as a fertilizer conversion reference point. However, when the second and subsequent flowers are used as the fertilizer conversion standard, the fruits to be harvested are limited to the fruits that have formed on the second and subsequent flowers. This is because, in a state where normal fertilizer is continuously given, the fruit that has been born absorbs many elements of normal fertilizer, so that, for example, low potassium fruit cannot be harvested.

Therefore, when the second and subsequent blooming flowers are used as the fertilizer conversion standard, it is preferable to prune the flowers that bloomed before the conversion standard. This is because if the flowers bloomed before the conversion standard are pruned, the fruits that have formed on the flowers before the conversion standard will not be harvested by mistake.
In addition, whether or not a specific flower that should be used as a reference has bloomed is confirmed by visual inspection. However, it may be determined that the flower has bloomed not only when the flower is completely opened, but also immediately before the flower is opened and the bud is slightly unrolled.

Example 1
Example 1 relates to the first tomato cultivation shown in FIG.
The tomato in Example 1 uses Carol Tree (trade name), and as shown in FIG. 2, two plants are planted in one 40-liter hydroponic container on the roof, and the cultivation period is 2011. It was 90 days from May 9, 2011 to August 7, 2011.

Then, when the normal fertilizer (stock solution) in FIG. 7 was diluted 400 times in the initial stage and given as shown in FIG. 3, the first flower bloomed in 1 strain on the 46th day. As a fertilizer conversion reference point, the invention fertilizer 1 containing no potassium was used for the subsequent 44 days. In addition, at the said conversion reference point, it was in the state which has not yet blossomed in the other stock | strain.
Moreover, the said invention fertilizer 1 consists of the stock solution of the hydroponics which does not contain potassium and sodium substantially, as shown in FIG. 4, and this stock solution makes content of magnesium into the main components of nitrogen, phosphorus, and calcium. The concentration was 23.2% by weight, and the stock solution was diluted 400 times.
In addition, the said invention fertilizer 1 contains trace components, such as zinc and copper, in addition to the said main component.

And the said hydroponic liquid is adjusted so that the pH value may maintain 5-9. The pH value may be adjusted by any method as long as it does not substantially contain potassium and sodium.
The phrase “substantially free of potassium and sodium” means that the inclusion of potassium or sodium in a negligible amount compared to the amount of other components during the preparation of fertilizer is allowed. For example, when tap water is used to dilute the hydroponic solution, sodium contained in the tap water is contained in the hydroponic solution, but sodium contained in this way is not intentionally added. In the invention, it cannot be said that it is substantially contained.

As described above, the fertilizer conversion reference point was used from the invention fertilizer 1 and harvested while observing the maturity level for about 44 days after the conversion reference point. The harvested tomato is shown in FIG. The results shown were obtained.
First, the harvest amount of the above tomatoes, while the harvest amount using the inventive fertilizer 1 is 30 on average, while the harvest amount of tomatoes grown using only normal fertilizer until the end is one strain. The average was 22.
It should be noted that the above yield can be obtained even for strains that have not blossomed at the fertilizer conversion reference point, and there is no difference in yield from the strain where the reference flowers have bloomed. It was.

Further, as apparent from FIG. 8 above, the harvest amount when using the inventive fertilizer 1 from the fertilizer conversion reference point is not inferior to the harvest amount when using only the normal fertilizer. When used, the total yield increases by an average of 8 pieces.
In addition, the growth degree of tomato can be seen by the average mass and average outer diameter of the tomato. In this case as well, the tomato harvested using the invention fertilizer 1 from the fertilizer conversion point is usually fertilizer until the end. It is clear that there is no inferior to the tomatoes harvested using only.
Furthermore, the growth rate of the tomatoes that grew on the strains that had not flowered at the fertilizer conversion reference point was almost the same as the tomatoes that had grown on the strains that had flowered as the conversion reference point.

  And the amount of the average potassium contained in the said tomato is less than the tomato normally harvested only using the fertilizer. In addition, the amount of sodium is not much different between the one using the invention fertilizer 1 and the one using the normal fertilizer, but since this used tap water, sodium contained in the tap water remained I think that the.

Example 2
Example 2 relates to the second tomato cultivation shown in FIG.
The tomatoes in Example 2 were prepared using autumn tomatoes (trade name Emson), and three planted two plants in one 40-liter hydroponic container were set up outdoors and their cultivation period. The period was 126 days from September 6, 2011 to January 25, 2012.

  And when the normal fertilizer (stock solution) of FIG. 7 was diluted 400 times at an initial stage and given, as shown in FIG. The first flower bloomed in the container stock, which was used as the fertilizer conversion reference point. At this time, the other strains were not yet in bloom.

After the fertilizer conversion reference point, invention fertilizers 1 to 3 containing no potassium were separately given to the strains of the first to third containers.
Inventive fertilizers 2 and 3 consist of a stock solution of a hydroponic solution substantially free of potassium and sodium, as shown in FIGS. 5 and 6, and the magnesium content of the stock solution is mainly composed of nitrogen, phosphorus and calcium. Invention fertilizer 2 was made into 6 and 5 weight% with respect to a component, and invention fertilizer 3 was made into 4 and 5 weight%, These undiluted | stock solutions were diluted 400 times and used.
The invention fertilizers 2 and 3 contain trace components such as zinc and copper in addition to the main components, as is apparent from FIGS.

  In addition, the hydroponics solution is the same as the invention fertilizer 1 in that the pH value is maintained at 5 to 9, and substantially does not contain potassium and sodium. This means that it is permissible to contain potassium or sodium in a negligible amount compared to the amount of ingredients. For example, when tap water is used to dilute the hydroponic solution, sodium contained in the tap water is contained in the hydroponic solution, but sodium contained in this way is not intentionally added. In the invention, it cannot be said that it is substantially contained.

As described above, the invention fertilizers 1 to 3 were separately used from the fertilizer conversion reference point, and harvested while looking at the maturity level for almost 90 days from the conversion reference point. ,
The result shown in FIG. 9 was obtained.
First, the harvest amount of the above-mentioned tomato, the harvest amount using the inventive fertilizer 1 is 72 per strain, the harvest using the inventive fertilizer 2 is an average of 78, and the harvest using the inventive fertilizer 3 is as follows. The average was 100 per share.

In contrast, the average yield of tomatoes grown using only normal fertilizers to the end was 65 per strain.
It should be noted that the above yield can be obtained even for strains that have not blossomed at the fertilizer conversion reference point, and there is no difference in yield from the strain where the reference flowers have bloomed. It was.

Further, as is clear from FIG. 9 above, the harvest amount when using the inventive fertilizers 1 to 3 after the conversion reference point of the fertilizer is not inferior to the harvest amount when using only the normal fertilizer. The total yield when using 1-3 is increasing.
Moreover, although the growth degree of a tomato can be seen by the average mass and average outer diameter of the said tomato as above-mentioned, the tomato harvested using the invention fertilizers 1-3 from the conversion point of a fertilizer also in this case It is clear that tomatoes harvested using only normal fertilizers are not inferior to the end.
Furthermore, the growth rate of the tomatoes that grew on the strains that had not flowered at the fertilizer conversion reference point was almost the same as the tomatoes that had grown on the strains that had flowered as the conversion reference point.

  And the amount of the average potassium contained in the said tomato is less than the tomato normally harvested only using the fertilizer. The amount of sodium is not much different between the ones using the inventive fertilizers 1 to 3 and the one using the normal fertilizer, but since this used tap water, sodium contained in the tap water remains. It seems to have done.

Example 3
In Example 3, as shown in FIG. 10, two cultivated cucumbers (Nikko Seed Co., Ltd.) were planted in one 40-liter hydroponic container on the rooftop, and the cultivation period was September 6, 2011. It was 66 days from November 11 to November 14, 2011.

  And when the same normal fertilizer as Example 1 was given in the initial stage, as shown in FIG. 3, since the first flower bloomed in one strain on the 36th day, it was used as a fertilizer conversion reference point. For the subsequent 30 days, the same inventive fertilizer 1 as in Example 1 was used. In addition, at the said conversion reference point, it was in the state which has not yet blossomed in the other stock | strain.

About the thing using invention fertilizer 1 from the conversion reference point of the fertilizer as described above, it was harvested while looking at the maturity level for almost 30 days from the conversion reference point. The harvested autumn cucumber is shown in FIG. The results shown were obtained.
First, it is the harvest amount of the above-mentioned autumn cucumber, but the harvest amount using the invention fertilizer 1 that does not contain potassium is 6 on average per strain, whereas the autumn cucumber grown using only normal fertilizer until the end The average yield was 14 pieces.

As described above, with regard to autumn cucumber, the harvest amount was about ½ when using the inventive fertilizer 1, but their average mass and average outer diameter were those using ordinary fertilizer until the end. There was not much difference.
It should be noted that the above yield can be obtained even for strains that have not blossomed at the fertilizer conversion reference point, and there is no difference in yield from the strain where the reference flowers have bloomed. It was.
Moreover, the average amount of potassium contained in the autumn cucumber is smaller than that of the autumn cucumber harvested using only the fertilizer. The average amount of sodium in both is small and not so significant.

Example 4
Example 4 relates to strawberries. As shown in FIG. 12, among Red Pearl (trade name) and Shohime (trade name), the above-mentioned 16 strains of Red Bar and 5 stocks of Shohime were installed in a room. The plant was planted in a hydroponic container of the type and irradiated with fluorescent light for 16 hours a day.
The cultivation period was 59 days from December 15, 2011 to February 28, 2012.

  Also in this Example 4, when the same normal fertilizer as in Example 1 was given at the initial stage, as shown in FIG. 3, the first flower bloomed in one strain on the 29th day, and this was used as the fertilizer. As a conversion reference point, the same fertilizer 1 as in Example 1 was used for the subsequent 30 days. In addition, at the said conversion reference point, it was in the state which has not yet blossomed in the other stock | strain.

About the thing using invention fertilizer 1 from the conversion reference point of a fertilizer as mentioned above, it harvested while seeing the maturity degree from the conversion reference point for about 30 days, The harvested strawberry is shown in FIG. The result was obtained.
First, the red pearl yield is red, but the yield using the fertilizer 1 that does not contain potassium is 5 on average for each strain, whereas the red grown using only normal fertilizer until the end. The average yield of pearls was 5 per strain.
And the average mass of those red pearls was hardly different between the one using the inventive fertilizer 1 containing no potassium and the one using only the normal fertilizer until the end.
Furthermore, the growth rate of red pearls that grew on the plants that had not flowered at the fertilizer conversion reference point was almost the same as the red pearls that had grown on the strains that had flowered as the conversion reference point.
And the potassium amount of the red pearl harvested using the invention fertilizer 1 was half that of the red pearl using the normal fertilizer.

In addition, the harvest amount of the above-mentioned chapter princess is an average of nine crop yields using the invention fertilizer 1 that does not contain potassium. The average yield was 7 for each strain, showing little difference.
In addition, their average masses were almost the same as those of the chapter princess harvested using the inventive fertilizer 1 from the conversion reference point and those of the chapter princess harvested using only the normal fertilizer until the end.
In addition, the growth rate of the chapter princesses that grew on the plants that had not flowered at the fertilizer conversion reference point was almost the same as that of the chapter princesses that had planted the flowers that had become the conversion reference point.
And the amount of potassium of Akihime harvested using Invention Fertilizer 1 was about half that of Akihime using normal fertilizer.

  The fruits and vegetables by the hydroponics method of this invention are suitable for cultivation of low potassium fruits and vegetables that can be eaten deliciously and safely by patients with kidney disease whose intake of potassium is restricted.

1-3 Hydroponic container

Claims (6)

A hydroponics method for fruit and vegetables grown in hydroponics containers,
Based on the time when a particular flower blooms in one or more strains that are hydroponically cultivated under the same cultivation conditions, such as planting time, fertilizer type or location environment of cultivation,
Before the above standards, use normal fertilizers containing at least three major elements of fertilizers, nitrogen, phosphorus and potassium,
After that standard, use fertilizer consisting of any fertilizer element with a lower standard concentration such as potassium,
A hydroponic cultivation method for fruit and vegetable that harvests fruits that are produced on the basis of a specific flower that determines the standard and a flower that blooms after the standard.   2. The hydroponic cultivation method for fruit vegetables according to claim 1, wherein a fertilizer that does not substantially contain potassium is used instead of the normal fertilizer after the standard.   2. The method for hydroponic cultivation of fruit vegetables according to claim 1, wherein fertilizers containing substantially no calcium and containing calcium, magnesium, phosphorus and nitrogen as main components are used after the standard.   2. The hydroponic cultivation method for fruit vegetables according to claim 1, wherein a fertilizer containing substantially no potassium and sodium and containing calcium, magnesium, phosphorus and nitrogen as main components is used after the standard.   The hydroponic cultivation method for fruit vegetables according to any one of 1 to 4, wherein the pH value of the aqueous solution of the main component of the fertilizer used after the standard is 5 to 9.   A fertilizer for hydroponics of fruit and vegetables, which is substantially free of potassium and sodium, is mainly composed of calcium, magnesium, phosphorus and nitrogen, and the aqueous solution of this main component has a pH value of 5 to 9. .

Images