JP2020080789A - Cultivation method of baby leaves - Google Patents

Abstract

To cultivate baby leaves with lower potassium.SOLUTION: A cultivation method of baby leaves in which plural times of harvesting are performed from a single stock in which first cultivation of cultivating baby leaves by using first fertilizer containing potassium and second cultivation of cultivating baby leaves by using second fertilizer containing no potassium are executed between first harvesting timing and subsequent second harvesting timing.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a method for growing baby leaves.

BACKGROUND ART Conventionally, low-potassium vegetables have been known as one of low-potassium foods that can be eaten by patients with kidney disease, and cultivation methods thereof have been studied (see, for example, Patent Documents 1 and 2).

Patent Document 1 discloses a nutrient solution containing a large amount of magnesium, which is as easily absorbed by vegetables as potassium and contributes to the growth of vegetables, in order to prevent an increase in sodium content due to NaOH (sodium hydroxide) used for pH adjustment. A hydroponic cultivation method using a fertilizer for cultivation is disclosed.

In the hydroponic cultivation method disclosed in Patent Document 1, as shown in FIG. 1, the cultivation period L is divided into an initial cultivation period L1 and a final cultivation period L2. In the initial final cultivation period L1, cultivation is performed using a normal fertilizer for hydroponic cultivation containing potassium, calcium, magnesium, phosphorus, and nitrogen as main components. In the final cultivation period L2, cultivation is performed using a fertilizer for hydroponic culture containing calcium, magnesium, phosphorus, and nitrogen as the main components, without adding potassium and sodium.

JP, 2012-183062, A JP, 2011-036226, A

However, none of the cultivation methods disclosed in Patent Documents 1 and 2 is suitable for cultivating baby leaves having a low potassium content.

An object of one aspect of the present disclosure is to provide a method for cultivating a baby leaf that has a low potassium content.

A baby leaf cultivation method according to an aspect of the present disclosure is a baby leaf cultivation method of harvesting a plurality of times from one strain, and comprises a first harvest timing and a second harvest timing after that. In the meantime, the 1st cultivation cultivated using the 1st fertilizer containing potassium, and the 2nd cultivation cultivated using the 2nd fertilizer which does not contain potassium are implemented.

According to the present disclosure, it is possible to grow a baby leaf having a low potassium content.

Diagram showing the cultivation period disclosed in Patent Document 1 The figure which shows the period of the cultivation method of the baby leaf which concerns on embodiment of this indication. The figure which shows the measurement result of the potassium content of the baby leaf which concerns on Examples 1-3 and Comparative Examples 1-3 of this indication. The figure which shows the potassium containing period and the potassium non-containing period in the cultivation days after the seedling raising period which concerns on Examples 1-3 and Comparative Examples 1-3 of this indication.

Hereinafter, a method of cultivating a baby leaf according to an embodiment of the present disclosure (hereinafter, referred to as a cultivating method of the present embodiment) will be described with reference to the drawings.

In the present embodiment, baby leaf refers to leafy vegetables (eg, mizuna, arugula, kale, etc.).

Further, in the present embodiment, low potassium refers to a state in which the content (also referred to as the concentration) of potassium per leaf of harvested baby leaf is 2000 ppm or less.

Further, in the present embodiment, a case of using a hydroponic cultivation method that is an example of hydroponic cultivation will be described as an example, but the invention is not limited to this, and other hydroponic cultivation (for example, a spray cultivation method, Solid medium cultivation method) may be used. The hydroponic culture is a method of cultivating a crop by using a liquid fertilizer (culture solution) in which nutrients necessary for growing the crop are dissolved in water without using soil as a medium.

In addition, the cultivation method of the present embodiment does not carry out harvesting for each strain like general vegetables, but leaves the root of the plant, plucks leaves of a certain size or larger, and thereafter It is a cultivation method that continues the harvest of. This allows one strain to be harvested multiple times.

The cultivation method of the present embodiment will be described with reference to FIG. FIG. 2 is a diagram showing a period of the cultivation method of the present embodiment.

As shown in FIG. 2, the total cultivation period L includes a seedling raising period A, a plurality of potassium-containing periods B (shown as B1 to Bn), and a plurality of potassium-free periods C (shown as C1 to Cn).

More specifically, in the cultivation method of the present embodiment, after raising a seedling to a certain size or more in the seedling raising period A, one cycle of a potassium-containing period B and a potassium-free period C is performed at least twice. It is characterized by repeating the above. One cycle means a total period of a series of potassium-containing period B and a series of potassium-free period C that follows. For example, the combined period of B1 and C1 shown in FIG. 2 corresponds to one cycle.

In FIG. 2, the potassium-containing period B in which the number of repetitions is the first is expressed as B1, and the potassium-free period C in which the number of repetitions is the first is expressed as C1. Further, in FIG. 2, the potassium-containing period B in which the number of repetitions is the Nth time is expressed as Bn, and the potassium-free period C in which the number of repetitions is the Nth time is expressed as Cn.

The total cultivation period L is a period from the seed sowing date to the harvest date (also referred to as harvest timing). In addition, the harvest date mentioned here refers to, for example, the final harvest date (for example, the 21st day shown in FIG. 4 to be described later) of one strain. This total cultivation period L can be set in advance according to the type of baby leaf to be cultivated. For example, when the cultivation target is mizuna, the total cultivation period L is set to 28 days. Further, for example, when the cultivation target is arugula, the total cultivation period L is set to 28 days. Further, for example, when the cultivation target is kale, the total cultivation period L is set to 28 days. Note that the total cultivation period L is not significantly affected by the type of fertilizer used.

The seedling raising period A is a period from the germination of seeds to the stable growth of seedlings. In other words, the seedling raising period A is a period from the seed sowing date to the start date of the potassium containing period B (B1 in FIG. 2). Generally, the seedling raising period A is about one week regardless of the type of baby leaf, but can be appropriately set based on the results of experiments and the like.

Here, the fertilizer used in each period shown in FIG. 2 will be described.

In the seedling raising period A, tap water or the first hydroponic fertilizer (an example of the first fertilizer) is used. In the potassium-containing period B, the first hydroponic fertilizer is used. In the potassium-free period C, the second hydroponic fertilizer (an example of the second fertilizer) is used.

The first hydroponic fertilizer is a hydroponic fertilizer containing potassium. More specifically, the first hydroponic fertilizer is a hydroponic fertilizer containing potassium, sodium, calcium, magnesium, phosphorus, and nitrogen as main components. As the first hydroponic fertilizer, for example, a commercially available OAT house fertilizer manufactured by OAT Agrio Co., Ltd. may be used. The method of cultivating baby leaves using the first hydroponic fertilizer during the entire cultivation period L corresponds to a normal baby leaf cultivation method (for example, Comparative Example 1 described later).

The second hydroponic fertilizer is a hydroponic fertilizer containing no potassium. More specifically, the second hydroponic fertilizer is a hydroponic fertilizer containing calcium, magnesium, phosphorus, and nitrogen as main components. Table 1 shows an example of the composition of the second hydroponic fertilizer.

The second hydroponic fertilizer may be any hydroponic fertilizer that does not contain potassium, and its main component is not limited to the composition shown in Table 1 and may be any composition.

The term "free of potassium" as used herein means that it does not substantially contain potassium. For example, when the potassium content is about 10 g/L or less (for example, the amount contained in tap water or the like), it can be said that “potassium is not included”. The amount of potassium can be measured by, for example, a compact potassium ion meter manufactured by HORIBA.

In the cultivation method of the present embodiment, by using the second hydroponic fertilizer during the potassium-free period C, low potassium baby leaves can be grown.

Cultivation using the first hydroponic fertilizer in the potassium-containing period B corresponds to an example of “first cultivation”. Cultivation using the second hydroponic fertilizer during the potassium-free period C corresponds to an example of “second cultivation”.

In addition, you may select only the seedlings which grew sufficiently in the seedling raising period A, and perform the cultivation method of this Embodiment with respect to the seedling. Specifically, the size of the baby leaf is measured at the start of the potassium-containing period B, only baby leaves that are growing above a predetermined size are selected, and one cycle is performed twice for that baby leaf. Repeat above. As a result, it is possible to grow baby leaves having a lower potassium content.

<Examples and Comparative Examples>
Examples 1 to 3 and Comparative Examples 1 to 3 of the present disclosure will be described below. Examples 1 to 3 satisfy all the cultivation conditions of the present embodiment described above. On the other hand, Comparative Examples 1 to 3 do not satisfy any of the cultivation conditions of the present embodiment described above.

In Examples 1 to 3 and Comparative Examples 1 to 3, the total cultivation period L was 28 days, the seedling raising period A was 7 days, and in the seedling raising period A, baby leaves (here, kale) were cultivated under the same conditions. .. The potassium-containing period B and the potassium-free period C in the subsequent 21 days were set as shown in FIG. 4 for each of Examples 1 to 3 and Comparative Examples 1 to 3.

In Comparative Example 1, the potassium-containing period B was 21 days, and the potassium-free period C was 0 day. This condition is a normal baby leaf cultivation condition that is not low potassium.

In Example 1, the potassium-containing period B was 5 days, the potassium-free period C was 2 days, and this was one cycle (7 days; the same applies hereinafter). Then, the one cycle was repeated three times. In other words, cultivation was carried out with the number of cycles being three times.

In Comparative Example 2, the potassium-containing period B was 12 days, the potassium-free period C was 9 days, and this was one cycle. Then, the one cycle was performed once. In other words, cultivation was performed with one cycle.

In Example 2, the potassium-containing period B was 4 days, the potassium-free period C was 3 days, and this was one cycle. Then, the one cycle was repeated three times. In other words, cultivation was carried out with the number of cycles being three times. The total number of days in the potassium-containing period B and the total number of days in the potassium-free period C in Example 2 are 12 days and 9 days, respectively, which are the same as those in Comparative Example 2.

In Comparative Example 3, the potassium-containing period B was 9 days, the potassium-free period C was 12 days, and this was one cycle. Then, the one cycle was performed once. In other words, cultivation was performed with one cycle.

In Example 3, the potassium-containing period B was 3 days, the potassium-free period C was 4 days, and this was one cycle. Then, the one cycle was repeated three times. In other words, cultivation was carried out with the number of cycles being three times. The total number of days in the potassium-containing period B and the total number of days in the potassium-free period C in Example 3 are 9 days and 12 days, respectively, which are the same as those in Comparative Example 3.

The conditions of the hydroponic fertilizer and the environment during each cultivation period in Examples 1 to 3 and Comparative Examples 1 to 3 are as follows.

In the raising period A, tap water was used. Further, in the potassium-containing period B, as the first hydroponic fertilizer, a commercially available OAT house fertilizer with SA formulation was used. In the potassium-free period C, the fertilizer having the composition shown in Table 1 above was used as the second hydroponic fertilizer.

Further, in the entire cultivation period L excluding the seedling raising period A, the first nutrient solution fertilizer and the second nutrient solution are adjusted so that the EC value becomes 1.4 to 2.0 and the pH value becomes 5.5 to 6.5. A hydroponic solution was prepared using cultivated fertilizer. At this time, the EC value and the pH value were controlled using a small nutrient solution circulation device MSOE-100 (product name) manufactured by SEM Corporation so that the EC value and the pH value were within the above ranges.

Although tap water was used in the seedling raising period A as an example here, the first hydroponic fertilizer may be used in the seedling raising period A as long as the EC value and the pH value are within the above ranges.

In addition, NaOH was used as a pH adjuster for the pH adjuster. An OAT down agent was used as the pH down agent.

Further, during the entire cultivation period L, the temperature was controlled to be 22° C. and the relative humidity was 75% when the lighting was turned on, and the CO ₂ concentration was set to 1000 ppm to 1200 ppm.

Next, the cultivation procedure in Examples 1 to 3 and Comparative Examples 1 to 3 will be described.

First, the seeds of black kale from the Nakahara Seedyard were placed on a urethane sheet soaked in tap water and germinated in the dark without turning on the lights. After germination, in the remaining seedling raising period A, the germinated seedlings were allowed to grow.

Next, a seedling with good growth is selected from seedlings grown in the seedling raising period A, and the seedling is transplanted to a culture solution prepared with the first hydroponic fertilizer (for example, a fertilizer of SA prescription of OAT house fertilizer). And was cultivated in the period B containing potassium.

Next, the seedlings were transplanted to a culture solution prepared with a second hydroponic fertilizer (for example, a fertilizer having the composition shown in Table 1) and cultivated in the potassium-free period C.

Then, for the purpose of evaluation, on the 7th, 14th and 21st days (an example of harvest timing) after the seedling raising period A was finished, the seedlings having a leaf length of 15 cm or more were picked. Here, the leaf length refers to the length from the root to the tip of each leaf. Here, the leaf length refers to the length from the root to the tip of each leaf.

Note that seedlings having a leaf length of less than 15 cm on the 7th or 14th day were continuously cultivated without being picked. On the 21st day after the seedling raising period A was finished, that is, on the last day of the entire cultivation period L, seedlings having a leaf length of less than 15 cm were picked and discarded.

The potassium content of the picked kale seedlings was measured using a compact potassium ion meter manufactured by HORIBA. The result of this measurement will be described below with reference to FIG.

As described above, Comparative Example 1 is a normal baby leaf cultivation method. The potassium content of the kale according to Comparative Example 1 was 2500 ppm or more at any of the 7th day, the 14th day, and the 21st day, and was the highest value especially on the 21st day. Therefore, it could be confirmed that the potassium content of the kale according to Comparative Example 1 was equivalent to the potassium content of the normal vegetables. That is, in the kale according to Comparative Example 1, low potassium is not realized.

The potassium content of the kale according to each of Comparative Example 2 and Comparative Example 3 in which the number of cycles was once decreased from the 7th day to the 21st day, and on the 21st day, the potassium content became a value below 1000 ppm. It was However, as the potassium content continued to decrease, potassium deficiency (for example, discoloration or deformation of leaves) frequently occurred.

Therefore, in Comparative Examples 2 and 3 in which the number of cycles is 1, the potassium-free period C is not included on the 1st to 7th days. Therefore, the potassium content of the kale harvested on the 7th day is not different from the potassium content of the kale cultivated by the usual baby leaf cultivation method (kale according to Comparative Example 1). Therefore, the kale harvested on the 7th day was not realized to be low in potassium.

Further, in Comparative Examples 2 and 3 in which the number of cycles was once, the result was that potassium deficiency occurred on the 21st day. Therefore, the kale harvested on the 21st day had a low potassium content but was of a low quality that could not be shipped as a product.

Therefore, in Comparative Examples 2 and 3, for example, when a harvest date is set once a week, low potassium is realized and the timing when high-quality (quality that can withstand shipping) kale can be harvested is , Only once on the 14th day. Therefore, the timing of harvesting is limited, and it is not possible to harvest multiple times from one strain.

In Comparative Examples 1 to 3 as described above, in Examples 1 to 3 in which the number of cycles was 3, as shown in FIG. 4, 1 to 7 days, 8 to 14 days, 15 to 21 days In each eye cycle, the potassium-free period C is included. Therefore, the potassium content of the kale according to each of Examples 1 to 3 is a value corresponding to about 60% to 75% of the potassium content of the kale according to Comparative Example 1 on each of days 7, 14, and 21. became. Moreover, the potassium content of the kale according to each of Examples 1 to 3 did not cause potassium deficiency.

Therefore, the kale according to Examples 1 to 3 had a lower potassium content and was of higher quality regardless of the timing of harvesting on 7, 14, or 21 days.

In addition, among Examples 1 to 3 in which the number of cycles is set to 3, in Example 1, the potassium-free period C is as short as 2 days in 1 cycle (7 days). Therefore, the potassium content on the 21st day is around 2000 ppm as shown in FIG. Therefore, in order to further reduce the potassium content, Examples 2 and 3 in which the potassium-free period C of 3 days or more is set in 7 days which are one cycle are preferable.

In addition, when the potassium-free period C is only one day in one cycle, the plant cannot sufficiently suck up the fertilizer, so that it is not possible to achieve low potassium.

Further, in Example 3 in which the potassium-free period C is 4 days in one cycle, the potassium content tends to gradually decrease. From this, if the potassium-free period C is set to 5 days or more in one cycle, potassium deficiency may occur. Therefore, it is desirable to set the potassium-free period C to 4 days or less in one cycle.

From the above, in order to grow high-quality baby leaves with low potassium, the number of cycles is set to 2 or more, and the potassium-free period C in one cycle is 28% of one cycle. It is desirable to set the ratio to not less than 57% and not more than 57%. In other words, the proportion of the series of potassium-free periods in the total of the series of potassium-containing periods B (corresponding to the implementation period of the first cultivation) and the series of potassium-free periods C (corresponding to the implementation period of the second cultivation) Is preferably set to a ratio of 28% or more and 57% or less. For example, when the number of days in one cycle is 7 days, it is desirable to set the potassium-free period C in the range of 2 to 4 days.

The reason for this is that if the potassium-free period C in one cycle is less than 28% of one cycle, low potassium cannot be realized, and if it exceeds 57% of one cycle, potassium deficiency may occur.

When the number of days of one cycle is 7 days, it is more desirable to set the potassium-free period C to 3 days or 4 days. At this time, the potassium-free period C in one cycle is 42% or more and 57% or less of one cycle. In other words, when the number of days in one cycle is 7 days, a series of potassium-containing period B (corresponding to the implementation period of the first cultivation) and a series of potassium-free period C (corresponding to the implementation period of the second cultivation) It is desirable to set the ratio of the series of potassium-free periods in the total of 42% to 57%.

When the number of days in one cycle is 7 days and the potassium-free period C is set to 2 days, the potassium content per leaf of the baby leaf is about 2000 ppm. On the other hand, when the number of days in one cycle is set to 7 days and the potassium content period C is set to 3 days, the potassium content per leaf of the baby leaf is about 1500 ppm, which further reduces the potassium content. Can be promoted.

Therefore, the potassium-free period C is more preferably set to 42% or more and 57% or less of one cycle.

As described above, in the baby leaf cultivation method of the present embodiment, the first harvest timing (eg, 7th day in FIG. 4) and the second harvest timing after that (eg, 14 in FIG. 4). 1st cultivation (cultivation in the potassium-containing period B), which is cultivated using the first fertilizer containing potassium, and the second cultivation (potassium, which is cultivated using the second fertilizer not containing potassium). Cultivation for the non-inclusion period C). This makes it possible to cultivate (harvest) baby leaves having a low potassium content.

In addition, in the baby leaf cultivation method of the present embodiment, by repeating the first cultivation and the second cultivation, the harvest timing is low at any harvest timing (for example, 7th day, 14th day, 21st day in FIG. 4). You can harvest baby leaves that have been potassiumated. That is, in the baby leaf cultivation method of the present embodiment, the second harvest timing (for example, the 14th day in FIG. 4) and the third harvest timing after that (for example, the 21st day in FIG. 4). ) And 1st cultivation and 2nd cultivation may be implemented.

<Summary of the present disclosure>
The summary of the present disclosure is as follows.

The baby leaf cultivation method of the present disclosure is a baby leaf cultivation method in which multiple harvests are performed from a single strain, and potassium is added between a first harvest timing and a second harvest timing after that. 1st cultivation cultivated using the 1st fertilizer containing is carried out, and 2nd cultivation cultivated using the 2nd fertilizer not containing potassium.

In the baby leaf cultivation method of the present disclosure, the first cultivation and the second cultivation may be performed between the second harvest timing and the third harvest timing after that.

In the baby leaf cultivation method of the present disclosure, the ratio of the second cultivation period to the total of the first cultivation period and the second cultivation period is 28% or more and 57% or less. Good.

In the baby leaf cultivation method of the present disclosure, the ratio of the implementation period of the second cultivation to the total implementation period of the first cultivation and the implementation period of the second cultivation is 42% or more and 57% or less. Good.

Note that the present disclosure is not limited to the above description of the embodiments, and various modifications can be made without departing from the spirit of the present disclosure.

The method for cultivating baby leaves of the present disclosure is useful for cultivating baby leaves having a low potassium content.

L Total cultivation period A Raising seedling period B Potassium-containing period C Potassium-free period

Claims (4)

A method for cultivating baby leaves, in which a single plant is harvested multiple times,
Between the first harvest timing and the second harvest timing after that, the first cultivation in which the first fertilizer containing potassium is used and the second cultivation in which the potassium is not contained are used. We carry out 2 cultivation,
How to grow baby leaves. Performing the first cultivation and the second cultivation between the second harvesting timing and the third harvesting timing after that.
The method for cultivating a baby leaf according to claim 1. The ratio of the implementation period of the second cultivation to the total implementation period of the first cultivation and the implementation period of the second cultivation is 28% or more and 57% or less,
The method for cultivating a baby leaf according to claim 2. The ratio of the implementation period of the second cultivation to the total implementation period of the first cultivation and the implementation period of the second cultivation is 42% or more and 57% or less,
The method for cultivating a baby leaf according to claim 3.

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