KR20210120273A - Shading cultivation method of tea plants - Google Patents

Abstract

The present invention relates to a method for cultivating a tea plant, and more particularly, to a method for efficiently cultivating a tea plant using a specific shading condition. According to the present invention, high-quality matcha can be efficiently obtained by increasing the chlorophyll content and consequently increasing the chromaticity of tea leaves and reducing the shading stress of the tea plant.

Description

Shading cultivation method of tea plants

The present invention relates to a method for growing a tea tree, and more particularly, to a method for efficiently growing a tea tree using a specific light-shielding condition.

The tea tree ( Camellia sinensis L. ) is an evergreen plant with green leaves for all four seasons belonging to the family Theaceae. It is also cultivated as an ornamental tree.

Although it is common for tea trees in Korea to grow with a height of less than 3 m in the wild state genetically, the shape and height of the trees vary depending on the growing environment, soil, mining, and whether or not they are cultivated. For example, in Hwagae-myeon, Hadong-gun, Gyeongsangnam-do, where the soil depth is shallow, there are many places with a well-developed bedrock layer, and in areas with strong winds due to the influence of the Seomjin River and Hwagae Stream, the semi-upright type and the open type (sideways spreading) It grows in the form of a shrub with low height. The tea tree is not a sunny plant in general, and the young wild tea tree, which should be grown in an evergreen forest that does not receive much sunlight due to its low tree height, has strong resistance to sunlight and prefers semi-shade.

On the other hand, the tea leaves of the tea tree are used as tea beverages such as green tea, green tea, black tea, white tea, and black tea through various methods.

Matcha tea is powdered by increasing the content of chlorophyll and amino acids and improving palatability such as color and umami by installing a 95% black shading film for a certain period (15 to 20 days) to block light during the shoot growth period of tea leaves. it means done Recently, the demand for green tea produced in this way is increasing as it is used for drinking directly or for ice cream, lattes, frappuccinos, cakes, and confectionery products. Because most tea is brewed in water, only some of the water-soluble substances such as catechin, caffeine, amino acids, and water-soluble vitamins are absorbed. It has the advantage of being able to absorb all water-soluble and insoluble components such as caffeine, catechins with excellent pharmacological effects such as antioxidants and anticancer, and theanine with high cognitive function improvement effects.

Studies on changes in the composition and color of tea leaves and matcha products due to shading have been steadily progressing, and recently, studies on the quality of matcha according to the shading type have been conducted. As a result, there was a clear difference in quality depending on the shading rate and duration as well as the shading type. Among them, the screen-type shading method saved labor and facilitated internal air circulation, making it possible to produce high-quality matcha by lowering the internal temperature of the shading net.

Photosynthesis is the conversion of light energy into chemical energy by plants, algae, and photosynthetic bacteria. This energy conversion is very complex and involves various factors. In photosynthesis of plants, light energy absorbed by chlorophyll is mainly transferred as excitation energy, aggregates in the reaction center, performs useful chemical reactions, and is emitted as heat or fluorescence. In general, since the emission of fluorescence is greatest when photosynthesis or heat emission is the lowest, the change in chlorophyll fluorescence reflects the emission of heat and changes in photosynthesis. Chlorophyll fluorescence analysis is a non-destructive analysis method for healthy plant growth and abiotic stress index research, so continuous research observation is possible.

An object of the present invention is to provide light-shielding conditions in which tea tree, which is a sound-tolerant tree, can produce high-quality matcha tea compared to general growth conditions.

For the purpose of the present invention, the present invention provides a tea tree cultivation method, characterized in that two types of light-shielding nets having different light-shielding rates are sequentially applied to doubly block the light.

According to an embodiment of the present invention, the double shading includes a first shading step of primary shading using a first shading network having a shading rate of 70 to 80%, and a second shading network having a shading rate of 90 to 99%. It is characterized in that it comprises a second shading step of shading the secondary light. Preferably, the first shading network has a shading rate of 75%, and the second shading net has a shading rate of 95%.

According to another embodiment of the present invention, the first shading step is performed for 12 to 15 days, and the second shading step is performed for 5 to 7 days.

According to another embodiment of the present invention, in the second shading step, it is characterized in that the total shading rate is 99% or more.

According to the present invention, high-quality matcha can be efficiently obtained by increasing the chlorophyll content and consequently increasing the chromaticity of tea leaves and reducing the shading stress of tea trees.

1 is a schematic diagram schematically illustrating a sequential light blocking method according to the present invention.
2 is a graph comparing quantitative changes in chlorophyll content (SPAD) of tea leaves of tea trees according to light-shielding conditions of Examples and Comparative Examples of the present invention.
3 is a comparative graph of the complex stress index of plants according to the light-shielding conditions of Examples and Comparative Examples of the present invention.
4 is a comparative graph of tea leaf growth indicators according to light-shielding conditions of Examples and Comparative Examples of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out the present invention. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

Throughout the specification of the present invention, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Throughout the specification of the present invention, when it is said that a step is located “on” or “before” another step, this means not only a case in which a step is in a direct time-series relationship with another step, but also a step of mixing after each step and Likewise, the order of two steps may include the same rights as in the case of an indirect time series relationship in which the time series order may change.

The terms "about", "substantially", etc. to the extent used throughout the specification of the present invention are used in or close to the numerical value when manufacturing and material tolerances inherent in the stated meaning are presented, and the present invention It is used to prevent unfair use by unconscionable infringers of the disclosure in which exact or absolute figures are mentioned to help understand. As used throughout this specification, the term “step of (to)” or “step of” does not mean “step for”.

Hereinafter, a tea tree cultivation method using sequential double shading according to an embodiment of the present invention will be described in detail, whereby the characteristics of the present invention can be understood in more detail.

1. Experimental design

This experiment was conducted in May 2019 at Teawon A (35°22′18″N, 127°64′07″E) and Teawon B (35°21′97″N, 127°64′84″E), Hwagae-myeon, Hadong-gun, Gyeongsangnam-do. Light-shielding experiments were conducted from the 8th to the 30th of May. Experiments were conducted by dividing into non-shielding (control), sequential double-shading, and single-shading.

(1) For the sequential double shading, 75% shading net was installed in one layer for 15 days from May 8th to 15 days in A tea garden to perform the first shading, and 15 days later, an additional 95% shading net was installed to block more than 99% of the shading. Second light-shielding was performed daily.

(2) The single shading was 95% shaded from May 8th to 22nd in Teahouse B.

Both A and B are screen-type light-shielding facilities, and light interference caused by indirect light is minimized by lowering light-shielding nets on both sides and front and rear.

2. Physiological growth characteristics of tea leaves

2-1. Determination of chlorophyll content

The chlorophyll content of tea leaves was measured by repeating the same area of the top 3 tea leaves 10 times using SPAD-502 (Konica minolta Inc., Japan), and chlorophyll fluorescence was measured using a Chlorophyll fluorometer (OS-30p, Opti-sciences, USA). A fixing pin was fixed to the third tea leaf using a chlorophyll fluorescence after partial dark treatment for 30 minutes. To measure the plant physiology index, PolyPen (RP 400, Photon Systems Instruments, Czech Republic) was used to measure the normalized difference vegetation index (NDVI) and simple ration index (SR). NDVI, SR measure the spectral reflectance, light transmittance, and absorbance of the leaf. It is the value calculated by the formula below by measuring the light reflectance and absorbance using the spectrum of the internal light source at a wavelength of 380 to 1050 nm.

NDVI = (R780 - R630) / (R780 + R630)

SR = R780 / R630

All measurements were repeated 10 times, and the results are shown in FIG. 2 .

Photosynthesis, which converts solar energy into binding energy of organic compounds, is an integrated metabolic system that constantly responds to environmental changes. Plants with low tolerance to light are inhibited from growing due to reduced light absorption and photosynthesis in an environment with insufficient light. The chlorophyll content (SPAD value) in the 1st week of shading was the highest at 95% shading with 31.6 unblocking, sequential double shading (75% shading) 58.5, and single shading (95% shading) 60.3, and non-shading 47.3, The chlorophyll content decreased at 95% shading compared to the first week of shading to 63.3 in sequential double shading (75% shading) and 56.3 in single shading (95% shading). Before harvest (3rd week), the chlorophyll content decreased to 40.2 non-shading, sequential double-shading (75%+95% shading) 52.7, and single shading (95% shading) 49.9. showed a slightly higher chlorophyll content. On the other hand, the decrease in the chlorophyll content in the unshielded light appears to reduce the absorption of excessive light due to the photoprotective action of the chlorophyll.

2-2. Measuring the stress index of tea trees

The chlorophyll fluorescence measurement method has been developed from the method of measuring the Kautasky effect by applying the fluorescence-induced phenomenon of a plant exposed to light. After 15 to 60 minutes in the dark state, it returns to the state in which the fluorescence phenomenon of the original state can appear. The maximum fluorescence value/minimum fluorescence value ratio (Fm/Fo ratio) is an indicator used in early studies related to plant stress.

Estimating the health of the tea tree using the maximum fluorescence value/minimum fluorescence value ratio (Fm/Fo ratio) shown in FIG. 3, non-shading was 2.27 at the 2nd week of shading, 3.09 in single shading (95% shading), and sequential double Shading (75% shading) showed 3.21, which was 1.4 times higher than that of non-shading. In the 3rd week of shading, non-shading was 2.15, single shading (95% shading) was 3.12, and sequential double shading (75% + 95% shading). Silver showed 3.66, 1.7 times higher soundness than non-shading.

Recently, the variable fluorescence value/maximum fluorescence value ratio (Fv/Fm ratio) is more commonly used than the Fm/Fo ratio, and this Fv/Fm ratio is used as a variable representing the maximum quantum yield in the primary photosystem II photochemical reaction. have. At the 2nd week of shading, non-shading was 0.562, single shading (95% shading) was 0.675, and sequential double shading (75% shading) was 0.686, which was 1.2 times higher than that of non-shading. At the 3rd week of shading, non-shading was 0.528, single shading (95% shading) was 0.672, and sequential double shading (75% + 95% shading) was 0.726, showing the maximum quantum yield 1.4 times higher than that of non-shading. The maximum quantum yield (Fv/Fm ratio) is closely related to the photosynthetic ability, and under non-shading conditions, shade-tolerant plants have a lower Fv/Fm value than sunny plants. The Fv/Fm ratio of leaves of healthy higher plants is always maintained at about 0.8, and a value lower than this is when the reaction center of photosystem II is damaged or in a stress environment. Single shading (95% shading) showed slightly decreased Fv/Fm ratios to 0.675 and 0.672 at 2nd and 3rd weeks of shading, whereas sequential double shading showed 0.686 at 2nd (75% shading) and 75% at 3rd week (75%). +95% shading) showed a tendency to increase to 0.726. It is thought that the long-term 95% shading condition in tea trees has a higher degree of stress than the sequential double shading condition. Most plants tend to decrease chlorophyll content and fluorescence value under environmental stress conditions such as drought, high temperature, and low temperature, but show different results under light-shielding stress. The chlorophyll content, activity, and morphological characteristics of leaves are changed by shading. Similar to tea tree, the higher the shading level, the higher the leaf area, moisture content, and chlorophyll content. As such, some plants have high photosynthetic properties under a certain level of light-shielding conditions, so that different light environmental conditions can be set for productivity improvement.

In addition, the ground state value (Fo) is called 'fluorescence', and when the number of chlorophyll molecules that cannot transmit energy to the reaction center increases, the Fo value increases. In general, plants increase under stress conditions. It showed a low value, but showed a slightly high value from the 3rd week of shading.

Contrary to the Fo value, the stressed plants usually have a decrease in the maximum fluorescence value (Fm). In the case of non-shading, there was little change to 0.489 and 0.497 in the 2nd and 3rd weeks of shading, respectively, and the single shading was 0.618 to 0.746, 1.2 The double shading increased by 1.3 times from 0.689 to 0.869.

The value obtained by subtracting Fo from Fm is called Fv (maximum variable fluorescence), and as the stress level increases, the Fv value tends to decrease. seemed

The regular vegetation index (NDVI) is a widely used index to evaluate the biomass, chlorophyll content and nitrogen status of vegetation as a function of the difference in light energy reflectance between visible and near infrared wavelengths. Recently, it is widely used in aerial imaging using drones. . In general, when environmental stress such as drought occurs, plants are stressed and the vitality of vegetation is lowered, resulting in low NDVI and SR values. The NDVI and SR values of non-shading at the 2nd week of blocking were the lowest at 0.562 and 1.373, and the single blocking (95% blocking) was the highest at 0.709 and 3.214. The values of 0.609 and 1.819 were higher in sequential double shading, which was shaded for 2 weeks with 75% shading. The NDVI and SR values of the 3rd week of shading were 0.645 and 2.299 for non-shading, which was higher than the 1 week before, and 0.701 and 2.821 for single shading (95% shading), which decreased compared to 1 week ago. On the other hand, in the sequential double shading (75% + 95% shading), the overall vegetation index increased by 1.7 times to 0.723 and 3.042 compared to the previous week. In case of single shading (95% shading), chlorophyll (content, fluorescence) and vegetation index (NDVI, SR) tend to decrease in the period from 2 weeks to 3 weeks of shading. In the case of sequential double shading, since shading proceeds at a low shading rate (75% shading) for 2 weeks, the degree of stress on the tea tree is low and it is applied at a shading rate (95% shading) after 5 to 7 days. Increasing the chromaticity of tea leaves through double shading is shown to be effective in terms of shading stress on tea trees.

3. Morphological growth characteristics of tea leaves

To check the growth characteristics of tea leaves according to the shading treatment, the upper 3 lobes except for each sample shoot were scanned using EPSON V700 (Seiko EPSON CORP. Japan), and WinFOLIA software (Regent Instruments, Inc. Quebec, QC, Canada) program to measure leaf length, leaf width, and leaf area, and leaf moisture content was measured using a moisture analyzer (MB45, Ohaus, NJ USA), and all surveys were repeated at least 10 times. The leaf chromaticity of tea leaves was obtained using a chroma meter (CR-400, Konica minolta Inc., Japan) to obtain the L*, a*, b* values of the CIE system, and the G value was investigated using the formula below. The measurement results are shown in FIG. 4 .

G value =

The leaf area at harvest time ^{was the smallest at 953 mm 2 without shading, and it was irradiated to 1,327 mm 2} , which increased 1.39 times in single shading with 95% shading for a long period of time, and ^{1,200 mm 2} , which increased by 1.26 times in sequential double shading. Leaf width and leaf length also increased by 1.11~1.21 times compared to non-shading, and 1.08~1.11 times in sequential double-shading. This is an active reaction form for plants to increase the efficiency of light absorption and photosynthesis under light-shading conditions. It was similar to the result of shading the tea leaves and growing them to become extremely soft, and it was found that the single shading with a relatively high shading rate and long shading progressed faster than the sequential double shading. Contrary to the leaf area, the internode length was the longest at 233 mm in the unshielded area, followed by 210 mm in double light and 157 mm in single light. In the case of tea tree, as the degree of shading was higher, it was changed to a form that satisfies the insufficient amount of light through leaf growth rather than length growth. The moisture content of the leaves is 71.9% for non-shading, 80.5% for single shading, and 81.7% for sequential double shading. As the shading net blocks direct sunlight and absorbs solar radiation, it suppresses the evaporation of moisture through the stomata and prevents the loss of moisture in the leaves by about 10%. showed high moisture content.

The color of the surface of powdered green tea is a factor at the highest priority in quality evaluation, and as the G value increases, it becomes clear and dark green. The color of the tea leaves before harvest was obtained using a colorimeter and the color of the leaf surface was obtained using the uniform color difference chromaticity system (L*, a*, b*) established by the Commission International de I'Eclairage (CIE). The G value obtained by using the a* values (-green, +red) and b* values (-blue, +yellow) of the standard chromaticity diagram is the highest G value with 51.9 for non-shading, 56.4 for single-shading, and 62.9 for sequential double-shading. showed value.

4. Review

All analysis results showed the mean value and standard deviation measured three times through the SAS program (Ver. 9.3, Cary, NC. USA), and the mean value p <0.05 by performing PROC ANOVA analysis of variance and Duncan's Multiple Range Test post-hoc test. Significance was compared at the significance level.

As a result of the experiment, the chlorophyll content before harvesting tea leaves was higher in the order of sequential double shading (52.7) > single shading (49.9) > non shading (40.2), and chlorophyll fluorescence (Fv/Fm) was sequentially double shading (0.73) > single shading. It was measured in the order of light blocking (0.67) > non-light blocking (0.53). The regular vegetation index (NDVI) was sequential double shading (0.72) > single shading (0.70) > non shading (0.65), and the simple vegetation index (SR) was sequential double shading (3.04) > single shading (2.82) > It was irradiated in the order of non-shielding (2.30). Leaf length, leaf width and leaf area showed the highest growth in the order of single shading > sequential double shading > non shading, and internode length was irradiated in the order of non shading > sequential double shading > single shading. The greenness (G-value) of the leaf surface was measured in the order of sequential double shading (62.9) > single shading (56.4) > non shading (51.9). Looking at the overall physiology and growth state, it was confirmed that the sequential double shading increases the chromaticity of tea leaves and is more effective in relieving the shading stress of tea trees than single shading.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. something to do.

Claims (5)

A method of growing a tea tree, characterized in that it is double-shielded by sequentially applying two types of shading nets with different shading rates. The method of claim 1,
The double shading includes a first shading step of primary shading using a first shading net having a shading rate of 70 to 80%, and a second shading of secondary shading by adding a second shading net having a shading rate of 90 to 99%. A method of growing tea trees, comprising the steps of. The method of claim 1,
A tea tree cultivation method, characterized in that the first shading net has a shading rate of 75%, and the second shading net has a shading rate of 95%. The method of claim 1,
The first shading step is 12 to 15 days, the second shading step is a tea tree cultivation method, characterized in that it is carried out for 5 to 7 days. The method of claim 1,
In the second shading step, the tea tree cultivation method, characterized in that the total shading rate is 99% or more.

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