JP2007232572A - Body moisture stress display sheet for plant, and plant moisture stress measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body moisture stress display sheet for a plant and moisture stress measuring method for a plant capable of estimating the moisture stress of a tree body easily, non-destructively without damaging the vegetated state. <P>SOLUTION: This sheet comprises a resin film 12 to be stuck to a leaf 32 by a pressure sensitive adhesive 18, cobalt chloride paper 16 that is disposed on the surface of the pressure sensitive adhesive 18 of the resin film 12 and has cobalt chloride adsorbed, and a color sample 24 that is printed on the resin film 12 near the cobalt chloride paper 16 and colors the cobalt chloride paper 16 by cobalt chloride. The color sample 24 is adjusted so that the degree of coloring of the cobalt chloride of the cobalt chloride paper 16 depends on the moisture evaporation amount made different by the degree of moisture shortage of the plant, and displays the degree of the moisture stress of the plant based on the moisture evaporation from the leaf 32. The cobalt chloride paper 16 is a hygroscopic sheet, and hydrophobic nonwoven fabric 20 is attached to the surface on the opposite side to the resin film 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plant water stress display sheet for plant and a plant water stress measurement method for measuring the water supply state to a plant.

  Understanding the water stress state of a plant is extremely important for high-quality cultivation. In citrus, moderate water stress in summer promotes the accumulation of sugar and contributes to good fruit production, but excessive water stress in summer affects trees, resulting in various factors such as a decline in excellent product rate and biennial results. It becomes a factor causing a problem.

  For high-quality citrus cultivation, rational management based on water stress from the summer to pre-harvest, watering intervals to correct water stress and watering amount is indispensable. However, in general citrus producers, the management of these water stresses is often based on empirical judgment by the producer's visual observation.

  As an evaluation of the moisture stress state of a tree body, there is one that uses changes in appearance such as leaf winding condition, leaf color, fruit enlargement and softening degree as indexes. On the other hand, as a quantitative measurement method of water stress, there is a method using a water potential value of a leaf or the like as an index using a pressure chamber method or a cyclometer method.

In summer, when sugar accumulation in citrus trees is promoted, when the water stress state of a tree is expressed by the water potential of leaves, it is considered to be important to manage at about -1.0 MPa to -1.5 MPa. The value of this water potential must be the value before sunrise or after sunset when the water state of the tree becomes homogeneous.
Japanese Patent Laid-Open No. 9-28191 JP 2001-272373 A JP 2005-308733 A

  However, these methods for measuring water stress are not practical at the production site, the measuring instruments are expensive, and it is difficult to say that the method is applicable to the judgment of the stress state of the tree by the producer. .

  In addition, in the case of a tree body, for example, citrus, when an excessive water stress state is continued, a reaction such as winding of a leaf, drooping or falling leaves is exhibited as a defense function of the living body, and it can be visually evaluated. It is difficult to determine whether it is (-1.0 MPa to -1.5 MPa). Therefore, there is a need for a simple and inexpensive method for evaluating the water stress state of plants.

Therefore, as a method for mechanically measuring water stress, the isotope ¹³ C (atomic carbon 13 isotope) and ¹² C (atomic carbon ¹² isotope) of plant leaves are measured and the ratio thereof is measured. Patent Document 1 discloses a method for measuring water stress. However, it is difficult to measure ¹³ C and ¹² C easily in the field, and there is a problem that it takes time and labor to measure in the field.

  In Patent Document 2, a first non-polarizable electrode is connected to a plant body, a second non-polarizable electrode is connected to the soil where the plant is vegetated, and a potentiometer is provided between the two electrodes. A method for measuring water stress applied to a plant by measuring electromotive force between both ends with the same potentiometer is disclosed. However, this method has a drawback that the error is large depending on the electrode connection position and soil conditions.

  Patent Document 3 discloses a method of measuring the water stress of a plant by irradiating the leaf of the plant with light and dispersing the reflected light, and comparing the spectral luminance of each wavelength with the reflected light of the reference. Has been. However, this method is also complicated and expensive, and cannot be easily and frequently measured by a fruit tree producer.

  On the other hand, although there are existing devices for measuring the amount of moisture transpiration of plants, these devices themselves are heavy, expensive, and not versatile measuring devices.

  The present invention is a method for discriminating a water stress state of a plant, and is an in-plant water stress display sheet for a plant that can easily and non-destructively estimate the water stress of a tree without losing the vegetation state. And a method for measuring plant water stress.

  The present invention clarifies the relationship with the amount of transpiration for a plurality of trees having different moisture stress states measured in advance by the pressure chamber method, and attaches an indicator that develops color depending on the amount of moisture to the back side of the leaf, thereby determining the amount of transpiration. It was made to reflect and color, and it came to be able to estimate a water stress state from the color development degree.

  The present invention includes a resin film adhered to a leaf surface with an adhesive, a holder such as cobalt chloride paper provided on the surface of the adhesive layer of the resin film to which cobalt chloride is adsorbed, and the holding of the resin film. Cobalt chloride of the holding body corresponding to the amount of moisture transpiration depending on the degree of moisture deficiency of the plant, provided in the vicinity of the body and provided with a color sample of the color of the holding body colored by the cobalt chloride The color sample is an in-plant moisture stress display sheet for displaying the degree of moisture stress of a plant based on moisture transpiration from the leaf surface.

  The holding body is a hygroscopic sheet, and a hydrophobic nonwoven fabric is attached to the surface of the holding body opposite to the resin film. Further, a plurality of the holding bodies are provided with different sensitivities with respect to the moisture adsorption amount. A watering index may be provided on the resin film in the vicinity of the holding body.

  A release paper is laminated on the pressure-sensitive adhesive layer on the resin film, and a part of the release paper is fixed so as not to be peeled off from the resin film, and the release paper is used as a display label of a sticking place. At this time, two release papers may be overlapped, and one of them may be used as a display label.

  In addition, the present invention is provided with a holding body on which the cobalt chloride is adsorbed on the surface of the adhesive layer of the resin film attached to the leaf surface by the adhesive, and printed near the holding body of the resin film. Using the color sample of the color developed by moisture absorption by the holding body and a display sheet provided with a watering index as appropriate, the holding body of cobalt chloride of the holding body corresponds to the amount of moisture transpiration depending on the degree of moisture deficiency of the plant. Adjust so that the degree of coloration is different, stick the holding body to the leaf surface to detect the amount of moisture transpiration from the leaf surface, and based on the moisture transpiration from the leaf surface based on the color sample, This is a plant water stress measurement method for determining the degree of water stress.

  The plant water stress display sheet and the plant water stress measurement method of the present invention can simply and inexpensively evaluate the water stress state of the tree by simply sticking the display sheet to a leaf. As a result, the producer can frequently and carefully grasp the moisture state of the tree, and can be used for cultivation management such as irrigation of the tree.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 4 show an embodiment of the present invention, and a moisture stress display sheet for plants 10 of this embodiment is provided with a resin film 12 serving as an adhesive sheet, and the material thereof is flexible and transparent. Made of a good resin. For example, polyolefin, polypropylene, polyester, polyvinyl chloride, polyvinylidene chloride, polyethylene, nylon, urethane and the like are used. The thickness is 20 to 100 microns, preferably 50 to 75 microns. The resin film 12 is cut into, for example, an oval shape. In addition, the resin film 12 should just be transparent as long as the display part 14 mentioned later is transparent, and may perform appropriate coloring or coating.

  Near the center of the surface of the resin film 12, for example, two rectangular transparent display portions 14 are provided side by side, and any color or pattern other than the display portion 14 is printed. The display unit 14 is visible through the resin film 12 and can see the color of the cobalt chloride paper 16 which is a holding body on which cobalt chloride is adsorbed. An adhesive 18 is applied to the entire back surface of the resin film 12. Cobalt chloride paper 16 having a different sensitivity is attached to the display unit 14. The cobalt chloride paper 16 is covered with a hydrophobic nonwoven fabric 20 on the side opposite to the adhesive 18.

  Release papers 21 and 22 are detachably attached to the adhesive 18 of the resin film 12. The release paper 22 of the two release papers 21 and 22 has a surface that has not been subjected to a release treatment, and the release paper 21 positioned on the inside has been subjected to a release treatment. The release paper 21 extends from one end of the resin film 12 to the vicinity of the other end, and covers the adhesive 18 so as to leave a part of the other end. The release paper 22 is bonded as an adhesive portion 22 a to a portion not covered with the release paper 21 and extends to the vicinity of one end of the resin film 12 so as to cover the release paper 21. Thereby, the release paper 22 maintains the state in which the adhesive portion 22 a is attached to the resin film 12. Various information for the test can be written on the surface 22b side of the release paper 22 and functions as a display label indicating a pasting place when the test is performed.

  A color sample 24 is printed on the resin film 12 on the side of the display unit 14. The color sample 24 is provided in, for example, four stages, and the lowermost section on the drawing of FIG. 1 is blue near the anhydrous salt of cobalt chloride, and the uppermost part is when the cobalt chloride completely absorbs moisture. It is pink.

  The cobalt chloride paper 16 is provided with a plurality of sheets having different sensitivities. As shown in FIG. 1, by measuring with two sheets, a clearer reaction can be displayed with different amounts of water, for example, classified into 4 to 10 stages, and the measurement accuracy can be increased.

  The method of using the display sheet 10 according to the embodiment of the present invention is as shown in FIG. The display sheet 10 is pasted so as not to straddle the central thick vein. As shown in FIG. 4, the part to be pasted is a leaf-use part 34 at the center of the height of the tree 30, and leaves that are sufficiently radiant on the south side are selected. Further, the release paper 22 adhered by the adhesive portion 22a via the adhesive 18 is not removed as it is, but is used as a mark for the position where the display sheet 10 is attached to the tree 30. In addition, information such as temperature, humidity, time, and the like at the time of pasting may be described on the surface 22b of the release paper 22.

  FIG. 9 shows the color change of the cobalt chloride paper 16 when the moisture stress display sheet 10 of this embodiment is attached to the back surface 32 a of the leaf 32. In FIG. 9, two sheets of cobalt chloride paper 16 are displayed as sheets A and B, and the cobalt chloride paper 16 in the case where the display sheet 10 is pasted on the leaf 32 for two types of trees, ie, a strong moisture stress tree and a weak tree. The time course of the color change was shown.

  Here, the relationship between moisture stress and the amount of transpiration will be described below.

  A citrus tree (Mayakawa Miyagi, 7-year-old) was used as a sample. In the following, water stress is a value based on the water potential using the pressure chamber method. It is a value using the method.

  FIG. 5 shows the daily changes over time in the amount of water transpiration due to the difference in water stress (water stress high: -2.2 MPa, during water stress: -1.1 MPa, water stress weak: -0.5 MPa). Thus, it was found that the moisture transpiration amount is smaller when the moisture stress is stronger.

  In the method for discriminating the water stress state of the plant of the present invention, the water stress state is discriminated from the amount of water transpiration from the leaf, and it can be sufficiently evaluated to contribute to the water stress early in the morning or after sunset. The amount of leaf transpiration cannot be obtained. Leaf transpiration is also affected by weather conditions such as solar radiation. Therefore, it is recommended to set the measurement time of transpiration for about 1 hour before and after noon during the day when the water stress state of the tree is prominently expressed as leaf transpiration.

  In the embodiment of the present invention, the leaves used for the measurement of transpiration are defined as the sites for measuring the transpiration amount for the leaves that are approximately facing solar radiation and are sufficiently exposed to solar radiation in consideration of variations in solar radiation. FIG. 6 shows the difference in leaf surface flow velocity resistance in various moisture stress states performed in the above-described prescribed measurement state. The degree of water stress indicates the blockage of the pores due to the defense function of the living body, and a positive correlation tendency is observed with the leaf surface flow velocity resistance.

  Furthermore, FIG. 7 shows the relationship between the amount of transpiration and leaf surface flow velocity resistance of trees in various water stress states. This shows an increasing tendency of the transpiration rate as the leaf surface flow velocity resistance decreases.

  From the above, it can be seen that the moisture stress state of the tree can be determined by measuring the moisture transpiration amount of the leaves 30.

FIG. 8 shows the relationship between the water potential indicating the water stress state and the amount of transpiration. From the relationship shown in FIG. 8, it can be said that it is appropriate to use a transpiration rate of 3.0 μg · cm ⁻² s ⁻¹ as a boundary for determining the water stress state of the tree.

However, as shown in FIG. 7, when the leaf surface flow velocity resistance is low, that is, when the degree of opening of the pores is large, the amount of transpiration varies. In FIG. 8, even when the moisture stress is weak, the transpiration amount is 3.0 μg · cm ⁻² s ⁻¹ or less.

Therefore, a tree with a low water stress, that is, a tree with a transpiration rate above the threshold, is randomly formed according to the measurement of the transpiration rate, and transpiration is performed with a low water stress tree. The ratio obtained at an amount of 3.0 μg · cm ⁻² s ⁻¹ or less was evaluated. As a result, it is statistically about 2% (standard deviation 1.83), and it is possible to evaluate the degree of water stress by trial of transpiration measurement at a plurality of positions on the specified leaf.

The aforementioned measurements, as a measure of summer, the average temperature 30.5 ° C., average relative humidity 40.4Rh%, average leaf area temperature 31.3 ° C., was carried out under conditions of photon density ^{1554 ± 279μmol · m -2 s -1} .

In the method of determining the state of water stress in the plants of the present invention, in consideration of these, as determined in water stress condition of the tree, the transpiration 3.0μg · cm ^-2 s ^-1 to determine whether the water stress condition The threshold is used.

In the method for discriminating the water stress state of the plant of the present invention, if the amount of transpiration is measured at a plurality of positions and a value of 3.0 μg · cm ⁻² s ⁻¹ or more cannot be obtained, the tree is in a water stress state. It can be determined that

Therefore, with the threshold value for determining whether or not water stress is present, the water content of water stress weak (-0.6MPa) and water stress strong (-2.1MPa) with the transpiration rate of 3.0μg · cm ^-2 s ^-1 as the boundary. The display sheet 10 of the present invention was affixed to the back surface of the leaves 32 for two sample trees in a stress state, and the color change was observed. The result is shown in FIG. In the present embodiment, for example, it can be said that the reaction time is preferably 5 minutes, that is, it is preferable to perform the evaluation based on the color change after the lapse of 5 minutes after the display sheet 10 is attached.

  According to the plant internal water stress display sheet and the plant water stress measurement method of this embodiment, it is possible to measure the water stress of a plant extremely easily, and it is possible to grasp the state of the water stress frequently without cost. It is possible to perform finer water stress management and contribute to quality improvement of fruits and the like.

It is a front view of the in-vivo moisture stress display sheet for plants of one embodiment of this invention. It is a side view of the display sheet of one embodiment of this invention. It is a perspective view which shows the use condition of the display sheet of one Embodiment of this invention. It is a perspective view which shows the use site | part with respect to the tree of the display sheet of one Embodiment of this invention. Fig. 2 shows the daily change over time in the amount of transpiration of water due to the difference in water stress of trees. The moisture stress state and leaf surface flow velocity resistance performed in the specified measurement state are shown. The relationship between the amount of water transpiration from the leaves and the leaf surface flow velocity resistance is shown. The relationship between the water potential indicating the water stress state and the amount of transpiration is shown. The color change of the cobalt chloride paper in the state which stuck the display sheet of this invention on the back surface of the leaf with respect to two sample trees of a different water stress state is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Display sheet 12 Resin film 14 Display part 16 Cobalt chloride paper 18 Adhesive 20 Nonwoven fabric 22 Release paper 22a Adhesion part 24 Color sample 30 Tree 32 Leaf 34 Display sheet use part

Claims (6)

  Printed in the vicinity of the holding body of the resin film, a resin film affixed to the leaf surface with an adhesive, a holding body provided on the side surface of the adhesive layer of the transparent display portion of the resin film and adsorbing cobalt chloride In addition, a color sample of the color that the support is colored by the cobalt chloride is provided, and the color of the cobalt chloride of the support is changed according to the amount of moisture transpiration depending on the degree of moisture deficiency of the plant. The in-vivo moisture stress display sheet for plants, wherein the degree of moisture stress of the plant is displayed based on the amount of moisture transpiration from the leaf surface.   The plant water stress display sheet for plants according to claim 1, wherein the holding body is a hygroscopic sheet, and a hydrophobic nonwoven fabric is attached to a surface of the holding body opposite to the resin film.   The plant water moisture stress display sheet according to claim 1, wherein a plurality of the holding bodies are provided with different sensitivities with respect to a moisture adsorption amount.   The in-vivo moisture stress display sheet for plants according to claim 1 or 2, wherein a watering index is provided on the resin film in the vicinity of the holding body.   A release paper is laminated on the pressure-sensitive adhesive layer on the resin film, a part of the release paper is fixed so as not to be peeled off from the resin film, and the release paper is used as a display label for a sticking place. The plant body water stress display sheet according to 1. A holding body that adsorbs cobalt chloride is provided on the surface of the pressure-sensitive adhesive layer of the resin film that is attached to the leaf surface with an adhesive, and the holder is printed in the vicinity of the holding body of the resin film so that the holding body absorbs moisture. By using a display sheet provided with a color sample of the color developed by the above, the degree of coloration of cobalt chloride of the holding body varies according to the amount of water evaporation depending on the degree of water deficiency of the plant. And affixing the holding body to the leaf surface, detecting the amount of water evaporation from the leaf surface, and determining the degree of water stress of the plant based on the water evaporation from the leaf surface based on the color sample. A characteristic method for measuring plant water stress.

Images