Methods for cultivating fruit trees and heat-insulating materials used therein
The two- or three-layer insulating member with overlapping bubble wrap and aluminum foil addresses the inadequacies of existing frost protection methods by maintaining stable temperatures, effectively preventing frost damage in fruit trees.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2026-05-18
AI Technical Summary
Existing frost protection methods for fruit trees in high-density cultivation, such as white coatings and materials combining aluminum vapor-deposited film with bubble wrap, are insufficient in preventing frost damage due to inadequate heat retention and air permeability, leading to high temperatures and weakened tree vigor.
A two- or three-layer insulating member is wrapped around the fruit tree trunk, comprising overlapping bubble wrap materials with sealed air bubbles and aluminum foil on the outer surfaces, effectively blocking transmitted light and maintaining consistent temperature.
The insulating member effectively suppresses temperature fluctuations, preventing frost damage by maintaining a stable internal temperature, even during large temperature differences, thus protecting the fruit trees.
Smart Images
Figure 2026080484000001_ABST
Abstract
Description
Technical Field
[0004] , , , , ,
[0003]
[0001] The present invention relates to a method for cultivating fruit trees and a heat-insulating member used therefor, and more particularly, to a method for cultivating fruit trees for suppressing frost damage and protecting fruit trees, and a heat-insulating member used therefor.
Background Art
[0002] In recent years, high-density cultivation has been carried out in order to obtain a high yield while reducing the labor required for plant cultivation. High-density cultivation is a technique for cultivating as many fruit trees as possible in a given area. For example, it is characterized by cultivating more than 300 fruit trees per 10 ares of area, and thus the number of fruit trees cultivated per unit area is large. This method is adopted to increase the yield while making effective use of limited land (see, for example, Patent Document 1). In high-density cultivation, since the spacing between the cultivated fruit trees is arranged closely, it is possible to efficiently utilize water and nutrients. In addition, it is a cultivation method that does not require advanced pruning techniques and can achieve early high yield, homogeneous production, and improved work efficiency compared to sparse cultivation. Examples of fruit trees for which high-density cultivation is used include apples, pears, grapes, and strawberries.
[0003] Among fruit trees, apples are relatively cold-resistant and are mainly cultivated in Aomori Prefecture, Nagano Prefecture, Iwate Prefecture, etc. in Japan. In those regions, there is snow accumulation in winter, and the meltwater generated by the melting of snow from April to May is retained in the soil and serves as a water supply source during the growth period of apples. However, due to the influence of recent warm winters and global warming, in recent years, even in March, the daytime temperature is high and it has become warmer than before, so snowmelt may occur even at that time. Apples absorb water well from the roots when there is a large difference between cold and warm, but at this time, the nighttime temperature is still very low, and the so-called frost damage, in which the water absorbed during the daytime freezes in the stems and branches due to a sudden drop in temperature at night, has become prominent. In particular, in the cultivation of apples by high-density cultivation, the trunks and branches are thin, so the influence is large, and especially near the root, the influence is more likely to be received because the temperature change on the ground surface is intense.
[0004] To prevent such frost damage, a protective material has been proposed that combines two or more layers of a base material made of sheets such as paper, nonwoven fabric, or plastic, forming at least one layer of the base material into a corrugated or uneven shape, and wrapping this around the fruit tree to create air bubbles between the material and the trunk and branches of the fruit tree (see Patent Document 2). In addition, a white coating agent is applied to the fruit tree at a height of about 1 m from the ground surface to suppress the effects of rapid temperature changes (see, for example, Non-Patent Document 1). [Prior art documents] [Patent Documents]
[0005] [Patent Document 1] Japanese Patent Publication No. 2023-42748 [Patent Document 2] Utility Model Registration No. 3215772 Gazette [Non-patent literature]
[0006] [Non-Patent Document 1] Aomori Prefectural Industrial Technology Center, a local independent administrative agency, states, "Applying a white coating to apple trees can suppress the rise in tree temperature during winter." (https: / / www.aomori-itc.or.jp / _files / 00041492 / H20-5.pdf) [Overview of the project] [Problems that the invention aims to solve]
[0007] Incidentally, Patent Document 2 points out that while white coatings provide a certain degree of sun protection, their effect is not sufficient. Furthermore, it is noted that materials combining aluminum vapor-deposited film and bubble wrap have excellent heat retention properties, but their poor air permeability and moisture permeability make it difficult for heat to escape from the inside, resulting in high temperatures and damp conditions inside, which weakens the tree's vigor due to root growth from the middle of the covered trunk. Indeed, when there are large temperature fluctuations, white coatings alone are insufficient to adequately prevent frost damage to fruit trees caused by temperature changes. Also, in the case of aluminum vapor deposition, the vapor-deposited film is thin, so a lot of light is transmitted, and it is conceivable that the internal temperature rises due to the transmitted light. On the other hand, materials with corrugated or unevenly shaped bubbles, as in Patent Document 2, have problems with heat retention because the inside is continuous with the outside air, so there has been a desire for a more effective heat-retaining material.
[0008] Therefore, after thorough investigation, we discovered that using a heat-insulating material that combines bubble wrap with aluminum foil can suppress temperature changes even more effectively than materials using white coatings or aluminum vapor deposition. In other words, the present invention aims to provide a method for cultivating fruit trees that protects them from frost damage, and a heat-insulating material used therein. [Means for solving the problem]
[0009] To solve the above problems, the present invention provides a method for cultivating fruit trees to protect them from frost damage, characterized in that a two-layer insulating member, in which two bubble wrap materials with sealed air bubbles are arranged so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces, is wrapped around the trunk of the fruit tree at a height of about 50 to 100 cm from the ground.
[0010] To solve the above problems, the present invention provides a method for cultivating fruit trees to protect them from frost damage, characterized in that a three-layer insulating member is wrapped around the trunk of the fruit tree at a height of about 50 to 100 cm from the ground. This insulating member has a two-layer structure in which two bubble wrap materials with sealed air bubbles are arranged so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces. This insulating member has a three-layer structure in which another bubble wrap material with sealed air bubbles and aluminum foil on its bottom is arranged so that its surface side overlaps each other.
[0011] To solve the above problems, the present invention provides a method for cultivating fruit trees according to claim 1 or 2, characterized in that the two-layered heat-insulating material or the three-layered heat-insulating member is wrapped around the trunk of the fruit tree in at least two layers and fixed in place.
[0012] To solve the above problems, the present invention provides a heat-retaining member for use in the fruit tree cultivation method described in claim 1, characterized in that it has a two-layer structure in which two bubble cushioning materials, each having sealed bubbles, are arranged so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces.
[0013] To solve the above problems, the present invention provides a heat-retaining member for use in the fruit tree cultivation method described in claim 2, characterized in that a two-layer heat-retaining member has two bubble cushioning materials with sealed air bubbles arranged so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces, and further, another bubble cushioning material has sealed air bubbles and aluminum foil is placed on the bottom surface, arranged so that its surface side overlaps the two-layer heat-retaining member.
[0014] To solve the above problems, the present invention provides a protective member for use in the fruit tree cultivation method described in claim 4, characterized in that the diameter of the bubbles in the bubble buffer material forming the two-layer heat-retaining member is 5 to 20 mm and the thickness is 2 to 15 mm.
[0015] In order to solve the above problems, the present invention provides a protective member used in the fruit tree cultivation method according to claim 5, wherein the diameter of the air bubbles in the air bubble buffer material forming the heat preservation member with the three-layer structure is 5 to 20 mm, and the thickness is 2 to 15 mm.
Effect of the Invention
[0016] According to the fruit tree cultivation method and the heat preservation member used therein according to the present invention, the surface sides of two air bubble buffer materials provided with sealed air bubbles are arranged so as to overlap each other, and a heat preservation member with a two-layer structure in which aluminum foils are arranged on both outer surfaces, and further, a heat preservation member with a three-layer structure is arranged so that the surface side of an air bubble buffer material provided with another sealed air bubble and having an aluminum foil arranged on the bottom surface overlaps. Since it is wound around the trunk of the fruit tree, it is surely shielded without the intrusion of transmitted light inside, so the temperature change inside the heat preservation member is also suppressed. Even in a period when the temperature difference between cold and warm is large and there is a possibility of frost damage, the temperature change of the fruit tree can be suppressed, and the effect is that frost damage can be surely prevented.
Brief Description of the Drawings
[0017] [Figure 1] It is a side cross-sectional view of an embodiment of a heat preservation member with a two-layer structure. [Figure 2] It is a side cross-sectional view of an embodiment of a heat preservation member with a three-layer structure. [Figure 3] It is a graph showing the test results from December 1 to December 10, 2022. [Figure 4] It is a graph showing the test results from December 11 to December 20, 2022. [Figure 5] It is a graph showing the test results from December 21 to December 31, 2022. [Figure 6] It is a graph showing the test results from January 1 to January 10, 2023. [Figure 7] It is a graph showing the test results from January 11 to January 20, 2023. [Figure 8] It is a graph showing the test results from January 21 to January 31, 2023. [Figure 9] It is a graph showing the test results from February 1 to February 15, 2023. [Figure 10] It is a graph showing the test results from February 22 to February 28, 2023. [Figure 11] It is a graph showing the test results from March 1 to March 10, 2023. [Figure 12] It is a graph showing the test results from March 11 to March 20, 2023. [Figure 13] It is a graph showing the test results from March 21 to March 31, 2023. [Figure 14] It is a graph showing the test results from April 1 to April 10, 2023. [Figure 15] It is a graph showing the test results from April 11 to April 20, 2023. [Figure 16] It is a graph showing the test results from April 21 to April 31, 2023. [Figure 17] It is a graph showing the test results from December 7 to December 16, 2023. [Figure 18] It is a graph showing the test results from December 17 to December 26, 2023. [Figure 19] It is a graph showing the test results from December 27 to December 31, 2023. [Figure 20] It is a graph showing the test results from January 1 to January 10, 2024. [Figure 21] It is a graph showing the test results from January 11 to January 20, 2024. [Figure 22] It is a graph showing the test results from January 21 to January 31, 2024. [Figure 23] It is a graph showing the test results from February 1 to February 10, 20 24. [Figure 24] It is a graph showing the test results from February 11 to February 20, 2023. [Figure 25] It is a graph showing the test results from February 21 to February 27, 2024. [Figure 26] This graph shows the test results from March 1st to March 10th, 2024. [Figure 27] This graph shows the test results from March 11th to March 20th, 2024. [Figure 28] This graph shows the test results from March 21st to March 31st, 2024. [Figure 29] This graph shows the test results from April 1st to April 10th, 2024. [Figure 30] This graph shows the test results from April 11th to April 20th, 2024. [Figure 31] This graph shows the test results from April 21st to April 30th, 2024. [Figure 32] This graph shows the test results from May 1st to May 10th, 2024. [Figure 33] This graph shows the test results from May 11th to May 17th, 2024. [Modes for carrying out the invention]
[0018] The following describes in detail, based on a preferred embodiment, the method for cultivating fruit trees according to the present invention and the heat-retaining material used therein. [Insulation material] First, an embodiment of a heat-retaining member used in a fruit tree cultivation method according to the present invention will be described. Figure 1 is a side cross-sectional view of an embodiment of a two-layer heat-retaining member, and Figure 2 is a side cross-sectional view of an embodiment of a three-layer heat-retaining member. The heat-retaining member 10 shown in Figure 1 is composed of two bubble cushioning materials 10a and 10b, one bubble cushioning material 10a having a plurality of sealed air bubbles 13a, 13a, and the other bubble cushioning material 10b having a plurality of similarly sealed air bubbles 13b, 13b, and the surfaces of the bubble cushioning materials 10a and 10b (the top sides of the air bubbles 13a and 13b) are arranged to overlap each other. When overlapping the surfaces of the two bubble cushioning materials 10a and 10b, a liner made of polyethylene (PE), polypropylene (PP), or polyolefin resin, for example, with a thickness of about 10 to 25 μm can be interposed between them. Furthermore, various sizes of bubbles 13a and 13b can be used, but for example, the diameter of the bubbles is 5 to 20 mm, preferably 7 to 15 mm, and the thickness is 2 to 15 mm, preferably 3 to 10 mm.
[0019] Aluminum foil 11a and 11b are placed on the outer surface (bottom surface) of each of the bubble wrap materials 10a and 10b. The aluminum foil 11a and 11b are made by rolling out aluminum into a thin film, and for example, a film rolled to a thickness of about 6 to 20 μm, preferably 7 to 12 μm, can be used. As a heat-insulating material 10 used in the fruit tree cultivation method according to the present invention, it is preferable to use aluminum foil 11a and 11b rather than aluminum vapor deposition due to its high light-blocking properties. In addition, aluminum vapor deposition is made by evaporating aluminum heated to a high temperature and attaching it to a film or the like, but in the case of normal aluminum vapor deposition, the aluminum layer is relatively thin, so there is a possibility that transmitted light will penetrate to the inside, so it is preferable to use aluminum foil 11a and 11b.
[0020] On the other hand, the second embodiment of the heat-insulating member 10' shown in Figure 2 has another bubble cushioning material 10c placed on top of the two-layer structure of the heat-insulating member 10 described above. That is, a bubble cushioning material 10c with multiple sealed bubbles 13c, 13c is placed on one side of the heat-insulating member 10. The bubble cushioning material 10c has the same structure as the bubble cushioning materials 10a and 10b, and aluminum foil 11c is placed on the bottom surface of the bubble cushioning material 10c. It is placed so that the bubble side 13c is in close contact with one of the surfaces of the heat-insulating member 10. Therefore, both outer surfaces of the heat-insulating member 10' are also made of aluminum foil. It should be noted that when layering the bubble cushioning material 10c on one side of the heat-insulating member 10, a liner can be interposed between them.
[0021] [Fruit tree cultivation methods] Next, a method for cultivating fruit trees using the above-described heat-retaining members 10 and 10' will be explained. The heat-retaining members 10 and 10' are wrapped around the trunk of the fruit tree so that they are, for example, about 50 to 100 cm above the ground. It is preferable to wrap them so that the upper ends of the heat-retaining members 10 and 10' are slightly higher than the normal snow depth in the fruit tree cultivation area. Furthermore, it is preferable to wrap the fruit tree so that at least two layers of heat-retaining members 10 and 10' are wrapped around the trunk of the fruit tree. This is because the overlapping of the heat-retaining members 10 and 10', each equipped with multiple aluminum foils, makes it possible to more reliably block transmitted light. The heat-retaining members 10 and 10' are securely fixed in an appropriate manner so that they do not come off due to weather or wind. For example, they are fixed in at least three places in the height direction—top, middle, and bottom—with cable ties or rubber bands.
[0022] The insulating materials 10 and 10' should be wrapped around the fruit trees before snowfall in November or December. Furthermore, to prevent rainwater or melted snow from entering the space between the insulating materials 10 and 10' and the trunk of the fruit tree when it rains or when snow accumulation exceeds the height of the upper side of the insulating materials 10 and 10', it is preferable to wrap the upper ends of the insulating materials 10 and 10' tightly to minimize any gaps between them and the trunk of the fruit tree. In this case, tape may be wrapped around the upper side of the insulating materials 10 and 10' to cover them. After winter, when the snow melts and the ground becomes exposed in March or April, the insulating materials 10 and 10' should be removed from the fruit trees.
[0023] [Examples] Verification tests using the 10' heat-retaining material were conducted at the JA Tsugaru Nishikita high-density cultivation model orchard (Tsugaru City, Aomori Prefecture). Specifically, the heat-retaining material used was a three-layer structure consisting of two layers of bubble wrap with a diameter of 10 mm and a thickness of 3.5 mm, each with a 12 μm thick layer of aluminum foil placed on top, with the surfaces of the bubbles overlapping, and then another layer of bubble wrap of the same structure placed on top. Five Fuji apple trees (1-year-old feather seedlings) planted in 2020 were used as the test plots, and the heat-retaining material was wrapped around the trunks of the trees so that the top edge was approximately 60 cm above the ground. As a control group, five Fuji apple trees were prepared, each coated with a white coating agent at a height of approximately 60 cm from the ground. In addition, temperature sensors were attached to the fruit trees in the test plot inside the insulation material wrapped around the trunk, and to the fruit trees in the control plot so as to be in contact with the trunk. Sensors for measuring ambient temperature were also placed near the test and control plots, and temperature data was recorded using data loggers.
[0024] Temperature data was recorded in two phases: the first phase from December 1, 2022 to April 31, 2023, and the second phase from December 7, 2023 to May 17, 2024. Temperature measurements were taken every 4-5 hours daily. Snow depth (height from the ground) was also measured simultaneously. Figures 3-16 show the data from the first phase for one tree in the test plot using insulation material and one tree in the control plot using white coating agent, while Figures 17-33 show the data from the second phase. Although each figure shows the results for one tree in the test and control plots, the results were nearly identical for the other trees in the test and control plots.
[0025] Referring to Figures 3-16 for the first test, although there was a small amount of snow on December 1, 2022, after the start of the test, the areas treated with insulation and white coating were almost completely exposed. In this condition, the white coating is thought to have a large temperature fluctuation range due to the influence of direct sunlight (sunlight hours and radiant heat), whereas the areas wrapped with insulation were less affected in this way, and therefore the temperature fluctuation range was smaller than that of the white coating. Subsequently, as shown in Figure 6, the amount of snow gradually increased from around January 7, 2023, and when it reached about 50 cm, the temperature of both the insulation and white coating remained almost unchanged at around 0°C. This is thought to be because the snowfall kept both materials in an insulated state at around 0°C.
[0026] Subsequently, as the amount of snowfall decreases, temperature changes also begin to appear in the insulation material and the white coating. For example, as shown in Figure 7, from around January 11th to 13th, 2023, the temperature fluctuation range of the white coating was smaller than that of the insulation material, and thereafter, the temperature fluctuation range of the insulation material became smaller than that of the white coating material. During this period from January 11th to 13th, 2023, there were large temperature fluctuations, and although the daytime was relatively warm, the white coating remained at around 0°C, while the insulation material was kept warm above 0°C as the outside temperature rose, thus protecting it from frost damage.
[0027] As shown in Figures 8-10, from around January 25th to March 1st, 2023, the snow depth exceeded 70 cm, and both the insulation material and the white coating maintained a temperature of approximately 0°C. Then, as shown in Figure 11, from around March 1st, 2023, the snow depth began to decrease and the outside temperature rose above 0°C. Consequently, the insulation material appears to have reacted to the outside temperature, but the white coating did not show such a change and continued to maintain a temperature of approximately 0°C. Subsequently, from March 7th, 2023 onward, the snow depth gradually decreased, and due to the effects of rising temperatures and sunshine hours, the temperature fluctuations of the white coating gradually became larger than those of the insulation material. After that, as shown in Figures 12-17, the temperature fluctuations of the insulation material remained smaller than those of the white coating, indicating that the insulation material was more resistant to temperature changes.
[0028] Next, referring to Figures 17-33, snowfall was observed from January 11, 2024 to March 11, 2024, but the snowfall amount was only about 20 cm, which was less than in the first test throughout the period. Therefore, in the second test, neither the insulation material nor the white coating material reached a state of insulation at approximately 0°C. Furthermore, it was confirmed that the insulation material exhibited less temperature fluctuation than the white coating material throughout the entire period. In other words, the temperature change in response to changes in outside temperature was less with the insulation material than with the white coating material, confirming that it provided better insulation.
[0029] The results were as described above, but it appears that there is no difference in effect depending on the apple variety. Furthermore, it is believed that there is no difference in effect for other fruit trees such as grapes and peaches. [Other embodiments]
[0030] Furthermore, the present invention is not limited to the above embodiments or examples, and various modifications are possible without departing from or changing the technical concept of the present invention. [Explanation of symbols]
[0031] 10 Insulation material 10' Insulation material 10a Bubble wrap 10b Bubble wrap 10c bubble wrap 11a Aluminum foil 11b Aluminum foil 11c aluminum foil 13a Air bubbles 13b Air bubbles 13c air bubbles
Claims
1. A method of cultivating fruit trees to protect them from frost damage, A method for cultivating fruit trees, characterized by arranging two bubble wrap cushions with sealed air bubbles so that their surfaces overlap each other, and wrapping a two-layer insulation member, which has aluminum foil on both outer surfaces, around the trunk of the fruit tree at a height of about 50 to 100 cm from the ground.
2. A method of cultivating fruit trees to protect them from frost damage, A method for cultivating fruit trees, characterized by wrapping a three-layer insulation member around the trunk of the fruit tree at a height of about 50 to 100 cm from the ground. This insulation member has a two-layer structure, in which two bubble wrap cushions with sealed air bubbles are placed so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces. The insulation member has a three-layer structure, in which another bubble wrap cushion with sealed air bubbles and aluminum foil on its bottom is placed so that its surface side overlaps each other.
3. In the method for cultivating fruit trees according to claim 1 or 2, A method for cultivating fruit trees, characterized by wrapping and securing the two-layered heat-insulating material or the three-layered heat-insulating member around the trunk of the fruit tree in at least two layers.
4. A heat-retaining member used in the fruit tree cultivation method described in claim 1, A heat-insulating component characterized by a two-layer structure in which two bubble cushioning materials, each containing a sealed bubble, are arranged so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces.
5. A heat-retaining member used in the fruit tree cultivation method described in claim 2, A heat-insulating member characterized by having a three-layer structure, in which two bubble cushioning materials with sealed bubbles are placed so that their surface sides overlap each other, and aluminum foil is placed on both outer surfaces of the two-layer heat-insulating member, and then another bubble cushioning material with sealed bubbles and aluminum foil on the bottom surface is placed so that its surface side overlaps each other.
6. A protective member used in the fruit tree cultivation method described in claim 4, A protective member characterized in that the bubble cushioning material forming the two-layer heat-insulating member has a bubble diameter of 5 to 20 mm and a thickness of 2 to 15 mm.
7. A protective member used in the fruit tree cultivation method described in claim 5, A protective member characterized in that the bubble cushioning material forming the three-layered heat-insulating member has a bubble diameter of 5 to 20 mm and a thickness of 2 to 15 mm.