JPH07227153A - High-ridge fruit plant cultivation method - Google Patents

Abstract

PURPOSE:To efficiently perform the cultivation of a high-ridge fruit plant and obtain a fruit having low citric acid content and improved polarization by covering the ridge surface around the root of a fruit plant with an air- impermeable synthetic resin film, etc., and covering the valley part of the ridge with an air-permeable porous synthetic resin film, etc. CONSTITUTION:A high-ridge fruit plant such as orange, apple, grape and watermelon is cultured by covering the ridge surface around the root part of the fruit plant with an air-impermeable synthetic resin film or sheet and covering the valley part between the ridges with an air-permeable porous synthetic resin film or sheet having an air-permeability of 200-5,000sec/100mL, a water-resistance pressure of >=500mmH2O and a moisture permeability of 1,000-10,000gH2O/m<2>.24 hr and laminated on at least one surface with a nylon, polyester or PE nonwoven fabric having an areal density of 15-30g/m<2> at a contact area ratio of 10-50%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a high ridge type fruit plant cultivation method in which a ridge is provided on the ground and a fruit plant is planted and cultivated in the ridge.

[0002]

2. Description of the Related Art As a method of cultivating a woody or herbaceous fruit plant such as mandarin orange, apple, grape and watermelon, there is a high ridge type cultivation method. This high-ridge type cultivation method is a method in which a ridge is provided by cultivating soil on the ground, and a plant is planted and cultivated in the ridge. Is used for.

On the other hand, as for fruits and vegetables, when water is supplied from the roots due to rainfall, etc., from 3 to 4 months before harvesting, at the time of harvesting,
It is known that water content and respiration volume in fruits are increased, sugar content and acidity decrease, and quality deteriorates. Therefore, for the purpose of quality improvement, it is generally considered that before the harvest, the ridges and the valleys between them are covered with a straw to block water from the soil. However, because the straw is not waterproof, it does not have a great effect.

A method of covering the ground surface such as ridges with a non-breathable vinyl sheet is also conceivable, but if the sheet is left covered with a non-breathable, non-moisture permeable sheet, breathability will be poor, resulting in breathing. The carbon dioxide gas generated by the above may fill the underground part, causing the roots to suffocate, which may have the opposite effect.Therefore, when the weather is fine, the ground is removed except for the sheet, and the surface is covered with the sheet only when it is raining. However, the work is complicated.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method capable of obtaining fruits and vegetables with improved quality in high ridge cultivation.

[0006]

Means for Solving the Problems The gist of the present invention is to form a ridge by cultivating soil on the ground, in a high ridge type fruit plant cultivation method for cultivating a fruit plant on the ridge, wherein the ridges around the root of the fruit plant are Cover with non-breathable synthetic resin film or sheet,
A method for cultivating a high ridge type fruit plant, which comprises covering a valley portion between the ridges with a porous film or sheet made of a synthetic resin having air permeability.

The non-breathable synthetic resin film or sheet used in the present invention means a single layer, a multi-layer, a coloring, etc. of a thermoplastic synthetic resin which is generally used in agriculture such as polyethylene, polypropylene and polyvinyl chloride. A non-colored film is used. By coating the ridge surface with such a non-breathable synthetic resin film, it serves to reduce the supply of water for several months before the harvest of fruit plants and improve the sugar content.

On the other hand, if the ridge surface or the valley portion between the ridges is covered with a non-breathable synthetic resin film, the above-mentioned suffocation of the roots is caused. Therefore, the valley portion between the ridges is covered with a breathable synthetic resin porous film or sheet to release the vapor in the ground and assist the roots in breathing.

The breathable film (synthetic resin porous film or sheet) used in the present invention is a film that is permeable to gases such as air and water vapor and impermeable to water droplets (liquid). The air permeability is 200 to 5,000, though it can be selected from a wide range as long as it has the above-mentioned performance.
A film having a performance of sec / 100 ml or water pressure resistance of 500 mmH ₂ O or more is preferable.

Here, the air permeability is the method specified in JIS-P-8117, the moisture permeability is the method specified in JIS-Z-0208, and the water pressure resistance is the value measured by the JIS-L-1092A method. is there. If the air permeability is too low, the gas permeability is poor, causing gas damage and damaging the roots.
Also, if the water pressure resistance is small, water droplets will soak into the soil and the soil will not be kept in an appropriate dry state, and the effect of quality improvement will be unclear.At the same time, it will be necessary to make the film thicker to increase waterproofness. Therefore, it becomes unsuitable due to poor handleability. There is no particular limitation on the film thickness, but it is practically 1
It is preferably 5 mμ to 50 mμ. Although the film material is not particularly specified, polyethylene,
A polyolefin resin film such as polypropylene is preferably used.

Such a film can be manufactured by the following method. The polyolefin resin (A) is a homopolymer of ethylene or propylene, or a density (ρ) of a copolymer of ethylene or propylene and another comonomer (a compound having at least one double bond having 4 or more carbon atoms in the molecule). 930 g / cm ³ or less, melt index (MI) 2 g / 10 minutes or less polyolefin-based thermoplastic resin, for example, low density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer, ultra-low density of 0.910 or less Any of density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-methacrylic acid ester or a mixture thereof may be used, but the density is preferably 0.91 to 0.95 g / cm ^3. 50-100 parts by weight of linear low density polyethylene Degrees 0.91g / c
m-less than ³ ethylene-α-olefin copolymer 50-0
Ρ consisting of parts by weight is 0.930 g / cm ³ or less, MI
Is a polyolefin-based thermoplastic resin of 2 g / 10 minutes or less.

The linear low-density polyethylene is a copolymer of ethylene and other α-olefin, for example, ethylene and its 1-butene of about 4 to 17% by weight, preferably about 5 to 15% by weight, 1-hexene, 1-octene, 1
It is produced by copolymerizing with other α-olefins such as decene and 4-methyl-1-pentene by using the Ziegler type catalyst or Phillips type catalyst used in the medium-pressure low-density polyethylene production.

The above ethylene-α-olefin copolymer is usually a copolymer of ethylene and an α-olefin having 3 or more carbon atoms and has a density of 0.91 g / cm 3.
It is preferably less than ³ , more preferably 0.85
It is 0.90 g / cm ³ . Examples of the α-olefin having 3 or more carbon atoms to be copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and the like.
It is also possible to use non-conjugated dienes such as hexadiene, dicyclopentadiene, ethylidene norbornene.

The above ethylene-α-olefin copolymer is produced by using a Ziegler type catalyst, especially a catalyst composed of a vanadium compound such as vanadium oxytrichloride and vanadium tetrachloride, and an organoaluminum compound, and ethylene and α
-It can be produced by copolymerizing with an olefin, and the ethylene content in the copolymer is in the range of 40 to 90 mol% and the content of the α-olefin is 10 to 60.
It is preferably in the range of mol%. Ethylene-α-
Examples of commercially available olefin copolymers include CdF
Chimie E. P. NORSOFLEX (FW
1600, FW1900, MW1920, SMW244
0, LW2220, LW2500. LW2550); flex resin (DFDA1137, manufactured by Nippon Unicar Co., Ltd.,
DFDA1138, DEFD1210, DEFD904
2); Tuffmer (A4085, A40 of Mitsui Petrochemical Co., Ltd.
90, P0180, P0480), J of Japan Synthetic Rubber Co., Ltd.
SR-EP (EP02P, EP07P, EP57P) etc. are mentioned.

When the density (ρ) of the polyolefin resin (A), which is used alone or as a mixture, is larger than 0.930 g / cm ³ , the synergistic effect of the plasticizer and the radical generator is small and the tear strength cannot be improved. On the other hand, when the MI is more than 2 g / 10 minutes, the tear strength of the film is lowered and the molding stability is lowered.

In the method of the present invention, the melt index (MI) is J, which is a reference standard of JIS-K-6760.
It is a value measured according to the condition 4 of Table 1 of IS-K-7210. In addition, a heat stabilizer, an ultraviolet stabilizer, a pigment, an antistatic agent, a fluorescent agent, etc. may be added to the polyolefin resin according to a conventional method.

Next, as the filler of the component (B), inorganic and organic fillers are used. As the inorganic filler, calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, barium carbonate, magnesium sulfate, barium sulfate, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, calcium oxide, magnesium oxide. , Titanium oxide, alumina, mica, asbestos powder, glass powder, shirasu balloon, zeolite, silicate clay and the like are used, and calcium carbonate, talc, clay, silica, diatomaceous earth, barium sulfate and the like are particularly preferable.

As the organic filler, cellulosic powder such as wood powder or pulp powder is used. These may be used alone or as a mixture. The average particle size of the filler is 30
It is preferably not more than 10 μm, more preferably not more than 10 μm, most preferably 0.8 to 5 μm. If the particle size is too large, the denseness of the pores of the stretched product will be poor, and if the particle size is too small, dispersibility in the resin will be poor and moldability will be poor.

The surface treatment of the filler is preferably carried out in terms of dispersibility in the resin and further stretchability, and treatment with a fatty acid or its metal salt gives preferable results. The plasticizer as the component (C) is a compound having an ester bond or an amide bond in the molecule and having a molecular weight of 100 or more and a boiling point of 200 ° C. or more and a melting point of 100 ° C. or less at normal pressure.
Examples thereof include oleic acid amide, stearic acid amide, dioctyl phthalate, trioctyl trimellitate and the like.

Preferably, the molecular weight is 350 or more, the boiling point at atmospheric pressure is 250 ° C. or more, the melting point is 50 ° C. or less, and the carbon number is 6
An ester compound composed of the above carboxylic acid and an alcohol having 5 or more carbon atoms, more preferably a molecular weight of 350 or more, a boiling point at atmospheric pressure of 250 ° C. or more and a melting point of 30 ° C. or less, and an aromatic carboxylic acid and carbon number. Ester compounds composed of 6 or more alcohols, for example, DOP, trioctyl trimellitate, DIDP and the like.

When the melting point is higher than 100 ° C., the effect of improving the tear strength by modification with a radical generator is small, and when the boiling point is lower than 200 ° C., smoke and foaming during molding process lower the molding / stretchability. When the molecular weight is small, bleeding of the plasticizer from the film is undesirably quick.

Next, as the radical generator of the component (D) used in the present invention, the decomposition temperature at which the half-life is 1 minute is 1
Those in the range of 30 to 300 ° C. are preferable, for example, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-
Butylperoxy) hexane, 2,5-dimethyl-2,
5-bis (t-butylperoxy) -3-hexyne,
α, α'-bis (t-butylperoxyisopropyl)
Examples thereof include peroxides such as benzene, dibenzoyl peroxide, and di-t-butyl peroxide.

In the present invention, 100 to 40 parts by weight of the polyolefin resin (A) and 100 to 40 parts of the filler (B) are used.
It is preferably used in an amount of 0 parts by weight, 1 to 100 parts by weight of the plasticizer (C), and 0.0001 to 0.1 parts by weight of the radical generator (D). If the proportion of the filler (B) is less than 100 parts by weight, the stretched film will not have sufficient pores and the degree of porosity will be low. In addition, the ratio of the filler is 40
If it exceeds 0 parts by weight, the kneadability, dispersibility, film or sheet moldability will deteriorate, and the surface strength of the stretched product will decrease.

In the present invention, a particularly preferable blending ratio is 120 to 300 parts by weight of the filler (B) with respect to 100 parts by weight of the polyolefin resin (A). Plasticizer (C)
When it is less than 1 part by weight, the effect of improving tear strength is not obtained, and when it is more than 100 parts by weight, the kneading property and dispersibility are deteriorated and the film formability is deteriorated and the stretchability cannot be secured. It is preferably 5 parts by weight or more and 50 parts by weight or less.

The radical generator (D) is from 0.0001 to
It is selected from the range of 0.1 parts by weight, and when it is less than this range, the tear strength cannot be improved by the synergistic effect with the plasticizer, and when it is more than this range, the melt index becomes too low, It is not preferable because film breakage is likely to occur during film formation, and roughening of the film surface occurs.

In the present invention, the polyolefin resin (A), the filler (B), the plasticizer (C), and the radical generator (D) are usually added in the above-mentioned amounts, for example, by the following method I or II. After mixing in a ratio, then kneading and pelletizing, inflation molding is performed to obtain an unstretched film. Method I: A polyolefin resin, a filler, a plasticizer, and a radical generator are mixed and kneaded using a kneader such as an extruder or a Banbury mixer, then pelletized, and inflation molding is performed using the pellets. Method II: A large amount of a radical generator 0.5-1% (about 5000-10000 ppm) is mixed with a polyolefin resin, and the mixture is melt-kneaded at a temperature at which the radical generator hardly reacts with the polyolefin and at a temperature higher than the melting point of the polyolefin. Then, a master batch in the form of pellets is prepared in advance, and the master batch is mixed with a polyolefin resin, a filler and a plasticizer, kneaded, and then pelletized, and inflation molding is performed using the pellets.

When the polyolefin resin is kneaded with a radical generator under heating (preferably at a temperature not lower than the half-life of the radical generator of 10 minutes) according to the method shown in I or II above, crosslinking by the radical generator is carried out. A reaction occurs, the polyolefin is intermolecularly coupled, a high molecular weight component is increased, and a modified polymer having a lowered melt index is obtained. This modified polymer is more likely to be oriented in the lateral direction during inflation molding as compared with the polymer before modification, and thus the film thus obtained is significantly improved in tensile strength and collision strength when stretched. .

To mix the polyolefin resin, the plasticizer, the radical generator and the filler, a drum, a tumbler type mixer, a ribbon blender, a Henschel mixer, a super mixer or the like is used. A mixer of the type is preferred and polyethylene is preferably supplied in the form of a powder, usually 10-150 mesh, especially 20-60 mesh. The kneading of the obtained mixture is carried out using a known kneading device such as a screw extruder, a twin screw extruder, a mixing roll, a Banbury mixer, a twin screw type kneader.

In the present invention, an unstretched film is formed from the above-obtained compound by an inflation method, and then this unstretched film is stretched. Inflation molding has a blow-up ratio (BUR) of 2-8. Preferably, the blow-up ratio is 3 to 6 and the height of the frost line is 2 to 50 times the diameter of the annular slit of the die. More preferably, the height of the frost line is in the range of 5 to 20 times the diameter of the annular slit of the die. When the blow-up ratio is lower than the above range, the tensile strength and impact strength of the film are lowered, and when it is higher than the above range, bubble forming stability is lowered, which is not preferable. Further, if the height of the frost line is lower than the above range, the tensile strength of the film is lowered, and if it is higher than the above range, the molding stability of bubbles is lowered, which is not preferable.

The unstretched film formed by the inflation method is then uniaxially stretched in the machine direction (film take-up direction). The roll stretching method is usually employed for the uniaxial stretching, but the uniaxial direction (the take-up direction) may be emphasized by the tubular stretching method. The stretching treatment may be performed in one stage or in multiple stages of two or more stages. The stretching treatment is performed in the range of a temperature 100 ° C. lower than the melting point of the resin composition to a temperature 20 ° C. lower than the melting point, particularly 9 ° C. lower than the melting point of the resin composition.
It is preferable to carry out in the range of 0 ° C. lower temperature to 50 ° C. lower than the melting point. At a temperature lower than this range, stretch unevenness occurs in the film, and at a temperature higher than this range, the porosity of the film tends to decrease. is there.

The draw ratio must be 1.2 to 8 times, and if it is less than this range, the stretched film has insufficient porosity and tensile strength. On the other hand, if the stretching ratio exceeds 8 times, the film will have excessive molecular orientation in the machine direction, and the surface strength of the film will decrease, which is not preferable. The dimensional accuracy of the film can be stabilized by heat treatment after uniaxial stretching, and known surface treatments such as corona treatment and flame treatment can be applied.

The thus-obtained fine pores have an air permeability of 200 to 5000 seconds / 100 ml,
Water pressure resistance 500mmH ₂ O or more, moisture permeability 1000-1
20,000 gH ₂ O / m ² · 24 hr. The synthetic resin porous film or sheet may be bonded to the non-breathable synthetic resin film or sheet in the longitudinal direction.

The non-breathable synthetic resin film or sheet and the synthetic resin porous film or sheet may be joined together by means of heat welding, ultrasonic welding, sewing, adhesion or the like. Such a film or sheet for cultivating fruits and vegetables is used for harvesting 3 to
It is used from 4 months before harvest to cover the ridges and valleys around the roots of woody or herbaceous fruit plants.
A porous film or sheet is used to cover the valleys between the ridges, and a non-breathable film or sheet is used to cover the ridges at the root of the fruit plant. In this way, the water content and respiration rate are adjusted to obtain fruits with high sugar content and acidity.

A nonwoven fabric may be attached to the porous film. Nonwoven fabric is nylon (eg nylon 6, nylon 6
6, nylon 12, etc.) or polyester (for example, polyethylene terephthalate, polybutylene terephthalate, etc.) or polyethylene, with a basis weight of 15 to 30 g /
m ² is used. Further, the embossing point density for fixing the fibers between the non-woven fabrics is about 60 / cm ^{2 to} 150 / cm ² , preferably about 80 / cm ^{2 to} 120 / cm ² . It is also possible to use a non-woven fabric having a light-reflecting ability by vapor-depositing aluminum or the like on the non-woven fabric.

As the polyethylene-based nonwoven fabric, it is preferable to use a fiber having a structure in which a polyester resin is used as a core material and coated with polyethylene. A split cloth made of polyethylene-based split fibers may be attached by a heat fusion method. The split cloth has a basis weight of 10 to 80 g / cm ² and a fiber thickness of 10 to 20.
It is preferably 00 denier, preferably 70 to 700 denier.

Such a porous film and a non-woven fabric or a split cloth are bonded with the following adhesive structure. That is,
For example, there is a method of applying a urethane-based two-component type adhesive in a dot shape with an application area (adhesion area) of 10% to 30% and adhering. Adhesive dots are 3.18 million pieces / m ² -1
About 10 million pieces / m ^{2 and} the diameter at that point is 0.1 to 0.5
It is good to set it to about mm. The dot application of such an adhesive may be performed by, for example, a transfer method using a gravure roll.

In the case of polyethylene-based non-woven fabric or split fabric, it is preferable to heat-bond it to the porous film. It is preferable that the adhesion area be approximately the same as above. Even if a non-woven fabric with many voids is used and the entire surface of the non-woven fabric is welded, the proportion of the adhered portion of the porous film may be within the above range. If the heat-bonded area is too large, the pores of the porous film will collapse, so care must be taken. It may be a three-layer laminated product of a porous film, a split cloth, and a polyethylene-based nonwoven fabric.

According to the laminate having the above-mentioned structure, the surface of the porous film has a very small adhesive portion for bonding the porous film and the non-woven fabric, and the surface of the porous film is affected by the thickness of the porous film. The surface becomes very smooth, and as a result, the printing on the surface can be made extremely clear, and the overall feeling is greatly improved without impairing the air permeability.

The non-woven fabric of the above-mentioned laminated body may be a non-woven fabric produced by various methods such as spunbonded non-woven fabric and needle punched non-woven fabric. Although the transfer method using a gravure roll is exemplified as the method for applying the adhesive for the adhesion of the both, a spray method or the like can also be used. However, as the adhesive used in this case, it is preferable to use, for example, an EVA adhesive, a rubber adhesive, or an acrylic adhesive.

By coating such a film or sheet for cultivating a fruit plant on the ridges and valleys around the root of the fruit plant from 1 to 2 months before harvest to the harvest, it is possible to improve the quality of fruits and vegetables which is the object of the present invention. Can be reached. The quality improvement effect varies depending on the type of fruits and vegetables, but specifically, the sugar content increases,
Prevents fruit cracking and improves color and luster. In the coating method, a non-breathable film or sheet is used to cover the ridges around the root of the fruit plant, and the porous film or sheet is used to cover the valley portion away from the root of the fruit plant. The kind of fruits and vegetables to which the film or sheet for cultivating a fruit plant of the present invention is applied is not particularly limited, and examples thereof include citrus fruits such as mandarin orange and hassaku, apples, pears, peaches, grapes, melons, watermelons and the like.

[0041]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Example 1 Linear low density polyethylene {melt index (M
I): 1.0 g / 10 minutes, flow ratio: 19, density: 0.9
21 g / cm ³ , copolymerization component: 1-butene, copolymerization amount:
10 parts by weight, melting point: 120 ° C.} pulverized into 40 mesh powder, 80 parts by weight and ethylene-propylene copolymer (EPR, EP07P manufactured by Japan Synthetic Rubber Co., Ltd.) pulverized into 40 mesh powder. 20 parts by weight are mixed by stirring in a Henschel mixer, and then 4 parts by weight of dioctyl phthalate as a plasticizer and 2,5-dimethyl-2,5-bis (t-butylperoxy) -3-hexyne as a radical generator. 0.03 parts by weight Add and mix with stirring.

Furthermore, calcium carbonate (average particle size 1.2 μ
m, fatty acid treatment) was added and mixed by stirring. The mixture thus obtained was mixed with a twin-screw kneader DSM-6.
5 (Double Screw Mixer, manufactured by Japan Steel Works, Ltd.) was kneaded and granulated. 40m
Inflation molding with mφ extruder, thickness 70μ
m film. The extrusion conditions are as follows.

[0043]

[Table 1] Cylinder temperature: 170-190-210-2
30 ° C Head, die temperature: 200 ° C Die diameter: 100mm Pulling speed: 8m / min Blow-up ratio: 3 Frost line height: 700mm Folding diameter: 471mm

The film thus obtained was slit in the take-up direction and uniaxially stretched by a roll stretching machine. The stretching conditions were as follows.

[0045]

Stretching temperature: 60 ° C. Stretching speed: 11.0 m / min Film thickness after stretching: 30 μm Physical properties of the obtained porous film are evaluated as follows.

[0046]

TABLE 3 air permeability 1800 seconds / 100ml moisture permeability 3800g / m ² / 24Hr water pressure resistance> 2000 mm H ₂ O tear strength 60 g / 1 sheet moldability ◎ flexibility ◎ stretchability ◎

The physical properties were evaluated as follows. 1) Water vapor transmission rate: According to ASTM E26-66 (E). 2) Tear strength: According to JIS-P-8116, the pulling direction of the film is measured, and the strength per sheet is determined by g. 3) Moldability: It was visually evaluated according to the following criteria. ◎: Bubble stable, no die line ○: 〃 With die line △: Film width fluctuation ×: Unmoldable

4) Flexibility: Feeling by hand, judged by the following criteria. ◎: Extremely soft ○: Soft △: Slightly hard ×: Hard 5) Stretchability ◎: No cutting, uniform stretching, no stretching unevenness ○: No cutting, stretching unevenness, almost no △: No cutting, stretching unevenness, somewhat × : Large uneven cutting or stretching

On the other hand, linear low density polyethylene (grade name: Mitsubishi Polyethylene LL, UA420) MI: 0.8 g /
1, the density was 0.925 g / cm ³ , and the molding machine was an air-cooled inflation molding machine manufactured by Placo Co., Ltd. {extruder water lily diameter 50 mmφ, screw L / D = 28, die diameter 3
50 mmφ (die slit gap 2.2 mm)}, molding temperature is 200 ° C., extrusion amount is 130 k
g / hr, take-up speed 35.5 m / min, blow ratio 3.
0 to form a non-breathable film having a thickness of 20 μm and a width of 1650 mm.

The above-obtained porous film and non-breathable film were applied to a high-ridge type mandarin orange field. The height of the ridges in the field is about 50 cm, and the pitch is about 100 cm. Satsuma mandarin is planted approximately every 100 cm in the longitudinal direction in the center of the ridge. The above-mentioned non-breathable film was applied to the ridge portion by forming an opening in the portion corresponding to the orange tree and forming a slit reaching the opening from the side portion of the film.

The above-mentioned porous film having a width of 150 cm was applied to the valley portion between the ridges. Construction was carried out 3 months before harvesting of oranges in Wenzhou (Qingdao Wenzhou) (August 15). Three months later (November 15th) fruits were harvested and examined for quality. The sugar content was measured by a Brix sugar meter and the water content was measured by a weight loss rate. As a result, the sugar content was 13 degrees and the citric acid content was 0.7.
Met. In addition, the fruit had uniform coloring regardless of the place where the fruit was set.

Comparative Example 1 The non-porous film used in Example 1 was laid as a film for cultivating fruit plants on all ridges and valleys. It was laid three months before the harvest of Satsuma mandarin (Qingdao Wenzhou) (August 15), and three months later (November 15), the fruits were harvested and the quality was investigated. The sugar content was measured with a Brix sugar meter, and the water content was measured with a weight loss rate. As a result, the sugar content was 11 degrees and the citric acid content was 1.2.
Met. Moreover, the coloring of fruits differed depending on the fruit setting site. The coloring of the fruit in the sun was good, but the fruit set in the shade or in the tree was poor in coloring.

[0053]

INDUSTRIAL APPLICABILITY Rainwater is adjusted by the method of the present invention, while gas and water vapor in the soil flow through the porous film surface laid in the valley. In this way, high-quality fruits and vegetables with high sugar content and low citric acid content can be obtained in high yield.

Claims (3)

[Claims] 1. A high ridge type fruit plant cultivation method in which a ridge is formed by cultivating soil on the ground, and a fruit plant is cultivated in the ridge, wherein the ridge surface around the root of the fruit plant is a non-breathable synthetic resin film or sheet A method for cultivating a high-ridge fruit plant, which comprises covering and coating a valley portion between the ridges with a porous film or sheet made of a synthetic resin having air permeability. 2. A synthetic resin porous film or sheet,
Air permeability is 200-5000 seconds / 100ml, water pressure resistance is 5
00 mmH ₂ O or more, water vapor transmission rate of 1000 to 10,000
gH ₂ O / m ² · 24 hr. The method according to claim 1, which is a porous film or sheet made of synthetic resin. 3. A synthetic resin porous film or sheet is prepared by laminating a nylon-based, polyester-based or polyethylene-based nonwoven fabric having a basis weight of 15 to 30 g / m ^{2 on} at least one side with an adhesive area of 10 to 50%. The method according to claim 1 or 2, characterized in that