Patent Publication Number: US-2022211032-A1

Title: Method for producing fruit having improved quality

Description:
TECHNICAL FIELD 
     The present invention relates to a method for producing fruit having improved quality. 
     BACKGROUND ART 
     It is important for producers and dealers of agricultural products to improve the quality of agricultural products. In particular, for fruit trees, people have a large interest in the quality of fruits that are harvests, and therefore, for example, fruits are graded according to the quality; thus, producers seek to have a higher yield of fruits belonging to a higher grade. To date, various methods for improving fruit quality have been developed. Methods described in Patent Literatures 1 and 2 are noted as examples of conventional methods for improving fruit quality. 
     A quality improvement method described in Patent Literature 1 is a method in which a composition containing a corn steep liquor and having nitrogen, phosphoric acid and potassium at a certain ratio is sprayed to leaves of fruit trees, thereby accelerating the coloration of fruits or increasing the sugar content of fruits. 
     A quality improvement method described in Patent Literature 2 is a method in which a plant is irradiated with one or a combination of blue light and red light which are absorbed specifically by chloroplasts of plants, whereby a photosynthetic reaction in the chloroplasts is activated to improve plant quality. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Literature 1: JP 5-43370 A 
         Patent Literature 2: JP 2000-316381 A 
       
    
     SUMMARY OF INVENTION 
     Technical Problems 
     However, in the method described in Patent Literature 1, since the effective application range of the corn steep liquor is limited, applicable plants are limited. Further, when the method described in Patent Literature 1 is used, the ratio between components in the composition containing the corn steep liquor needs to be adjusted according to the purpose of use (e.g., a target effect), and substantial time and energy are required to find an appropriate ratio. 
     Aside from that, since the method described in Patent Literature 2 requires adjustment of irradiation light, this is suitable for the use in indoor cultivation or greenhouse cultivation but unfit for the use in large-scale agricultural fields. 
     The present invention has been made in view of the above circumstances and aims at achieving the following object. 
     An object of the present invention is to solve the problems of the conventional art as above and to provide a method for producing fruit having improved quality, which method is less affected by locational and other limitations and is usable more easily. 
     Solution to Problems 
     The present inventors have conducted an intensive study to attain the above-described object and found that application of nanobubble water to a plant belonging to fruit trees can result in production of fruit having improved quality, and the present invention has been thus completed. 
     That is, the present inventors found that the above-described object can be attained by the following constitution. 
     [1] A method for producing fruit having improved quality, the method comprising application of nanobubble water to a plant belonging to fruit trees.
 
[2] The method for producing fruit having improved quality according to [1], wherein at least one of sprinkling the nanobubble water, supplying a nutrient supply material having the nanobubble water added thereto, and spraying an agrochemical diluted with the nanobubble water is carried out.
 
[3] The method for producing fruit having improved quality according to [1] or [2], wherein the nanobubble water contains bubbles with a modal particle size of 10 to 500 nm.
 
[4] The method for producing fruit having improved quality according to any one of [1] to [3], wherein bubbles contained in the nanobubble water include at least one gas selected from the group consisting of oxygen, nitrogen, carbon dioxide, and ozone.
 
[5] The method for producing fruit having improved quality according to any one of [1] to [4], wherein the nanobubble water contains bubbles in an amount of 1×10 8  to 1×10 10  bubbles/ml.
 
[6] The method for producing fruit having improved quality according to any one of [1] to [5], wherein the nanobubble water contains bubbles with a zeta potential of −50 mV to −30 mV.
 
[7] The method for producing fruit having improved quality according to any one of [1] to [6], wherein the nanobubble water is applied to the plant plural times.
 
[8] The method for producing fruit having improved quality according to any one of [1] to [7], wherein the plant is a rosaceous plant, a vitaceous plant, an ebenaceous plant or a rutaceous plant.
 
[9] The method for producing fruit having improved quality according to any one of [1] to [8], wherein the plant is an apple, a Nashi pear, a pear, a cherry, a grape, a persimmon, a peach or  Citrus unshiu.  
 
[10] The method for producing fruit having improved quality according to any one of [1] to [9], wherein as quality, a sugar content of the fruit is improved.
 
[11] The method for producing fruit having improved quality according to any one of [1] to [10], wherein in cases where fruits are graded into plural grades according to quality, the nanobubble water is applied to the plant to increase a percentage of fruits falling under a high grade category among the plural grades of quality.
 
     Advantageous Effects of Invention 
     The method for producing fruit having improved quality according to the invention can be utilized regardless of, for example, whether it is an indoor or outdoor environment and of the size of the cultivation site. In addition, it is only necessary to apply nanobubble water generated with water and predetermined gas to plants, so that the method does not require much time and effort for adjusting the blending ratio of components of a composition used for quality improvement. That is, the present invention makes it possible to provide a method for producing fruit having improved quality, which method is less affected by locational and other limitations and is usable more easily. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic view showing an example of a nanobubble generating apparatus. 
         FIG. 2  is an image of Nashi pears cultivated in a test area I of Test 1. 
         FIG. 3  is an image of Nashi pears cultivated in a test area II of Test 1. 
         FIG. 4  is an image showing Nashi pears graded as Excellent (right) and Nashi pears graded as Very Good (left). 
         FIG. 5  is an image showing a cherry cultivated in a test area A1 of Test 2 (right) and a cherry cultivated in a test area A2 thereof (left). 
         FIG. 6  is an image showing a peach tree cultivated in a test area C2 of Test 4, especially leaves of the peach tree affected with a peach shot hole disease. 
         FIG. 7  is an image showing, of pears cultivated in a test area D2 of Test 5, a pear damaged by a pest. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is described below in detail. While the constitutional requirements may be described below based on a typical embodiment of the present invention, the present invention is not limited to the embodiment. 
     In the description, a numerical range stated using the form of “(from) . . . to . . . ” should read as a range including the former number as the lower limit value and the latter number as the upper limit value. 
     The method for producing fruit having improved quality according to the invention is a method for producing fruit having improved quality that comprises application of nanobubble water to a plant belonging to fruit trees. 
     The term “method for producing fruit having improved quality” herein refers to a method for producing fruit whose quality is improved compared to fruit obtained by an ordinary fruit production method (i.e., a method that does not involve application of nanobubble water to a plant) and includes, for instance, a method that allows the index used for fruit quality evaluation, such as the sugar content, to be higher than that in the case of using an ordinary production method, or a method that increases the percentage of fruits falling under a high grade category in cases where fruits are graded according to the quality. 
     The term “nanobubble water” refers to water that contains bubbles having a diameter of less than 1 μm, more precisely, water in which nanobubbles are incorporated. In connection with the expression “water in which nanobubbles are incorporated,” water used for generation of nanobubble water (i.e., raw water of nanobubble water; for instance, well water containing impurities) and inevitably containing nanobubbles due to its properties and the like is excluded from the “water in which nanobubbles are incorporated.” 
     The diameter (particle size) of bubbles contained in nanobubble water, and the modal particle size of bubbles and the number of bubbles, both of which are described later, are values obtained by measuring the Brownian motion-moving speed of bubbles in water by a nanoparticle tracking analysis method. In the present description, numeral values obtained by measurement using a nanoparticle analysis system of NanoSight series (manufactured by NanoSight Ltd.) are used. The nanoparticle analysis system of NanoSight series (manufactured by NanoSight Ltd.) can measure the Brownian motion speed of particles and calculate the diameter (particle size) based on the measured speed. The modal particle size can be determined as the mode diameter from the particle size distribution of existing nanoparticles. 
     According to the present invention, by applying nanobubble water to a plant belonging to fruit trees, it is possible to improve fruit quality through relatively easy operation regardless of the cultivation site and the like. 
     Although the reasons of this are not clear for details, the present inventors infer that, for example, application of nanobubble water improves resistance of a plant to diseases and pests, and as a result, fruits in which nutrients are accumulated at the end are to have improved quality. Thus, in the present invention, what is needed to improve fruit quality is only application of nanobubble water, it is not necessary to prepare a special fertilizer or adjust irradiation light, and in addition, the method is not greatly affected by the location conditions, the size and other factors of the cultivation site. Therefore, the present invention makes it possible to improve fruit quality more easily regardless of the location and the like. 
     In the present invention, the fruit quality refers to properties other than the magnitude of size and weight. The fruit quality includes the quality evaluated based on the appearance, such as the shape, the color, and the presence or absence of blemishes, the quality evaluated based on contained components, such as the sugar content (ripeness) and the acidity, and the quality evaluated based on human&#39;s sensibilities, such as the texture and the deliciousness. 
     The fruit quality varies depending on the type of fruits and sometimes varies among producers and locations. In Japan, generally, there is the case that fruits of each type are graded into plural grades including Excellent, Very Good and Good according to the quality or the case that fruits are graded into plural grades ranging from good products to inferior products according to the quality. 
     Grade classifications of fruits are described by taking grade classifications defined for such type of fruits as  Citrus unshiu , cherry, grape, peach, apple, persimmon, Nashi pear, and pear as examples of standards regarding the fruit quality. Those grade classifications described below are only an example and may vary depending on the producer and the location as described above. 
     (Regarding  Citrus unshiu  Quality) 
     The  Citrus unshiu  quality is classified into five grades of “Choicest,” “Excellent,” “Very Good,” “Good” and “Substandard” according to the sugar content (ripeness) as shown in Table 1 below. As shown in the table, applicability conditions of the grades may differ between the varieties. The grade of  Citrus unshiu  is determined in terms of other items (e.g., the shape, the degree of coloring, and the like) than the items shown in Table 1 below in some cases. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Choicest 
                 Excellent 
                 Very Good 
                 Good 
                 Substandard 
               
               
                   
               
             
            
               
                 Early-maturing 
                 Sugar content of 
                 Sugar content of 
                 Sugar content of 
                 Sugar content of 
                 Having 
               
               
                 variety 
                 12 degrees or 
                 11 degrees or 
                 10 degrees or 
                 less than 10 
                 blemishes or 
               
               
                   
                 more 
                 more 
                 more 
                 degrees 
                 cracks 
               
               
                 Aoshima 
                 Sugar content of 
                 Sugar content of 
                 Sugar content of 
                 Sugar content of 
                 Having 
               
               
                   
                 13 degrees or 
                 12 degrees or 
                 11 degrees or 
                 less than 11 
                 blemishes or 
               
               
                   
                 more 
                 more 
                 more 
                 degrees 
                 cracks 
               
               
                   
               
            
           
         
       
     
     (Regarding Cherry Quality) 
     The cherry quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the colored area (that is the area percentage of a colored portion on a fruit and is equivalent to the degree of coloring), the shape, the ripeness and other factors, as shown in Table 2 below. For the grades of cherries, other standards than those shown in Table 2 may be present, and in Test 2 to be described later, the grades are defined with classifications different from those of Table 2 (see Table 18). 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Cherry 
                 Colored area of 70% or 
                 Colored area of 60% or 
                 Colored area of 50% or 
               
               
                   
                 more 
                 more 
                 more 
               
               
                   
                 Ones of the same variety; 
                 Ones of the same variety; 
                 Ones of the same variety; 
               
               
                   
                 having the variety-specific 
                 having the variety-specific 
                 having the variety-specific 
               
               
                   
                 shape, excellent color and 
                 shape, very good color and 
                 shape, good color and 
               
               
                   
                 gloss, and excellent 
                 gloss, and good uniformity 
                 gloss, and good uniformity; 
               
               
                   
                 uniformity and 
                 and appearance; having 
                 no having almost no damage 
               
               
                   
                 appearance; having no 
                 damage caused by 
                 caused by diseases or 
               
               
                   
                 damage caused by 
                 diseases or pests; having 
                 pests; having good 
               
               
                   
                 diseases or pests; having 
                 proper ripeness 
                 ripeness 
               
               
                   
                 proper ripeness at uniform 
                   
                   
               
               
                   
                 ripeness level 
               
               
                   
               
            
           
         
       
     
     (Regarding Grape Quality) 
     The grape quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the shape, the color, the sugar content (ripeness) and other factors as shown in Table 3 below. For the grape quality, applicability conditions of the grades differ depending on the difference in variety or cultivation method (i.e., whether it is greenhouse cultivation or open-field cultivation), as shown in Tables 4 to 7. For the grades of grapes, other standards than those shown in Tables 3 to 7 may be present, and in Test 3 to be described later, the grades are defined with classifications different from those of Tables 3 to 7 (see Table 20). 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Common 
               
            
           
           
               
               
               
            
               
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
               
                 Ones of the same variety; 
                 Ones of the same variety; 
                 Ones of the same variety; 
               
               
                 having a salable shape; 
                 having a salable shape; 
                 haying a salable shape; 
               
               
                 being excellent in the color 
                 being very good in the 
                 being good in the color and 
               
               
                 and gloss, the uniformity 
                 color and gloss, the 
                 gloss, the uniformity of 
               
               
                 of clusters, and the size 
                 uniformity of clusters, and 
                 clusters, and the size and 
               
               
                 and appearance of a grape; 
                 the size and appearance of 
                 appearance of a grape; 
               
               
                 having no damage caused 
                 a grape; having no damage 
                 having almost no damage 
               
               
                 by diseases or pests and 
                 caused by diseases or 
                 caused by diseases or 
               
               
                 no cracking; having the 
                 pests and no cracking; 
                 pests and almost no 
               
               
                 most excellent ripeness 
                 having very good ripeness 
                 cracking; having good taste 
               
               
                 and taste 
                 and taste 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Delaware (Greenhouse, Open-field) 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Taste 
                 Most excellent 
                 Very good 
                 Good 
               
               
                 (ripeness) 
                 (saccharimeter reading of 
                 (saccharimeter reading of 
                 (saccharimeter reading of 
               
               
                   
                 18 degrees or more and pH 
                 18 degrees or more and pH 
                 17 degrees or more and pH 
               
               
                   
                 of 3.2 or more) 
                 of 3.2 or more) 
                 of 3.2 or more) 
               
               
                 Coloring 
                 Most excellent 
                 Almost no difference 
                 Not reaching the Excellent 
               
               
                   
                   
                 between the front and 
                 or Very Good level but 
               
               
                   
                   
                 back sides 
                 having salability 
               
               
                 Shape 
                 Having the most excellent 
                 Having a very good variety- 
                 Not reaching the Excellent 
               
               
                   
                 variety-specific shape 
                 specific shape (with stems 
                 or Very Good level but 
               
               
                   
                 (with stems being not 
                 being slightly seeable 
                 having salability 
               
               
                   
                 seeable even when a 
                 when a cluster of grapes is 
                   
               
               
                   
                 cluster of grapes is laid) 
                 laid; and with lack of up to 
                   
               
               
                   
                   
                 3 grapes) 
                   
               
               
                 Resilience/ 
                 Having the most excellent 
                 Having very good variety- 
                 Not reaching the Excellent 
               
               
                 Size uniformity 
                 variety-specific resilience 
                 specific resilience and size 
                 or Very Good level but 
               
               
                   
                 and size uniformity (grape 
                 uniformity (with slightly 
                 having salability 
               
               
                   
                 size having no variation 
                 insufficient thinning) 
                   
               
               
                   
                 and having uniformity) 
                   
                   
               
               
                 Cracking 
                 No cracking 
                 No cracking 
                 No cracking 
               
               
                 Rusty discoloration 
                 No discoloration 
                 Slightly discolored (up to a 
                 At the third best level 
               
               
                   
                   
                 third of one grape and up 
                 following Very Good (up to 
               
               
                   
                   
                 to 10% of one cluster) 
                 a half of one grape and up 
               
               
                   
                   
                   
                 to 20% of one cluster) 
               
               
                 Bloom 
                 Well-covered with bloom 
                 Slightly inferior 
                 Inferior 
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Damage caused by 
                 No damage 
                 No damage 
                 No damage 
               
               
                 diseases or pests 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Shigyoku ″seedless″ (Greenhouse, Open-field) 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Taste 
                 Most excellent 
                 Very good 
                 Good 
               
               
                 (ripeness) 
                 (saccharimeter reading of 
                 (saccharimeter reading of 
                 (saccharimeter reading of 
               
               
                   
                 17 degrees or more and pH 
                 17 degrees or more and pH 
                 16 degrees or more and pH 
               
               
                   
                 of 3.2 or more) 
                 of 3.2 or more) 
                 of 3.2 or more) 
               
               
                 Coloring 
                 Having the variety-specific 
                 Having the variety-specific 
                 Not reaching the Excellent 
               
               
                   
                 color and gloss and being 
                 color and gloss and being 
                 or Very Good level but 
               
               
                   
                 colored in dark purple color 
                 colored in dark purple color 
                 having salability 
               
               
                   
                 thoroughly even around 
                 in at least two thirds of 
                   
               
               
                   
                 the peduncle 
                 each grape 
                   
               
               
                 Shape 
                 Having excellent 
                 Having compactness 
                 Not reaching the Excellent 
               
               
                 (cluster shape) 
                 compactness (with no gap) 
                 (with a few gaps) 
                 or Very Good level but 
               
               
                   
                   
                   
                 having salability 
               
               
                 Resilience/ 
                 Having the most excellent 
                 Having the most excellent 
                 Not reaching the Excellent 
               
               
                 Size uniformity 
                 variety-specific resilience 
                 variety-specific resilience 
                 or Very Good level but 
               
               
                   
                 and size uniformity of 
                 and size uniformity of 
                 having salability 
               
               
                   
                 grapes (a target weight of 
                 grapes (a target weight of 
                   
               
               
                   
                 one grape is at least 11 g) 
                 one grape is at least 9 g) 
                   
               
               
                 Cracking 
                 No cracking 
                 No cracking 
                 No cracking 
               
               
                 Rusty discoloration/ 
                 Not present 
                 Not very noticeable (with 
                 At the third best level 
               
               
                 Rubbing 
                   
                 grapes each having a 5- 
                 following Very Good 
               
               
                   
                   
                 mm or smaller mark 
                 (with grapes each having a 
               
               
                   
                   
                 accounting for up to 20% 
                 10-mm or smaller mark 
               
               
                   
                   
                 of one cluster) 
                 accounting for up to 30% 
               
               
                   
                   
                   
                 of one cluster) 
               
               
                 Bloom 
                 Well-covered with bloom 
                 Slightly inferior 
                 Inferior 
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Damage caused by 
                 No damage 
                 No damage 
                 No damage 
               
               
                 putrefactive disease 
                   
                   
                   
               
               
                 (e.g., ripe rot) 
                   
                   
                   
               
               
                 Thrips 
                 No damage 
                 No damage 
                 A little damage but having 
               
               
                   
                   
                   
                 salability 
               
               
                 Other damage 
                 No damage 
                 No damage 
                 A little damage but having 
               
               
                 caused by diseases 
                   
                   
                 salability 
               
               
                 or pests 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Wasekaiji, Kaiji (Greenhouse, Open-field) 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Taste (ripeness) 
                 Most excellent 
                 Very good 
                 Good 
               
               
                   
                 (saccharimeter reading of 
                 (saccharimeter reading of 
                   
               
               
                   
                 17 degrees or more) 
                 17 degrees or more) 
                   
               
               
                 Coloring 
                 Having the variety-specific 
                 Having the variety-specific 
                 Not reaching the Excellent 
               
               
                   
                 color and gloss and being 
                 color and gloss, with 
                 or Very Good level but 
               
               
                   
                 colored up to the region 
                 coloring being slightly 
                 having salability 
               
               
                   
                 around the peduncle 
                 inferior to the Excellent 
                   
               
               
                   
                   
                 level 
                   
               
               
                 Shape 
                 Having excellent 
                 Having compactness 
                 Not reaching the Excellent 
               
               
                 (cluster shape) 
                 compactness 
                   
                 or Very Good level but 
               
               
                   
                   
                   
                 having salability 
               
               
                 Resilience/ 
                 Grapes having the variety- 
                 Grapes having slightly 
                 Not reaching the Excellent 
               
               
                 Size uniformity 
                 specific resilience, and 
                 inferior varity-specific 
                 or Very Good level but 
               
               
                   
                 large and uniform size 
                 resilience and uniformity in 
                 having salability 
               
               
                   
                   
                 size 
                   
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Berry shrivel 
                 Not present 
                 Not noticeable (20% or 
                 Not reaching the Excellent 
               
               
                   
                   
                 less) 
                 or Very Good level but 
               
               
                   
                   
                   
                 having salability 
               
               
                 Other damage 
                 No damage 
                 No damage 
                 Having a little damage but 
               
               
                 caused by diseases 
                   
                   
                 having salability 
               
               
                 or pests 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Shine Muscat (Greenhouse, Open-field) 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
               
                 Taste (ripeness) 
                 Most excellent 
                 Very good 
                 Good 
               
               
                   
                 (saccharimeter reading of 
                 (saccharimeter reading of 
                   
               
               
                   
                 18 degrees or more) 
                 18 degrees or more) 
                   
               
               
                 Coloring 
                 Having the variety-specific 
                 Having the variety-specific 
                 Not reaching the Excellent 
               
               
                   
                 color and gloss 
                 color and gloss, and being 
                 or Very Good level but 
               
               
                   
                   
                 discolored due to sunburn 
                 having salability 
               
               
                   
                   
                 but not very noticeable 
                   
               
               
                 Shape 
                 Haying excellent 
                 Having compactness 
                 Not reaching the Excellent 
               
               
                 (cluster shape) 
                 compactness 
                   
                 or Very Good level but 
               
               
                   
                   
                   
                 having salability 
               
               
                 Resilience/ 
                 Grapes having the variety- 
                 Grapes having slightly 
                 Not reaching the Excellent 
               
               
                 Size uniformity 
                 specific resilience, and 
                 inferior variety-specific 
                 or Very Good level but 
               
               
                   
                 large and uniform size 
                 resilience and size 
                 having salability 
               
               
                   
                   
                 uniformity 
                   
               
               
                 Rusty discoloration/ 
                 Not present 
                 Not very noticeable 
                 At the third best level 
               
               
                 Rubbing 
                   
                   
                 following Very Good 
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Other damage 
                 No damage 
                 No damage 
                 No damage 
               
               
                 caused by diseases 
                   
                   
                   
               
               
                 or pests 
               
               
                   
               
            
           
         
       
     
     (Regarding Peach Quality) 
     The peach quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the shape, the color, the sugar content (ripeness) and other factors as shown in Table 8 below. For the peach quality, applicability conditions of the grades differ depending on the difference in cultivation method (i.e., whether it is greenhouse cultivation or open-field cultivation), as shown in Tables 9 and 10. For the grades of peaches, other standards than those shown in Tables 8 to 10 may be present, and in Test 4 to be described later, the grades are defined with classifications different from those of Tables 8 to 10 (see Table 22). 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 Common 
               
            
           
           
               
               
               
            
               
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
               
                 Ones of the same variety; 
                 Ones of the same variety; 
                 Ones of the same variety; 
               
               
                 having the variety-specific 
                 having the variety-specific 
                 having the variety-specific 
               
               
                 shape, excellent color and 
                 shape, very good color and 
                 shape, good color and gloss, 
               
               
                 gloss, and very good 
                 gloss, and good uniformity 
                 and good appearance; having 
               
               
                 uniformity and appearance; 
                 and appearance; having no 
                 almost no damage caused by 
               
               
                 having no damage caused by 
                 damage caused by diseases 
                 diseases or pests; showing 
               
               
                 diseases or pests; showing 
                 or pests; showing proper 
                 good ripeness 
               
               
                 proper ripeness at the 
                 ripeness 
                   
               
               
                 uniform ripeness level 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9 
               
             
            
               
                   
               
               
                 Greenhouse cultivation 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
               
                 Ripeness 
                 One whose variety-specific 
                 Same as Excellent 
                 One whose decolorization of 
               
               
                   
                 base color has been 
                   
                 the base color is slightly less 
               
               
                   
                 decolorized by amount 50% 
                   
                 than ones of Excellent and 
               
               
                   
                 and which is not overripe 
                   
                 Very Good and which is not 
               
               
                   
                   
                   
                 unripe 
               
               
                 Color and gloss 
                 One whose 30% or more has 
                 One having a coloring 
                 One having a coloring 
               
               
                 (Coloring) 
                 been colored from the fruit 
                 percentage of 20% or more, 
                 percentage of 20% or less 
               
               
                   
                 tip and having the variety- 
                 being colored from the fruit 
                 and being colored from the 
               
               
                   
                 specific color and gloss 
                 tip, and having the variety- 
                 fruit tip 
               
               
                   
                 (For reference: In cases 
                 specific color and gloss 
                   
               
               
                   
                 that a peach is of “25 
                 (For reference: In cases 
                   
               
               
                   
                 peaches per box” type, when 
                 that a peach is of “25 
                   
               
               
                   
                 three fingers are put along 
                 peaches per box” type, when 
                   
               
               
                   
                 the seam, a colored portion is 
                 a thumb is put along the 
                   
               
               
                   
                 largely out of those fingers) 
                 seam, a colored portion is 
                   
               
               
                   
                   
                 partly out of the thumb) 
                   
               
               
                 Shape 
                 Having a normal shape 
                 Having a slightly abnormal 
                 Having the shape being not 
               
               
                 (cluster shape) 
                   
                 shape 
                 remarkably abnormal 
               
               
                 Leaf rubbing 
                 No mark above the equator/ 
                 Having at most three linear 
                 Having a most three marks 
               
               
                   
                 On one fruit, having at most 
                 marks of up to 1 cm on one 
                 of up to 1 cm square size on 
               
               
                   
                 one linear mark of up to 1 cm 
                 fruit, the marks being not 
                 one fruit 
               
               
                   
                 below the equator, the mark 
                 remarkably noticeable, where 
                   
               
               
                   
                 being unnoticeable 
                 at most one mark is allowed 
                   
               
               
                   
                   
                 above the equator 
                   
               
               
                 Cracking 
                 No cracking 
                 No cracking 
                 Slightly cracked to the extent 
               
               
                   
                   
                   
                 it would not trigger rot 
               
               
                 Pit split 
                 One whose pit split is hardly 
                 One having slightly poor 
                 One equivalent to Good, 
               
               
                   
                 recognizable from the 
                 appearance due to pit split, 
                 having the stalk, with a small 
               
               
                   
                 appearance 
                 and no cracking at the stalk 
                 hole recognizable 
               
               
                   
                 One in which the stalk may 
                 portion 
                   
               
               
                   
                 have come off but a skin in 
                   
                   
               
               
                   
                 the stalk portion is not 
                   
                   
               
               
                   
                 peeled, and having a trace of 
                   
                   
               
               
                   
                 the stalk 
                   
                   
               
               
                 Sunburn 
                 No sunburn 
                 No sunburn 
                 Not very noticeable 
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Stem pressing 
                 One in which a mark of stem 
                 Same as Excellent 
                 Same as Excellent 
               
               
                   
                 pressing at the stalk portion 
                   
                   
               
               
                   
                 is smaller than the width of a 
                   
                   
               
               
                   
                 little finger and not 
                   
                   
               
               
                   
                 associated with overripeness; 
                   
                   
               
               
                   
                 however, this does not apply 
                   
                   
               
               
                   
                 to the other region than the 
                   
                   
               
               
                   
                 stalk portion 
                   
                   
               
               
                 Scab 
                 No black spot 
                 No black spot above the 
                 Having black spots not 
               
               
                   
                   
                 equator 
                 clustering on a fruit and not 
               
               
                   
                   
                 Having up to five black spots 
                 resulting in unpleasant 
               
               
                   
                   
                 below the equator, those 
                 appearance 
               
               
                   
                   
                 spots being scattered and 
                   
               
               
                   
                   
                 not clustering 
                   
               
               
                 Other damage 
                 No damage 
                 No damage 
                 No damage 
               
               
                 caused by diseases 
                   
                   
                   
               
               
                 or pests 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 Open-field cultivation 
               
            
           
           
               
               
               
               
            
               
                   
                 Excellent 
                 Very good 
                 Good 
               
               
                   
               
               
                 Ripeness 
                 One whose variety-specific 
                 Same as Excellent 
                 One whose decolorization of 
               
               
                   
                 base color has been 
                   
                 the base color is slightly less 
               
               
                   
                 decolorized by about 50% 
                   
                 than ones of Excellent and 
               
               
                   
                 and which is not overripe 
                   
                 Very Good and which is not 
               
               
                   
                   
                   
                 unripe 
               
               
                 Color and gloss 
                 One whose 40% or more has 
                 One having a coloring 
                 Same as Very Good 
               
               
                 (Coloring) 
                 been colored from the fruit 
                 percentage of 20% or more, 
                   
               
               
                   
                 tip and having the variety- 
                 being colored from the fruit 
                   
               
               
                   
                 specific color and gloss 
                 tip, and having the variety- 
                   
               
               
                   
                 (For reference: In cases 
                 specific color and gloss 
                   
               
               
                   
                 that a peach is of type “25 
                 (For reference: In cases 
                   
               
               
                   
                 peaches per box”, when 
                 that a peach is of type “25 
                   
               
               
                   
                 three fingers are put along 
                 peaches per box”, when a 
                   
               
               
                   
                 the seam, a colored portion is 
                 thumb is put along the seam, 
                   
               
               
                   
                 largely out of those fingers) 
                 a colored portion is partly out 
                   
               
               
                   
                   
                 of the thumb) 
                   
               
               
                 Shape 
                 Having a normal shape 
                 Having a slightly abnormal 
                 Having the shape being not 
               
               
                 (cluster shape) 
                   
                 shape 
                 remarkably abnormal 
               
               
                 Leaf rubbing 
                 No mark above the equator/ 
                 Having at most three linear 
                 Having a most three marks 
               
               
                   
                 On one fruit, having at most 
                 marks of up to 1 cm on one 
                 of up to 1 cm square size on 
               
               
                   
                 one linear mark of up to 1 cm 
                 fruit, the marks being not 
                 one fruit 
               
               
                   
                 below the equator, the mark 
                 remarkably noticeable, where 
                   
               
               
                   
                 being unnoticeable 
                 at most one mark is allowed 
                   
               
               
                   
                   
                 above the equator 
                   
               
               
                 Cracking 
                 No cracking 
                 No cracking 
                 Slightly cracked to the extent 
               
               
                   
                   
                   
                 it would not trigger rot 
               
               
                 Pit split 
                 One in which pit split is 
                 One having slightly poor 
                 One equivalent to Very Good, 
               
               
                   
                 hardly recognizable from the 
                 appearance due to pit split, 
                 having the stalk, with a small 
               
               
                   
                 appearance 
                 and no cracking at the stalk 
                 hole recognizable 
               
               
                   
                 One in which the stalk may 
                 portion 
                   
               
               
                   
                 have come off but a skin in 
                   
                   
               
               
                   
                 the stalk portion is not 
                   
                   
               
               
                   
                 peeled, and having a trace of 
                   
                   
               
               
                   
                 the stalk 
                   
                   
               
               
                 Sunburn 
                 No sunburn 
                 No sunburn 
                 Not very noticeable 
               
               
                 Dirt 
                 No dirt 
                 No dirt 
                 No dirt 
               
               
                 Stem pressing 
                 One in which a mark of stem 
                 Same as Excellent 
                 Same as Excellent 
               
               
                   
                 pressing at the stalk portion 
                   
                   
               
               
                   
                 is smaller than the width of a 
                   
                   
               
               
                   
                 little finger and not 
                   
                   
               
               
                   
                 associated with overripeness; 
                   
                   
               
               
                   
                 however, this does not apply 
                   
                   
               
               
                   
                 to the other region than the 
                   
                   
               
               
                   
                 stalk portion 
                   
                   
               
               
                 Scab 
                 No black spot 
                 No black spot above the 
                 Having black spots not 
               
               
                   
                   
                 equator 
                 clustering on a fruit and not 
               
               
                   
                   
                 Having up to five black spots 
                 resulting in unpleasant 
               
               
                   
                   
                 below the equator, those 
                 appearance 
               
               
                   
                   
                 spots being scattered and 
                   
               
               
                   
                   
                 not clustering 
                   
               
               
                 Other damage 
                 No damage 
                 No damage 
                 No damage 
               
               
                 caused by diseases 
                   
                   
                   
               
               
                 or pests 
               
               
                   
               
            
           
         
       
     
     (Regarding Apple Quality) 
     The apple quality is classified into four grades of “Excellent,” “Very Good,” “Good” and “Average” according to the coloring, the shape and other factors as shown in Table 11 below. For the grades of apples, other conditions than those shown in Table 11 may be present, and in Test 6 to be described later, the grades are defined with conditions different from those of Table 11 (see Table 25). 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 11 
               
               
                   
               
             
            
               
                   
                 Excellent 
                 Very Good 
                 Good 
                 Average 
               
               
                   
               
               
                 Standards for fruit 
                 Ones of the same variety; 
                 Ones of the same variety; 
                 Ones of the same variety; 
                 Not reaching 
               
               
                 grading 
                 having the variety-specific 
                 having the variety-specific 
                 having the variety-specific 
                 the Excellent, 
               
               
                   
                 shape; having at least the 
                 shape; having at least the 
                 shape; having at least the 
                 Very Good or 
               
               
                   
                 color and gloss percentage 
                 color and gloss percentage 
                 color and gloss percentage 
                 Good level but 
               
               
                   
                 specified in the appendix 
                 specified in the appendix 
                 specified in the appendix 
                 having 
               
               
                   
                 table; having no damage 
                 table; having no damage 
                 table; having no damage 
                 salability 
               
               
                   
                 caused by diseases or pests, 
                 caused by diseases or pests, 
                 caused by diseases or pests, 
                   
               
               
                   
                 as well as no other types of 
                 as well as no other types of 
                 as well as no other types of 
                   
               
               
                   
                 damage; having the most 
                 damage; having very good 
                 damage; with size uniformity 
                   
               
               
                   
                 excellent size uniformity and 
                 size uniformity and ripeness 
                 and ripeness following Very 
                   
               
               
                   
                 ripeness 
                   
                 Good 
                   
               
               
                 Coloring rate 
                 Having at least the color and 
                 Having at least the color and 
                 Having at least the color and 
                   
               
               
                   
                 gloss percentage specified in 
                 gloss percentage specified in 
                 gloss percentage specified in 
                   
               
               
                   
                 the appendix table and 
                 the appendix table and 
                 the appendix table and 
                   
               
               
                   
                 taking on excellent ripe color 
                 taking on very good ripe color 
                 taking on the third best ripe 
                   
               
               
                   
                   
                   
                 color following Very Good 
                   
               
               
                 Shape 
                 Having an excellent variety- 
                 Having a very good variety- 
                 At the third best level 
                   
               
               
                   
                 specific shape 
                 specific shape 
                 following Very Good 
                   
               
               
                 Russeting at or 
                 Having russeting around the 
                 Having russeting extending 
                 Having russeting extending 
                   
               
               
                 around the stalk 
                 stalk but not noticeable 
                 up to the shoulder part, 
                 up to the shoulder part and 
                   
               
               
                 cavity 
                   
                 having a linear shape, and 
                 being larger than 10 yen coin 
                   
               
               
                   
                   
                 being larger than 10 yen coin 
                 size 
                   
               
               
                   
                   
                 size. 
                   
                   
               
               
                 Other russeting 
                 No russeting but having 
                 Having russeting that may be 
                 Having russeting that 
                   
               
               
                   
                 russeting spreading below 
                 present even above the 
                 occupies ⅓ or less of the 
                   
               
               
                   
                 the equator on the fruit 
                 equator on the fruit surface 
                 fruit surface and is not 
                   
               
               
                   
                 surface, which is not 
                 but spreads, occupies ⅕ or 
                 remarkable even when 
                   
               
               
                   
                 noticeable 
                 less in total, and is not 
                 present above the equator 
                   
               
               
                   
                   
                 noticeable 
                   
                   
               
               
                 Sunburn 
                 No sunburn 
                 Having a portion of at most 2 
                 Having sunburn occupying 
                   
               
               
                   
                   
                 cm diameter (1 yen coin) 
                 ⅕ or less of the fruit 
                   
               
               
                   
                   
                 colored into pale pink 
                 surface but not remarkable, 
                   
               
               
                   
                   
                   
                 where browned ones are 
                   
               
               
                   
                   
                   
                 excluded 
                   
               
               
                 Scale insect 
                 No scale insect 
                 No scale insect 
                 Having a little damage and 
                   
               
               
                   
                   
                   
                 having salability 
                   
               
               
                 Absence of the 
                 Having the stalk 
                 One whose stalk has come 
                 One whose stalk has come 
                   
               
               
                 stalk 
                   
                 off but whose color and 
                 off but whose color and 
                   
               
               
                   
                   
                 gloss are graded as Excellent 
                 gloss are graded as Very 
                   
               
               
                   
                   
                   
                 Good 
                   
               
               
                 Upside-down apple 
                 No upside-down one 
                 No upside-down one 
                 Not remarkable 
                   
               
               
                 Damage caused by 
                 No damage 
                 No damage 
                 Slightly damaged and having 
                   
               
               
                 diseases or pests 
                   
                   
                 salability 
                   
               
               
                 Blemish damage 
                 No damage 
                 No damage 
                 Not remarkable 
               
               
                   
               
            
           
           
               
            
               
                 Appendix table Color and gloss percentage (Coloring including ripe color) 
               
            
           
           
               
               
            
               
                   
                 Grade 
               
            
           
           
               
               
               
               
            
               
                 Item 
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
               
                 Tsugaru 
                 40% or more 
                 20% or more 
                 At least 
               
               
                   
                   
                   
                 slightly colored 
               
               
                 Fuji 
                 80% or more 
                 60% or more 
                 40% or more 
               
               
                 Senshu 
                   
                   
                   
               
               
                 Yoko 
                 90% or more 
                 70% or more 
                 50% or more 
               
               
                   
               
            
           
         
       
     
     (Regarding Persimmon Quality) 
     The persimmon quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the shape, the color and other factors as shown in Tables 12 and 13 below. For the persimmon quality, applicability conditions of the grades may differ between varieties. 
     
       
         
           
               
             
               
                 TABLE 12 
               
             
            
               
                   
               
               
                 Common 
               
            
           
           
               
               
               
            
               
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
               
                 Ones of the same  
                 Ones of the same  
                 Ones of the same  
               
               
                 variety; having the  
                 variety; having the  
                 variety; having the  
               
               
                 variety-specific shape,  
                 variety-specific shape,  
                 variety-specific shape,  
               
               
                 excellent color and  
                 very good color and  
                 good color and gloss,  
               
               
                 gloss, and very good  
                 gloss, and good  
                 and good uniformity;  
               
               
                 uniformity and  
                 uniformity and  
                 having almost no  
               
               
                 appearance; having no  
                 appearance; having no  
                 damage caused by  
               
               
                 damage caused by  
                 damage caused by  
                 diseases or pests;  
               
               
                 diseases or pests;  
                 diseases or pests;  
                 showing proper  
               
               
                 showing proper  
                 showing proper ripeness 
                 ripeness 
               
               
                 ripeness at the uniform  
                   
                   
               
               
                 ripeness level 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                 TABLE 13 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Shape 
                 Having the variety-specific 
                 Having minor depression in a 
                 Not reaching the Excellent or 
               
               
                   
                 shape, with minor defects of 
                 fruit tip region, with 
                 Very Good level but having 
               
               
                   
                 fruit shape due to lack of 
                 unremarkable defects of fruit 
                 salability 
               
               
                   
                 seeds or other reasons 
                 shape due to lack of seeds or 
                   
               
               
                   
                   
                 other reasons 
                   
               
               
                 Color and gloss 
                 One in orange yellow color and 
                 One in orange yellow color, 
                   
               
               
                   
                 colored up to the region 
                 with nonuniform coloring/Or 
                   
               
               
                   
                 around the calyx 
                 one in yellow color and colored 
                   
               
               
                   
                 (For reference: The fruit color 
                 up to the region around the 
                   
               
               
                   
                 according to a color chart is 5 
                 calyx 
                   
               
               
                   
                 to 6 at or around the fruit tip 
                 (For reference: The fruit color 
                   
               
               
                   
                 region) 
                 according to a color chart is 4 
                   
               
               
                   
                   
                 at or around the fruit tip 
                   
               
               
                   
                   
                 region) 
                   
               
               
                 Sooty mold 
                 No damage 
                 Having damage only around 
                   
               
               
                   
                   
                 the calyx and not noticeable 
                   
               
               
                 Scale insect 
                 No damage 
                 No damage 
                   
               
               
                 Other damage 
                 No damage 
                 No damage 
                   
               
               
                 caused by 
                   
                   
                   
               
               
                 diseases or pests 
                   
                   
                   
               
               
                 Blemish damage 
                 No damage 
                 In the case of having damage 
                   
               
               
                   
                   
                 such as stem rubbing, the 
                   
               
               
                   
                   
                 damage occupying 5% or less 
                   
               
               
                   
                   
                 of the fruit surface in total 
                   
               
               
                 Calyx gap 
                 One in which no gap is 
                 One in which a gap at the 
                   
               
               
                   
                 recognizable at the calyx 
                 calyx attachment portion is 
                   
               
               
                   
                 attachment portion 
                 not remarkable 
                   
               
               
                 Other deficiencies 
                 One in which deficiencies 
                 One in which deficiencies 
                   
               
               
                   
                 such as sunburn, 
                 such as sunburn, 
                   
               
               
                   
                 agrichemical-induced damage 
                 agrichemical-induced damage 
                   
               
               
                   
                 and other damage occupy 5% 
                 and other damage occupy 10% 
                   
               
               
                   
                 or less of the fruit surface in 
                 or less of the fruit surface in 
                   
               
               
                   
                 total and are not noticeable 
                 total and are not remarkable 
                   
               
               
                   
                 (one not contaminated by 
                 (one slightly contaminated by 
                   
               
               
                   
                 Bordeaux mixture) 
                 Bordeaux mixture) 
                   
               
               
                 Bloom 
                 Well-covered with bloom 
                 Slightly inferior 
               
               
                   
               
            
           
         
       
     
     (Regarding Nashi Pear Quality) 
     The Nashi pear quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the shape, the color, the ripeness and other factors as shown in Table 14 below. For the quality of Nashi pears cultivated in greenhouses, “Average” is added to the foregoing three grades, and thus, the quality is classified into four grades as shown in Table 15 below. 
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 Common 
               
            
           
           
               
               
               
            
               
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
               
                 Ones of the same  
                 Ones of the same  
                 Ones of the same  
               
               
                 variety; having the  
                 variety: having the  
                 variety; having the  
               
               
                 variety-specific shape;  
                 variety-specific shape;  
                 variety-specific shape;  
               
               
                 having no damage  
                 having no damage  
                 having almost no  
               
               
                 caused by diseases or  
                 caused by diseases or  
                 damage caused by  
               
               
                 pests; having the most  
                 pests: having color and  
                 diseases or pests;  
               
               
                 excellent color and  
                 gloss and ripeness  
                 having color and gloss  
               
               
                 gloss and ripeness 
                 slightly inferior to the  
                 and ripeness slightly  
               
               
                   
                 Excellent level 
                 inferior to the Very  
               
               
                   
                   
                 Good level 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
             
            
               
                   
               
               
                 Greenhouse cultivation 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Excellent 
                 Very Good 
                 Good 
                 Average 
               
               
                   
               
               
                 Color and gloss/ 
                 Having the variety-specific 
                 Having the variety-specific 
                 At the third best level 
                 Not reaching 
               
               
                 Shape 
                 color and gloss and shape 
                 color and gloss and shape 
                 following Very Good 
                 the Excellent, 
               
               
                   
                 and the most excellent 
                 and very good quality 
                   
                 Very Good or 
               
               
                   
                 quality 
                   
                   
                 Good level 
               
               
                 Russeting/ 
                 Having russeting or 
                 Not remarkable 
                 Not unpleasant 
                 but having 
               
               
                 Dappling 
                 dappling below the equator 
                   
                   
                 salability 
               
               
                   
                 and not noticeable 
                   
                   
                   
               
               
                 Sunburn 
                 Sunburned below the 
                 Not remarkable 
                 Not unpleasant 
                   
               
               
                   
                 equator and not noticeable 
                   
                   
                   
               
               
                 Damage caused by 
                 No damage 
                 No damage 
                 Slightly damaged and 
                   
               
               
                 diseases or pests 
                   
                   
                 having salability 
                   
               
               
                 Blemish damage 
                 No damage 
                 No damage 
                 Having minor damage  
                   
               
               
                   
                   
                   
                 such as stem rubbing 
                   
               
               
                 Absence of stalk 
                 Having the stalk 
                 One whose stalk has come 
                 One whose stalk has  
                   
               
               
                   
                   
                 off but graded as Excellent 
                 come off but graded as  
                   
               
               
                   
                   
                 in other factors 
                 Very Good in other  
                   
               
               
                   
                   
                   
                 factors 
               
               
                   
               
            
           
         
       
     
     (Regarding Pear Quality) 
     The pear quality is classified into three grades of “Excellent,” “Very Good” and “Good” according to the shape, the color and other factors as shown in Table 16 below. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 16 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Shape 
                 Having the variety-specific 
                 Having the variety-specific 
                 Not reaching  
               
               
                   
                 properties and the most 
                 properties and good quality 
                 the Excellent  
               
               
                   
                 excellent quality 
                   
                 or Very Good  
               
               
                 Color and gloss/ 
                 Having the variety-specific 
                 Having the variety-specific 
                 level but having  
               
               
                 Ripeness 
                 properties and good 
                 properties and good 
                 salability 
               
               
                   
                 uniformity 
                 uniformity 
                   
               
               
                   
                 (unripe/overripe ones 
                 (unripe/overripe ones 
                   
               
               
                   
                 excluded) 
                 excluded) 
                   
               
               
                 Uniformity 
                 Not including one belonging 
                 Same as the left 
                   
               
               
                   
                 to a different size category 
                   
                   
               
               
                 Sunburn 
                 Not noticeable 
                 Not remarkable 
                   
               
               
                 Damage caused by 
                 No damage 
                 No damage 
                   
               
               
                 diseases or pests 
                   
                   
                   
               
               
                 Absence of the stalk 
                 Having the stalk 
                 Having the stalk 
                   
               
               
                 Blemish damage 
                 Not having blemish damage 
                 Slightly having blemish 
                   
               
               
                   
                 such as sting damage or 
                 damage such as sting 
                   
               
               
                   
                 bumping damage 
                 damage or bumping damage 
                   
               
               
                 Russeting 
                 Not remarkable 
                 At the second best level 
                   
               
               
                   
                   
                 following Excellent 
               
               
                   
               
            
           
         
       
     
     while the quality standards of fruits differ among varieties as described above, according to the present invention, the application of nanobubble water makes it possible to improve the quality of various fruits, specifically increase the percentage of fruits falling under a high grade category among plural grades of quality for each type of fruit, for instance, increase the percentage of fruits falling under the “Excellent” category or the “Choicest” category that is higher in grade than “Excellent” (hereinafter also called “excellent product percentage”) (see Examples to be described later). That is, the use of the production method of the invention can increase the excellent product percentage of fruits compared to usual production methods (i.e., production methods not using nanobubble water). 
     For reference, the excellent product percentages obtained with usual production methods are shown for the fruits listed below. However, the values below are reference values of the excellent product percentage and, needless to say, the excellent product percentage may vary depending on the variety, the cultivation location, the grower and other factors. 
       Citrus unshiu  (variety: Aoshima) The percentage of Choicest: 20%, the percentage of Excellent: 50% 
     Cherry (variety: Sato Nishiki) The percentage of Choicest: 40%, the percentage of Excellent: 70% 
     Grape (variety: Kyoho) 80% 
     Peach 10% The percentage of Choicest: 10%, the percentage of Excellent: 60% 
     Apple (variety: Fuji) The percentage of Choicest: 10%, the percentage of Excellent: 60% 
     Nashi pear 60% 
     Pear 70% 
     Aside from that, while the quality standards differ among varieties as described above, for the sugar content which is one item of quality evaluation for respective fruits, common improvements can be made across varieties owing to the present invention (see Examples described later). That is, the use of the production method of the invention can improve (increase) the sugar content of fruits as the quality compared to usual production methods (i.e., production methods not using nanobubble water). 
     For reference, the sugar contents obtained with usual production methods are shown for the fruits listed below. However, the values below are reference values of typical sugar contents of the respective fruits and, needless to say, the sugar content may vary depending on the variety, the cultivation season, the cultivation location and other factors. 
       Citrus unshiu  (variety: Aoshima) 11 degrees 
     Cherry (variety: Sato Nishiki) 14 degrees 
     Grape (variety: Kyoho) 18 degrees 
     Peach 13 degrees 
     Apple (variety: Fuji) 15 degrees 
     Persimmon 15 degrees 
     Nashi pear 14 degrees 
     Pear 15 degrees 
     In the present invention, the modal particle size of bubbles contained in the nanobubble water is preferably from 10 to 500 nm and more preferably from 30 to 300 nm because a fruit quality improving effect is further increased, and even more preferably from 70 to 130 nm because, in particular, bubbles may remain for a longer period of time. 
     The gas constituting bubbles contained in the nanobubble water is not particularly limited but is preferably a gas other than hydrogen from the view point of a longtime existence in water. Specific examples of the gas include air, oxygen, nitrogen, fluorine, carbon dioxide, and ozone. 
     Among these, it is preferable to contain at least one gas selected from the group consisting of oxygen, nitrogen, carbon dioxide and ozone because the fruit quality improving effect is further increased, and it is more preferable to contain oxygen and/or carbon dioxide because bubbles can remain for a longer period of time. 
     Here, the expression “contain oxygen and/or carbon dioxide” means containing oxygen and/or carbon dioxide at a higher concentration than the oxygen concentration in air. The same applies to nitrogen and ozone. The concentration of oxygen is preferably not less than 30 vol % of bubbles and more preferably more than 50 volt and not more than 100 vol %. The concentration of carbon dioxide is preferably not less than 1 volt of bubbles and more preferably more than 10 vol % and not more than 100 volt. 
     The nanobubble water contains bubbles in an amount of preferably 1×10 8  to 1×10 10  bubbles/ml because the fruit quality improving effect is further increased, and more preferably more than 1×10 8  bubbles/ml and less than 1×10 10  bubbles/ml and even more preferably 5×10 8  to 5×10 9  bubbles/mi because, particularly, the bubble generation time and the bubble remaining property are well balanced. 
     The zeta potential of bubbles contained in the nanobubble water is preferably a negative value and more preferably a potential of not more than −20 mV because the fruit quality improving effect is further increased, and even more preferably −50 mV to −30 mV for the purpose of, in particular, increasing the effect of controlling damage caused by diseases or pests. The value of zeta potential is known to vary depending on the type of bubbles, and it is further preferable that the zeta potential be lower (on a more negative side) than the zeta potential of bubbles constituted of air. The zeta potential is measured by, for instance, microscopic electrophoresis and can be measured with a known zeta potential measurement device employing this method (one example of such a measurement device is “Zata View” manufactured by MicrotracBEL Corp.). 
     The nanobubble water may further contain a component other than water and bubbles. 
     Exemplary methods of generating the nanobubble water include a static mixer method, a venturi method, a cavitation method, a vapor condensation method, an ultrasonic method, a swirling flow method, a pressurized dissolution method, and a fine pore method. 
     The method for producing fruit having improved quality according to the invention may include a generation step of generating the nanobubble water prior to application of the nanobubble water. That is, the method for producing fruit having improved quality according to the invention may include a generation step in which water is introduced from a water source such as a water storage tank, a well or agricultural water into a nanobubble generating apparatus to thereby generate nanobubble water and an application step in which the generated nanobubble water is applied to a plant. 
     In the foregoing generation step, exemplary techniques of introducing water from a water source into a nanobubble generating apparatus include a technique in which water drawn from a water source using a tub, a pump or another means is supplied to the nanobubble generating apparatus. Another technique thereof is a technique in which a flow path installed between a water source and a nanobubble generating apparatus is connected to the nanobubble generating apparatus and water is directly supplied from the flow path to the nanobubble generating apparatus. 
     As an apparatus used for generating the nanobubble water, it is favorable to use an apparatus that does not intentionally generate a radical, and a specific example thereof is a nanobubble generating apparatus described in paragraphs [0080] to [0100] of JP 2018-15715 A. The contents of the above reference are incorporated in the present description. 
     Except for the apparatus described in the above patent publication, another example of an apparatus capable of generating nanobubble water is an ultrafine bubble generating apparatus shown in  FIG. 1  including a liquid discharger that discharges water, a gas incorporating device that pressurizes gas and incorporates the gas into the water discharged from the liquid discharger, and an ultrafine bubble generator that allows the water having the gas incorporated therein to pass through an inside of the ultrafine bubble generator to generate ultrafine bubbles in the water, wherein, between the liquid discharger and the ultrafine bubble generator, the gas incorporating device pressurizes gas and incorporates the gas into a liquid being in a pressurized state and flowing toward the ultrafine bubble generator. 
     A nanobubble generating apparatus  10  shown in  FIG. 1  includes therein a liquid discharger  30 , a gas incorporating device  40  and a nanobubble generating nozzle  50 . 
     The liquid discharger  30  constituted of a pump draws in raw water of nanobubble water (e.g., well water) and discharges the raw water. The gas incorporating device  40  includes a vessel  41  in which compressed gas is enclosed, and a substantially cylindrical gas incorporating device body  42 . The gas incorporating device  40  introduces the compressed gas in the vessel  41  into the gas incorporating device body  42  while allowing the water discharged from the liquid discharger  30  to flow inside the gas incorporating device body  42 . Consequently, gas-incorporated water is generated in the gas incorporating device body  42 . 
     The nanobubble generating nozzle  50  generates nanobubbles in the gas-incorporated water according to the principle of pressurized dissolution when the gas-incorporated water passes through the inside of the nanobubble generating nozzle  50 , and for the structure thereof, the same structure as that of the nanobubble generating nozzle described in JP 2018-15715 A may be employed. Nanobubble water generated in the nanobubble generating nozzle  50  is ejected from a tip end of the nanobubble generating nozzle  50 , then flows out the nanobubble generating apparatus  10 , and is delivered to a predetermined destination via a flow path that is not shown. 
     As described above, between the liquid discharger  30  and the nanobubble generating nozzle  50  in the nanobubble generating apparatus  10 , the gas incorporating device  40  incorporates compressed gas into water (raw water) being in a pressurized state and flowing toward the nanobubble generating nozzle  50 . Owing to this configuration, defects such as cavitation that may occur when gas is incorporated into water on the intake side (suction side) of the liquid discharger  30  can be avoided. Besides, since gas in a pressurized (compressed) state is incorporated into water, gas can be incorporated into water against the water pressure at the place where the gas is incorporated. Accordingly, gas can be appropriately incorporated into water without particularly generating a negative pressure at the place where the gas is incorporated. 
     In addition, the liquid discharger  30  is connected on the suction side thereof with the flow path of water supplied from a water source such as a well or a water tap, and the pressure of the water flowing from the upstream side of the liquid discharger  30  into the liquid discharger  30  in the flow path (i.e., the water pressure on the suction side) is preferably a positive pressure. When this is the case, the above-described configuration is more effective. More specifically, when the water pressure (the suction pressure) on the upstream side of the liquid discharger  30  is a positive pressure, gas is to be incorporated into water on the downstream side of the liquid discharger  30 , and this further emphasizes the significance of the configuration of the nanobubble generating apparatus  10  capable of appropriately incorporating gas into water also on the downstream side of the liquid discharger  30 . 
     Water (raw water) used to generate the nanobubble water is not particularly limited, and use can be made of, for example, rainwater, tap water, well water, surface water, agricultural water and distilled water. Raw water may be subjected to another treatment before being used to generate nanobubble water. Examples of such another treatment include pH adjustment, precipitation, filtration and disinfection (sterilization). Specifically, when agricultural water is used for instance, agricultural water having been subjected to precipitation and/or filtration may typically be used. 
     In the present invention, a mode of applying the nanobubble water to a plant varies depending on the plant cultivation method and thus is not particularly limited, and examples thereof include a mode where the nanobubble water is sprinkled in the soil culture, the nutrient-solution soil culture (irrigation and fertilization culture) or the like (the nanobubble water is irrigated in the case of nutrient-solution soil culture). In this case, a specific water sprinkling method is not particularly limited, and examples thereof include a method involving spraying nanobubble water over the whole of a plant, a method involving spraying nanobubble water over a part (e.g., stems or leaves) of a plant, and a method involving spraying nanobubble water over soil in which a plant is planted. 
     As the mode of applying the nanobubble water to a plant, another conceivable mode is a mode where a nutrient supply material having the nanobubble water added thereto is supplied in the soil culture, the nutrient-solution soil culture or the like. Examples of the “nutrient supply material having the nanobubble water added thereto” include a culture solution generated using the nanobubble water, a fertilizer fermented using the nanobubble water, and a nutritional supplement diluted with the nanobubble water. The method of supplying the nutrient supply material is not particularly limited, and examples thereof include a method involving sprinkling the material to soil in which a plant is planted, a method involving pouring the material to the whole of a plant, a method involving applying the material to a part (e.g., stems or leaves) of a plant, and a method involving supplying a culture solution at the time of irrigation. 
     As the mode of applying the nanobubble water to a plant, still another conceivable mode is a mode where an agrochemical diluted with the nanobubble water is sprayed in the soil culture. Examples of an agrochemical spraying method include a method involving spraying the agrochemical over the whole of a plant and a method involving spraying water over a part (e.g., stems or leaves) of a plant. 
     The mode of applying the nanobubble water to a plant is also applicable to other cultivation methods (e.g., hydroponic culture, spray culture, and solid medium culture) than the soil culture and the nutrient-solution soil culture. 
     The number of times of application of the nanobubble water is not particularly limited. The nanobubble water may be applied at least one time during a cultivation period including a fruit cluster enlargement period and is preferably applied plural times in order to effectively exert the fruit quality improving effect; for instance, it is better to apply the nanobubble water ten or more times during a period of time from bearing of a flower bud until the harvest time. 
     In the present invention, a plant applied with the nanobubble water is not particularly limited as long as it is a plant belonging to fruit trees, and is preferably a rosaceous plant, a vitaceous plant, an ebenaceous plant or a rutaceous plant because effects of the invention can be exhibited in a meaningful way. 
     Exemplary fruit trees of rosaceous plants include apples, Nashi pears, pears, cherries,  Prunus mume , loquats, apricots, peaches, plums, and prunes. Exemplary fruit trees of vitaceous plants include grapes,  Vitis coignetiae , and  Ampelopsis glandulosa  var.  heterophylla . Exemplary fruit trees of ebenaceous plants include persimmons,  Diospyros lotus , and  Diospyros rhombifolia . Exemplary fruit trees of rutaceous plants include  Citrus unshiu , kumquats, grapefruits, lemons, limes, yuzu, kabosu, sudachi, and  Citrus depressa.    
     Of the types listed above, apples, Nashi pears, pears, cherries, grapes, persimmons, peaches and  Citrus unshiu  are particularly preferred. 
     Examples 
     The present invention is described below more specifically by way of examples (Tests 1 to 6). The materials, amounts of use, ratios, treatments, treatment procedures and the like illustrated in the examples below may be modified as appropriate as long as they do not depart from the scope and spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited to the following examples. 
     Note that the determination of grading in Tests 1 to 6 was all carried out by farmers proficient in plants subjected to the tests as well as in grading of those plants. 
     &lt;Details of Test 1&gt; 
     Test 1 was carried out in an agricultural field for cultivation of Nashi pears (variety: Hosui) in Inzai city, Chiba from October, 2017 to August, 2018 with the following separated areas. 
     Test area I: In the open-field culture, an agrochemical was diluted with nanobubble water generated using well water as source water by the method described below, and the diluted agrochemical was sprayed by a speed sprayer method. 
     Test area II: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, well water used as the source water of the nanobubble water in the test area I), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas I and II were situated side by side, and 50 Nashi pear trees were cultivated in each test area. In each test area, the number of times of spraying of the agrochemical was 18 times in total based on a disease and pest control calendar for Nashi pears, and the spraying was carried out at the same timing in those test areas. The amount of sprayed agrochemical in each time was adjusted to be substantially the same between those test areas, specifically adjusted to the amount consumed while a speed sprayer with a tank volume of 600 L was operated one time. 
     &lt;Nanobubble Water Generation Method&gt; 
     Nanobubble water was generated using an existing nanobubble generating apparatus (200 V, 10 L/min type; manufactured by Kakuichi Co., Ltd.) where bubbles (nanobubbles) were generated in water by a pressurized dissolution method. 
     Water used to generate nanobubble water was well water as described above, and the gas used to form bubbles was oxygen (industrial oxygen, oxygen concentration: 99 volt). 
     The conditions for generation of nanobubbles using the above nanobubble generating apparatus were as follows. 
     Number of bubbles per milliliter of water: 5×10 9  bubbles/mL 
     Size (modal particle size) of bubbles: 100 nm 
     Zeta potential of bubbles: −35 mV 
     &lt;Quality Evaluation&gt; 
     (1-1) Number of Excellent-Grade Products 
     For each test area, of the harvest number, the numbers of fruits falling under the Excellent category (Excellent-grade products), fruits falling under the Very Good category (Very Good-grade products), and fruits falling under the Good category (Good-grade products) in quality grade as well as the percentages thereof relative to the total number were obtained. 
     The evaluation results are shown below. The harvest numbers shown below are the number of shippable products, and the number of products that obviously should be discarded are not included in the harvest number below. 
     The harvest number in the test area I: 16,000
         The number of Excellent-grade products: 13,000 (81%)   The number of Very Good-grade products: 2,400 (15%)   The number of Good-grade products: 600 (4%)       

     The harvest number in the test area II: 15,500
         The number of Excellent-grade products: 9,000 (58%)   The number of Very Good-grade products: 4,600 (30%)   The number of Good-grade products: 1,900 (12%)       

     As described above, the percentage of Excellent-grade products is higher in the test area I than in the test area II, and it can be seen that the fruit quality improving effect was exhibited in the test area I. 
     The fruit quality improving effect was already confirmed during the cultivation period; in the test area I, the shape of fruits during the fruit cluster enlargement period satisfied the shape standard of Excellent-grade products as shown in  FIG. 2 , whereas in the test area II, the shape of fruits during the fruit cluster enlargement period was out of the shape standard of Excellent-grade products as shown in  FIG. 3 . Note that the shape of Excellent-grade products (Nashi pears on the right side in  FIG. 4 ) is more rounded than the shape of non-Excellent grade products, e.g., Very Good-grade products (Nashi pears on the left side in  FIG. 4 ). 
     (1-2) Measurement of Sugar Content 
     For each test area, of harvested Nashi pears, nine samples of Excellent-grade products were randomly chosen, and the sugar contents of those samples were each measured with a sugar content meter. The measurement results and the average thereof for each test area are shown in Table 17 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 17 
               
               
                   
               
               
                   
                 Sugar content of 
                 Sugar content of 
               
               
                   
                 Excellent-grade product 
                 Excellent-grade product 
               
               
                   
                 in test area I 
                 in test area II 
               
               
                   
               
             
            
               
                 Measurement 1 
                 14.9 
                 14.5 
               
               
                 Measurement 2 
                 14.6 
                 13.6 
               
               
                 Measurement 3 
                 13.6 
                 14.8 
               
               
                 Measurement 4 
                 15.7 
                 14.1 
               
               
                 Measurement 5 
                 15.4 
                 13.4 
               
               
                 Measurement 6 
                 13.4 
                 15.0 
               
               
                 Measurement 7 
                 15.0 
                 14.6 
               
               
                 Measurement 8 
                 14.8 
                 14.0 
               
               
                 Measurement 9 
                 14.5 
                 14.1 
               
               
                 Average 
                 14.7 
                 14.2 
               
               
                   
               
            
           
         
       
     
     As evident from Table 17 above, the sugar contents of Excellent-grade products cultivated in the test area I are higher than those of Excellent-grade products cultivated in the test area II, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 1 show that the fruit shape improved through the application of nanobubble water, and this confirmed that, as the quality of Nashi pears, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of Nashi pears, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for Nashi pears, the present invention comprehensively improves the quality in terms of the appearance, the contained components, the sensibilities and the like. 
     &lt;Details of Test 2&gt; 
     Test 2 was carried out in an agricultural field for cultivation of cherries (variety: Sato Nishiki) in Higashine city, Yamagata with the following separated areas. 
     Test area A1: In the open-field culture, an agrochemical was diluted with nanobubble water generated using well water as source water, and the diluted agrochemical was sprayed by the speed sprayer method. 
     Test area A2: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, well water used as the source water of the nanobubble water in the test area A1), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas A1 and A2 were situated side by side, and 25 cherry trees were cultivated in each test area. In each test area, the number of times of spraying of the agrochemical was 12 times in total based on a disease and pest control calendar for cherries, and the spraying was carried out at the same timing in those test areas. The amount of sprayed agrochemical in each time was adjusted to be substantially the same between those test areas, specifically adjusted to the amount consumed while a speed sprayer with a tank volume of 1000 L was operated one time. 
     Nanobubble water used in the test area A1 was generated under the same conditions as those for the nanobubble water used in the test area I of Test 1 by use of an existing nanobubble generating apparatus (100 V, 10 L/min type; manufactured by Kakuichi Co., Ltd.). The gas used in generation of nanobubble water was oxygen (industrial oxygen, oxygen concentration: 99 vol %). 
     &lt;Quality Evaluation&gt; 
     (2-1) Number of Excellent-Grade Products 
     In Test 2, none of harvested cherries fell under the Good category (Good-grade products), so that the harvested cherries were classified into either Excellent-grade products or Very Good-grade products, while products that obviously should be discarded were removed. Accordingly, for each test area, of the harvest number of cherries (the number of shippable products), the numbers of those falling under the Excellent category (Excellent-grade products) and those falling under the Very Good category (Very Good-grade products) in quality grade as well as the percentages thereof relative to the harvest number were obtained. The determination of grading was carried out not with the grade classifications for cherries shown in Table 2 described above but with the grade classifications shown in Table 18 below, specifically based on the colored area of a 
     
       
         
           
               
               
               
               
             
               
                 TABLE 18 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Test 2 
                 Colored area of  
                 Colored area of  
                 Colored area of  
               
               
                   
                 70% or more 
                 60% or more 
                 50% or more 
               
               
                   
               
            
           
         
       
     
     The evaluation results are shown below. 
     The harvest number in the test area A1: 170,000
         The number of Excellent-grade products: 153,000 (90%)   The number of Very Good-grade products: 17,000 (10%)       

     The harvest number in the test area A2: 160,000
         The number of Excellent-grade products: 120,000 (75%)   The number of Very Good-grade products: 40,000 (25%)       

     As described above, the percentage of Excellent-grade products is higher in the test area A1 than in the test area A2, and it can be seen that the fruit quality improving effect of nanobubble water was exhibited in the test area A1. The fruit quality improving effect was already confirmed during the cultivation period; in the test area A1, the colored area in the stage immediately before harvesting (specifically, June 13) was larger than that in the test area A2. 
     Note that  FIG. 5  shows cherries harvested in the respective test areas, that is, a fruit harvested in the test area A1 on the right side and a fruit harvested in the test area A2 on the left side in the figure. As evident from this figure, the one harvested in the test area A1 has a larger colored area than that harvested in the test area A2 even though the both are the Excellent-grade products. 
     (2-2) Measurement of Sugar Content 
     For each test area, of Excellent-grade products of harvested cherries, 10 samples having substantially same colored area and size were chosen, and the sugar contents of those samples were each measured with a sugar content meter. The measurement results and the average thereof for each test area are shown in Table 19 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 19 
               
               
                   
               
               
                   
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 Excellent-grade product  
                 Excellent-grade product  
               
               
                   
                 in test area A1 
                 in test area A2 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Measurement 1  
                 18.1 
                 18.2 
               
               
                 Measurement 2  
                 18.6 
                 18.0 
               
               
                 Measurement 3  
                 18.6 
                 18.7 
               
               
                 Measurement 4  
                 18.0 
                 18.9 
               
               
                 Measurement 5  
                 19.7 
                 18.5 
               
               
                 Measurement 6  
                 19.6 
                 17.7 
               
               
                 Measurement 7  
                 18.7 
                 17.9 
               
               
                 Measurement 8  
                 18.5 
                 17.6 
               
               
                 Measurement 9  
                 20.5 
                 18.0 
               
               
                 Measurement 10 
                 18.8 
                 18.5 
               
               
                 Average 
                 18.91 
                 18.20 
               
               
                   
               
            
           
         
       
     
     As evident from Table 19 above, the sugar contents of cherries cultivated in the test area A1 are higher than those of cherries cultivated in the test area A2, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 2 show that the colored area increased through the application of nanobubble water, and this confirmed that, as the quality of cherries, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of cherries, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for cherries, the present invention comprehensively improves the quality in terms of the appearance, the contained components, the sensibilities and the like. 
     &lt;Details of Test 3&gt; 
     Test 3 was carried out in an agricultural field for cultivation of grapes (variety: Shine Muscat) in Nirasaki city, Yamanashi with the following separated areas. 
     Test area B1: In the open-field culture, an agrochemical was diluted with nanobubble water generated using agricultural water as source water, and the diluted agrochemical was sprayed by the speed sprayer method. 
     Test area B2: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, agricultural water used as the source water of the nanobubble water in the test area B1), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas B1 and B2 were situated side by side, where 15 grape trees were cultivated in the test area B1 and 10 grape trees were cultivated in the test area B2. In each test area, the number of times of spraying of the agrochemical was nine times in total based on a disease and pest control calendar for grapes, and the spraying was carried out at the same timing in those test areas. The way of spraying the agrochemical in each test area and the conditions for generation of the nanobubble water used in the test area B1 are the same as those in Test 2. 
     &lt;Quality Evaluation&gt; 
     (3-1) Number of Excellent-Grade Products 
     For each test area, a shippable grape cluster was randomly chosen from the harvested clusters, and of a predetermined number of grapes picked from the chosen cluster, the numbers of those falling under the Excellent category (Excellent-grade products), those falling under the Very Good category (Very Good-grade products), and those falling under the Good category (Good-grade products) in quality grade as well as the percentages thereof relative to the total number of the picked grapes were obtained. 
     The determination of grading into Excellent, Very Good and Good products was carried out not with the grade classifications for Shine Muscat shown in Table 7 described above but with the grade classifications shown in Table 20 below, specifically based on the sugar content, the presence or absence of blemishes and marks of rubbing, and the weight of one grape. For the sugar content, the standard for shipping was specified to 17 degrees, and it was determined whether a grape satisfied this standard for shipping or not. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 20 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Test 3 
                 Sugar content of  
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 17 degrees or  
                 17 degrees or more 
                 17 degrees or more 
               
               
                   
                 more 
                 No blemish and no  
                 Slightly having  
               
               
                   
                 No blemish and  
                 mark of rubbing 
                 blemishes and  
               
               
                   
                 no mark of  
                 Weight of one grape:  
                 marks of rubbing 
               
               
                   
                 rubbing 
                 The second best level  
                 Weight of one  
               
               
                   
                 Weight of one  
                 following Excellent 
                 grape: The third  
               
               
                   
                 grape of 10 g 
                   
                 best level following  
               
               
                   
                 or more 
                   
                 Very Good 
               
               
                   
               
            
           
         
       
     
     The evaluation results are shown below. 
     The harvest number in the test area B1: 1,500
         The number of Excellent-grade products: 1,200 (80%)   The number of Very Good-grade products: 300 (20%)   The number of Good-grade products: 0 (0%)       

     The harvest number in the test area B2: 1,000
         The number of Excellent-grade products: 700 (70%)   The number of Very Good-grade products: 200 (20%)   The number of Good-grade products: 100 (10%)       

     As described above, the percentage of Excellent-grade products is higher in the test area B1 than in the test area B2, and it can be seen that the fruit quality improving effect of nanobubble water was exhibited in the test area B1. Note that for each test area, given five clusters were chosen, and two grapes from the top of each of the clusters, that is, ten grapes in total were measured in weight. As a result, the weight was 90 g in the test area B1 and 85 g in the test area B2. 
     (3-2) Measurement of Sugar Content 
     For each test area, 10 samples were randomly chosen from harvested Excellent-grade grapes, and the sugar contents of those samples (the sugar contents at the time before shipping) were each measured with a non-destructive type sugar content meter. The measurement results and the average thereof for each test area are shown in Table 21 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 21 
               
               
                   
               
               
                   
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 Excellent-grade product  
                 Excellent-grade product  
               
               
                   
                 in test area B1 
                 in test area B2 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Measurement 1  
                 17.2 
                 17.3 
               
               
                 Measurement 2  
                 16.2 
                 17.3 
               
               
                 Measurement 3  
                 17.6 
                 11.0 
               
               
                 Measurement 4  
                 16.9 
                 15.7 
               
               
                 Measurement 5  
                 16.4 
                 15.7 
               
               
                 Measurement 6  
                 16.4 
                 15.2 
               
               
                 Measurement 7  
                 19.0 
                 15.7 
               
               
                 Measurement 8  
                 19.6 
                 14.3 
               
               
                 Measurement 9  
                 16.8 
                 16.0 
               
               
                 Measurement 10 
                 16.9 
                 14.4 
               
               
                 Average 
                 17.30 
                 15.26 
               
               
                   
               
            
           
         
       
     
     As evident from Table 21 above, the sugar contents of grapes cultivated in the test area B1 are higher than those of grapes cultivated in the test area B2, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 3 show that the number of grapes with no blemish or mark of rubbing increased through the application of nanobubble water, and this confirmed that, as the quality of grapes, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of grapes, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for grapes, the present invention comprehensively improves the quality in terms of the appearance, the contained components, the sensibilities and the like. 
     &lt;Details of Test 4&gt; 
     Test 4 was carried out in an agricultural field for cultivation of peaches (variety: Ichinomiya Suimitsu) in Higashine city, Yamagata with the following separated areas. 
     Test area C1: In the open-field culture, an agrochemical was diluted with nanobubble water generated using well water as source water, and the diluted agrochemical was sprayed by the speed sprayer method. 
     Test area C2: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, well water used as the source water of the nanobubble water in the test area C1), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas C1 and C2 were situated side by side, and three peach trees were cultivated in each test area. In each test area, the number of times of spraying of the agrochemical was 11 times in total based on a disease and pest control calendar for peaches, and the spraying was carried out at the same timing in those test areas. The way of spraying the agrochemical in each test area and the conditions for generation of the nanobubble water used in the test area C1 are the same as those in Test 2. 
     &lt;Quality Evaluation&gt; 
     (4-1) Number of Excellent-Grade Products 
     For each test area, of the harvested peaches, the numbers of those falling under the Excellent category and those falling under the Very Good category in quality grade and the other ones (products to be discarded) as well as the percentages thereof relative to the harvest number were obtained. Not the grade classifications for peaches shown in Tables 8 to 10 described above but different grade classifications shown in Table 22 below were employed to determine as to whether a peach corresponds to the Excellent-grade product or the Very Good-grade product. Products to be discarded are ones damaged by diseases or pests or having remarkable blemishes in their appearance. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 22 
               
               
                   
               
               
                   
                   
                 Excellent 
                 Very Good 
               
               
                   
               
             
            
               
                 Test 4 
                 Fruit of different  
                 Not mixed 
                 Same as the left 
               
               
                   
                 variety 
                   
                   
               
               
                   
                 Rotten and 
                 Not mixed 
                 Same as the left 
               
               
                   
                 deteriorating fruit 
                   
                   
               
               
                   
                 Shape 
                 Having characteristics of the 
                 Having characteristics of the 
               
               
                   
                   
                 variety and most excellent 
                 variety and very good 
               
               
                   
                 Color and gloss 
                 Having excellent variety-specific 
                 Having very good variety-specific 
               
               
                   
                   
                 color and gloss 
                 color and gloss 
               
               
                   
                 Ripeness 
                 Having highly uniform ripeness 
                 Having uniform ripeness (unripe 
               
               
                   
                   
                 (unripe and overripe fruits 
                 and overripe fruits excluded) 
               
               
                   
                   
                 excluded) 
                   
               
               
                   
                 Uniformity 
                 Ones meeting a predetermined 
                 Same as the left 
               
               
                   
                   
                 standard and highly uniform in 
                   
               
               
                   
                   
                 size 
                   
               
               
                   
                 Damage caused by 
                 Ones not damaged by Monilinia 
                 Ones not damaged by Monilinia 
               
               
                   
                 diseases or pests 
                 fructicola or the like, with other 
                 fructicola or the like, with other 
               
               
                   
                   
                 damage caused by diseases or 
                 damage caused by diseases or 
               
               
                   
                   
                 pests being only in fruit skin and 
                 pests being only in fruit skin and 
               
               
                   
                   
                 hardly present 
                 not noticeable 
               
               
                   
                 Pit split 
                 One with pit split being hardly 
                 One with pit split being 
               
               
                   
                   
                 recognizable from the appearance 
                 unnoticeable from the appearance 
               
               
                   
                 Sunburn 
                 No sunburn 
                 Not noticeable 
               
               
                   
                 blemish damage 
                 Having no fresh blemish or no 
                 Having no fresh blemish or no 
               
               
                   
                   
                 blemish due to pressing, with 
                 blemish due to pressing, with 
               
               
                   
                   
                 other blemish damage being 
                 other blemish damage not greatly 
               
               
                   
                   
                 unnoticeable if present 
                 impairing the appearance if 
               
               
                   
                   
                   
                 present 
               
               
                   
                 Other deficiencies 
                 Almost no deficiencies 
                 Not impairing the apparance 
               
               
                   
               
            
           
         
       
     
     The evaluation results are shown below. 
     The harvest number in the test area C1: 550
         The number of Excellent-grade products: 510 (93%)       

     The number of products to be discarded: 40 (7%) 
     The harvest number in the test area C2: 510
         The number of Excellent-grade products: 390 (76%)       

     The number of products to be discarded: 120 (24%) 
     As described above, the percentage of Excellent-grade products is higher in the test area C1 than in the test area C2, and it can be seen that the fruit quality improving effect of nanobubble water was exhibited in the test area C1. The fruit quality improving effect was already confirmed during the cultivation period; in the test area C2, there was seen a disease (peach shot hole disease) causing browned portions which in turn form holes in a leaf as shown in  FIG. 6 , whereas occurrence of such a disease was minimized in the test area C1, resulting in excellent fruition. 
     (4-2) Measurement of Sugar Content 
     For each test area, of Excellent-grade products of harvested peaches, six samples were randomly chosen, and the sugar contents thereof were each measured. The measurement results and the average thereof for each test area are shown in Table 23 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 23 
               
               
                   
               
               
                   
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 Excellent-grade product  
                 Excellent-grade product  
               
               
                   
                 in test area C1 
                 in test area C2 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Measurement 1 
                 15.4 
                 11.4 
               
               
                 Measurement 2 
                 14.4 
                 10.8 
               
               
                 Measurement 3 
                 14.1 
                 12.0 
               
               
                 Measurement 4 
                 13.8 
                 11.3 
               
               
                 Measurement 5 
                 14.9 
                 11.5 
               
               
                 Measurement 6 
                 13.3 
                 11.4 
               
               
                 Average 
                 14.32 
                 11.40 
               
               
                   
               
            
           
         
       
     
     As evident from Table 23 above, the sugar contents of peaches cultivated in the test area C1 are higher than those of peaches cultivated in the test area C2, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 4 show that the shape and the color and gloss of fruits, and the presence or absence of damage caused by diseases or pests improved through the application of nanobubble water, and this confirmed that, as the quality of peaches, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of peaches, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for peaches, the present invention comprehensively improves the quality in terms of the appearance, the contained components, the sensibilities and the like. 
     &lt;Details of Test 5&gt; 
     Test 5 was carried out in an agricultural field for cultivation of pears (variety: La France) in Higashine city, Yamagata with the following separated areas. 
     Test area D1: In the open-field culture, an agrochemical was diluted with nanobubble water generated using well water as source water, and the diluted agrochemical was sprayed by the speed sprayer method. 
     Test area D2: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, well water used as the source water of the nanobubble water in the test area D1), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas D1 and D2 were situated side by side, and 20 pear trees were cultivated in each test area. In each test area, the number of times of spraying of the agrochemical was 16 times in total based on a disease and pest control calendar for pears, and the spraying was carried out at the same timing in those test areas. The way of spraying the agrochemical in each test area and the conditions for generation of the nanobubble water used in the test area D1 are the same as those in Test 2. 
     &lt;Quality Evaluation&gt; 
     (5-1) Number of Excellent-Grade Products 
     For each test area, the harvested pears were classified into the grade classifications including products falling under the Excellent category (Excellent-grade products) in quality grade, products with the size smaller than that of the Excellent-grade products and having a few blemishes (products to be processed), and the other products (products to be discarded); and the numbers of the products of the respective grades and the percentages thereof relative to the harvest number were obtained. Products to be discarded are ones damaged by diseases or pests or having remarkable blemishes in their appearance. 
     The evaluation results are shown below. 
     The harvest number in the test area D1: 13,000
         The number of Excellent-grade products: 12,300 (94%)       

     The number of products to be processed: 500 (4%) 
     The number of products to be discarded: 200 (2%) 
     The harvest number in the test area D2: 10,000
         The number of Excellent-grade products: 10,000 (84%)       

     The number of products to be processed: 1,000 (8%) 
     The number of products to be discarded: 1,000 (8%) 
     As described above, the percentage of Excellent-grade products is higher in the test area D1 than in the test area D2, and it can be seen that the fruit quality improving effect of nanobubble water was exhibited in the test area D1. That is, in the test area D2, damage caused by pests was seen on fruits as shown in  FIG. 7 , whereas in the test area D1, pests were controlled, so that the number of fruits corresponding to the Excellent-grade product increased as shown in the foregoing. In addition, for each test area, 10 pears (which correspond to the Excellent product or the product to be processed) were randomly chosen, and the weights thereof were measured to obtain the average. The average was 296.3 g in the test area D1 and 282.2 g in the test area D2. 
     (5-2) Measurement of Sugar Content 
     For each test area, of Excellent-grade products of harvested pears, 10 samples were randomly chosen, and the sugar contents thereof were each measured. The sugar content was measured at the time (October 30) after a storage period (normally, about two to three weeks) has passed from the harvest date (October 14). 
     The measurement results and the average thereof for each test area are shown in Table 24 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 24 
               
               
                   
               
               
                   
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 Excellent-grade product  
                 Excellent-grade product  
               
               
                   
                 in test area D1 
                 in test area D2 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Measurement 1  
                 14.5 
                 15.3 
               
               
                 Measurement 2  
                 15.3 
                 13.4 
               
               
                 Measurement 3  
                 15.0 
                 14.0 
               
               
                 Measurement 4  
                 15.3 
                 13.5 
               
               
                 Measurement 5  
                 15.4 
                 14.1 
               
               
                 Measurement 6  
                 15.3 
                 13.7 
               
               
                 Measurement 7  
                 15.4 
                 12.8 
               
               
                 Measurement 8  
                 14.1 
                 15.4 
               
               
                 Measurement 9  
                 15.1 
                 14.1 
               
               
                 Measurement 10 
                 15.5 
                 13.8 
               
               
                 Average 
                 15.09 
                 14.01 
               
               
                   
               
            
           
         
       
     
     As evident from Table 24 above, the sugar contents of pears cultivated in the test area D1 are higher than those of pears cultivated in the test area D2, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 5 show that the presence or absence of blemishes, damage caused by diseases or pests, and the like improved through the application of nanobubble water, and this confirmed that, as the quality of pears, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of pears, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for pears, the present invention comprehensively improves the quality in terms of the appearance, the contained components, the sensibilities and the like. 
     &lt;Details of Test 6&gt; 
     Test 6 was carried out in an agricultural field for cultivation of apples (variety: Fuji) in Nagano city, Nagano with the following separated areas. 
     Test area E1: In the open-field culture, an agrochemical was diluted with nanobubble water generated using tap water as source water, and the diluted agrochemical was sprayed by the speed sprayer method. 
     Test area E2: In the open-field culture, an agrochemical was diluted with non-nanobubble water (specifically, tap water used as the source water of the nanobubble water in the test area E1), and the diluted agrochemical was sprayed by the speed sprayer method. 
     The test areas E1 and E2 were situated side by side, where 35 apple trees were cultivated in the test area E1 and 140 apple trees were cultivated in the test area E2. In each test area, the number of times of spraying of the agrochemical was 10 times in total based on a disease and pest control calendar for apples, and the spraying was carried out at the same timing in those test areas. The way of spraying the agrochemical in each test area and the conditions for generation of the nanobubble water used in the test area E1 are the same as those in Test 2. 
     &lt;Quality Evaluation&gt; 
     (6-1) Number of Excellent-Grade Products 
     For each test area, of the harvest number of apples (the number of shippable products), the numbers of those falling under the Excellent category (Excellent-grade products), those falling under the Very Good category (Very Good-grade products) and those falling under the Good category (Good-grade products) in quality grade as well as the percentages thereof relative to the harvest number were obtained. The determination of grading was carried out according to the classifications specified in Table 11 described above, specifically with the classifications shown in Table 25 below, based mainly on the shape and the color of a fruit. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 25 
               
               
                   
               
               
                   
                 Excellent 
                 Very Good 
                 Good 
               
               
                   
               
             
            
               
                 Test 6 
                 Having  
                 Having very good  
                 Having the shape at  
               
               
                   
                 excellent  
                 variety-specific  
                 the third best level  
               
               
                   
                 variety-specific  
                 shape 
                 following Very Good 
               
               
                   
                 shape 
                 Having the color  
                 Having the color and 
               
               
                   
                 Having the  
                 and gloss  
                 gloss percentage at or 
               
               
                   
                 color and gloss  
                 percentage at or  
                 above the standard  
               
               
                   
                 percentage at  
                 above the standard  
                 value and taking on  
               
               
                   
                 or above the  
                 value and taking  
                 the third best ripe  
               
               
                   
                 standard value  
                 on excellent ripe  
                 color following Very  
               
               
                   
                 and taking on  
                 color 
                 Good 
               
               
                   
                 excellent ripe  
                   
                   
               
               
                   
                 color 
               
               
                   
               
            
           
         
       
     
     The evaluation results are shown below. 
     The harvest number in the test area E1: 42,000
         The number of Excellent-grade products: 18,900 (45%)   The number of Very Good-grade products: 21,000 (50%)   The number of Good-grade products: 2,100 (5%)       

     The harvest number in the test area E2: 160,000
         The number of Excellent-grade products: 56,000 (35%)   The number of Very Good-grade products: 88,000 (55%)   The number of Good-grade products: 16,000 (10%)       

     As described above, the percentage of Excellent-grade products is higher in the test area E1 than in the test area E2, and it can be seen that the fruit quality improving effect of nanobubble water was exhibited in the test area E2. 
     (6-2) Measurement of Sugar Content 
     For each test area, of Excellent-grade products of harvested apples, 12 samples were randomly chosen, and the sugar contents thereof were each measured with a sugar content meter. The measurement results and the average thereof for each test area are shown in Table 26 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 26 
               
               
                   
               
               
                   
                 Sugar content of  
                 Sugar content of  
               
               
                   
                 Excellent-grade product  
                 Excellent-grade product  
               
               
                   
                 in test area E1 
                 in test area E2 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Measurement 1  
                 16.7 
                 17.6 
               
               
                 Measurement 2  
                 17.2 
                 16.2 
               
               
                 Measurement 3  
                 16.1 
                 15.5 
               
               
                 Measurement 4  
                 18.6 
                 16.6 
               
               
                 Measurement 5  
                 16.1 
                 17.2 
               
               
                 Measurement 6  
                 18.6 
                 15.9 
               
               
                 Measurement 7  
                 16.1 
                 19.1 
               
               
                 Measurement 8  
                 17.8 
                 16.4 
               
               
                 Measurement 9  
                 16.3 
                 16.8 
               
               
                 Measurement 10 
                 18.4 
                 16.7 
               
               
                 Measurement 11 
                 17.9 
                 15.6 
               
               
                 Measurement 12 
                 17.9 
                 16.0 
               
               
                 Average 
                 17.31 
                 16.63 
               
               
                   
               
            
           
         
       
     
     As evident from Table 26 above, the sugar contents of apples cultivated in the test area E1 are higher than those of apples cultivated in the test area E2, and this revealed that the sugar content as the quality improved (increased) owing to the application of nanobubble water. 
     The results of Test 6 show that the shape and the color and gloss of fruits improved through the application of nanobubble water, and this confirmed that, as the quality of apples, the quality evaluated based on the appearance improves owing to nanobubble water. Furthermore, since the sugar content increased through the application of nanobubble water, this confirmed that, as the quality of apples, the quality evaluated based on the contained components improves owing to nanobubble water. It can be understood from the foregoing that for apples, the present invention comprehensively improves the quality in terms of the appearance, the contained components, sensibilities and the like. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  nanobubble generating apparatus 
               30  liquid discharger 
               40  gas incorporating device 
               41  vessel 
               42  gas incorporating device body 
               50  nanobubble generating nozzle