• Korean journal of applied entomology
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• v.54 no.2
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• pp.121-125
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• 2015

This study was conducted to examine the feeding effect of Halyomorpha halys ($St{\aa}l$) (Hemiptera: Pentatomidae) on the fruit drop and decay rate of Mandarin citrus fruits (Citrus unshiu). The feeding of H. halys before fruit coloring caused a severe fruit drop, while the feeding after fruit coloring induced a low level of fruit drop. However, the feeding of H. halys before or after fruit coloring did not induce significant fruit decay during cold storage. The results are expected to be useful in managing H. hlays of late season mandarine, because citrus farmers follow calendar spray to prevent fruit drop and fruit decay.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.750-752
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• 1999

This experiment was conducted to evaluate preharvest drop control in 'Tsugaru' apple with combined treatments of aminoethoxyvinylglycine (AVG) and several adhesive agents. AVG+Silwet L-77 at $75+1,000mg{\cdot}L^{-1}$ was most effective among the tested combinations. Little or no significant difference was observed among the different application times of AVG+Silwet L-77. AVG+Silwet L-77 significantly reduced preharvest drop while increasing fruit weight, fruit length, diameter and fruit firmness. All the tested combinations were generally effective in reducing preharvest drop as compared to dichlorprop and in maintaining better fruit quality.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.309-315
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• 2013

Fruit drop is a serious problem in plum trees during fruit development after pollination and fertilization. In order to increase fruit yields, physiological fruit drop in plum trees at the early stages of fruit development must be reduced. In this study, the effect of gibberellic acid paste (GA paste 2.7%) applied on 'Formosa' plum was determined to reduce fruit drop. GA paste was applied one time on one set of the fruit stalk at 3 days after full bloom (DAFB), and on another set of the fruit stalk at 13 DAFB, and then the fruit-set rate was observed at 70 DAFB. GA paste application increased the fruit-set rate up to 61%. In 'Formosa', the time of GA application had a strong influence on reducing fruit drop. GA application increased the fruit-set rate up to 61% in treatments at 3 DAFB, and to 15% in treatments at 13 DAFB when the fruit-set rate was 5% in the control group. The same results were observed in 'Honey Red' and 'Akihime' plums. GA application impacted on fruit enlargement in the 'Formosa' cultivar, compared with the control trees, which had no GA application. The rate of fruit enlargement with GA application was similar to that of the control fruits until 70 DAFB, whereas the enlargement rate was slightly higher in the GAtreated trees than the control from 70 DAFB until harvest. In GA-treated fruit, fruit weight increased more than in the control, while total acidity and firmness was lower than in the control group. Additionally, GA application accelerated sucrose increase in maturing fruit. Our data indicated that GA paste application can reduce fruit drop, and subtly promote fruit enlargement and maturation in plum trees.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.461-468
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• 2001

Impact between fruits and other materials is a major cause of product damage in harvesting and handling systems. The oriental pears are more susceptible to bruising than other fruits such as European pears and apples, and are required more careful handling. The interest in the handling of the pears for the processing systems has raised the question of the allowable drop height to which pears can be dropped without causing objectionable damage. Drop tests on pears were conducted using an impact device developed by authors to estimate the allowable drop height without bruising. The impact device was constructed to hold in a selected orientation and to release a fruit by vacuum for dropping on to a force transducer. The drop height was adjustable for zero to 60 cm to achieve the desired distance between the bottom of the fruits and the top of the impact force transducer. The transducer was secured to 150 kg$\sub$f/ concrete block. The transducer signal was sampled every 0.17 ms with a strain gage measurement board in the micro computer where it was digitaly stored for later analysis. The selected sample fruit was Niitaka cultivar of pears which is one of the most promising fruit for export in Korea. The pears were harvested during the 1998 harvest season from an orchard in Daejeon. The sample fruit was selected from two groups which were stored for 3 months and 5 months respectively by the method of current commercial practice. The pears were allowed to stabilize at environmental condition(18$^{\circ}C$, 65% rh) of the experimental room. One hundred fifty six pears were tested from the heights of 5, 7.5. 10 and 12.5 cm while measurement were made of impact peak force, contact time, time to peak force, dwell time, pear diameter and mass. The bioyield strength and modulus of elasticity were measured using UTM immediately after each drop test. The allowable drop height was estimated on the base of bioyield strength of the pears in two ways. One was assumed the peak force during impact test increasing linearly with time, and the other was based on the actual drop test results. The computer program was developed for measuring the impact characteristics of the pears and analyzing the data obtained in the study. The peak force increased while contact times decreased with increasing drop height and contact times of the sample from the hard tissue group. The allowable drop height increased with increasing bioyield strength and contact times, and also varied with Poisson\`s ratio, mass and equilibrium radius of the pears. The allowable drop height calculated by a theoretical method was in the range from 1 to 4 cm, meanwhile, the estimated drop height considering the result of the impact test was in the range from 1 to 6 cm. Since the physical properties of fruits affected significantly the allowable drop height, the physical properties of the fruits should be considered when estimating the allowable drop height.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.391-394
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• 2000

Girdling and girdling+pinching treatments on 'Sekaiichi' apple remarkably reduced June drop and accelerated fruit growth in early stage of fruit development. Girdling+pinching and pinching reduced bourse shoot growth compared with non-treated control. There were no significant differences in flower bud formation in the following year among treatments. It was assumed that the optimum period for girdling is between 5 days before full bloom and full bloom period.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.565-570
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• 2017

In a plumcot 'Harmony' cultivar, which is an interspecific hybrid between plum and apricot, canopy occupation and productivity according to tree training system, Y shape with no trellis (YNT) and Y-palmette with trellis (YPT), were compared. According to the survey results for 5 years of planting, tree growth was similar in two training systems. However, canopy occupation and fruit yield of YPT were significantly higher than those of YNT. The fruit weight and sugar content were not significantly different between two systems. The fruit drop rate tended to be lower in YPT than in YNT. From the above results, it is expected that the YPT type will contribute to the increase of canopy occupation and fruit yield and reducing the fruit drop rate compared to the YNT.

• Journal of Biosystems Engineering
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• v.21 no.1
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• pp.44-51
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• 1996

The purpose of this paper is to obtain the basic data for design of pressure cooling system. Static pressure drop, as a function of superficial velocity, was measured for different stacking methods and stacking heights of some fruits and vegetables. At given superficial velocity, sphericity and void fraction had a much greater influence on static pressure drop than average diameter of spherical fruits such as apple, peach, tomato and kiwi fruit. Among cylindrical vegetables such as cucumber, carrot, radish and chinese cabbage, cucumber showed different pattern of static pressure drop because of its bended shape, radish showed less static pressure drop than other vegetables because its large sizes of voids. When cucumber and spinach were stacked vertically and horizontally to air flow, a much greater static pressure drop was shown in vertical than in horizontal type, therefore static pressure drop was affected not only by void fraction but also by void shape. Also, in packed-beds of fruits and vegetables, static pressure drop could be estimated very well by Ramsins equation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.152-158
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• 2006

The objective of this study is to investigate change in diurnal respiration and transpiration of the fruits of kiwifruit during fruit growth. Three-hourly fruit transpiration and respiration rate were measured by a chamber technique. Results showed a tendency of higher transpiration and respiration in at maturation to commercial harvest period in 1995 fruit than in 1996 fruit. Fruit respiration rates were very similar to the transpiration rates. The air temperature record for the fruit maturation period in 1996 showed a sudden drop on September $19{\sim}24$ and October 14 down to $7{\sim}13^{\circ}C$. These results suggest that abnormal fruit transpiration and respiration rate in the fruit maturation period might be influenced by the air temperature.

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.24-29
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• 2016

The objective of this study was to examine the changes in temperature drop and fruit production due to low pressure fog system in plastic greenhouses during summer cultivation of Korean melon. The indoor temperature of plastic house was dropped by $7.6^{\circ}C$ compared to control on July 26th, 2015 from 10:00 to 18:00. Fruit weight was smaller and lighter by 96g compared to control. The sugar content and color parameter were also enhanced due to application of low pressure fog system. The fraction of malformed fruits was decreased by 15.3% in plots where low pressure fog system was applied. The fraction of marketable fruit and yield were increased by 15.3% and 26% compared to control, respectively. As a result, high quality fruit production within plastic house of summer was increased by applying low pressure fog system and it is positively affected the drop of indoor temperature.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.896-905
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• 1996

Pressure drop, as a function of air flow, was measured for tomatoes and mandarins in bulk with different sizes, stacking arrangements and bed porosities. Pressure drop was also measured on carton vent holes and on a carton of packed fruits . and the cumulative effects of air flow resistance of vent holes and packed fruits in bulk on the air flow resistance of a carton of fruits were evaluated . Equation were presented to describe pressure drop bulk fruits, of an empty carton and of a carton of packed fruits as related to the air velocity , the bed porosity, the fruit diameter and the opening ratio of the vent hole.