• Horticultural Science & Technology
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• v.32 no.4
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• pp.440-447
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• 2014

For this analysis, canopies of slender-spindle 'Hongro'/M9 apple trees were divided into 4 positions: upper, lower, exterior, and interior parts. The photosynthetic rate was highest in the external part of the upper canopy of the tree, where it was 4.5 times higher than in the internal part of the lower canopy. This difference was closely associated with differences in light penetration based on canopy position. Analysis of leaf growth characteristics showed that the leaves situated in the internal part of the canopy were larger and thinner than those in the external part of the canopy. The difference in leaf thickness was mainly due to thickness of the primary layer of palisade tissues (68.5 and $110.3{\mu}m$ for internal and external leaves, respectively). Fruit weight and quality were closely related to the extent of light penetration. Fruit weight, soluble solid content, and red skin color were higher in the fruits from the external part of the canopy. Thus, fruit maturity was delayed in the internal part of canopy. The fruit skin and wax layer were thicker in fruits from the internal canopy than in those from the external canopy. Therefore, our results indicate a need for improved light penetration in internal parts of the canopy and for split harvesting depending on maturity at different canopy positions.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.203-210
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• 2013

This study was conducted to investigate the optimum storage temperature and the effect of 1-methylcyclopropene (1-MCP) on the postharvest physiology and quality of plumcot (Prunus salicina Lindle. ${\times}$ Prunus armeniaca L.) 'Harmony' fruits. plumcot fruits were stored at 0, 5, 10, and $20^{\circ}C$, respectively, with three different ripeness stages grouped by skin color development. Furthermore, we treated $1{\mu}L{\cdot}L^{-1}$ 1-MCP was treated at $10^{\circ}C$ for 17 hours and stored at $10^{\circ}C$ for 12 days to evaluate the effectiveness for better shelf-life. The results indicated that lower storage temperature than room temperature effectively reduced the respiration rate with delaying quality changes. While, the fruits showed worse fruit taste than the fruits stored at 10 and $20^{\circ}C$. Reversely, the fruits stored at $20^{\circ}C$ showed more respiration rate and ethylene production. 1-MCP treatment effectively reduced the skin red color development, ethylene production, $CO_2$ and softening of plumcot 'Harmony' fruits. Overall data indicated that the optimum harvest time and storage temperature could be 30-50% red color and near $10^{\circ}C$. Postharvest 1-MCP application at the level of $1.0{\mu}L{\cdot}L^{-1}$ could maintain fruit quality well in plumcot fruits.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.195-201
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• 2012

We tested for pesticide residues in 124 samples of 22 different items of imported fruits circulated in Gyeonggido. Total 218 pesticides were analyzed by multi-residue method using gas chromatography/nitrogen phosphorus detector-electron capture detector (GC/NPD-ECD), time of flight/mass spectrometer (TOF/MS), ultra performance liquid chromatography/photo diode array (UPLC/PDA), high performance liquid chromatography/fluorescence detector (HPLC/FLD) and mass spectrometer (LC/MS/MS). The pesticides were detected in 18 fruits samples, ranging 0.003~0.3 mg/kg and no samples had violative residue. The separation test to 14 sample pesticides detected was conducted to monitor the current status of pesticide residues according to the partial characteristic. The pesticides were detected in 14 peels ranging 0.03~1.5 mg/kg and 2 fleshes in less than detection limits. These results indicate that imported fruits are safe when the human takes normally but even the small amount of pesticides is harmful when the human takes it in a prolonged period. Therefore, the pesticide residual amounts of imported friuts should be constantly monitored for food safety.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.367-373
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• 2010

The study was established to compare fruit qualities and antioxidant compounds in 'Niitaka' pear (Pyrus pyriforia) trees grown in the organic and conventional farming systems. Fruits in the organic system appeared to have dark red color on the fruit surface. Fruit weight, soluble solids, acidity, firmness, and stone cells were not different between the farming systems. Organic fruits had a greater potassium concentration than the conventional fruits, but phosphorous, calcium, and magnesium concentrations in fruits were not different between the treatments. Peel, flesh, and juice parts in the organic fruits had greater phenolic compounds compared to the conventional fruits. Peel parts had much greater antioxidant compounds than the flesh parts, regardless of the treated-fruits. All fruits grown in the conventional and organic systems had a similar DPPH ($\alpha$, $\alpha$-diphenyl-$\beta$-picryl-hydrazyl) radical-scavenging activity in the peel, but flesh parts in organic fruits had a greater DPPH than the conventional fruits. Phenol and flavonoid compounds in the peel and flesh were positively related to the DPPH radical-scavenging activity. There were no significant differences for the nitrite scavenging activity in the peel and flesh parts between the treatments.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.313-317
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• 2016

The congener and sympatric species, Grapholita molesta (Busck) and G. dimorpha Komai, are economically important pests against various Rosaceae fruit trees in Korea. In this study, we identified the species from the larvae of these two insects collected from damaged fruits of peach, plum, apple, pear, and quince by using a molecular diagnostic method and compared the distribution ratios of the two species within the fruits of each of these trees. Most (99.7%) of the larvae collected from peach fruits were identified as G. molesta, while all of the larvae found in plum fruits were G. dimorpha. Both species were found in the other three fruits, but G. molesta was significantly dominant in pear fruits. G. dimorpha was more abundant in apple and quince fruits, without any significant difference between the distribution ratios of two insects. The results suggest that development of further realistic strategies is necessary for the management of these two pests in Korean orchards.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.672-679
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• 2006

Postharvest nut quality, and changes of soluble solids content and kernel hardness during cold storage in 13 Korean prevailing chestnut cultivars were investigated to establish the chestnut grading and standardization for marketing and processing industry. Chestnut quality attributes such as nut weight, soluble solids content, kernel hardness, % with the pericarp split, and % of polyembryonic nuts were measured from 2001 to 2005. There were significant difference among cultivars in quality characteristics, and also annual variation within same cultivar, corresponded to the high genetic and environmental variability. During cold storage at $2^{\circ}C$ for 16 weeks, remarkable changes in soluble solids content were observed, and Isseumo showed the highest increase of 8% at 16 weeks of cold storage compared with postharvest. In case of most cultivars except early ripening cultivars, soluble solids content of chestnut increased until 12 weeks during cold storage, followed by decreased gradually thereafter. Kernel hardness of most cultivars except lshizuchi during cold storage increased slightly, but it was not statistically significant. This work would be a useful reference to the quality of each chestnut cultivar for the growers and breeders alike.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.283-287
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• 2004

Persimmons suffer from such physiological disorders as flesh softening, peel blackening, and flesh browning, which occur rapidly particularly when exposed to ambient temperature after storage at low temperature, In this study causes of these disorders were examined in terms of respiration and ethylene production of the fruits. Jelly-like flesh softening, considered as symptom of chilling injury, rapidly developed within 3 days of exposure to ambient temperature without modified atmosphere (MA) packaging after low temperature storage. Disorder development was more suppressed at $30^{\circ}C$ than at $20^{\circ}C$; such temperature dependence is closely connected to ethylene production rate of fruits at both temperatures. Inhibition of ethylene production through MA packaging effectively reduced disorder development, which indicates ethylene production is closely related to jelly-like flesh softening disorder. Development of black-staining on peels occurs in fruits exposed directly to ambient temperature, but not in those packaged with thick PE-film. Flesh browning developed only under anaerobic respiration condition of high temperature and MA packaging with thick PE film, and occurred at quick reduction of available oxygen inside MA package at high temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.743-752
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• 2013

The objective of this study was to investigate the quality characteristics of spirits derived from fruit using copper distillation equipment. First, optimal yeast strains were chosen through a fermentation test on raw materials (apples, mandarins and rowanberries). The normal fermentation condition for rowanberries observed at a rowanberry concentration of 8% during mashing included chaptalization with sugar to increase the alcohol content. During the mashing, fruits were fermented and distilled through one of three different types of distillation apparatuses (pot distiller, vacuum distiller, or multistage distiller made of copper). The results revealed that the type of apparatus used affects the content of alcohol and flavor components. The distilled spirits prepared through a copper multistage distiller had a much higher tendency to retain components of fruit aromas such as ethyl acetate and provided higher yields than spirits prepared with a pot distiller or vacuum distiller. Thus, the copper multistage distiller apparatus can be applied to positively influence the taste and flavor of fruit distilled spirits by enhancing fruit aromas, removing impurities such as sulfur components and enhancing yields.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.193-199
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• 2018

The fungus, Podosphaera pannosa, was identified in 1991 as the cause of powdery mildew symptoms on peach (Prunus persica var. persica) fruit from Korea based on the morphological characteristics of the conidial state. Recently, however, in Serbia and France, the cause of 'rusty spot' found on peach fruit was identified as P. leucotricha, and the cause of 'powdery mildew' on nectarine (Prunus persica var. nucipersica) fruit was identified as P. pannosa. To confirm the identity of the Korean pathogen, we collected four samples of powdery mildew from Korean peach fruit: three with the 'powdery mildew' symptom and one with the 'rusty spot' symptom. Morphological examination of the four samples confirmed P. pannosa as the pathogen. Internal transcribed spacer sequences of rDNA were analyzed for molecular characterization. A phylogenetic tree showed that the Korean isolates were clustered into a clade containing P. pannosa from Rosa species, with high sequence similarities of more than 99%. Thus, we showed that the powdery mildew and rusty spot symptoms on peach fruits from Korea are associated with P. pannosa.

• Korean Journal of Organic Agriculture
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• v.19 no.3
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• pp.405-416
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• 2011

Organic materials, such as chitin incubated solution (CIS) combined with neem oil (NO), nano silver silica (NSS), and Bordeaux mixture (BDM), were applied with and without agricultural chemicals (AC) (insecticide and fungicide) to investigate scab and mealybug occurrences and fruit qualities on 'Niitaka' pear trees in orchards in 2006. Fruits and leaves grown under CIS+NO without AC had less than 30%, scab occurrence, but CIS+NSS or CIS+BDM without AC had higher scab occurrence. Organic materials with AC decreased the scab to less than 20%. All treatments decreased mealybug occurrences to less than 10%, except for the fruits grown under CIS+BDM without AC. Fruit qualities varied among the treatments. Hunter value a, representing for the redness degree, was higher for fruits treated with CIS+NSS and CIS+BDM without AC than those with AC. Fruits treated with organic materials without AC had greater total phenolic and flavonoid compounds as well as antioxidant capacity in flesh and greater total phenolc compounds and antioxidant capacity in peel than those treated with the AC.