• The Plant Pathology Journal
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• 제17권5호
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• pp.300-304
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• 2001

Apple is the most economically important fruit in Korea. The suspected viroid disease of dapple apple was found in apple fruits cultivated in Kyungpook province. Symptoms begin in mid-July as small circular spots, which stand out against the background color on the young fruit. Dappling of the fruit becomes more intense and easier to detect as the fruit approaches maturity; the affected spots remain yellowish as the fruit matures. no leaf or bark syndromes have been associated with this disease. The infected fruits are downgraded considerably during quality grading. The low molecular weight RNA containing viroid RNA molecules were extracted from the peels of the apples with dapple symptoms. The RNA molecules were extracted from the apples using Qiagen column chromatography. The purified RNAs were used for the synthesis of cDNA with RT-PCR. The PCR products were then ligated into a pGEM-T Easy vector, cloned and sequenced. The sequence of the viroid RNA molecule shows 331 nucleotides with one base difference ("G" insertion between the position of 133 and 134) compared with that of the Apple scar skin viroid (ASSVd) reported by Hashimoto and Koganezawa in Japan. This is the first report on the occurrence of the ASSVd in apple trees cultivated in Korea, as well as the identification of a new Korean strain of the ASSVd.the ASSVd.

• 생물환경조절학회지
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• 제25권3호
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• pp.173-176
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• 2016

무측지성 수분수용 사과 품종 개발을 위해 '홍로'를 자방친, '메이폴'을 화분친으로 하여 교배한 교배실생을 조사 선발하여 '팅커벨'로 명명, 국립종자원에 품종보호 등록을 완료하였다. '팅커벨' 육성 과정은 2003년에 인공교배를 실시하여 2009년까지 과실 및 생육특성을 조사하여 1차 선발하였다. 계통명 '03-2-095'로 2010년부터 2012년까지 과일특성 및 주요 품종과의 교배친화성을 평가한 후 최종 선발하였다. '팅커벨'은 대조품종 '메이폴'에 비해 만개기가 약 2일 정도 늦고, 수세가 약하고 가지 발생이 거의 없는 무측지성을 보인다. 대조품종 '메이폴'의 과형이 '타원형'인데 비해 '팅커벨'의 과형은 '넓은 타원형'이다. '팅커벨'은 117g으로 '메이폴'보다 과실이 크고, 과피가 매끈하며 과분이 없다는 점에서 차이가 있었다. '팅커벨'의 당도는 $12.3^{\circ}Bx$로 '메이폴' $10.75^{\circ}Bx$ 보다 높고, 산도는 1.2%로 '메이폴' 1.8% 보다 낮아서 당산비가 '메이폴' 보다 개선되었다. 주요 품종과의 인공교배시 착과율은 '후지' 90.8%, '홍로' 94.9%, '쓰가루' 71.0%로 매우 높을 뿐만 아니라 수폭은 70cm이므로 사과 밀식재배체계에 아주 적합한 수분수용 신품종으로 판단된다.

• 한국자원식물학회지
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• 제32권6호
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• pp.677-682
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• 2019

Hand leaf thinning for improvement of fruit coloration and quality is one of the most labor-consuming works in Korean apple cultivation. The study was aimed at investigating whether foliar application of two chelate compounds (Cu-EDTA, Fe-EDTA) could defoliate effectively 'Hongro'/M.9 apple leaves and enhance fruit coloration and quality. At 30 days before harvest, foliar spray with two chelate compounds defoliated significantly the apple leaves. Chelate treatments did not affect the leaf chlorophyll content. High concentration of chelates decreased drastically photosynthetic rate of true leaves, and then it stayed in low levels, whereas low levels of chelates reduced sharply the photosynthetic rate but it was gradually restored over time. Cu-EDTA regardless of its concentration triggered higher defoliation compared to Fe-EDTA. Consequently, higher defoliation improved light interception of fruits and accumulated more anthocyanin. Particularly, Cu-EDTA could target mainly fruit cluster leaves which affect directly light interception of the fruits, i.e. more selective defoliants compared to Fe-EDTA. However, 3% Cu-EDTA rather defoliated excessively, accompanying with reduction of fruit weight and soluble solids. Therefore, our results suggest that 1% Cu-EDTA which defoliates properly the fruit cluster leaves could improve coloration and quality of 'Hongro'/M.9 apple fruits.

• 한국식품저장유통학회지
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• 제4권3호
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• pp.227-235
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• 1997

The internal breakdown of Fuji apple during CA storage classified as watercore breakdown, low temperature breakdown and CO2 injury. This study was undertaken to investigate the watercore breakdown injury factors of Korean Fuji apple during CA storage. The development of internal breakdown was more increased with the larger size, the later harvest time and the hither CO2 gas level. But in internal breakdown fruit of the titratable acidity and soluble solid decreased significantly, the pH of fruit juice and the production of carbon dioxide was greatly increased. The best gas levels of CA storage was 2% oxygen and 3% carbon dioxide. Thus, the predictable parameters of internal breakdown of fruit were increase in pH on decrease titratable acidity within 2 months of CA storage, increase carbon dioxide. So, it was found that the best CA sotrage for internal breakdown control of fruit during CA storage was delayed CA storage methods after low temperature storage immediate harvest of apple and than took a step. The delayed CA storage after low temperature storage for 2 months was more effective in the prevention of development of internal breakdown than immediate CA storage after harvest.

• 한국식품저장유통학회지
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• 제3권1호
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• pp.77-82
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• 1996

Most of countries differ from their favors, in Taiwan fruit juice and sweet taste are emphasized while external appearance in Japan. During transportation, movement of the container, fluctuation of temperature, decrease of the fruit freshness and undesirable packing materials tend to decline fruit marketability. For these problems, it is believed that shortening of boarding time by utilization of plate and styro form box for packing, the author believed.

• 한국환경농학회지
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• 제41권3호
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• pp.199-205
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• 2022

BACKGROUND: The freezing injury by pruning can be reduced by suspending pruning work when severe cold weather (-23 to -49℃) is forecast. Minimum air temperature of the study area, Gunwi region at February 3, 2012 was -21.9℃, and the subzero temperature continued until April 8, 2012. This study was conducted in two years to investigate the effect of delaying winter pruning until full bloom on shoot growth and fruit quality of 'Fuji'/M.9 apple trees. METHODS AND RESULTS: The time of pruning were March 26 for dormant, April 3 for bud break, and May 2 for full bloom. The winter pruning at full bloom significantly reduced fruit weight for two years compared with the control (winter pruning at dormant), and shoot growth was reduced only in the following year. There was no significant effect of delaying winter pruning at bud break on soluble solid content, fruit red color, return bloom, and pruning weight for two years compared with the control. CONCLUSION(S): These results indicated the delaying winter pruning at bud break of 'Fuji'/M.9 apple tree did not offer any disadvantage over comparable dormant pruning, since the fruit quality was not affected. The delayed pruning at full bloom resulted in decreased fruit weight, though shoot growth, fruit quality, and return bloom were not affected by the delayed pruning. So, the delayed pruning should be considered carefully only for the fruit tree orchards in diseases.

• 한국식물병리학회지
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• 제14권2호
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• pp.109-114
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• 1998

To investigate Phomopsis species causing fruit decays of Japanese apricot, apple and kiwifruit, we collected diseased fruits from the fruit markets in 1995 and 1996 respectively. Phomopsis mali Roberts was identified based on cultural characteristics, morphological aspects and pathogenicity. There were no remarkable differences with respect to $\alpha$ and $\beta$ conidia, growth rates and colony characters among the isolates from Japanese apricot, apple and kiwifruit. The pathogens grew more than 70 mm on potato dextrose agar in 5 days at $25^{\circ}C$. The agar was slightly discolored by the production of a reddish purple pigment under the light at $25^{\circ}C$ and 3$0^{\circ}C$ respectively. Only $\alpha$ spores of the different isolates of P. mali were formed at 15$^{\circ}C$ and $\beta$ spores were mainly produced at 3$0^{\circ}C$, but and $\alpha$ and $\beta$ spores were produced in approximately equal numbers at 2$0^{\circ}C$ and $25^{\circ}C$. Pycnidia were a few under the dark condition but were abundant at wide range of 15~3$0^{\circ}C$ under near ultra violet illumination. Conidia were two types : $\alpha$ spores were unicellar, fusoid, hyaline and biguttulate, whereas $\beta$ sores were unicellar, acicular to filiform, straight or hooked and hyaline. An ascigerous stage was not formed in cultures or in nature. Isolates of Phomopsis mali from japanese apricot, apple and kiwifruit could infect fruits of apple, pear, apricot, Japanese apricot and kiwifruit. There were some differences in pathogenicity depending on stocks of fruit crops tested.

• 한국환경농학회지
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• 제41권4호
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• pp.328-334
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• 2022

BACKGROUND: The low temperature at flowering period break the balance between vegetative and reproductive growth of apple tree. Summer pruning has been used to control vegetative growth. So, this study was conducted to investigate the effect of summer pruning time on shoot growth and fruit quality of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period. METHODS AND RESULTS: The following treatments were applied to tree : a) control (no summer pruning), b) pruned 26 June, c) pruned 30 July, d) pruned 28 August, and e) pruned 26 September. The summer pruning significantly increased light penetration and fruit red color by reducing the total shoot growth compared with control. And the summer pruning control the outbreak of apple valsa canker. But the summer pruning at the end of June increased regrowth of shoot and pruning weight compared with the summer pruning at the end of August. The summer pruning at 30 July had the highest fruit weight, but return bloom was the highest in the summer pruning at 28 August. CONCLUSION(S): These results indicated the optimum summer pruning time of 'Fuji'/M.9 apple trees damaged by the low temperature at flowering period were the end of August.

• 한국자원식물학회지
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• 제26권3호
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• 자연과학논문집
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• 제11권1호
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• pp.113-117
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• 1999

사과 스타크림손품종에 질소시용량을 달리하였을 때 질소 다량 시용구가 표준 시용구보다 과실의 칼슘함량이 적었다. 칼슘용액의 수관살포로 과실 칼슘함량이 증가되었고 반점성 생리장해발생이 감소되었는데 특히 질소표준구에서 칼슘함량 증가가 뚜렷하였다. 사양토에 재식된 후지품종에 대한 관수는 과실의 비대와 잎과 과실의 칼슘함량을 증가시키는 효과가 있었다.