• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.171-176
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• 2010

To investigate the effect of leaf removal on enlargement and coloring of persimmon fruits (Diospyros kaki L. cv. 'Fuyu'), four treatments control (0%), 20%, 50%, and 100% depend on leaf removal of fruit bearing branch were applied to persimmon trees. Sunlight intensities around fruits with treatments depend on removal level, compared with natural sunlight intensity (100 percentage level), was 7.9%, 13.6%, 16.4%, and 30%, respectively. Hunter $a^*$ of the fruit with control and 20% removal treatments to harvest season increased continuously. $Chroma^*$ of the fruit since the removal treatments of leaves increased continuously in all treatments, but from seventh week that had a decreasing tendency. The fruit weight and diameter were significantly heavy and short in treatments with 100% removal level. L/D ratio of the fruits had a significant difference between control and the other treatments. Soluble solids of the fruits lowed significantly in treatment with 50% removal level. Hunter $a^*$ of the fruits was better in treatments with control and 20% removal levels, Hunter $b^*$ and $Chroma^*$ lowed significantly in treatment with 20% removal level. $\beta$-Carotene and lycopene concentration of the fruits lowed in treatment with the higher of removal level, total chlorophyll contents had the opposite tendency to the pigments. All results considered, removal level of leaves around fruit on bearing branch in fruit maturation stage had effect on fruit coloring improvement.

• Food Science and Preservation
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• v.16 no.5
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• pp.675-679
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• 2009

We investigated how Germanium (Ge) application, and the application method, affected 'Niitaka' (Pyrus pyrifolia) fruit quality in a conventional orchard. Ge-treated pears weredark yellow in color, indicating appropriate maturation. Other fruit characteristics, and weight, did not significantly differ between tests and controls. Compared to controls, fruit from Ge-treated trees had more soluble solids, a lower acid content, and fewer stone cells, which reduced fruit chewiness. Ge-treated trees showed a higher Ge concentration in fruit but a lower calcium (Ca) concentration. Other fruit mineral nutrients, includingP, K, and Mg, did not differ in level between Ge-treated fruit and controls. Ge-treated fruit showed greater firmness and a heavier specific weight during 6 months of storage, compared to control fruit. Therefore, Ge treatment reduced fruit pithiness, which can be a problem in 'Niitaka' pears. Overall, there was no significant difference between Ge-treated and control fruit qualities, but a combined Ge treatment (fertilization plus foliar application plus trunk injection) slightly improved fruit quality.

• Korean Journal of Plant Resources
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• v.13 no.2
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• pp.111-117
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• 2000

In an attempt to select grape bag, which elevates grape quality and make easy maturation period determination, the following research was carried out at Chungbuk Institute of Agricultural Technology, Grape Experiment Station. Light transmittance rate of bag reached to 11-65% with non-woven fabric and non-dripped vinyl bags. Non-dripped vinyl perforation and white painting bag resulted in 50 and 75%, respectively. Berry weights in non-woven fabric and non-dripped vinyl bag were high than that in paper bag. Non-dripped vinyl perforation 50%, white painting bag brought into fruit cracking, shattering, and rotten fruit, making the investigation difficult. Maturation period preceded about 1-4 day with non-woven fabric and non-dripped vinyl compared with that in paper bag. Soluble solids content with non-woven fabric and non-dripped vinyl bags was high and acidity showed a reverse result. Coloring extent was developed rapidly with non-woven fabric and non-dripped vinyl than paper bag. During initial state of coloring, coloring was rapid with Maekban-Stone mixed non-woven fabric and non-dripped vinyl + non-woven fabric bag. This was rapid with non-woven fabric bag as long appropriate maturation period. Abnormal berry rate was 5.4-7.0% with paper and non-woven fabric bags but brought about as much as 16.6-100% with non-dripped vinyl and it's mixed bags. Appearance quality was the best with index 9.0 for non-woven fabric bag. Maekban-Stone mixed non-woven fabric but non-dripped vinyl performance 50% white painting bag was the least, showing index 1.0. The time consumed for maturation determination was reduced to 74-93% with non-woven fabric and non-dripped vinyl bag compared with 17.4h/10a with paper bag.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.437-446
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• 2013

This study was conducted for three years (2007, 2009, and 2010) to investigate the changes in fruit quality during maturation, and the quality and storage ability of fruits harvested at different times of 'Fuji' apple in Daegu region with a high air temperature during the fall season. Changes in apple fruit quality during the maturation period were investigated from 120-135 days to 183-198 days after full bloom. In comparing quality and storage ability of fruits harvested at different times, fruits harvested more than 180 days after full bloom were used. During the maturation period, poor coloring was the problem for 'Fuji' apple in Daegu region by the high air temperature about $20^{\circ}C$. In comparing quality of fruits harvested at different times, the soluble solid contents and hunter a value were increased by the extended harvest time. Fruit weight during harvest was not affected by different harvest time, while the fruit firmness and titratable acidity during harvest were decreased critically when the freezing damage happened. Ethylene production, fruit firmness, and titratable acidity during cold storage for twenty weeks did not differ according to the different harvest time. Soluble solid contents of fruits harvested at 216 days after full bloom in 2009 were similar at the time of harvest and cold storage. For fruits harvested at 201 days after full bloom, soluble solid content during cold storage was higher than during harvest time. However fruit firmness, soluble solid content, and titratable acidity after cold storage of fruit harvested after freezing damage was lower than those of the fruit harvested before freezing damage. The results show that the extended harvest time of 'Fuji' apples about 2-4 weeks from 180-200 days after full bloom in area with above-air temperature during fall season was seemed to be beneficial to enhancing soluble solid contents and fruit red color, but harvesting after the middle of November was dangerous because minimum air temperature began to fall under $-3.0^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.19 no.1
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• pp.9-15
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• 1992

This experiment was conducted to find the effect of gibberellin paste on the growth and maturation of 'Hosui' pear fruit and to develop a cultural technique in the middle area of Korea, where fruit quality is often poor due to the short growing season. The application of $GA_{3+4+7}$ paste on the petioles at the young stage of development resulted in the early increase of fruit diameter and weight. Although fruit firmness was slightly low by the $GA_{3+4+7}$ paste treatment, compared to that of control, there were no differences in other quality actors such as soluble solid content and acidity. However, $GA_3$ alone did not affect the fruit growth and quality. Are increase of ethylene evolution of fruit was not confirmed hut ground color development was hastened, resulting in the stimulation of maturity by 3~5 days. Thus, these results may be applicable to the production of high quality 'Hosui' pears in the area where growing season is relatively short.

• Korean Journal of Agricultural Science
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• v.45 no.4
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• pp.601-614
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• 2018

Chitosan with a natural antimicrobial property has been introduced to protect horticultural crops from diseases as an environmentally friendly method. The purpose of this study was to investigate the effects of the pre-harvest application of chitosan on growth and quality during the late stage of fruit development and on the simulated marketing of the peach fruit (Prunus persica L.). The application of chitosan with calcium chloride ($100mg{\cdot}L^{-1}$) three times at one week intervals 4 weeks before the harvest significantly increased the fruit weight, changed the fruit shape, and reduced the fruit length/diameter ratio giving the peach fruits a round oblate shape. The calcium treatment contributed to enhancing or maintaining the storage potential by increasing the flesh firmness. However, at higher concentrations of $CaCl_2$, i.e., > $600mg{\cdot}L^{-1}$, the positive effects of the chitosan application were offset, and fruit growth was not affected by calcium alone. The application of the chitosan/calcium mixture delayed fruit softening; however, this effect was shortened when the storage temperature was $20^{\circ}C$ rather than $15^{\circ}C$. The internal quality of the fruit was profoundly affected by the concentration of calcium added to the chitosan, and delayed fruit maturation was observed at a higher concentration of calcium. The pre-harvest application of chitosan with calcium contributes to the enhancement of food safety by inhibiting the occurrence of diseases during postharvest handling. Considering the above results, chitosan has the potential to improve both the yield of peach fruits and their storability. Because chitosan can enhance the freshness and shelf-life of fresh produce, it is necessary to examine its effects on other horticultural crops.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.517-526
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• 2023

The harvest time of the late-ripening 'Fuji' apple (Malus × domestica) is variable, depending on the coloration of the fruit skin. Ethephon, a plant growth regulator, promotes the ethylene production and induces physiological responses associated with fruit maturation in climacteric fruit crops, such as apples. This study aimed to investigate the effect of ethephon treatment on fruit characteristics after fruit enlargement, with the objective of proposing an economical and stable harvest control method for 'Fuji'/M.26 apples. Fruit characteristics were assessed at 10-days intervals following the application of 100 mg/L ethephon and mixture of 100 mg/L ethephon and 0.5% CaCl₂ at 145 days after full bloom (DAFB). Starch contents of ethephon-treated (ET) and ethephon with CaCl₂-treated (EC) apples began to decrease from 155 DAFB, and the starch contents of ET and EC at 10 days before harvest were similar to those of control at harvest time. Red coloration of fruit skin in EC was lower compared to ET but higher than control. The average fruit firmness was low in ET, while the control and EC exhibited similar levels of firmness. Fruit sugar acid ratios did not show significant differences between treatments. However, the titratable acidity of EC was significantly lower than that of the control at 10 days before harvest. Moreover, fruit sugar acid ratio of ET and EC at 10 days before harvest in 2021 was similar to their sugar acid ratio at harvest time. Therefore, it was thought that fruit maturation and skin coloration could be accelerated by 10 days from the harvest time through the combined treatment of 100 mg/L ethephon and 0.5% CaCl₂ at the end of fruit enlargement in 'Fuji'/M.26.

• Korean journal of applied entomology
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• v.40 no.2
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• pp.117-123
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• 2001

The occurrence and damage by the oriental fruit moth, Grapholita molesta (Busck) were investigated on pear trees from 1996 to 2000 in the Naju, Korea. The number of overwintering larvae in pear trees considerably varied depending on the maturation time of varieties. The density of overwintering larvae on late cultivars such as Gamcheonbae and Okusankichi was high, but relatively low on early cultivars. Trunk and main branch of pear trees were main overwintering sites. In 1997, overwintering larvae began to pupate from middle February, and to emerge from late March. Male moths were caught in the sex pheromone traps from late March until early October with four peaks of flight in 1996~2000. In every generation larvae damaged both the shoots and fruits of pear tree, but the first and second generation larvae tended to damage mainly shoots, while most of the injured fruits were due to the third and fourth generation larvae. In pear fruits damaged by fruit moths, most of these were caused by oriental fruit moth larvae and none of pear fruits were damaged by peach fruit moth or pear fruit moth larvae in 1998~2000.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.40-60
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• 2003

Fruit ripening represents a genetically synchronized system that involves developmental process unique to plant species, The phenomenon of ripening includes changes in color, texture, respiration rate, flavor, and aroma. Ripe fruits generally exhibit increased susceptibility to pathogen infection. However, fruits as a reproductive organ have their own protection mechanism against pathogens to maintain their integrity during seed maturation. In several nonclimacteric fruits, such as cherry, grape, and pepper, that do not have an ethylene burst during ripening, resistance against phytopathogens increases during ripening. Colletotrichum gloeosporioides is a causal agent of anthracnose disease in pepper plants (Capsicum annuum). We have established that C. gloeosporioides has susceptible and resistant interactions with pepper fruits during pre- and post-ripening stages, respectively. And we have interested in looking for a molecular mechanism that would explain the fungal resistance during ripening of nonclimacteric pepper fruit. In this presentation, a molecular characterization of the pepper esterase gene (PepEST) that is highly expressed in the resistant response will be demonstrated as an example of development and industrial applications of versatile-usable genes of plant.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.82-82
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• 2003