• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.186-193
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• 2007

Effects of deficit irrigation by different soil moisture-based water potential on the reduction of green shoulder fruits in fresh tomato were investigated. Deficit irrigation with -30 kPa treatment significantly reduced green shoulder fruit by 53.7% compared to the -15 kPa treatment. The total concentrations of potassium in levels of whole fruit was not different between normal red fruit (NRF) and green shoulder fruit (GSF). However, the concentrations of potassium in distal part of GSF lower than that of a basal part of GSF Total soluble sugar contents in NRF and GSF were increased during the maturation periods. Contents of starch in NRF and distal part of GSF were decreased during the maturation periods. However, contents of starch in basal part of GSF was not change during the maturation periods. Activity of sucrose phosphate synthase was higher in NRF than that of GSF. Activity of acid invertase in NRF and GSF decreased rapidly during the maturation periods. Activity of acid invertase was significantly different in distal and basal part of GSF. Total activities of peroxidase and alcohol dehydrogenase in NRF were higher than that of GSF.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.264-270
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• 2015

Tropical night phenomenon has been increasing due to global warming recently, it is expected that fruit quality of apples will decrease due to elevated night temperature condition. In the present study, fruit quality at maturity, periodic anthocyanin biosynthetic gene expression and sugar contents in leaves and fruit flesh were investigated to establish the physiological responses of 'Fuji' apples under high night temperature. The night temperature were treated with such as ambient (control), ambient $-4^{\circ}C$, and ambient $+4^{\circ}C$. After the treatment, high night temperature didn't affect fruit diameter, weight, and soluble sugar contents. Coloration of ambient $+4^{\circ}C$ was poor than that of control, however there was no significant difference between these genes expression of control and that of ambient $+4^{\circ}C$ treatment in the late coloration season. Increase of sorbitol and glucose contents at ambient $+4^{\circ}C$ in leaves were smaller than those at control, and then sorbitol and sucrose contents in fruit flesh at ambient $+4^{\circ}C$ were smaller than those at control. The cross section of leaves showed that there were no differences with the structure of parenchyma and epidermis tissues between the treatments, but starch granules in the palisade parenchyma cells decreased in high night temperature treatments. Consequently, high night temperature didn't affect the fruit quality, but changed sugar contents in leaves and fruit flesh, and suppressed coloration regardless of anthocyanin biosynthetic gene expression.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.256-260
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• 2012

This study was carried out to improve the fruit color through ABA treatment and to determine the optimum harvest time for producing high quality fruits in 'Hongisul' grapes. Spraying of $1000 mg{\cdot}L^{-1}$ exogenous ABA at early verasion (70 days after full bloom, DAFB) brought increase of endogenous ABA and soluble solid contents and enhanced fruit coloration. So, it was possible to harvest ABA treated fruits from 85 days after full bloom (15 days after treatment) by accelerated anthocyanin content which increased continuously until 110 DAFB. An increase of soluble solid and decrease of total acidity appeared steadily with the onset of berry ripening. After 100 DAFB, soluble solid content and total acidity did not change significantly, but the berry firmness was suddenly decreased. Consequently, it was suggested that ABA treated fruits need to be harvested at about 100 DAFB because of their short period of marketing by over ripening. On the contrary, harvesting of untreated fruit was totally impossible at 85 DAFB because of their poor berry coloration. But it was possible to harvest them at 100 DAFB based on the soluble solid/acidity ratio, whereas the berry coloration was progressed poorly. On the other hand, the fruits harvested at 110 DAFB showed acceptable berry coloration but their berry firmness was dropped significantly coincide with overripening. Therefore, it was needed to develop an altered production system for improving coloration at around 100 DAFB in 'Hongisul' grapes.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.665-676
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• 2016

As high temperature during citrus growing season has caused a serious problems including inferior coloration in production of mandarins in Korea, we were to investigate the expression pattern of several genes related with coloration during the ripening in high temperature condition of citrus fruits. The expression of genes related with sugar metabolism, cell wall degradation, and flavonoid synthesis in high temperature conditions was investigated in fruits of 'Haryejosaeng' (Citrus unshiu) and 'Shiranuhi' mandarin (C. reticulata). While the expression of beta-amylase (BMY), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and flavanone 3-hydroxylase (F3H) was differently induced, expression of polygalacturonase (PG) decreased dependently on temperature conditions. In 'Haryejosaeng' mandarin, while the expression of genes related to the skin coloration, such as CHS and F3H genes increased at $25^{\circ}C$, the expression of PAL and stilbene synthase (STS) genes were induced at $30-35^{\circ}C$ in all ripening stages. In 'Shiranuhi' mandarin, the expression of the BMY gene decreased at early time point in all temperature condition and then increased at $30-35^{\circ}C$ than at $25^{\circ}C$ in the ripening stage 2 to 3 of fruits. F3H and STS genes also showed the tendency to decrease at $30-35^{\circ}C$. Although the expression levels of genes in ripening stage 1 and stage 2 of fruits showed similar patterns in both 'Haryejosaeng' and 'Shiranuhi', the expression levels of genes were down-regulated in late ripening stage of 'Shiranuhi' fruits compared to 'Haryejosaeng'. In general, the mRNA levels of seven tested genes were higher in 'Haryejosaeng' than in 'Shiranuhi' mandarin, and expression of genes by high temperature was regulated sensitively in 'Haryejosaeng' compared to 'Shiranuhi' mandarin. Further investigations of expression of various genes based on transcriptome analysis in early ripening stage can provide valuable information about the responses to climatic changes in ripening citrus fruits.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.213-221
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• 2018

We analyzed the skin coloration and anthocyanin composition of 'Kyoho' and 'Heukboseok' grape berries to determine the cause of poor coloring in 'Kyoho' berry skins under high temperature (HT) at veraison. Although the skin coloration inhibited in both 'Kyoho' and 'Heukboseok' berries under HT for 30 days from veraison, the total anthocyanin content in 'Heukboseok' berry skins increased to the level of control after the end of temperature treatment, but 'Kyoho' did not increase. Malvidin derivatives were most significantly reduced in 'Kyoho' berry skins, followed by those of delphinidin and petunidin. Among individual anthocyanins, diglucosides and acylated malvidin derivatives were most decreased in 'Kyoho' berry skins. Acylated and tri-hydroxylated anthocyanins were reduced more than those of non-acylated and dihydroxylated, respectively. All different types of anthocyanin components in 'Kyoho' berry skins decreased by HT, and they were similar to that of total anthocyanin. In 'Heukboseok' berry skins, accumulations of all different types of anthocyanins were inhibited by HT, and increased to the level of control after the end of the treatment. These results suggest that the poor coloration of 'Kyoho' under HT at veraison was not caused by the decrease of specific anthocyanins but because the whole anthocyanin biosynthesis was suppressed by HT.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.303-309
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• 2014

The purpose of this study is to suggest indicators and proper standards to forecast the sensory quality of 'Hongisul' grape. Further, this study determines the optimum fruit load of 'Hongisul' grape reflecting consumer preference. Among several quality attributes, identified through instrumental and sensory evaluation, soluble solid-acid ratio was the most useful indicator of consumer preference for 'Hongisul' grapes. The ideal soluble solid-acid ratio for marketable grapes was found to be higher than 86.3. Analysis on the effects of fruit load control on fruit quality revealed a negative correlation where the latter increased as the former decreased. This trend is common for all grape species. The field with a fruit load of $1,400kg{\cdot}10a^{-1}$ exhibited a soluble solid-acid ratio of less than 86.3, uneven coloring and slow softening texture at the mature stage. However, fruit quality proved excellent in the field with a fruit load of $1,200kg{\cdot}10a^{-1}$ or less. It is therefore proposed that fruit load should be controlled to $1,200kg{\cdot}10a^{-1}$ or less when growing 'Hongisul' grapes to produce high quality grapes. We believe that this result can be used as a standard in judging harvest time and evaluating fruit quality.

• 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 $-3.0^{\circ}C$.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.81-89
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• 2004

The effects of developed grape bags on the micro-climate changes of bag, physiological disorder, pathogenic decay, quality and harvest time evaluation in 'Campbell Early' grapevines were studied. The temperature and light transmittance of developed grape bags showed no differences compared with the onces of conventional bag and non-bagging, but relative humidity and the amount of water evaporation were changed in all treatments. The occurrence of unfertilized fruit, poorly colored fruit, russet and gray mold rot showed no significant difference in all treatment at harvest time. Developed grape bags decreased effectively the occurrence of cracking fruit and bitter rot in 'Campbell Early' fruit. There was no difference in growth of cluster and berry, soluble solids and total acidity in fruits, degree of skin color and bloom appearance at harvest time. The skin color and fruit boom and harvest time evaluation in developed grape bags were resulted excellent compared with the once of conventional bag and non bagging.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.126-133
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• 2019

In recent years, the deterioration of fruit quality caused by poor coloration and sunburn disorder has become serious problems in apple market, which is a result of the increase of surface temperature due to the abnormal temperature increase during summer season. This study was conducted to investigate the effect of wind net shading and fine water spray using sprinkler on fruit coloration, sunburn damage and overall fruit quality of 'Fuji' and 'Hongro' apples. Fifteen sprinklers (7L/hr) were installed at the orchard of the Chungcheongnam-do Agricultural Research and Extension Services, located in Sinam-myeon Chungcheongnam-do Korea, at a height of 3m above the apple tree of $1.5m{\times}3.5m$ north-south direction. Fine water spraying treatment was divided into day time spray (10:00 am to 6:00 pm) and all day spray (10:00 am to 10:00 pm) from early July to 10 days before harvest in 2017 and 2018 season, respectively. Temperature of the surface of apple fruit, characteristic of fruit, and degree of sunburn damage were investigated. In 'Fuji', the fruit surface temperature checked at 2 pm on August 10 was decreased considerably in the day time spray ($35.6^{\circ}C$) and wind net ($39.0^{\circ}C$) when compared with the untreated control ($44.4^{\circ}C$). Similarly, the fruit surface temperature also decreased considerably in the all day spray ($35.1^{\circ}C$) and wind net ($36.9^{\circ}C$) treatments when compared with the untreated control ($46.5^{\circ}C$) in 'Hongro' apples. The incidence of sunburn disorder was significantly decreased with day time spray (5.0%), all day spray (5.8%) and wind net (7.0%) when compared with untreated control (23.4%) in 'Fuji' apples. As a results, the treatment of fine water spray and wind net consequently showed 26% and 34% increase of redness ($a^*$) value in the skin color difference, respectively, in 'Fuji' apples.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.2
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• pp.93-100
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• 2011

The study was conducted to investigate the correlation analysis between fruit quality and climatic parameters in grapevines. 'Campbell Early', one of the major grape cultivars, occupies more than 70% of cultivated areas in Korea. Recent research results have shown that the movement of cultivation area of fruit production resulted from the temperature increase. In this study, we investigated the relationship between fruit quality and climatic conditions in 13 major 'Campbell Early' grape producing areas (i.e., Sacheon, Jinju, Naju, Dangjin, Cheonan, Gimcheon, Yeongdong, Okcheon, Sangju, Suwon, Yeongju, Gangneung, Chuncheon, and Yanggu). The earliest and latest full blooming days of grapevines were ovserved on May 25 in Sacheon area and on June 7 in Yanggu area, respectively. At least 90 days are required for grapes to mature enough for the production of highquality fruits. The southern areas with less than 90 days of maturity period had difficulty in the production of good fruit. However, the areas with longer maturity period of 100 to 110 days produced grapes with with high sugar content and good coloring. The fruit qualities of 'Campbell Early' grapes are more closely related with temperature than other climatic factors. High temperature resulted in fruits with high acidity and delayed the coloration of the fruit skin in the southern area. The fruit skin was thin in the southern area and inclined to be thicker in the northern areas. Therefore, grape should be cultivated in regions with long maturity period to have high quality.