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

• Korean Journal of Organic Agriculture
• /
• v.10 no.3
• /
• pp.57-66
• /
• 2002

The experiment described in this paper focused on determining the effects of high-temperature(20$^{\circ}$) treatment of Satsuma mandarins, prior to their storage, on their color development and quality. High-temperature treatment promoted fruit skin color during the storage, decreased the weight loss regardless of their color at the time of their harvest and reduced the decay occurrence until the middle of March, but there was no difference between treatments after the end of March. There was a tendency of higher soluble solid and acid levels in the fruit when high-temperature treatment was applied but this difference was not significant.

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

• Journal of Bio-Environment Control
• /
• v.22 no.1
• /
• pp.55-59
• /
• 2013

This study was evaluated that seasonal change of the hesperidin content was in relation to the skin color and weight of fruit in outer or inner side of the canopy, for determine the optimum time and the index of most abundant hesperidin content in lemon fruits juice. The hesperidin content was different with fruit growth and on fruit bearing site of the tree. The fruits of the either side contained the highest hesperidin value at 162 and 176 days after anthesis just after de-greening and the value was highest in the fruits of outer side of the canopy. This time also corresponded to the time just before the cessation of fruit growth. These results suggested that the optimum harvesting period for more hesperidin content was the stage just after de-greening and just before fruit growth cessation.

• Horticultural Science & Technology
• /
• v.31 no.4
• /
• pp.437-446
• /
• 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 Bio-Environment Control
• /
• v.18 no.4
• /
• pp.431-435
• /
• 2009

This study was conducted to compare the effect of various LED and UVa light to enhanced coloration of paprika fruits cultivars; 'Special', 'Helsinki'. Immatured paprika fruits were irradiated with red LED, blue LED and UVa lights which were high intensity (red: $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $70{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and low intensity (red: $20{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $0.25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The coloration of 'Special' cultivar was increased the fastest in high intensity UVa light for 2 days after treatment. There were no significantly difference among treatments except the low intensity UVa light. The coloration of 'Helsinki' was increased the fastest in blue LED light, and followed by red LED light and UVa light for 2 days after treatment. The $a^*/b^*$ value of 'Special' and $b^*$ value of 'Helsinki' that indicated the paprika fruit coloration were generally higher high intensity LED and UVa lights than low intensity LED and UVa lights. We couldn't find out any significantly different coloration effect among all treatments in final days of coloration. and rather than UVa treatment fruit shrunk the surface of paprika fruits.

• Horticultural Science & Technology
• /
• v.29 no.2
• /
• pp.81-86
• /
• 2011

The effects of girdling on fruit quality and cold resistance of 'Kyoho' grapes were investigated. Girdling treatment was conducted on the trunk at 10 cm above ground with 1 cm width and grapes were harvested at 90 and 110 days after full bloom to compare the fruit quality. First harvesting rate in girdling treatment was higher than that in non-girdling treatment and coloration was also higher in girdled vines at the final harvest. In other words, coloring process of grape was promoted and enhanced by girdling, but this effect of coloring improvement was decreased after successive girdling treatment. Fruit quality showed no difference between the treated and non-treated berries, but fruit cracking rate was lower in girdled treated berries. Girdled trees were weakened and suffered from freezing damage. Especially, most grapevines withered up after being girdled for three consecutive years. Although girdling had effect on improving the berry coloring significantly, the effect wore off with continuous girdling. And it was possible that consecutive girdling leaded to wither and growth suppression especially in grapevines. These adverse effects may make the continuous girdling technique unsuitable in practice for 'Kyoho' grape.

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

• Journal of Bio-Environment Control
• /
• v.28 no.4
• /
• pp.302-310
• /
• 2019

This study was conducted to investigate the effects of LEDs on the fruit qualities of two strawberry (Fragaria ${\times}$ ananassa Duch.) cultivars such as hardness, phytochemicals, and antioxidant activity using the strawberry fruits, which were harvested by 50% and 100% ripening levels of fruits grown under LEDs illuminated during 6 hours after sunset from November 2018 to January of the following year. In the hardness of strawberry fruit, when two strawberry cultivars were illuminated red LED light, in 50% ripening as well as 100% ripening fruit of both 'Daewang' and 'Seolhyang' cultivars were significantly higher compared to other treatments. Also, in the sugar content on 50% ripening fruit of two cultivars, the fruit of red LED light was significantly higher than in the other LEDs and control. On the other hand, in the acidity of 50% and 100% ripening levels of strawberry fruit, the fruit under control condition was higher in than that of LEDs. The phenolic compounds of strawberry fruit grown in control was much higher than that of strawberry treated with LEDs. However, the influence of LEDs on flavonoid and anthocyanin content of strawberry fruit did not affected. Changes in the phytochemicals contents of the strawberry tends to be affected depending on the maturity of fruit. Antioxidant activity such as DPPH and ABTS of were not different by maturity of fruit, and supplementation of LEDs during 6 hours at night. Therefore, we concluded that lighting of LEDs is effective for fruit quality in terms of sugar accumulation and fruit hardness.

• Horticultural Science & Technology
• /
• v.28 no.5
• /
• pp.757-761
• /
• 2010

This research was conducted to investigate effect of ethephon on fruit enlargement and coloring of 'Fuyu' persimmon ($Diospyros$ $kaki$). At 7 weeks after ethephon treatment, fruit weight and diameter became significantly heavier and longer in 80 and $100mg{\cdot}L^{-1}$ than the other concentrations of ethephon. Fruit peel hardness decreased with increasing ethephon concentration. The decreased levels were apparent with the treatments beyond $40mg{\cdot}L^{-1}$ at the beginning, and then with those beyond $60mg{\cdot}L^{-1}$. Hunter $a^*$ and $Chroma^*$ of fruit peel treated with ethephon over $20mg{\cdot}L^{-1}$ were significantly higher compared to those with control ($0mg{\cdot}L^{-1}$), but there were no significant differences among those with the ethephon treatments over $20mg{\cdot}L^{-1}$. The increased levels of the $Chroma^*$ were apparent with the treatments beyond $60mg{\cdot}L^{-1}$ at the beginning and then with those of 20 and $40mg{\cdot}L^{-1}$. ${\beta}$-Carotene and lycopene contents of fruit peel were higher with the ethephon treatment beyond $40mg{\cdot}L^{-1}$. Although the ethephon application at 20 and $40mg{\cdot}L^{-1}$ had no effects on fruit enlargement, but fruit coloring was advanced by 2 weeks with the application at $40mg{\cdot}L^{-1}$.