• 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.

• The Korean Journal of Food And Nutrition
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• v.13 no.5
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• pp.440-445
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• 2000

To develop a new processed foods with prepersimmon, the contents of approximate composition, free sugar, organic acid, mineral and vitamins in prepersimmon(Diospyros kaki Thumb. cv. Fuyu) were investigated. The approximate composition was 89.08% of moisture, 0.26% of crude ash, 0.56% of crude fat and 0.75% of crude protein respectively. Free sugars were composed of glucose, fructose and sucrose. Glucose(3.34%) and fructose(3.01%) were major free sugars, and sucrose was detected a small quantities. The organic acids were composed of citric acid. maleic acid, fumalic acid and lactic acid. Lactic acid(68.65mg%) was major a organic acid and took 79% of total organic acid amount. Minerals were K, P, Na. Ca, Fe and Zn, and K was a major mineral and detected 126.l2mg%, and Fe and Zn were a small quantities. The content of vitamin A was 33.95 R.E., and less than that in hard persimmon, and the content of vitamin C was 171.01 mg%, 10 times higher in comparison with that in hard persimmon, and vitamin B$_1$ and B$_2$ were detected a small quantities.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.201-205
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• 1982

As a series of study on the removal of astringency and production of tannin substances, this experiment was conducted to investigate changes of tannin contents and microscopic observation on leaves of persimmon(Diospyros kaki L.). Changes of tannin contents of leaves and fruits in Daegu Bansi(astringent variety) were of similar tendency in content of total and soluble tannin during growth. It seemed therefore that tannin contents of leaves in astringent variety were closely concerned with tannin of fruits. But Fuyu(sweet variety) was different from each other during its growth. Histological form of leaves in microscopic observation had similar tendency between astringent and sweet varieties. It was observed that tannin substances were contained in epidermis cells of levels, that tannin substances were transfered in phloems of nerves system, and that tannin cell existed too in the vicinity of nerves system.

• Journal of Plant Biotechnology
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• v.42 no.1
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• pp.43-48
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• 2015

It is a serious situation that the farmers' income has gradually decreased due to the decline of productivity of fruit trees infected with viroids. It has been known that Persimmon viroid (PVd) and Citrus viroid (CVd) are economically important viroids that can infected persimmon. In this study, the incidence of CVd and PVd in 'Fuyu' persimmon were identified as 41% and 34% in JeollaNam-do, respectively. The collected persimmon samples infected by both PVd and CVd were used for testing efficiency of the viroid inactivation methods. The samples were subjected to single treatment of the heat treatment ($37^{\circ}C$), cold treatment ($4^{\circ}C$), or antiviral agent treatment (Ribavirin), and double treatment of combinations of the three methods. Viroid inactivation efficiency was confirmed through RT-PCR. In the case of the samples subjected to cold treatment for 4 weeks, the viroid inactivation efficiency was most significantly high as 67% against the survival rate of 100%. In addition, in the case of the samples treated for 2 weeks with the antiviral agents and cold treatment, the viroid inactivation rate was similar to that of the cold treatment. In conclusion, the cold treatment showed the highest viroid inactivation efficiency, and this result will provide valuable information for production of viroid-free persimmon.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.728-734
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• 2010

We studied the accumulation and partitioning of dry weight (DW) and nitrogen (N) in different parts of field-grown 'Fuyu' persimmon to elucidate that the foliar applications of supplemental N in June or September compared favorably with the traditional soil application in securing leaf area and fruit production. We also estimated the proportion of N permanently removed from the tree at the end of a growing season. Urea was applied either to leaves in June and/or September or to the soil in June and September for three consecutive years, and the trees were excavated in November for analyses. Total DW ranged from 4.2-4.8, 8.7-9.2, and 17.1-21.5 kg in a 4-, 5-, and 6-year-old tree, respectively, without statistical difference among the four treatments. Of the total DW, 3.3-10.2% was in shoots, 5.7-10.5% in leaves, 8.3-31.4% in aerial woods, 13.0-27.0% in root, and 28.0-59.3% in fruits. As the trees became more productive, DW proportion of fruits significantly affected that of the root: in 6-year-old trees, root DW accounted for only 10.6-15.8% of the tree total when fruit DW accounted for 50-60%. N contents ranged from 24.6-28.3, 48.3-53.5, and 98.3-122.6 g in a 4-, 5-, and 6-year-old trees, respectively, without statistical difference among the treatments. Of the total N, 6.2-11.5% was in shoots, 16.7-24.3% in leaves, 17.6-23.5% in aerial woods, 17.2-37.5% in roots, and 16.9-34.4% in fruits. As in DW, the increase in the proportion of N in fruits decreased in the root most significantly. Application methods for supplemental N did not affect the proportion of DW and N removed from the tree through abscising leaves and harvested fruits. Percentage of DW removal was 41 in 4- and 5-year-old trees, but it was 61 in more productive 6-year-old trees; that of N was 39, 43, and 49%, respectively. No significant changes in the contents of DW and N in field-grown trees, as well as their percentages removed from the tree at the end of the season, demonstrated that foliar application of supplemental N was as good as soil applications with much less N.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.166-170
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• 2013

BACKGROUND: Persimmon growers have often tried various regimens of K fertilization to improve fruit quality. This experiment was conducted to determine the effects of K rates on concentration of inorganic elements in different tree organs and on fruit characteristics. METHODS AND RESULTS: Six-year-old non-astringent 'Fuyu' persimmons, grown in 50-L pots, were used. Total K amounts of 0 (no-application), 12, 25, 37, and 66 g were fertigated to a pot with KCl solution at 3-to 4-day intervals from July to September. The 0 K trees received no K fertilizer for the two previous years. Leaves, fruits, and shoots were sampled in November. K concentrations in leaves and shoots increased significantly by increasing K rate; leaf K, 0.49% for the 0 K, increased to 3.09% for the 37 g and 3.11% for the 66 g trees. Fruit K was notably lower for the 0 K, but there were no significant differences among the trees as long as they were supplied with more than 12-g K. In the trees with 0 K, leaf necrosis in the margin was apparent in June and the symptom progressed toward the midrib. Some leaves scorch-rolled from the margin in August. The greatest effect of K rates was on fruit size; it significantly increased to 181 g for the 12 g, 203 g for the 37 g, and 206 g for the 66 g compared with 150 g for the 0 K trees. However, K rates did not affect firmness and soluble solids of the fruits. The fruits of the 0 K trees were characterized by better coloration. CONCLUSION(S): The K-rate effect on inorganic elements depended on tree organs and fruit size was the major parameter to be affected by the K rates.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.53-57
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• 2013

A severe defoliation by typhoon in early autumn reduces fruit quality for the current season and reserve accumulations for the next season. This study was conducted to determine the effects of foliar applications during the autumn on alleviating the damages after defoliation. Leaves of 2-year-old 'Fuyu' trees, grown in 50-L pots under a rain-shelter, were 75%-defoliated on September 9. In mid-September and early October, trees were treated either with eight foliar applications of urea or with four alternating applications of urea and $KH_2PO_4$ (urea + KP application), all at 0.5% (w/v). Trees untreated after the defoliation served as the control. The urea applications slightly increased N and P concentrations of the leaves collected on November 6, while urea + KP applications significantly increased P and K concentrations. Foliar applications did not affect fruit growth, but tended to decrease skin coloration. Fruit soluble solids increased by 1.5 and $1.0^{\circ}Brix$ for urea and urea + KP applications, respectively. There was a significant increase in dry weight of fine root for the foliar application treatments but not in those of aerial woods and larger roots. With the foliar applications, N concentration tended to increase in the permanent organs but not P and K, whereas soluble sugars and starch notably increased in shoot, trunk, or fine root regardless of the different applications. Results indicated that the foliar applications could partially help to restore fruit quality and carbohydrate accumulations in the defoliated trees.

• Journal of Bio-Environment Control
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• v.19 no.3
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• pp.165-170
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• 2010

This experiment was conducted to select the affected main factors on growth and fruit characteristics of 'Fuyu' persimmon (Diospyros kaki Thunb.) in 25 factors of air temperature factors in Naju. Mean air temperature, cumulative temperature and days for March and April of 25 factors were the highest annual variation. Number of the first and second principal components extracted from 25 air temperature factors were 14 and 3 factors related with mean temperature for annul and April, and cumulative contribution of these was 52.2%. Also the affected years by the first principal components were 1990, 1980 and 1986. Annual standard deviation on leafing, flowering and maturing date were 4.0~6.7 days range, and flowering date and days from leafing to flowering had the highest coefficient of variation. Annual variation of days from flowering to maturing date was affected by greatly mean air temperature and days of cumulative temperature in October, days from March 1 to leafing date was affected by cumulative temperature for growing period, days from leafing to flowering date was affected by mean air temperature in April. Annual variation of fruit weight was affected by mean air temperature for March and October.

• 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.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.309-314
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• 2006

This study was performed to confirm the physicochemical properties and physiological activities according to cultivar and parts of Ulsan sweet persimmons. The proximate composition of the sweet persimmons was moisture $77.68{\sim}84.65%$, crude ash $0.3{\sim}0.6$, crude fat $0.29{\sim}0.39$ and crude protein $0.52{\sim}0.61%$. Confirmed organic acids and free sugars in sweet persimmons were malic, citric, succinic, and fumaric acids, along with fructose, glucose and sucrose. The major fatty acids were linolenic, vaccenic and palmitic acids. Also, K is the highest mineral in sweet persimmons that accounts for the majority of mineral, more than 60% as $84.9{\sim}103.7mg%$. Contents of vitamin C, total phenolic compounds and flavonoids were the highest in Fuyu peel as 139.91, 169.36 and 60.79mg%, respectively, Electron donating ability and xanthine oxidase inhibition were the highest in Fuyu peel as $30.6{\sim}91.2$ and $26.3{\sim}91.9mg%$, respectively. Nitrite scavenging activity was higher in peel than flesh as $51.0{\sim}76.4mg%$ with slight difference depending on cultivar.