• Horticultural Science & Technology
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• v.18 no.5
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• pp.605-611
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• 2000

This experiment was conducted to examine the effects of foliar application of ethychlozate and ethyclozate mixed with different calcium formulae (clef-non, suical, cell-bine, and calcium acetate monohydrate) on the fruit quality and peel puffing of 'Miyagawa Wase' satsuma mandarin cultivated in a plastic film house. Foliar application of ethychlozate mixed with clef-non or suical showed a result that the 'a' value of peel chromaticity was increased, which are supposed to accelerate peel coloration without peel puffing. The reducing sugar levels of fruits in control, ethychlozate, ethychlozate+celef-non, ethychlozate+suical, ethychlozate+cell-bine, and ethychlozate+calcium acetate monohydrate treatment were 4.98, 5.30, 5.59, 5.00, 5.20, and 4.27%, respectively. Especially, in the case of ethychlozate mixed with clef-non, the reducing sugar level was 0.61% higher than that of control. Sucrose and total sugar content also had a similar trend as that in the reducing sugar contents. The sugar contents of fruits in various ethychlozate treatments mixed with different calcium formulae except those in ethychlozate treatment or ethychlozate treatment mixed with calcium acetate monohydrate were higher than $12^{\circ}Brix$. Especially, the treatment of ethychlozate treatment mixed with clef-non showed the highest sugar content with $12.7^{\circ}Brix$. The ratio of soluble solids to acidity also showed the similar tendency, but there was no significant difference in acidity among the treatments.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.40-45
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• 2021

Prior studies of physiologically active substances in grapes have focused only on the fruit, pericarp, and branches, as well as the pulp and seeds. The present study assessed the changes in quercetin-3-O-glucuronide (Q3OG) and flavonol glycoside content using grape leaves from Vitis labruscana B. and V. coignetiae at different growth stages and provided basic data for quality control. Content analysis showed that both varieties differed in Q3OG and flavonol glycoside content by growth stage, and the components were found to be high in the order of fruit, maturation, and coloration. Also, Vitis labruscana B. has a better vascular relaxation effect than Vitis coignetiae. These results suggest that in the use of grape leaves as a functional raw material, Q3OG and flavonol glycosides can be used as indicator components. In addition, if raw materials for each growth stage are mixed in a particular ratio, it will be a way to manage the specific efficacy and content of indicator components.

• Korean Journal of Environmental Agriculture
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• v.38 no.2
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• pp.89-95
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• 2019

BACKGROUND: Liquid pig manure (LPM) has been used as an alternative for conventional fertilizers on some gramineous crops. However, its chemical properties varied widely depending on the degree of the digestion. A pot experiment was conducted to determine the responses of persimmon trees to immature (not well-digested) LPM application. METHODS AND RESULTS: Ten application levels of immature LPM, consisted of a total of 3 to 30 L in 3-L increment, were applied during summer to 5-year-old 'Fuyu' trees grown in 50-L pots. Increasing the LPM application rate caused defoliation, wilting, and chlorosis in leaves. When applied with the rate of 3 L during summer, the tree produced small fruits with low soluble solids and bore few flower buds the following season, indicating insufficient nutritional status. In trees applied with the LPM rates of 6~12 L, both fruit characteristics and above-ground growth of the trees appeared normal but some roots were injured. However, application of higher LPM rates than 27 L resulted in small size, poor coloration, or flesh softening of the fruits the current season. Furthermore, the high LPM rates caused severe cold injury in shoots during winter and weak shoot growth the following season. It was noted that the application of higher LPM rate than 9 L damaged the root, even though above-ground parts of the tree appeared to grow normally. CONCLUSION: The results indicated that an excessive immature LPM application could cause various injuries on leaves, fruits, and the roots in both the current and the following season.

• Journal of Environmental Science International
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• v.33 no.9
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• pp.613-623
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• 2024

This study was conducted in the greenhouse of the Citrus Research Institute of the Rural Development Administration with the aim of analyzing electron transfer efficiency in citrus under high temperatures caused by climate change and selecting photophysiological indicators to identify high temperature resistant varieties. The "Shiranuhi" cultivar showed no change in maximum fluorescence or Origin-Jump transition stage due to the heat treatment. However, chlorophyll fluorescence parameters, such as RC/CS, ABS/CS, and ETo/CS, increased. Consequently, it was judged that there was no decrease in photosynthetic performance due to high temperature. However, compared to mandarin orange, "unshiu Marcow" was found to have damage to the photosynthetic apparatus due to a significant increase in chlorophyll fluorescence in the O-J transition stage. It was also evaluated as Group III, with the lowest level of high-temperature resistance even in the high-temperature stress index analysis using PI ABS, making it the most vulnerable to high temperatures among the five varieties tested. In conclusion, chlorophyll fluorescence reaction analysis can be used for heat cultivation technology by selecting resistant varieties and identifying the appropriate temperatures.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.261-271
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• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.1-16
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• 2000

This study was carried out to examine the process of plant succession through vegetation invasion and to select appropriate endemic plant species for rapid stabilization and good visual effect on cut-slopes of forest roads. Establishing total of sixty $1m{\times}1m$ sample plots. fifteen for each forest road constructed in the year of '93 (six-year-old), '95(four-year-old), '97(two-year-old), and '98(one-year-old), the ecological attributes of invading vegetation on cut-slopes were analyzed. The results are summarized as follows: 1. The rate of vegetation coverage was highly associated with soil hardness and aspect of cut-slope. Higher rate of vegetation coverage was caused by larger number of invading plant species. 2. The dominant woody species were Rubus crataegifolius, Rhus chinensis, Lespedeza bicolor, Salix hulteni, Alnus hirsuta, and Pinus densiflora. The visual attractive for the fruit of Rubus crataegifolius and the autumn coloration of Rhus chinensis was noteworthy. The dominant herbaceous species were Youngia sonchifolia, Spodiopogon sibiricus, and Lysimachia clethroides in all study forest roads. Spring flower of Potentilla freyniana and Viola rossii: summer flower of Lysimachia clethroides, Commelina communis, Glycine soja. Persicaria sieboldi, and Oenothera odorata: and autumn flower of Artemisia stolonifera and Impatiens textori were abundant and remarkable. 3. The diversity index of woody species tended to be increased as years passed after construction, and that of herbaceous species were decreased. 4. The dominance of Th of dormancy form was early high in the first year of construction, getting decreased thereafter. And that of MM + M + N was increased as years passed after construction. but that of Ch+H+G+Th+HH was decreased. 5. The degrees of succession were estimated by 359, 111, 97, and 87 for the construction year of '93, '95, '97, and '98. respectively, increased as years passed after construction.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.1-9
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• 1991

This experiment was aimed to develop possible methods to control the maturity of grape berries through the application of exogenous plant growth substances and physical treatments such as defoliation or girdling. 1. Chlormequat and paclobutrazol increased anthocyanin but did not affect soluble solids contents and maturity. Girdling enhanced maturation and solids accumulation whereas defoliation delayed maturity. Solids content of berries in defoliation treatment did not reach to the level of other treatments even when fully ripened. 2. Ripening of grapes is greatly delayed for 20 to 30 days by the application of auxins (2,4-D and fenoprop) compared to the untreated control. Uneven ripening of berries in those clusters was observed when the concentration of auxin was over 50 ppm. Thus, about 30% of berries remained green until the normal berries were overripened. 3. Gibberellin did not affect the maturity of grape berries but maturity was greatly delayed when GA was applied with auxins. Also, uneven coloration between berries was observed such as in the application of auxin alone. 4. Ethephon application combinded with calcium at veraison showed no effect on berry ripening but increased anthocaynin contents. It can be concluded that harvest time of 'Campbell Early' grapes can be effectively extended by delaying the maturity through the application of auxin.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.706-713
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• 2013

With pot-grown 4-year-old 'Fuyu' persimmon trees, this study evaluated the effect of different nitrogen (N) rates during summer on fruit characteristics, changes of leaf nutrients after harvest, reserve accumulation, and early growth the following year. A total of 0, 36 g N in June, and 72 g N in June and July was fertigated to each tree using urea solution. All the fruits were harvested on Nov. 3. Although not significant, fruits were larger for the 36 g and 72 g N than the 0 g N. Fruits for the 0 g N, having lower N concentration, were softer and had a better coloration and higher soluble solids, indicating that they matured earlier. SPAD value on Nov. 3 was 19.2 for the 0 g N and 54.9 for the 72 g N, and then the values linearly decreased in all the treatments by Nov. 14, exhibiting rapid leaf senescence. Specific leaf weight, being the lowest for the 0 g N, also gradually decreased during this period. Increasing N level significantly increased cross-sectional area of the trunk. Leaf N concentration on Nov. 3 was 0.87% for the 0 g N, whereas it was 1.18 and 1.52% for the 36 g and 72 g N, respectively. The N fertigation tended to increase leaf concentrations of soluble sugars, starch, and amino acids. Contents of N, P, K, soluble sugars, starch, and amino acids per unit leaf area gradually decreased in all the treatments during the 11 days after harvest, and the extent of the decrease was the lowest for the 0 g N. On the other hand, those of Ca, Mg, and protein did not consistently change during this period. The N fertigation resulted in higher concentrations of N in dormant shoots on Nov. 14, and although not great, it also increased soluble sugars, starch, amino acids, and protein. Clear differences were found in number of flower buds per one-year-old branch and total shoot length per tree the following year. The 72 g N trees had 5.6-fold more flower buds and 1.9-fold more shoot length, compared with those of 0 g N trees. However, it was noted that tree growth the following year was not significantly different between the 36 g and 72 g N the previous year. It was concluded that N rate during summer should be adjusted with considering the changes of fruit maturation, mobilization of leaf nutrients, and reserve accumulation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.1
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• pp.1-8
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• 2013

This study was conducted to compare the local climate conditions and growth periods for the apple (Malus domestica 'Borkh') orchards at different altitudes (330, 500, and 670 m) in Jangsu-Gun, Korea. Observation data for the growth period show that the monthly mean air temperatures at the 'Hongro' apple orchard sites decrease with height at the rate of 1.0 to $3.0^{\circ}C$/100 m. The monthly minimum temperatures in April (blooming period for 'Hongro' apple) were 4.3, 2.9, and $0.4^{\circ}C$ at 330, 500, and 670 m, respectively. The monthly mean temperatures in September (i.e., the coloration and maturation period) were 20.6, 18.7, and $14.5^{\circ}C$, respectively. The annual precipitation range varied from 1,234 to 1,439 mm, which tended to increase with height. The heavy rainfall occurred in summer (June to August) and amounted to 827-933 mm. No significant differences in the duration of sunshine were observed amongst the orchards at three different altitudes. The earliest bud break was observed at the 330 m altitude (18 March 2009), which was 4 and 11 days earlier in comparison to those at 500 and 670 m, respectively. The time of full bloom at 330 m was 12 days ahead of that at 670 m. The optimal maturation of fruit (based on skin redness > 80%) was observed between 7 and 10 September at 330 m, 15 and 18 September at 500 m, and 21 and 23 September at 670 m.