• Horticultural Science & Technology
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• v.29 no.4
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• pp.317-325
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• 2011

This study was conducted to examine the effect of supplemental lighting on the growth and yield of hydroponically grown sweet pepper (Capsicum annuum L. cv. sprit) under low levels of natural light in winter. The plants were treated with natural light only (control), 3-hour supplemental lighting before sunrise, after sunrise and after sunset with high pressure sodium (HPS, 400W). As the result of these three treatments, the supplemental lighting promoted photosynthesis in the low light intensity condition and particularly photosynthesis was more active right after sun rise in the morning, 1.5-$3.0{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$ comparing to those of supplemental lighting after sunset, 0.5-$1.5{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$. Transpiration rate and stomatal conductance sharply increased with supplemental lighting after sunrise then they decreased again after turning the lights off. Stomatal size was observed $32.2{\mu}m^2$ after supplemental lighting, whereas the size of the natural light was almost closed at $7.7{\mu}m^2$. The average plant height of sweet papper cv. spirit was 185 cm before sunrise, 188 cm after sunrise and 208 cm after sunset with supplemental lighting for 3hours while the control was 171 cm. With supplemental lighting a better number of fruit set per plant was measured 4.3 before and after sunrise, 3.7 after sunset but 2.6 in the control. Interestingly, there were no significant differences in the sugar content ($^{\circ}Brix$) degree between treatment of supplemental lighting, whereas slight differences between seasons were seen. The marketable fruit yield of sweet pepper (cv. spirit) was $116.0kg{\cdot}ha$ with supplemental lighting, whereas the control (natural light only) was $75.8kg{\cdot}ha$. Despite of spending electricity and depreciation cost, the economic analysis showed net income with supplemental lighting after sunrise was 51% higher than control treatment in cv. spirit.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.692-700
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• 2016

The objective of this study was to determine the differences in fruit growth, fruit quality, and particularly the pedicel vascular bundles of 'Shigyoku' and 'Heukboseok' grapes, which appeared to be different in softening at harvest. 'Shigyoku' grape matured faster (by about 20 days) than 'Heukboseok' grape with slight fruit enlargement after veraison. However, fruit of 'Heukboseok' grapes showed remarkable enlargement in both the primary and secondary fruit enlargement periods. Hypodermal cell layers were not different after veraison in 'Shigyoku' grape, but degradation of the hypodermis cell wall continued in 'Heukboseok' grape, resulting in a gradual decline in firmness. The numbers of hypodermal cell layers in 'Shigyoku' and 'Heukboseok' grapes were 14.2 and 9.0, respectively. The average content of soluble solids in 'Shigyoku' grape ($19.5^{\circ}Brix$) was significantly ($p{\leq}0.01$) higher than that of 'Heukboseok' grape ($17.0^{\circ}Brix$). Xylem of the pedicel did not differ between the two varieties. However, average phloem area after veraison of 'Shigyoku' grape ($19044.8{\mu}m^2$) was about 1.8 fold greater than that of 'Heukboseok' grape ($10509.4{\mu}m^2$), based on the number of cells constituting the phloem. The cell number and area of the phloem might affect the accumulation of sugars, the main constituents of the cell wall, thus maintaining the firmness of grapes until late maturity. Therefore, the increased softening of 'Heukboseok' grapes at harvest might due to their phloem structure.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.607-615
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• 2016

This research was conducted to investigate the influence of different kinds of acids added to irrigation water containing high levels of bicarbonate on the growth and daughter plant production during the propagation of 'Seolhyang' strawberry. Fertigation solution was prepared with equal concentrations of essential nutrients as found in Hoagland solution, plus $240mg{\cdot}L^{-1}\;HCO_3{^-}$. The concentrations of $HCO_3{^-}$ in the treatment solution were decreased to $60mg{\cdot}L^{-1}$ by the addition of $HNO_3$, $H_3PO_4$, $H_2SO_4$, $HNO_3+H_3PO_4$, or salicylic acid. The mother plants transplanted to raised beds were treated with a specific treatment solution for 126 days and growth and daughter plant productions were monitored. The fresh weight of mother plants in the -control treatment ($240mg{\cdot}L^{-1}\;HCO_3{^-}$) was significantly lower than those in acid containing treatments. The number of daughter plants produced per mother plant was 13 in the -control treatment, but 19.4, 20.1, 18.6, 22.4, and 18.9 in the treatments of $HNO_3$, $H_3PO_4$, $H_2SO_4$, $HNO_3+H_3PO_4$ and salicylic acid, respectively. The substrate pHs after 126 days of treatment were 8.2 and 7.3 in the -control and salicylic acid treatments, respectively, but 5.5, 5.4, 5.3, and 5.5 in the treatments of $HNO_3$, $H_3PO_4$, $H_2SO_4$, and $HNO_3+H_3PO_4$ treatments, respectively. The tissue Ca and Mg contents of mother plants were significantly higher in +control ($90mg{\cdot}L^{-1}\;HCO_3{^-}$) and various acid blending treatments compared to the -control treatment. By contrast, Ca and Mg contents were not significantly different among treatments with acids. The Fe, Mn, Zn, and Cu contents in plant tissue of -control were also significantly lower than those in all other treatments.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.736-745
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• 2016

This research was conducted to evaluate the impact of various pre-planting $NH_4{^+}:NO_3{^-}$ ratios on the growth of plug seedlings of 'Bool-am No.3' Chinese cabbage. With fixation of the pre-planting N concentrations to $300mg{\cdot}kg^{-1}$ in a peatmoss+coir dust+perlite (3.5:3.5:3, v/v/v) medium, the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, 100:0. Then, the each of root media containing various ratios of $NH_4{^+}:NO_3{^-}$ as well as equal concentrations of other essential nutrients was packed into 72-cell plug trays. After seeds of 'Bool-am No.3' Chinese cabbage were sown, the seedling growths were measured 2 and 4 weeks after sowing. The weekly analysis of root media and end-crop tissue analysis for mineral nutrients 4 weeks after seed sowing were also conducted. As the seedlings grew up, the pH of the root media increased, however ECs in all treatments of $NH_4{^+}:NO_3{^-}$ ratios decreased. The concentrations of K, Ca and Mg in root media were higher in the treatments of $NH_4{^+}:NO_3{^-}$ (100:0) and $NH_4{^+}:NO_3{^-}$ (73:27) than those of $NH_4{^+}:NO_3{^-}$ (0:100) and $NH_4{^+}:NO_3{^-}$ (27:73) 2 weeks after seed sowing. But the concentrations of K, Ca, Mg and Zn were get lowered in all treatments and the differences among treatments were not significant 4 weeks after sowing. The highest $NH_4{^+}$ and lowest $NO_3{^-}$ concentrations of the root media were observed in the $NH_4{^+}:NO_3{^-}$ (100:0) among all treatments. Contrary to these, the treatment of $NH_4{^+}:NO_3{^-}$ (0:100) had the lowest $NH_4{^+}$ and highest $NO_3{^-}$ concentrations. The seedling growth in terms of fresh and dry weights of aerial part were the highest in the treatment of $NH_4{^+}:NO_3{^-}$ (23:73) at 2 weeks after sowing and those of $NH_4{^+}:NO_3{^-}$ (50:50) at 4 weeks after sowing. The survival rate of seedlings in $NH_4{^+}:NO_3{^-}$ (100:0) treatment were 19% and the growth of aerial part 4 weeks after sowing was the poorest among all treatments tested. The results mentioned above indicate that the pre-planting $NH_4{^+}$ ratio in inert media should not exceed 25% in plug stage 1 through 3 (until 2 true leaf development) and 50% in plug stage 4 (after 2 true leaves to transplant).

• 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.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.308-316
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• 2013

Fresh ginseng has a limited storage life due to the quality change caused by microbial spoilage as well as physiological deterioration. The present study investigated the effects of 1-methylcyclopropene (1-MCP) treatment, an inhibitor of ethylene action, on the microbial growth and quality maintenance of fresh ginseng during storage. Harvested fresh ginsengs were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 20 hours at $4^{\circ}C$ and then stored at room temperature (RT) for 18 days or low temperature ($4^{\circ}C$) for 160 days. After 18 days of storage at RT, the percentage weight loss in 1-MCP treated fresh ginseng (8.3%) is lower than that of control (10.1%). During long-term storage at $4^{\circ}C$, weight losses were increased slightly until 120 days without difference between non-treated and 1-MCP ginsengs. In contrast, after 120 days of storage at $4^{\circ}C$, higher increase in weight loss was observed in non-treated ginsengs than in 1-MCP treated ginsengs. Respiration rate and ethylene production of fresh ginseng were reduced by 1-MCP treatments at RT. The 1-MCP treatment also resulted in lower microbial population compared to those of non-treated ginsengs at RT. However, in ginsengs stored at $4^{\circ}C$ for short-term (45 days), no differences were noted in weight loss and microbial population between 1-MCP treated and non-treated ginsengs. Major ginsenosides was not changed by 1-MCP treatment during the 7 days of storage at RT. Results suggest that 1-MCP treatment can be used to maintain the freshness of ginseng at room temperature for short term storage and at low temperature for long term storage. 1-MCP treatment could be applied on fresh ginseng to avoid deleterious effect of exogenous ethylene during storage and shipping.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.359-365
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• 2013

Chrysanthemum is one of the most popular ornamental plants worldwide. Recently, lots of new and novel chrysanthemum varieties have been developed using mutagenesis. However, there was no study for comparison of tissue culture condition among the mutant varieties derived from one original variety, until now. This study was conducted to compare the efficient regeneration condition of the two chrysanthemum mutant varieties, 'ARTI-purple' and 'ARTI-queen'. Two different flower parts (disk and ray florets) at the unopened and early blooming stages were used for comparison of regeneration condition on MS medium supplemented with combinations of three growth regulators (BA, NAA, and IAA). The highest regeneration rate was identified on the NAA and BA combination when the disk florets at unopened blooming stage are used. The best optimum combinations of growth regulators were identified as NAA $1.0mg{\cdot}L^{-1}$ and BA $0.5mg{\cdot}L^{-1}$ at 'ARTI-purple', which displayed 47.9% regeneration. However, regeneration of 'ARTI-queen' was the highest as 25.6% at NAA $2.0mg{\cdot}L^{-1}$ and BA $1.0mg{\cdot}L^{-1}$. There results indicate that there is a difference for the optimum regeneration condition between the mutant varieties derived from one original variety. These results will be useful for construction of efficient regeneration system of diverse chrysanthemum mutants developed by mutation breeding.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.24-29
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• 1999

Naturally-occurring iron minerals, goethite, magnetite, and hydrogen peroxide were used to catalyze and initiate Fenton-like oxidation of silica sand contaminated with mixture of diesel and kerosene in batch system. Optimal reaction conditions were investigated by varying pH(3, 7), $H_2O_2$ concentration(0%, 1%, 7%, 15%, 35%), initial contaminant concentration(0.2, 0.5, 1.0 g-mixture of diesel and kerosene/ kg-soil), and iron mineral contents(1, 5, and 10 wt % magnetite or goethite). Contaminant degradations in silica sand-iron mineral-$H_2O_2$ systems were identified by determining total petroleum hydrocarbon(TPH) concentration. The optimal pH of the system was 3. The system which iron minerals were the only iron source was more efficient than the system with $FeSO_4$ solution due to lower $H_2O_2$ consumption. In case of initial contaminant concentration of 1g-contaminant/kg-soil with 5 wt % magnetite, addition of 0%, 1%, 7%, 15%, and 35% of $H_2O_2$ showed 0%, 24.5%, 44%, 52%, and 70% of TPH reduction in 8 days, respectively. When the mineral contents were varied 0, 1, 5, and 10wt%, removal of contaminants were 0%, 33.5%, 50%, and 60% for magnetite and 0%, 29%, 41%, and 53% for goethite, respectively. Reaction of magnetite system showed higher degradation than that of goethite system due to dissolution of iron and mixed presence of iron(II) and iron(III); however, dissolved iron precipitated on the surface of iron mineral and seemed to cause reducing electron transfer activity on the surface and quenching $H_2O_2$. The system using goethite has better treatment efficiency due to less $H_2O_2$ consumption. When cach system was mixed by shaker, removal of contaminants increased by 41% for magnetite and 30% for goethite. Results of this study showed catalyzed $H_2O_2$ system made in-situ treatment of soil contaminated with petroleum possible without addition of iron source since natural soils generally contain iron minerals such as magnetite and goethite.

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.808-818
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• 1994

Effects of ceria additive on the activity and thermal aging behavior of supported Ru catalysts were investigated using Ru/${\gamma}$-$Al_2O_3$and Ru/$CeO_2$-${\gamma}$-$Al_2O_3$. The catalysts were characterized by $^{129}Xe$-NMR and $H_2$ chemisorption. The cataltic activity for conversion of CO, HC and $NO_x$ was measured using simulated automobile engine exhausts under lean, rich and stoichiometric conditions. For both fresh and aged catalysts, Ru/$CeO_2$-${\gamma}$-$Al_2O_3$ was more active than Ru/${\gamma}$-$Al_2O_3$ for all three pollutants. Results of $^{129}Xe$-NMR and $H_2$ chemisorption indicated that sintering of Ru particles occurred to the same extent for both catalysts during the thermal aging process. After thermal aging at 673K, however, the catalytic activity of the aged Ru/$CeO_2$-${\gamma}$-$Al_2O_3$ was substantially higher than that of the fresh one, while the activity of Ru/${\gamma}$-$Al_2O_3$ decreased after the thermal aging. This finding may suggest new active sites were created during the thermal aging, probably in the vicinity of the interface between Ru and Ce. For more quantitative investigation of the effect of a cation such as Ce on the thermal aging of Ru metal particles, Ru catalysts supported on cation-exchanged Y-zeolites were used as the model catalysts. The results indicated that when Ba, Ca, La, Y or Ce was used for the cation exchange, the exchanged cation did not affect the thermal aging behavior of Ru in Y-zeolite, as evidenced by $^{129}Xe$-NMR and EXAFS.

• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.49-63
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• 2003

Recently, two international standard organizations, ISO and OGC, have done the work of standardization for GIS. Current standardization work for providing interoperability among GIS DB focuses on the design of open interfaces. But, this work has not considered procedures and methods for designing GIS DB. Eventually, GIS DB has its own model. When we share the data by open interface among heterogeneous GIS DB, differences between models result in the loss of information. Our aim in this paper is to revise the design guidelines for geographic information databases in order to make consistent spatial data models, logical structures, and semantic structure of populated geographical databases. In details, we propose standard guidelines which convert ISO abstract schema into relation model, object-relation model, object-centered model, and geometry-centered model. Furthermore, we provide sample models for applying these guidelines in commercial GIS S/Ws. Building GIS DB based on design guidelines proposed in the paper has the following advantages: the interoperability among databases, the standardization of schema definitions, and the catalogue of GIS databases through.