• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.549-565
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• 2015

This study was conducted to investigate the growth characteristics and functional materials of baby vegetables as affected by different LEDs and luminous intensity at Anseongsi, Gyeonggi Province, in 2014. Test crops were beet, chicory, spinach, red leaf lettuce, crown daisy and red mustard purchased from the seed company of Dongbu Hannong and Jinheung. Growth characteristics were measured and the content of functional materials was analyzed 40 days after seeding at plug plate. Treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity showed the highest number of leaves in five baby vegetables of beet, chicory, red leaf lettuce, crown daisy and red mustard. The highest shoot length of chicory, spinach, red leaf lettuce, crown daisy and red mustard was obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Fresh weight and dry weight of all six baby vegetables were the highest in treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Content of chlorophyll a and chlorophyll b of spinach, red leaf lettuce and red mustard showed the highest in Fluorescent lamp at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity whereas other crops did not show definite trend under different LEDs lights and luminous intensity. The highest total content of anthocyanins and polyphenol were obtained from the treatment of Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity in all six baby vegetables. Free radical scavenging activity was highest in all six vegetable crops at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity, but it was not different significantly between LEDs. As a result, the growth and the content of functional material of baby vegetables are generally to be increased in Red+Blue (4:1) at $150{\mu}mol\;m^{-2}s^{-1}$ luminous intensity. Mixed light of Red+Blue is thought to give good effect on the growth and the content of functional material in baby vegetable crops. Because there are many differences in regard of LED lights, crop varieties, cultivation and experimental methods in their impact on the growth and functional materials of baby vegetables among researchers, it is considered that a more precise studies are needed for the crop responses to LED light and luminous intensity.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.456-461
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• 2010

A study was conducted to investigate the effect of topophysis, and uniting method of rootstock and scion on rooting and subsequent growth of stenting-propagated cut rose ($Rosa$ $hybrida$ Hort.) in an effort to develop an efficient stenting propagation method for domestic rose cultivars. Four cultivars used in this study were two standard type cultivars 'Sweet Yellow' and 'Hanmaum', and two spray type cultivars 'Chelsi' and 'May'. Scions were grafted on cuttings of a rootstock $Rosa$ $indica$ 'Major'. The stenting-propagated scion-rootstock unions were planted in rockwool cubes ($50{\times}50{\times}50mm$, Delta, Grodan, Denmark) and were placed in a graft-take chamber for five days before being placed on misted greenhouse beds. The rootstock was removed of all leaves and nodes. Both the base of scions and top of stocks were simultaneously cut at a $45^{\circ}$ angle for grafting. Scions were prepared as single node cuttings, each with a five-leaflet leaf. Three positions of topophysis used were 7-9th (top), 4-6th (middle), and 1st-3rd (bottom) nodes from the stem base. Four uniting materials used were tube, tube + parafilm wrap, tube + clothespin, and clothespin. Rooting and growth were affected by the topophysis and cultivar. The best topophysis for rooting was 7-9th (top) nodes in all cultivars. Topophysis affected percent rooting, and number of roots, length of the longest root, and but not weight, shoot length and graft-take. Rooting and growth were affected by the uniting method and cultivar. Tube uniting method generally showed higher percentage graft-take, percent rooting, and number of roots than other methods. However, rootstock and scion union was not complete in this treatment. On the whole, the greatest rooting and subsequent growth of stenting-propagated plants were found in the tube + clothespin method. Except 'Sweet Yellow', rooting and growth were not adequate in the clothespin method. The results suggested that a tube + clothespin method was the most effective, and this method may be used as a substitute to save labor compared to a tube + parafilm wrap method which is currently being used in commercial nurseries.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Horticultural Science & Technology
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• v.34 no.1
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• pp.77-83
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• 2016

The measurement of total fresh weight of plants provides an essential indicator of crop growth for monitoring production. To measure fresh weight without damaging the vegetation, image-based methods have been developed, but they have limitations. In addition, the total plant fresh weight is difficult to measure directly in hydroponic cultivation systems because of the amount of nutrient solution. This study aimed to develop a real-time, precise method to measure the total fresh weight of Romaine lettuce (Lactuca sativa L. cv. Asia Heuk Romaine) with growth stage in a plant factory using a nutrient film technique. The total weight of the channel, amount of residual nutrient solution in the channel, and fresh shoot and root weights of the plants were measured every 7 days after transplanting. The initial weight of the channel during nutrient solution supply (Wi) and its weight change per second just after the nutrient solution supply stopped were also measured. When no more draining occurred, the final weight of the channel (Ws) and the amount of residual nutrient solution in the channel were measured. The time constant (${\tau}$) was calculated by considering the transient values of Wi and Ws. The relationship of Wi, Ws, ${\tau}$, and fresh weight was quantitatively analyzed. After the nutrient solution supply stopped, the change in the channel weight exponentially decreased. The nutrient solution in the channel slowly drained as the root weight in the channel increased. Large differences were observed between the actual fresh weight of the plant and the predicted value because the channel included residual nutrient solution. These differences were difficult to predict with growth stage but a model with the time constant showed the highest accuracy. The real-time fresh weight could be calculated from Wi, Ws, and ${\tau}$ with growth stage.

• Journal of Korean Society of Forest Science
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• v.12 no.1
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• pp.13-21
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• 1971

As one part of the ecological studies of Korean white pine plantation, a synecological survey was made on the undergrowth vegetation of Korean white pine plantations of different age class i.e., 5, 15, 25, 35, and 40 year age classes under which shrub and ground vegetation were distinctly different. And, the results are summarized as follows. 1. In shrub, the important species is Corylus heterophylla var. japonica and the dominant species in each age-class stand are as follows; 5 year-class ; Quercus mongolica, Lespedeza Maximowiczi. 15 year-class ; Corylus heterophylla var. japonica, Lespedeza Maximowiczi. 25 year-class ; Corylus heterophylla var. japonica. 35 year-class ; Corylus heterophylla var. japonica, Maackia amurensis. 40 year-class ; Corylus heterophylla var. japonica. 2. The higher the age class of the plantation are, the lower the height and the density of the shrub become. 3. Dominant species of ground-vegetation under the shrub of each age-class are as follows; 5 year-class ; Arundinella hirta var. cilia, Miscanthus purpurascens. 15 year-class ; Arundinella hirta var. ciliata, Potentilla Freyniana. 25 year-class ; Physematium manchuriense, Viola xanthopetala, Rubus craegifolius. 35 year-class ; Viola xanthopetala, Rubus crataegifolius. 45 year-class ; Viola xanthopetala, Rubus crataegifolius. 4. The standing crops of ground vegetation under the shrub were decreased with increasing age-class, which also caused the decreasing height and density and changing floristic composition of the shrub. 5. The ratio of the standing crop of root to the standing crop of shoot was increased as the age class increased. 6. The floristic composition of ground vegetation has shown a change from heliophyte to sciophytes on the sere.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.57-62
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• 2011

This study was conducted to determine the distribution of nitrogenous compounds to various tree parts and the extent of reserve accumulation in persimmon (Diospyros kaki) under various fruit-loads. This study also ascertained the proportion of storage nitrogen made available for the new growth the following year. On June 15, the fruit-load was adjusted to a leaf-fruit (L/F) ratio of 10, 20, and 30, and some trees were completely defruited. Between June 15 and November 11, the increase of total amino acids were greater with a high L/F ratio. The amino acids increased in the root were negligible at the 10-L/F ratio. Of the total amino acids increased during this period, the proportion distributed to the root was 64% in the 20-L/F, 18.5% in the 30-L/F, and 81% in the defruited trees, and the distribution to the fruits was 81% in 10-L/F, 12% in 20-L/F, and 35% in the 30-L/F trees. Leaf amino acids decreased in the 10-L/F trees. Total proteins increased in autumn were greater as the L/F ratio was higher. Total proteins were in the fruits the most, and the distribution to the permanent parts was decreased as the L/F ratio was decreased. At the L/F ratio of 30, 59% of the total proteins increased in the autumn was distributed to the fruits and 40% to the root. Leaf proteins decreased at 10 and 20 L/F ratios. During the new growth from April 10 to June 10 the following year, amino acids decreased in the old wood and 1-yr-old shoot, whereas proteins decreased only in the 1-year-old shoots. Amino acids and protein decreased by 540 mg and 610 mg, respectively, in the roots of the defruited trees. Total amino acid and proteins in the newly-grown parts were the most at 730 mg and 1290 mg, respectively, when defruited the previous year. They were the least at the 10-L/F ratio, being 120 mg and 400 mg, respectively.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.187-191
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• 2011

Rising soil temperature was effectively controled by shading net of 50% and cooled water to maintain average $18.8^{\circ}C$ (maximum $23^{\circ}C$), then shading net of 50% and ground water to maintain average $23.2^{\circ}C$ (max. $28.5^{\circ}C$), shading paint of 30% and shading net (50%) to maintain average $24^{\circ}C$ (max. $30^{\circ}C$) in that order. Alstroemeria 'Modena' most affected by shading and cooling water was better in shoot length as 95.9 cm and fresh weight as 67 g than those of other treatments. The production of cut flower was increased more 121% with treatment 50% shading net and cooling water, 59% with 50% shading net and ground water, and 65% with 30% shading paint than that of 50% shading net, respectively. Soil temperature was higher $8^{\circ}C$ with the plot of circulating warm water than untreated control plot. Alstroemeria 'Aspen', 'Modena', and 'Chanel' increased more plant growth such as plant height, fresh weight in warm water than in untreated control plot, but Alstroemeria 'Bordeaux' decreased plant height. Because of increasing plant growth, flower quality such as peduncle length, peduncle diameter, floret number and flower weight of 4 all cultivar was better in the plot of circulating warm water than untreated control plot. Also, the production of cut flower was increased the most in Alstroemeria 'Modena' by 38%, 'Aspen', 'Bordeaux', and 'Chanel' in that order.

• FLOWER RESEARCH JOURNAL
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• v.19 no.2
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• pp.81-88
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• 2011

Effect of concentrations of different plant growth retardants (PGRs) supplied to a recirculated nutrient solution in an ebb and flow system on the growth and development of potted Spathiphyllum 'Top-Pin' and 'Mini' was examined. Plants were planted in 10 cm diameter plastic pots filled with a mixture of peat moss and perlite (1 : 1, v/v) on 30 June 2005 and grown until 23 Sep. 2005. In a closed ebb and flow system, 50, 200, 350, $500mg{\cdot}L^{-1}$ daminozide (B-9), 10, 40, 70, $100mg{\cdot}L^{-1}$ paclobutrazol (Boundy), 5, 15, 25, $35mg{\cdot}L^{-1}$ ethephon (Florel), and 1, 4, 7, $10mg{\cdot}L^{-1}$ uniconazole (Sumagic) were supplemented to a nutrient solution at the initiation of experiment. On every irrigation, the nutrient solution containing PGRs was supplied at a 2 cm depth and kept for 15-20 minutes. The surplus nutrient solution was drained back into the tank for next irrigations. Paclobutrazol gave the most pronounced effect in inhibition of stretchiness. The greatest reduction of leaf length, fresh and dry weights of shoot, and elevated chlorophyll content were recorded in Spathiphyllum, with increasing paclobutrazol concentration. Daminozide concentration greater than $200mg{\cdot}L^{-1}$ resulted in minor stunting. The lowest concentration ($1mg{\cdot}L^{-1}$) of uniconazole showed greater leaf length, leaf width, and leaf petiole length than the control ($0mg{\cdot}L^{-1}$). Uniconazole concentration greater than $1mg{\cdot}L^{-1}$ resulted in similar plant growth as the plant in the control ($0mg{\cdot}L^{-1}$). High concentration ($35mg{\cdot}L^{-1}$) of ethephon resulted in the shortest leaf length, and the greatest chlorophyll content. Inhibition of stretchiness was observed even in the lowest concentration treatments. Among the PGRs, paclobutrazol was most effective in suppressing plant stretchiness. In both cultivars, ethephon and paclobutrazol, but not daminozide and uniconazole, significantly inhibited stretchiness. The results suggested that plant growth retardants (ethephon or paclobutrazol) selected in this study may be used as the most effective agents for inhibition of stretchiness in Spathiphyllum.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.396-403
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• 2019

This study was conducted to investigate the growth of grafted cucumber seedlings in biodegradable paper pot trays influenced by seedling age, nutrient management before transplanting, and night temperature after transplanting. Grafted cucumber seedlings in paper pot trays were supplied with different nutrient solution concentrations of 0.5 x full strength (S) (EC $0.8dS{\cdot}m^{-1}$), 1.0S(EC $1.6dS{\cdot}m^{-1}$), 2.0S(EC $3.2dS{\cdot}m^{-1}$) two times a week until transplanting. 26, 33, 40, and 47 day-old cucumber grafted seedlings were transplanted and grown at three levels of night temperature (10, 15, and $25^{\circ}C$) during ten days. Increasing nutrient solution concentration enhanced the shoot length, number of leaves, leaf area, dry weight, and relative growth rate of seedlings. With increasing seedling age, the differences in growth were greater among nutrient treatments. The dry matter percentage increased with the seedling age, but was lower with higher nutrient concentration. The specific leaf area showed the opposite results. In cucumbers transplanted at 26- or 33-day seedling ages, night temperature did not affect the growth at ten days after transplanting. However, the growth of 40 or 47 day-old seedling decreased at $10^{\circ}C$. Compared with $25^{\circ}C$, the dry weight of cucumbers transplanted at 40- or 47-day seedling ages was depressed by 58% or 71%, respectively, at $10^{\circ}C$. Accordingly, it was concluded that the optimum nutrient solution concentrations and seedling age for the production of grafted cucumber seedlings in biodegradable paper pot trays can be 1.0S and about 30 days, respectively, and night temperature should be maintained at the range of $15-25^{\circ}C$ for promoting the growth after transplanting.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.331-344
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• 2009

Buffalograss is an important turfgrass species with excellent cold, heat, and drought tolerance. Understanding the physiological integration of buffalograss under heterogeneous conditions helps to develop cultural practices that better use limited resources for uniform turf quality. The objective of this study was to evaluate physiological integration of buffalograss under water deficit stress and the involvement of lipid peroxidation and antioxidants in the process. In one experiment, buffalograss was planted in the center of a four-compartment growth unit. Watering frequencies, once a week(+) and once in two weeks(-), were combined with the sand(S) or peat(P) in each unit to generate five total treatments(P+S-P-S+, P+P+P+P+, S-S-S-S-, P-P-P-P-, and S+S+S+S+). The average number of shoot established from the heterogeneous root-zone medium was higher than the average of four possible homogeneous media. In second experiment, single ramet in Hoagland solution($S_0$) or single ramet in Hoagland solution with 20% PEG-6000($S_s$) were compared with two connectedramets under different treatments. Treatments for connected ramets were young ramet in Hoagland solution($Y_{os}$) and old ramet in Hoagland solution with 20% PEG-6000($O_{os}$), and old ramet in Hoagland solution($O_{ys}$) and young ramet in Hoagland solution with 20% PEG-6000($Y_{ys}$). Lipid peroxidation, antioxidants, and proline showedphysiological integration between ramets subjected to different levels of water stress. Superoxide dismutase(SOD), Guaiacol peroxidase(G-POD), malondialdehyde(MDA), and free proline also showed different time courses and relative activities during the physiological integration.