• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.294-298
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• 2009

A glasshous experiment was carried out in 2002 to evaluate growth differences between two wick types, and to determine the optimum number of wicks in a wick-based hydroponics for production of 'Dejima' seed potatoes (Solanum tuberosum L.). The six minitubers ($7.0{\pm}0.2g$/tuber) produced through aeroponics were planted in a polystyrene box (51 cm long $\times$ 31 cm wide $\times$ 20 cm high) containing growth medium (perlite+peatmoss 1:2, v/v mixtures). Before the boxes were filled with the medium, 6 wicks per box were vertically and 2 to 10 wicks were horizontally installed, respectively, at the bottom of the boxes through holes. Comparing with 6 vertical wick treatment, 6 horizontal wick treatment increased the number of tubers per plant, but decreased average tuber weight. Yield of tubers greater than 5 g (seed potatoes) was not significantly affected by wick type. As the number of the horizontal wicks per box was increased from 2 to 6, the number of seed potatoes increased from 2.8 to 8.0/plant and then leveled off. Average tuber weight increased with increasing the number of the wicks up to 8 and then leveled off. As the number of the wicks per box was increased from 2 to 6, seed potato yield increased from 1.81 to 6.59 kg/$m^2$ and then slowly increased up to 10 wicks per box, reaching 12.9 kg/$m^2$. The results indicate that installing 8 wicks per box ($0.16m^2$) horizontally for the wick culture system in production of 'Dejima' seed potatoes is beneficial considering seed potato yield, cost of wicks, and convenient filling with medium.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.201-207
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• 2017

Objective of this research was to investigate the influence of pre-plant nitrogen levels in root media on plug seedling growth of radish cv. Soksungbommu. To achieve the research purpose, a root medium, the mixture of perlite, coir dust, and peatmoss (volume percentage of 30:35:35) was formulated and the N levels incorporated during mixing were controlled to 0, 100, 250, 500, 750, 1,000, and $1,500mg{\cdot}L^{-1}$. Then, the seeds were sown into 72-cell plug trays in which the root medium was packed. The measurements of growth and analysis of tissue and root media were conducted 2 and 4 weeks after sowing. Elevation of pre-plant N levels raised EC and turned down pH of root media. But, as seedling grew, the pH rose and EC get lowered in all treatments. The EC as well as $NH_4-N$ and $NO_3-N$ concentrations of root media declined gradually until week 2, but those declined sharply between weeks 2 to 4. The seedling growth 2 weeks after sowing showed quadratic response to pre-plant N levels with the highest growth in $250mg{\cdot}L^{-1}$ treatment and lagging growth in the treatments of lower or higher N levels than $250mg{\cdot}L^{-1}$. The seedling growth 4 weeks after sowing showed also quadratic response with the highest growth in $500mg{\cdot}L^{-1}$ treatment. The tissue N contents were get higher and those of K, Ca, and Mg were get lower as pre-plant N levels were elevated. Above results suggest that lower than $250mg{\cdot}L^{-1}$ in pre-plant N levels is optimistic for growth of plug seedling and avoidance of toxic injury in very young stage.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.203-211
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• 2005

The experiment was conducted to investigate the nutrition absorption pattern in the growth stages and develope the optimal nutrient solution hydroponically grown the tomato in closed substrate culture system with the nutrient solution of National Horticultural Research Station in Japan into 1/2S, 1 S, and 2S. When plant was grown in 1/2 S, the growth and yield were high and the pH and EC in the rooting zone were stable. Suitable composition of nutrient solution for tomato was $NO_3-N$ 7.1, $PO_{4}$-P 2.1, K 4.0, Ca 3.1, Mg 1.2, and $SO_{4}-S\;1.2\;me{\cdot}L^{-1}$ in the early growth stage and $NO_3-N$ 6.5, $PO_4-P$ 2.3, K 3.4, Ca 3.1, Mg 1.1, and $SO_4-S\;1.1\;me{\cdot}L^{-1}$ in the late growth stage by calculating a rate of nutrient and water uptake. To estimate the suitability for the nutrient solution of tomato in a development of optimum nutrient solution of tomato developed by Wonkwang university in korea (WU), plant was grown in perlite substrate supplied with different solution and strengths(S) by research station for greenhouse vegetable and floricultuin in the Netherlands (Proefstation voor tuinbouw onder glas te Naaldwijk; PTG) of 1/2 S, 1 S and 2 S, respectively, The growth was good at the PTG and WU of 2 S in early growth stage, and at the WU 2S in late growth stage. The highest yield of tomato obtained in the WU of 2 S, although blossom-end rot was appeared in all treatments. pH and EC in root zone of WU of 2 S were stable during the early and late growth stage. Therefore when plant was grown in WU of 2 S, N and P content in the nutrient solution need to low, according N and P content of their leaves were high in WU of 2 S.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.148-154
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• 1994

As a vegetative propagation method for ash species, which is a dioecism and a long cycle of fructification, cut-stem was soaked in water to induce adventitious sprouts, and 2-year-old ash seedling was cut in a nursery to induce adventitious sprouts. We obtained the 1,019 adventitious sprouts from branches of 101 plus trees througout the country. The mean ortet-age is 48. There is not a correlation between ortet ages and production of adventitious sprouts. These sprouts were placed in a cutting bed for rooting. Root ability varied with environmental factors of cuttings. The best rooting(87%) resulted from cutting performed in a vinyl-plastic greenhouse. Rooting was better on perlite+peat moss(2 : 1) medium than other media tested. The rooting ability was generally higher in 2-year-old ortet than plus tree ortet. In the root development of cuttings the non-container cuttings was better than container cuttings.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.3
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• pp.98-106
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• 2010

This study focuses on the appropriate planting soil for Vitex rotundifolia by planting soil. Different soil depth levels were achieved at 15cm and 25cm in the green roof module system that was created with woody materials for a $500{\times}500{\times}300mm$ area. The soil mixture ratio was $S_{10}$, $L_{10}$, $S_7L_3$, $S_5L_5$, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$. This study was carried out over five months between April and September, 2006. The amount of soil moisture tends to decrease according to the planting soil. For the experimental items $S_{10}$, $S_7L_3$ and $S_5L_5$, the amount of soil moisture tends to decrease rapidly. However, for the experimental items $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$, conditions containing perlite and peat moss, the amount of moisture tends to decrease more gradually. As a result, the use of soil-improving amending for the afforestation planting of roofs with a low level of management is need. After experimenting with the ratio of soil mixture for Vitex rotundifolia, the planting soil for experimental item $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ appeared excellent. For experimental item $S_{10}$, the growth of Vitex rotundifolia seemed to be weaker than that of others, because of the low levels of moisture and organic matter in the soil. For experimental item $L_{10}$, there appeared to be a low level of growth, even when the levels of moisture and organic matter were high. This may have occurred because of the low level of soil pH and the excessive amount of exchangeable cation. At the depth of 25cm, the growth of Vitex rotundifolia is vigorous overall. For experimental item at 15cm, Vitex rotundifolia was able to survive for 14 days without any rainfall and Vitex rotundifolia was better in amended soil, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$, than natural soil, SL.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.16-22
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• 2011

In developing soil wetting agent using polyoxyethylene nonylphenyl ether (PNE) and polyoxyethylene castor oil (1:1; v/v), the effect of application rates on changes in concentration of PNE, initial wetting of peatmoss + perlite (7:3) medium, and growth of hot pepper (Capsicum annuum L. 'Knockwang') plug seedlings were investigated. The elevation of application rates of wetting agent increased the amount of water retained by the root media. The treatment of 2.5 $mL{\cdot}L^{-1}$ showed similar water retention to + control ($AquaGro^L$ 3.0 $mL{\cdot}L^{-1}$). Most of the liquid wetting agent (LWA) incorporated during the medium formulation leached out in the first and second irrigation, then it decreased gradually until 10 times in irrigation. In investigation of the influence of LWA on position of water infiltrating into root media, the vertical water movements in treatments of 0.5, 1.0, and 1.5 $mL{\cdot}L^{-1}$ were much faster than those in 0.0 $mL{\cdot}L^{-1}$ (-control), but relative speed of water movement decreased by the elevation in application rate of LWA to 2.0 or 2.5 $mL{\cdot}L^{-1}$. The evaporative water loss of root media that to contained various rate of LWA and irrigated to reach container capacity was the fastest in -control among the treatments and it delayed as the application rate of LWA was elevated. The plant height of 22.2 cm in 0.5 $mL{\cdot}L^{-1}$ and stem diameter of 3.26 mm in 1.0 $mL{\cdot}L^{-1}$ were the highest among the treatments tested. The treatment of 1.0 $mL{\cdot}L^{-1}$ also had the heaviest fresh and dry weights such among treatments tested as 3.08 g and 0.861 g per plant, respectively. The elevated application rate over than 1.5 $mL{\cdot}L^{-1}$ resulted in decreased seedling growth. The results mentioned above indicate that optimum application rate of LWA is 1.0 $mL{\cdot}L^{-1}$.

• FLOWER RESEARCH JOURNAL
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• v.16 no.2
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• pp.112-117
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• 2008

Plug seedlings of vinca (Catharanthus roseus L. 'Pacifica Punch') and salvia (Salvia splendens F. Sellow ex Roem & Schult 'Maestro') were transplanted into square plastic pots (145 mL volume) filled with a soilless growing medium. To determine the effect of application rate on the growing medium EC and growth of plants, 0, 0.5, 1.0, 1.5, 2.0 and 4.0 g per pot of a controlled release fertilizer (14-14-14 Osmocote, 14N-6.2P-11.6K) were mixed with the growing medium. Plants were subirrigated daily with tap water. In both vinca and salvia, growing medium EC increased as application rate was elevated. Growing medium EC was relatively constant over a whole crop period when the application rate was less than 1.5 g per pot, while it decreased throughout the experiment at higher application rates such as 2.0 to 4.0g per pot in both species. The greatest leaf area, plant height, and shoot dry weight of vinca were obtained when plants were fertilized with 2.0 to 4.0 g per pot of the fertilizer, resulting in a growing medium EC of $1.0{\sim}1.7dS{\cdot}m^{-1}$ throughout the experiment. Leaf area, shoot dry weight, and chlorophyll content of salvia increased with elevated application rates. Leaf area, shoot dry weight, and chlorophyll content of salvia were the greatest when plants were fertilized with 4.0 g per pot, resulting in growing medium EC of $1.0{\sim}4.0dS{\cdot}m^{-1}$ throughout the experiment. Plant height of salvia was the greatest when plants were fertilized with 2.0 to 4.0g per pot. Concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and sulfur (S) in the shoots of vinca increased, while concentration of calcium (Ca) decreased with elevated application rates. Concentrations of boron (B) and manganese (Mn) in the shoots of vinca increased as the application rate decreased.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.73-80
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• 2011

To investigate the characteristics of plant growth and flower quality of gerbera 'Sunny Lemon' by amount of nutrient solution, young seedling plants, 'Sunny Lemon' were transplanted to rock-wool and medium of peat moss and perlite mixed with 1 to 2 and they were acclimatized in greenhouse during about 1 month. Nutrient solution supplied to the plants is sonneveld solution of 1/2 concentration and treatments launched June 24, 2010 when average plant height was $20{\pm}1cm$. Nutrient contents as a standard for starting point of irrigation by time domain reflectometry (TDR) were determined with 60-65%, 70-75%, and 80-85%. Results of growth during vegetative growth, plant height, leaf width and leaf number increased by 10% in rockwool, but they were not significantly different. As for plant growth depending on nutrient content, 80-85% treatment showed the highest values. Leaf number increased by 60%, and leaf width and plant height had a about 40% increase than initial growth. Effectiveness for flower quality, yield and days to flowering were superior when nutrient content of media was higher than in the others. Especially, average days to flowering in 80-85% content was advanced by 7-10 days compared to the day in 60-65% treatment. The total amount of nutrient supply per plant was higher in mixed medium than in rockwool, but change patterns of EC and pH were enhanced in rockwool. Based on our results, we recommended that growth, cut flower, and yield of gerbera 'Sunny Lemon' were more effective when nutrient content of mixed medium was maintained at 80-85%.

• 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.