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The objective of this study was to create a method to evaluate the aging of coir dust. A rainproof plastic house was used to monitor the fresh coir dust for 24 weeks, and the samples were collected every 2 weeks during aging. The aging effects on coir dust were investigated with the changes in mineral nutrient contents and plug seedling growth in four different vegetables. Experiments were conducted to determine the appropriate degree of aging by analyzing the changes of total phenol and tannin contents, color, and near-infrared spectral characteristics as influenced by the aging duration of coir dust. The pH, electrical conductivity (EC), and cation exchange capacity (CEC) values of the non-aged coir dust were 5.04, 9.19 dS m−1, and 75.2 cmol+ kg−1, respectively. The concentrations of Cl and K in the non-aged coir dust were 4061.8 and 3487.4 mg kg−1, respectively. The contents of total phenol and tannin in the non-aged coir dust were 168.8 and 38.8 mg kg−1, respectively. The pH rose continuously to 5.94 at 24 weeks, and the EC decreased to 1.8 dS m−1 after 4 weeks of aging and then remained at a similar level. The concentrations of elements decreased drastically except for NH4+ and NO3− until 4 weeks of aging, and later they remained at a similar level. The total phenol content decreased greatly at 2 weeks of aging, and the tannin content decreased continuously from 38.8 mg kg−1 in week 0 to 0.15 mg kg−1 at 24 weeks of aging. The color indicators b* and C* decreased until 12 weeks of aging, and after that, they remained at a similar level. The optimum aging of coir dust was judged based on b* and C* values. The spectral analysis showed that the coir dust aged over 18 weeks could be distinguished from the earlier stage of aging with 91% accuracy. When the coir dust with varied aging durations was used as a root substrate, the fresh weights of radish, Korean cabbage, tomato, and red pepper increased quadratically as the aging period of the coir dust became longer (R2 = 0.7824, 0.7529, 0.4718, and 0.5458 in radish, Chinese cabbage, tomato, and red pepper, respectively; p ≤ 0.001).

In raising vegetable seedlings using cylindrical paper pots, the root substrates inside paper pots dry out fast mainly due to air spaces between paper pots created by chinks between the pot’s exterior and the holding tray. Frequent watering is necessary that contributes to the loss of nutrients by leaching during seedling production. This study was carried out to investigate the appropriate concentration of nitrogen required as a pre-planting fertilizer for growing fruit-bearing vegetable seedlings in cylindrical paper pots. For the experiment, the paper pots were made with the root substrate containing perlite (1–3 mm) and peat moss (10-mesh, 10–20% by volume) and they were placed into the 40-cell trays. The concentrations of all essential elements except nitrogen was equal in all treatments and the N concentration was adjusted to 0, 150, 250, 500, and 750 mg L−1 during the substrate formulation. Then, seedling grafts of cucumber, watermelon and tomato were transplanted and seeds of hot pepper were sown directly into the paper pots. The growth of cucumber, watermelon, and tomato plants were measured at 15, 18, and 21 days after transplanting and pepper at 5 weeks after seed sowing. The concentrations of macro-elements, pH, and EC of root substrates were analyzed every week. The pH of root substrates gradually increased during the seedling growth, but the differences in pH among N treatments is not significant. The EC in all treatments did not changed until one week after the transplanting of cucumber, watermelon, and tomato seedling grafts and 3 weeks after seed sowing of pepper. The concentration of Ca remained similar over time during the entire experimental period, but the concentration of Mg and K decreased 3 weeks after the seed sowing for the pepper growing root substrate. The concentrations of Ca, Mg, and K gradually decreased after one week of transplantation (cucumber, watermelon, and tomato). Based on the results, the optimal concentration of N required is 250 mg L−1 for tomato and 500 mg L−1 for cucumber, watermelon, and pepper respectively. In summary, the appropriate N concentration in the root substrate of paper pot is 250–500 mg L−1, and post-planting fertilization period is 1 week after transplanting for cucumber, watermelon and tomato and 3 weeks after seed sowing for hot pepper.

There is an increasing trend of producing seedlings of Panax ginseng in amended root media in raised beds. Precise control of the fertility of root media is essential for raising healthy seedlings, especially when inert media with a low buffering capacity are used. The objective of this study was to investigate the influence of fertility (as measured by EC) of the nutrient solution used for seedling production. One thousand eight hundred seeds were sown for five treatments and a control (300 seeds per treatment, 3 × 3 cm spacing) using root medium [composed of peat moss + perlite (7:3, v/v)] on raised beds with measurements, 120 × 60 × 25 cm (L × W × H) on Mar 9, 2018. Five nutrient solutions with different strengths (0.4, 0.6, 0.8, 1.0, 1.2 dS m−1 EC) were prepared with ground water (0.25 dS m−1) and a fertilizer stock solution (2 mM NH4+-N, 12 mM NO3−-N, 1 mM H2PO4−, 8 mM K+, 2 mM Ca2+, 1 mM Mg2+, 1 mM SO42−). Fertigation of the beds started on May 21 using each of six nutrient solutions and fertigation frequencies were controlled using an EC5 soil moisture sensor. The stock solutions were automatically supplied for 30 min when the volumetric water content decreased to 36%. Plant growth measurement and soil analyses were carried out twice: first at 144 days and subsequently at 197 days (from the day of seeds sown). For the first growth measurement, elevated EC in the fertilizer solution resulted in enhanced growth, but statistical differences among treatment solutions were not significant except for the case of ground water. In the second measurement, the seedling growth in terms of dry weight of above- and below-ground plant parts increased significantly in plants treated with the 1.0 dS m−1 EC solution and decreased in plants treated with the (1.2 dS m−1 EC) solution. In both the first and second measurements, the ground tissue nutrient content (T-N, P, K and Ca) was significantly different among treatments. The EC of root media in the case of 1.0 dS m−1 treatment, where the seedling growth was the highest among treatments, was 0.54 dS m−1 at the first measurement and 0.82 dS m−1 at the second measurement. In summary, a root medium with a mixture of peat moss + perlite (7:3, v/v), a leaching percentage of 20–30%, and a nutrient solution with a concentration of 1.0 dS m−1 EC is suitable for the healthy growth of ginseng seedlings.

This research was conducted to evaluate various levels of dolomitic lime incorporated as pre-planting fertilizers on the growth of red-leaf lettuce. To achieve this, three root media were formulated by mixing coir dust with expanded rice hull (CD+ERH, 8:2, v/v), carbonized rice hull (CD+CRH, 6:4, v/v), and ground pine bark (CD+GRPB, 6:4, v/v). During formulation, equal amounts of essential nutrients, except dolomitic lime, were incorporated into all root media and the levels of dolomitic lime were varied from 0 to 7.5 g L -1 at 1.5 g increments. Seedlings of red-leaf lettuces at the 3rd leaf stage were transplanted into each medium treatment. Crop growths were measured 5 weeks after transplant and soil solutions were collected every week and analyzed for pH, EC, and nutrient concentrations. The treatments showing the heaviest fresh and dry weights in CD+ERH, CD+CRH, and CD+GRPB were 4.5 g, 4.5 g, and 7.5 g L -1 of dolomite, respectively. The pHs of three root media yielding the highest crop growths were in the ranges of 6.4 to 7.1. These ECs in CD+CRH medium were around 1.0 dS m -1 higher than those of CD+ERH and CD+GRPB when application rates of dolomitic lime were equal. K⁺ concentrations were higher than Ca +2 and Mg +2 concentrations until week 2 in three root media. But Ca +2 and Mg +2 concentrations were higher than K⁺ concentrations after week 3 in all root media. The concentrations of PO₄-3 in all root media got abruptly lower until week 2. These results indicate that appropriate levels of dolomitic lime, as pre-planting nutrient charge fertilizers in CD+ERH and CD+GRPB media, are 4.5 and 7.5 g L -1 , respectively.

This research was conducted to evaluate the influence of root restriction materials and media on the growth of runner plantlets of ‘Seolhyang’ strawberry in a nursery field. To achieve this, the influence of three kinds of root media on the growth of runner plantlets was monitored when polyethylene film was used as the root restriction material. In addition, the influence of various root restriction materials (RRS) such as transparent polyethylene film (PE), non-woven fabric (NF), perforated pol yethylene film (PP) a,nd root proofing sheet (RPS) on the changes in volumetric water content (VWC) and temperature of root media as well as growth of runner plantlet were investigated when expanded rice hull (ERH) was used as the root medium I.n the compariso n of root media, growth parameters such as leaf area and crown thickness at 20 d after fixation as well as crown thickness and fresh weights of root and above-ground tissue at 40 d after runner plantlet fixation were higher in the ERH treatment than in sandy loam and loamy sand. When the influence of RRS was compared, the VWC of ERH was 55% just after irrigation, but decreased to 26% at just before irrigation. Ranges of the VWC as influenced by irrigation cycle were 16 to 10% in the PP and less than 10% in the NF and RPS. The soil temperature in the PE treatment was around 1°C lower than in NF, PP, and RPS. The differences between day and night temperatures were also smaller in the PE treatment rather than those in NF, PP, and RPS. The growths of runner plantlet 50 d after fixation showed that plant heights as well as fresh weights of root and above-ground tissue were higher in the PE treatment than in NF, PP, and RPS. NF and PP did not effectively restrict roots inside the medium and the root s of runner plantlets penetrated through the root restriction materials resulting in the formation of root system below the restr iction materials. The above results indicate that ERH is more effective than sandy loam or loamy sand as root medium. PE rather than NF, PP, or RPS as root restriction material resulted in better growth of runner plantlets in propagation of ‘Seolhyang’ strawbe rry. The results of this research will be used for production of high quality runner plantlets in strawberry propagation.Additional key words

Objective of this research was to investigate the influence of compositions and concentrations of fertilizer solutions on the vegetative growth and nutrient uptake of 'Seolhyang' strawberry. To achieve this, the solutions of acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) were prepared at concentrations of 100 or based on N and applied during the 100 days after transplanting. The changes in chemical properties of the soil solution were analysed every two weeks, and crop growth measurements as well as tissue analyses for mineral contents were conducted 100 days after fertilization. The growth was the highest in the treatments with BF, followed by those with NF and AF. The heaviest fresh and dry weights among treatments were 151.3 and 37.8 g, respectively, with BF . In terms of tissue nutrient contents, the highest N, P and Na contents, of 3.08, 0.54, and 0.10%, respectively, were observed in the treatment with NF . The highest K content was 2.83%, in the treatment with AF , while the highest Ca and Mg were 0.98 and 0.42%, respectively, in BF . The AF treatments had higher tissue Fe, Mn, Zn, and Cu contents compared to those of NF or BF when fertilizer concentrations were controlled to equal. During the 100 days after fertilization, the highest and lowest pH in soil solution of root media among all treatments tested were 6.67 in BF and 4.69 in AF , respectively. The highest and lowest ECs were in BF and in BF , respectively. For the concentrations of macronutrients in the soil solution of root media, the AF treatment gave the highest concentrations followed by NF and AF . The K concentrations in all treatments rose gradually after day 42 in all treatments. When fertilizer concentrations were controlled to equal, the highest Ca and Mg concentrations were observed in AF followed by NF and BF until day 84 in fertilization. The BF treatments produced the highest concentrations, followed by NF and AF. The trends in the change of concentration were similar in all treatments. The concentrations were higher in treatments with AF than those with NF or BF until day 70 in fertilization. These results indicate that compositions of fertilizer solution should to be modified to contain more alkali nutrients when 'Seolhyang' strawberry is cultivated through inert media and nutri-culture systems.

Influence of root substrate formulations, leaching fractions (LF) of fertigation during seedling growth before grafting and fertilizer N concentrations after grafting on growth of tomato grafted seedlings and changes in root substrate chemical properties were investigated. Sphagnum peatmoss + perlite (7:3, v/v, PP) and coir + perlite (7:3, CP) containing pre-plant fertilizers were used as substrates. LF (volume leached/applied) was set as 0, 0.25, 0.50, 0.75 and 0.9 during seedling cultivation. Seedlings of rootstock (J3B Strong) and scion (Sunmyung) were grown in 50- and 105-cell trays, respectively. Plants were fed with 50, 100, or 200 mg·L−1 N using 14-0-14 and 20-10-20 commercial fertilizers alternatingly for seedling stages 2, 3, and 4, respectively. Grafted tomato seedlings planted in 50-cell trays containing PP or CP were callused and rooted inside a humid greenhouse plastic tunnel for 7 days. When grafted tomato seedlings were rooted after acclimation under lower humidity condition, N fertilizers with 4 different concentrations (0, 50, 100, 200 mg·L−1) were applied. During 31 days of culture, highest fresh weight of rootstocks was obtained with 0.75x LF in CP, while PP showing no influence on seedling growth by LF. Electrical conductance (EC) of CP with 0.75x LF was 2.88 dS·m−1. Growth of scion seedlings was largest with 0.25x LF in PP, and EC of this treatment was 0.855 dS·m−1. For 13 days post-grafting, plant growth was better as LF increased for both substrates. When seedlings were grown with 0.90x LF, EC for PP and CP was 0.833 and 2.923 dS·m−1, respectively. Fresh weight of grafted plants grown for 31 days after grafting was the highest with 50 mg·L−1 N for PP and 0 mg·L−1 N for CP. Substrate EC in these treatments were 0.66 and 1.42 dS·m−1, respectively. This study suggests that LF and fertilizer N concentration must be optimized according to substrate formulations for growing high-quality grafted seedlings.

The aim of this study was to investigate which hydroponic system is the optimum for growth and photosynthetic characteristics of Angelica gigas during experiment. Angelica gigas ‘Manchu’ were sowed and managed under a growth room chamber. The environmental conditions (temperature 22℃/18℃ (day/night), relative humidity 50-70%, photosynthetic photon flux density (PPFD) 120±6 μmol m -2 s -1 ) were maintained for 3 weeks. Forty eight seedlings with 4-5 leaves were transplanted in deep flow technique (DFT), substrate, and spray culture systems [culture bed: 800 (L) x 800 (W) x 400 mm(H)] under 150±5 μmol m -2 s -1 PPFD provided with fluorescence lamps and cultivated for 11 weeks. At the end of the experiment, fresh and dry weights, leaf lenghth and width, SPAD, root fresh, and dry weights, and root volume of Anglica gigas were measured. Photosynthetic rate of Anglica gigas were measured with portable photosynthesis systems to investigate optimum PPFD, CO₂ concentration, and air temperature conditions. Fresh and dry weights of Anglica gigas grown in substrate were significantly greater than DFT-treated, but there were not significant with spray treatment. Leaf photosynthesis of Anglica gigas showed the tendency to sharply increase as PPFD was increased from 50 to 200 μmol m -2 s -1 . Though CO₂ saturation point was around 1000-1200 μmol mol-1, increase in air temperature from 16 to 26℃ did not quite affect photosynthesis of Anglica gigas. In conclusion, Anglica gigas may be optimally cultivated with a spray culture system as air temperature, PPFD, and CO₂ concentration for environment are controlled at 20±3℃, 150 μmol m -2 s -1 , and around 1000 μmol mol -1 for mass production.

We quantified the effects of the composition and concentration of fertilizer solutions on the growth and nutrient uptake of 'Maehyang' strawberry at the vegetative growth stage. Acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) with concentrations of 100 or 200 mg·L -1 based on N, were formulated and applied during the 100 days after transplanting, at which point crop growth and tissue nutrient contents were analyzed. The soil solutions were sampled every two weeks to measure the pH, EC and nutrient concentrations. BF was a more effective fertilizer compared to AF and NF for growth of 'Maehyang' strawberry when fertilizer concentrations were controlled to 100 mg·L -1 . By contrast, the fresh and dry weights were greatest in the NF treatment when fertilizer concentrations were controlled to 200 mg·L -1 . The tissue contents of N, P, and Na were 2.20, 0.51 and 0.10%, respectively, in the NF 200 treatment, and these were the highest among all treatments tested. The highest contents of K, Ca and Mg were 2.60% in AF 200, 0.95% in BF 200 and 0.45% in BF 100, respectively. During the fertilization period, the highest and lowest pHs were 6.13 in BF 100 and 4.92 in AF 200. The lowest EC was 1.376 dS·m -1 in BF 100 and the highest was 4.936 dS·m -1 in NF 200 treatments. The highest NH4 + concentrations in the soil solution occurred during the AF 200 treatment, followed by those with NF 200 and AF 100. When fertilizer concentrations were equal, AF treatment gave rise to the highest Ca +2 and Mg +2 concentrations, followed by NF and BF, until day 84 of fertilization. The BF treatments had the highest NO3 - concentrations followed by NF and AF. The trends for PO4 -3 concentrations were similar in all fertilizer treatments when the fertilizer concentrations were equal. The above results indicate that neutral and basic fertilizers were most effective to promote 'Maehyang' strawberry growth when fertilizer solutions were controlled to low or high concentrations, respectively. These findings are useful for planning fertilization programs for vegetative propagation of 'Maehyang' strawberry.

Objective of this research was to develop root media containing expanded rice hull (ERH) and carbonized rice hull (CRH). To achieve this, the physico·chemical properties of two materials were analysed and blended with peatmoss (PM) or coir dust (CD) with various ratio. Based on the physical properties of the blended materials, 4 root media were selected for future experiment. After the analysis of pH and EC of the selected root media, the kinds and amount of pre-planting nutrient charge fertilizers (P NCF) incorporated into each root medium were varied, and then, final chemical properties of the root media were analysed. The total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were 81.3%. 39.9%, and 41.4% in ERH and 77.6%, 64.1%, and 13.5% in CRH, respectively. The percentage of easily available water (EAW, from CC to 4.90 kPa tension) and bufferin g water (BW, 4.91-9.81 kPa tension) were 11.37% and 5.27%, in ERH and 17.26% and 14.28% in CRH, respectively. The pH of ERH was 7.1, but it was extremely high in CRH such as 11.2. The EC and CEC were 1.31 dS·m -1 and 12.1 meq·100 g -1 in ERH and 6.53 dS·m -1 and CEC 7.79 meq·100 g -1 in CRH, respectively. The ranges of TP, CC and AFP in 4 selected media (PM + ERH, 6:4, v/v; CD + ERH, 8:2; PM + CRH, 7:3; CD+CRH 6:4) were 89.2-90.3%, 67.3-81.8%, and 8.3-21.9%, respectively. The pHs and ECs in root media containing peatmoss such as PM + ERH (6:4) and PM + CRH (7:3) were 4.0-4.3 and 0.33-0.365 dS·m -1 , whereas those of CD + CRH were 7.4-7.9 and 1.282 dS·m -1 . The pHs and ECs, however, analysed before and after the incorporation of PNCF in each root medium were not significant different. This result indicated that the incorporated fertilizers in PNCF to adjust medium pH did not dissolve enough to influence medium pH, but it is very normal in root media containing dolomitic lime and sulfur powder in adjusting pH. The Information obtained in this study may facilitate an effective formulation of root media containing rice hulls.

When highly shrinkable materials such as coir dust are major component of root media, the degrees of compaction during container filling of root media severely influences the physical properties of root media. It results in the changes in total porosity (TP), container capacity (CC) and air-filled porosity (AFP). This research was conducted to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. To achieve this, three root media were formulated by blending coir dust (CD) with expanded rice hull (CD + ERH, 8:2, v/v), carbonized rice hull (CD + CRH, 6:4) and ground and raw pine bark (CD + GRPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120 and 130% based on the weight of root media. Then the changes in TP, CC, and AFP were measured. Elevation of the packing amount of root media in all sizes of pot resulted in the decrease of TP. But the decrease was more severe in CD + ERH and CD + CRH than those in CD + GRPB. The CC also decreased gradually as the packing amounts were elevated in three root media, but the decreases were severe as the container sizes became larger. The AFP decreased drastically by the elevation of the packing amount of root media in all sizes of pot. The AFP was the highest in CD + CRH medium when pot sizes were smaller than 7 cm, but that was the highest in CD + ERH when the pot sizes were larger than 8.5 cm among the 3 root media tested. In this research, the elevation of packing amount of three root media influenced more severely the AFP rather than CC. This result indicates that the packing amount should be controlled to maintain appropriate level of AFP because AFP rather than CC influence severely crop growth. The results obtained through this study can be used to predict the changes in physical properties of root media as influenced by packing amount in various sizes of pots.

The objective of this research was to secure the fundamental information in changes of soil physical properties as influenced by the compaction of root media during container filling. Three root media were formulated by blending peatmoss (PM) with expanded rice hull (PM + ERH, 8:2, v/v), carbonized rice hull (PM + CRH, 6:4) and ground and aged pine bark (PM + GAPB, 8:2). Based on the optimum bulk density, the amount of root media filled into 6.0, 7.5, 8.5, 10.5 and 12.5 cm were adjusted to 90, 100, 110, 120, and 130%, then the changes in total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were measured. The TP decreased significantly as the packing amount of three root media were elevated in all sizes of container. The TP did not show significant differences among the root media in small sizes of containers, but showed significant differences when sizes of containers became larger. As packing amount of three root media were elevated, the CCs in all sizes of containers were decreased. The PM + CRH had the lowest CC among three root media in containers smaller than 8.5 cm, but had the highest CC in those larger than 10.5 cm. These results indicated that the decreases in CC were influenced by the sizes of containers as well as kinds of root media. The elevation of packing amount in three root media diminished significantly the AFP. The AFP in PM + GAPB medium was two times as high as those of PM + ERH or PM + CRH when equal packing densities were applied in all sizes of containers. As the container sizes became larger in three root media, the extents in decreasing of CC were distinct than those of AFP. Above results indicate that elevation in packing amount of three root media decreased significantly the TP, CC and AFP, but these were influenced differently by sizes of containers and kinds of root media. The results would be useful for expectation in the changes of physical properties in various sizes of containers filled with peatmoss based root media.

In this study, an efficient machine vision based inspection system is developed for the in-line measurement of phosphor resin dispensing shapes on LED chip package. Since the phosphor resin (target material) has semitransparent characteristics, illuminated light beam is reflected from the bottom of the chip as well as from the surface. Since such phenomenon can deteriorate inspection reliability, a white LED and a 635nm laser slit beams are experimentally tested to decide suitable illumination optics. Also, specular and diffuse reflection methods are tested to decide suitable optical triangulation. As a result, it can be known that the combination of a white slit beam source and specular reflection method show the best inspection results. The Catmull-Rom spline interpolation is applied to the obtained data to form smoother surface. From the results, it can be conclude that the developed system can be sucessfully applied to the in-line inspection of LED chip packaging process.

This research was conducted to evaluate the influence of ratios in fertilizer solution on the vegetative growth and fruit yield of hot pepper (Capsicum annuum L.) through pot cultivation. The Hoaglad's solution was modified to contain various ratios such as 100:0 (A), 73:37 (B), 50:50 (C), 27:73 (D), 0:100 (E), and no nitrogen (F). Plants were transplanted into root substrates and the modified solutions were applied as plant needed in plastic house. There were no statistical significances among the treatments from A through D in the fresh and dry weights, and number of leaves 31 days after transplanting, but elevation of ratios in the solution decreased the fresh fruit weight 62 days after transplanting with statistical differences. In the results of inorganic element analysis based on the dry weight of fully expanded mature leaves, N and P contents as well as micro cations such as Fe, Mn, Zn, and Cu increased as ratios were elevated 62 days after transplanting. However, those of macro cations such as K, Ca, and Mg resulted in decreasing tendency. The elevation of ratios in fertilizer solution resulted in the increase of EC and total N concentrations (), but this decreased the pH as well as Ca and Mg concentrations in soil solution 62 days after transplanting. The K concentration in soil solution was the highest in the treatments of C and followed by D, B, E, and A. The above results indicate that the proper ratio in the nutrient solution is 73:27 (B) or 100:0 (A) and the B solution is proper for the vegetative growth and that of A is proper for reproductive growth stage.

‘Seolhyang’ strawberries (Fragaria ananassa Duch.) were grown in a soilless substrate with fertigation solutions to evaluate the effects of six different P concentrations (0, 0.5, 1, 2, 4, and 6 meq·L−1) on the growth and nutrient contents in dry matter of above-ground tissue and petiole sap. The changes in electrical conductivity (EC) and pH of the root substrate were also investigated. Deficient and excess concentrations of phosphorus, such as 0 and 6 meq·L−1, seriously restricted the plant growth. These two treatments showed the least values in leaf number, plant height, leaf length and width, petiole length, and fresh and dry weights. The solution containing 1 meq·L−1 of phosphorus showed the greatest plant growth compared to the other treatments. The macro-element contents such as P, K, Ca, and Mg showed increased tendencies as P concentrations were elevated but, micro-elements such as Fe and Mn showed decreased tendencies in dry matter of above-ground tissue. When P concentrations were elevated, the pH and EC in the soil solution of root substrate decreased. Considering the crop growth and tissue nutrient contents, the P concentrations should be between 0.5 to 2.0 meq·L−1 and the P contents in the dry matter and petiole sap were 0.23 to 0.62% and 205 to 305 mg·kg−1.

The Ca deficiency is a serious problem in the propagation of domestically bred 'Seolhyang' strawberry through soil cultivation. The objective of this research was to investigate the impact of the Ca containing fertilizers on the decrease of Ca deficiency symptoms and in the growth of mother and daughter plants. To achieve this, chemicals of 1.125 mM Ca(OH)2, 0.375 mM MgCl2, and 1.25 mM KCl were blended to contain the K:Ca:Mg (4:2:1) and the influence was compared to a commercial fertilizer, Azuro-Calma (NO3-N 13%, K2O 1%, CaO 16%, MgO 6%), when those were applied as solutions with the electrical conductivity (EC) controlled to 0.6 or 1.0 dS·m -1 . During 120 days after transplant, the Azuro-Calma was more effective than the combined fertilizer in the reduction of mother and daughter plants on which Ca deficiency was appeared. The application of two Ca containing fertilizers resulted in the heavier fresh and dry weights of mother plants. The treatments of 1.0 dS·m -1 of two fertilizers were more effective than those of 0.6 dS·m -1 . The combined fertilizer was also more effective than Azuro-calma on the growth of above ground plant tissue. The results in length, fresh and dry weight of runners occurred from a mother plants showed that the treatment of 1.0 dS·m -1 of combined fertilizer was most effective followed by those of 1.0 dS·m -1 of Azuro-Calma, 0.6 dS·m -1 of combined fertilizer, 0.6 dS·m -1 of Azuro-Calma, and control. The fresh weights of daughter plants were heavier in the treatments of Ca application than those in the control treatment, but the differences between 0.6 dS·m -1 and control were not significant. The above results indicate that Azuro-Calma is more effective in decreasing plants showing the Ca deficiency symptoms. However, the combined fertilizer of K:Ca:Mg is more desirable when we are concerned about the decrease of crops showing Ca deficiency as well as increase of the growth in above ground plant tissue.

The dispenser ejects the ceramic filler and phosphor-containing liquid for making various products. When the particle-containing liquid is ejected under high-velocity conditions, however, the ejection reliability decreases because of the wear of the contact surface between the rod and nozzle even though these components are made of hard materials. It is therefore necessary to characterize the friction and wear properties of the hard materials, tungsten carbide (WC) and zirconium (Zr), with the high-viscosity liquid-containing nitride or yttrium aluminum garnet (YAG) particles under reciprocating conditions. Particle contents of 15 wt.% and 30 wt.% are added to the liquid. A reciprocating test was implemented to this end, and WC and Zr specimens were used. The liquid used in the experiment contains nitride and YAG. The experimental results show that the particles inside the liquid are worn out, leading to particle lubrication and the decrease in the coefficient of friction. Also, it is confirmed that the more the particles are, the less the coefficient of friction is due to particle lubrication. For each experimental condition, the coefficient of friction is measured and compared. Moreover, the contact surface of the specimen is analyzed using an electron microscope, and a profilometer is used to measure the surface roughness of the specimen before and after the test. The reciprocation friction and wear characteristics of WC and Zr with phosphor-containing liquid are evaluated by analyzing the experimental results.

딸기를 이용한 건강막걸리를 개발하고자, 딸기를 첨가하여 막걸리를 제조한 후 이들의 품질 특성을 조사하였다. 먼저 딸기막걸리 제조에 적합한 효모를 선발하기 위해 시판 알코올 발효효모와 배재대학교에서 분리 보관중인 알코올 발효효모를 이용하여 딸기막걸리를 제조한 결과 분리 효모인 Saccharomyces cerevisiae JSK...

This research was conducted to determine the effects of four different substrates, expanded rice hulls (ERH), commercial substrates for strawberries (CSS), clay sand (CS), and loamy sand (LS), on the inhibition of anthracnose crown rot (ACR) in strawberry. Mother plants of ‘Seolhyang’ strawberry were transplanted into an elevated bed in March, 2013 and March, 2014 and the runners connecting mother plants and daughter plants were cut in early August of both years. After separation, growth characteristics of the daughter plants were measured and then each daughter plant was inoculated with conidial suspensions of Colletotrichum fructicola, one of several species of Colletotrichum that causes ACR in strawberries. The incidence of ACR as influenced by the different substrates was investigated in both years. The daughter plants grown on CSS had the highest values for shoot height, leaf area, and fresh weight. Those grown on ERH and LS substrates also displayed good above-ground growth characteristics except for fresh weight, but the daughter plants grown on CS had the poorest above-ground growth characteristics. The ERH and CS treatments resulted in the highest number of primary roots and the greatest root weight. The CSS-grown daughter plants had the highest ACR disease index, followed by the CS and LS treatments, but there were no significant differences among the three substrates. However, the ERH-grown daughter plants had a markedly lower ACR disease index on October 11, 2013 and October 7, 2014. The CSS-grown daughter plants had high nitrogen and potassium contents and low calcium content, whereas the ERH-grown daughter plants had low nitrogen levels and high silicon levels. The results of this study provide basic information on the ability of the different substrates tested to provide disease suppression of ACR in the propagation of strawberry transplants.

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 240 mg·L -1 HCO₃ - . The concentrations of HCO₃ - in the treatment solution were decreased to 60 mg·L -1 by the addition of HNO₃, H₃PO₄, H₂SO₄, HNO₃ + H₃PO₄, 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 (240 mg·L -1 HCO₃ - ) 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 HNO₃, H₃PO₄, H₂SO₄, HNO₃ + H₃PO₄ 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 HNO₃, H₃PO₄, H₂SO₄, and HNO₃ + H₃PO₄ treatments, respectively. The tissue Ca and Mg contents of mother plants were significantly higher in +control (90 mg·L -1 HCO₃ - ) 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.