• Journal of Biosystems Engineering
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• v.28 no.2
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• pp.151-156
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• 2003

This study was performed to investigate the effect of light quality on evapotranspiration and graft-taking characteristics of watermelon grafted seedlings using blue, red and far-red light-emitting diodes (LED). At initial stage of graft-taking, blue light increased the evapotranspiration rate (EVTR) of grafted seedlings as compared to effects of red and far-red on EVTR of grafted seedlings. Grafted seedlings graft-taken under red and blue LED showed the high graft-taking of 100% and 96%, respectively. However, grafted seedlings graft-taken under far-red LED showed the graft-taking of 80% and survival of 60% with low seedlings quality after hardening. The stem of grafted seedlings graft-taken under red light was elongated but blue light suppressed the stem elongation. The leaf area of grafted seedlings graft-taken under red light was increased. It is concluded that the effect of light quality using LED on graft-taking of watermelon grafted seedlings was significantly recognized. Considering the duration of quality of grafted seedlings graft-taken under artificial lighting, LED could be used as an effective lighting sources to validate the continuance of seedling quality.

• Journal of Biosystems Engineering
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• v.26 no.4
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• pp.379-384
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• 2001

To enhance the smooth graft-taking of grafted seedlings, the excessive evapotranspiration from grafted seedlings just after grafting should be avoided. A measurement system of the evapotranspiration rate of grafted seedling under artificial lighting was set up to investigate the effect of physical environment on the evapotranspiration and graft-taking characteristics of grafted seedlings quantitatively. The evapotranspiration rate of grafted seedlings affected by relative humidity and light intensity were analyzed using the measurement system. The hypocotyl of watermelons (Citrullus vulgaris cv. Sweetdew, Hungnong Seed Co.) was slantly cut and then inserted into a hole on the stem of rootstock (Lagenaria siceraria cv. FR-King, Hungnong Seed Co.). Grafted seedlings were healed and joined for 5 days under cool-white fluorescent lamps (FL20SEX-d/18, Keumho Electric Co.) with photoperiod of 12h$.$d$\^$-1/ except dark period for one day after grafting in a closed graft-taking enhancement system developed by Kim(2000). The evapotranspiration rate and graft-taking of grafted seedling at air temperature of 23$\^{C}$ and air current speed of 0.1m$.$s$\^$-1/ was highly affected by relative humidity. But light intensity showed higher effect on the stem length of scion than relative humidity. In conclusion, it was suggested that relative humidity should be controlled at higher than 90% with photosynthetic photon flux of 50$\mu$mol$.$m$^2$$.$s$\^$-1/ to increase the survival of grafted seedlings and to produce healthy seedlings.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.632-638
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• 2000

This paper represents the characteristics of evapotranspiration rate (EVTR) and graft-taking of watermelon grafted seedlings in a graft-taking enhancement system using fluorescent lamps as artificial lighting source. Four air temperature levels of 23, 25, 27 and 29C, three humidity levels of 85, 90 and 95%R.H. and two photosynthetic photon flux (PPF) levels of 30 and 50 ${\mu}$mol m$\^$-2/ S$\^$-1/ were provided to investigate the effects of air temperature, relative humidity and light intensity on EVTR and graft-taking of grafted seedlings. EVTR of grafted seedlings increased with increasing air temperature and the passage of time after grafting. Also EVTR increased with decreasing relative humidity. As relative humidity decreased and air temperature increased, vapor pressure deficit increased and thus EVTR increased. It is required to maintain a low level vapor pressure deficit for suppressing EVTR of grafted seedlings during first 1-2 days after grafting. Therefore, less EVTR at initial stage after grafting would be adequate for smooth joining of the scion and rootstock.

• Journal of Biosystems Engineering
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• v.31 no.5 s.118
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• pp.449-453
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• 2006

Effect of light quality on plant temperatures at joining parts of grafted watermelon seedlings was investigated using a thermal imaging system in this study. Plant temperatures at joining parts lowered than those at stem region during graft-taking. However, difference in plant temperatures at joining parts and at stem region decreased by days after graft-taking. Plant temperatures of grafted seedlings graft-taken under white, blue, red, and blue + red fluorescent lamps repeatedly fluctuated high at photoperiod and low at dark period. Considering the variation of plant temperatures at joining pa퍼5, the illumination of blue and red light as well as white light will be effective for grafting of grafted watermelon seedlings. It is recommended that air temperature around grafted seedlings should be maintained at 27 to $29^{\circ}C$ for enhancing the physiological reaction of callus and for the smooth joining of scion and rootstock.

• Journal of Life Science
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• v.5 no.4
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• pp.190-202
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• 1995

Two oriental melons cultivars, ‘Geumssaragi Euncheon’(GSEC) and ‘House Eunchon’(HEC), were grafted onto different rootstocks and the growth, mineral contents and fruit quality were examined. The seedlings grafted onto‘Geumtozwa’rootsticks showed about 10% defected seedling loss(wilting or dwarfing0as compared to the little or no loss in the seedlings grafted onto 'Sintozwa' or 'Chamtozwa' rootstocks. The seedings grafted onto 'Sintozwa' or 'Chamtozwa' rootstocks also exhibited better vine growth as compared to the intact seedlings or the seedlings grafted onto 'Geumtozwa' rootstocks. The fruits growth, as measured by fruits length, fruit diameter and fruit fresh weight, was accelerated by the rootstocks especially by 'Sintozwa' and 'Chamtozwa' . Intact oriental melons showed the highest soluble solids content in the fruit pericarp followed by 'Chamtozwa' rootstocks. Sucrose contents were higher in the seedling grafted onto 'Sintozwa', whereas higher glucose and fructose contents were measured in intact GSEC fruits or HEC fruits on 'Chamtozwa' rootstock. As compared to the intact plants, the seedling grafted onto 'Sintozwa' rootstock showed higher N. P and K and lower Ca and Mg contents in leaves, stems, roots and fruits. 'Geumtozwa' rootstock, developed specially for oriental melons, showed very similar pattern of mineral absorption or distribution as compared to the intact plants.

• Journal of Biosystems Engineering
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• v.25 no.3
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• pp.213-220
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• 2000

Grafting of fruit-bearing vegetables has been widely used to increase the resistance to soil-borne diseases, to increase the tolerance to low temperature or to soil salinity, to increase the plant vigor, and to extend the duration of economic harvest time. After grafting, it is important to control the environment around grafted seedlings for the robust joining of a scion and rootstock. Usually the shading materials and plastic films are used to keep the high relative humidity and low light intensity in greenhouse or tunnel. It is quite difficult to optimally control the environment for healing and acclimation of grafted seedlings under natural light. So the farmers or growers rely on their experience for the production of grafted seedling with high quality. If artificial light is used as a lighting source for graft-taking of grafted seedlings, the light intensity and photoperiod can be easily controlled. The purpose of this study was to develop a prototype system for the graft-taking enhancement of grafted seedlings using artificial lighting and to investigate the effect of air current speed on the distribution of air temperature and relative humidity in a graft-taking enhancement system. A prototype graft-taking system was consisted by polyurethane panels, air-conditioning unit, system controller and lighting unit. Three band fluorescent lamps (FL20SEX-D/18, Kumho Electric, Inc.) were used as a lighting source. Anemometer (Climomaster 6521, KANOMAX), T-type thermocouples and humidity sensors (CHS-UPS, TDK) were used to measure the air current speed, air temperature and relative humidity in a graft-taking system. In this system, air flow acted as a driving force for the diffusion of heat and water vapor. Air current speed, air temperature and relative humidity controlled by a programmable logic controller (UP750, Yokogawa Electric Co) and an inverter (MOSCON-G3, SAMSUNG) had an even distribution. Distribution of air temperature and relative humidity in a graft-taking enhancement system was fairly affected by air current speed. Air current speed higher than 0.1m/s was required to obtain the even distribution of environmental factors in this system. At low air current speed of 0.1m/s, the evapotranspiration rate of grafted seedlings would be suppressed and thus graft-taking would be enhanced. This system could be used to investigate the effects of air temperature, relative humidity, air current speed and light intensity on the evaportranspiration rate of grafted seedlings.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.352-357
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• 2006

Results of development and activity of roots by rootstock sort of oriental melon were followed; Grafted seedlings had higher root growth than self-roots seedlings and among grafted seedlings, Shintozoa and Elite rootstocks had higher root growth. Grafted seedlings had more xylem exudate, which connects activity of roots, than self-root seedlings. Development of roots and increase of xylem exudate were better in higher temperature. Marketable yield was higher in grafted seedling and quality of fruit was higher in self-root seedling.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.358-363
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• 2006

Results on growth and fruit elongation and quality by rootstock sort of oriental melon were followed; Growth of upper part of oriental melon was faster grafted seedlings than self-root seedlings and among grafted seedlings, Elite and Shintozoa rootstocks were better than Hongtozoa. Growth of Elite and Shintozoa rootstocks, stem length and leaf number, were laster after 30 days of seedling transplant. Fruit elongation had no difference in rootstocks sort. Fruit weight was higher Elite and Shintozoa grafted seedlings than self-root seedlings but soluble solid contents of fruit was higher self root seedlings, $13.9^{\circ}Brix$, than Elite grafted seedlings, $12.5^{\circ}Brix$.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.275-283
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• 2010

This study was conducted to examine the changes in growths of tomato and watermelon seedlings and the relationship among growth parameters which are used to evaluate healthy seedling as affected by shading. Plants were grown under 0%, 25%, 50%, and 75% shadings using polyethylene films. Leaf area index (LAI) of tomato and grafted watermelon seedlings increased under 50% and 75% shading. Total dry weight decreased with increase of shading level. The growth rates of stem diameter, LAI, total weight were faster under 50% and 75% shading with increase of integral radiation than under 0% and 25% shading. Stem diameters of tomato and grafted watermelon seedlings showed no significant differences among shading regimes. Stem diameters of tomato seedlings had upward tendency with increase of total dry weight and shoot height, but there were no significant differences among shading regimes. Stem diameters of grafted watermelon seedlings had no relationship with shoot height. These results indicate that stem diameter of tomato seedlings is not appropriate for assessing seedlings quality but stem diameter of grafted watermelon seedlings with shoot height is available.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.231-238
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• 2018

Chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings as affected by photosynthetic photon flux (PPF) of LED lamps were analyzed in this study. Four PPF levels, namely 25, 50, 100, $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ were provided to investigate the effect of light intensity on the chlorophyll fluorescence, chlorophyll content, graft-taking and growth of grafted cucumber seedlings. Air temperature, relative humidity, and photoperiod for graft-taking were maintained at $25^{\circ}C$, 90%, $16h{\cdot}d^{-1}$, respectively. Maximum quantum yield (Fv/Fm) of rootstock as affected by PPF was found to be 0.84-0.85 and there was no significant change in Fv/Fm. Even though Fv/Fm of scion measured at 2 days after grafting was lowered to 0.81-0.82, after then it gradually increased with increasing PPF. At 4 days after grafting, the chlorophyll content extracted from scion increased with increasing PPF. Graft-taking ratio of grafted cucumber seedlings was 90-95% as PPF was ranged from $25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ to $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. However, the graft-taking ratio of grafted seedlings healed under PPF of $150{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ was decreased to 80%. Maximum PPF measured required for smooth joining of rootstock and scion was assumed to be $100{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. At healing stage of grafted cucumber seedlings, Fv/Fm of scion decreased and at least two days after grafting were required for rooting of grafted seedlings. Chlorophyll fluorescence response of rootstock and scion was linked to light irradiation. Therefore, it was concluded that physical environment including light and humidity during healing process of grafted seedlings should be controlled more precisely to facilitate root formation and to prevent scion from lowering Fv/Fm. Further studies are required to investigate the effects of root development and joining of vascular bundles of grafted seedlings on the chlorophyll content of scion.