• Journal of Biosystems Engineering
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• v.41 no.1
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• pp.21-33
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• 2016

Purpose: In order to ensure that vegetable seedlings (with a soil block around their roots) are planted in an upright orientation after metering in a vegetable transplanter, they need to be dropped freely from a certain height. The walk-behind hand-tractor-powered machines do not have sufficient space to drop the seedlings from that height. In the present work, a hopper-type planting device was developed for the walk-behind hand-tractor-powered vegetable transplanter to ensure that the soil block seedlings are planted in an upright orientation. Methods: Various dimensionless terms were developed based on the dimensional analysis approach, and their effect on the planting of soil block seedlings in an upright orientation (planting efficiency) was studied. The optimum design dimensions of the hopper-type planting device were identified by the Taguchi method of optimization. Results: The ratio of the height of free fall to the sliding distance of the seedling on the surface of the hopper had the highest influence on planting efficiency. The planting efficiency was highest for plants with a height $15{\pm}2cm$. The plant handling Froude number, in interaction with the design of the hopper-type planting device, also significantly affected the planting efficiency. Of the hopper design factors, the length of the slide of the seedlings on the surface of the hopper was most important, and induced sufficient velocity and rotation to cause the seedling to fall in an upright orientation. An evaluation of the performance of the planting device under actual field conditions revealed that the planting efficiency of the developed planting device was more than 97.5%. Conclusions: As the seedlings were fed to the metering device manually, an increase in planting rate increased missed plantings. The planting device can be adopted for any vegetable transplanter in which the seedlings are allowed to drop freely from the metering device.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.23-28
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• 2002

This experiment was conducted far the efficient use of plant growth retardants (PGR) for suppression of plug seedling height. 'Seokwang' tomato seeds were soaked in I5 mL solution of daminozide (1,000, 10,000, or 100,000 mg.L-1) or uniconazole (1, 10, or 100 mg.L-1). And then, they were put in $25^{\circ}C$ chamber for one or three days. Seeds were washed in tap waters and were dried in 5$^{\circ}C$ chamber for one day. Dried tomato seeds were sown and seedlings were raised in 288-cell plug trays. Seedlings grown were evaluated at 21 and 38 days after sowing. Treatments of 10 or 100 mg.L-1 uniconazole as compared to the control had significantly suppressed hypocotyl length and seedling height, but fresh and dry weights of roots, emergence, no. of leaves, chlorophyll concentration, dry matter, and T/R ratio were not significant by different among treatments.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.7-13
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• 1999

Thirty bacteria were isolated from the red pepper rhizosphere. The isolates were screened for antagonism to Alternaria alteranta causing red pepper black rot. Antagonistic bacterium No. J-24 was selected among the isolated bacteria and was identified as Bacillus subtilis based on morphological and physiological characteristics and MIDI system. B. subtilis J-24 showed antifungal activities against A. alternata(inhibition percentage, 99%), Botrytis cinerea, Phytophthora capsici, Pythium ultimum, Colletotrichum gloeosporioides, Stemphylium botryosum. The growth of red pepper seedling was promoted as compared to control when the microbial inoculants was mixed in bed soil. In the mixed microbial inoculants bed soil, the leaf area of red pepper was increased of 15 percent, the hypocotyl weight 12 percent, the root length 12 percent, total dry weight 13 percent as compared to those grown in the general bed soil.

• Journal of Ecology and Environment
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• v.41 no.8
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• pp.202-212
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• 2017

Background: To reveal establishment strategy of Sparganium erectum, we tried to find realized niche of adults through field survey and effects of water level on the establishment process through mesocosm experiments. Results: In the field survey, the height and coverage of community living in deeper water were greater than those of community living in shallow water. There was no statistically significant difference (p > 0.05) in the means of water and soil properties between the two communities. In mesocosm experiments, we found no correlation between water levels and germination rates, but S. erectum seedlings have characteristics of post germination seedling buoyancy when S. erectum seeds germinated in inundation conditions. Shoot height, total leaf length, and survival rates of sinking seedlings in shallow water levels at -5, 0, and 5 cm were higher than those in deeper water levels at 10 and 20 cm. Floating seedlings established in water levels of 3 and 6 cm only. The seedlings could live up to 6 weeks in floating state but died if they were unable to establish. Conclusions: The water level around adult S. erectum communities in the field were different from the water level at which S. erectum seedlings can survive in the mesocosm experiments. The findings provided not only understanding of S. erectum habitat characteristics but also evidence to connect historical links between the early seedlings stage and adult habitat conditions. We suggested the logical establishment strategy of S. erectum based on the data.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.407-414
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• 2009

A cDNA clone encoding phytocystatin was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (name as Brcpi1; GenBank accession no.: EF079953) had a total length of 881 bp with an open reading frame of 609 bp, and encoded predicted polypeptide of 203 amino acid (aa) residues including a putative N-terminal signal peptide. Other relevant regions found its sequence included the G and PW conserved aa motifs, and the consensus LARFAV sequence for phytocystatins and the reactive site QVVAG. The BrCPI1 protein shared 95, 94, 81, 80 and 78% identity with other CPI proterins isolated from Brassica oleracea (BoCPI-1), Arabidopsis thaliana (AtCY SB), Glycine max (GmCPI), Oryza sativa (OsCYS-2) and Zea may (ZmCPI) at amino acid level, respectively. Southern blot analysis showed that Brcpi1 was a low copy gene. Expression pattern analysis revealed that Brcpi1 was a tissue-specific expressing gene during reproductive growth and strongly expressed at mature seedling stages. Furthermore, overexpression of Brcpi1 in transgenic Arabidopsis was enhanced tolerance to salt and cold stresses. Meanwhile the juvenile seedling of Brcpi1 transgenic plants was not affected by various concentrations ABA in MS medium. Taken together, the results showed that Brcpi1 functioned as a cysteine protease inhibitor and it exhibited a protective agent against diverse types of abiotic stress, which induced this gene in a tissue- and stress-specific manner.

• Korean Journal of Medicinal Crop Science
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• v.22 no.5
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• pp.384-390
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• 2014

This study was carried out in order to investigate the early growth and root development characteristics of Peucedanum japonicum container seedlings. The experiment was performed by containers (128 and 200 cavities containers) and shading levels (0%, 35%, 50% and 75% shading). Germination rate of P. japonicum seeds was getting higher in the lower shading level and the highest in the full sunlight (71.9%). Plant height was the highest under 50% shading of all containers. Fresh weight and dry weight of the shoot (leaves + stem) were the highest under 50% shading of all containers, too. Meanwhile, fresh weight and dry weight of the root per plant were the highest under the full sunlight of 128 cavities container such as 0.34 g and 0.03 g, respectively. Total root length, root project area and root surface area were higher under the full sunlight of 128 cavities container such as 234.5 cm, $6.6cm^2$ and $20.8cm^2$, respectively and the next higher was under 35% shading such as 201.7 cm, $5.9cm^2$ and $18.4cm^2$, respectively. A case of root volume was the highest with $0.15cm^3$ under the full sunlight. As a result of the surveying the whole experiment, it is concluded that the shoot and root of P. japonicum seedling grow nicely by maintaining 35% shading.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.276-280
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• 2013

D. kaki and D. lotus are used as rootstocks for astringent persimmons in Korea but characteristics of their seedlings have not been determined. In this experiment, their seeds were sown in 3-L pots on April 18 and the seedlings were grown until October 24. Growth and nutrient absorption were compared at the end of the season after destructively harvesting the seedlings. Seedling growth of D. lotus was much faster than that of D. kaki in terms of total stem length, stem diameter, and number of leaves. However, chlorophyll value and specific leaf weight were higher in D. kaki than in D. lotus. Dry weight of D. lotus was 3.6- and 3.7-fold higher than that of D. kaki in above-ground parts and the root, respectively. D. kaki seedlings were characterized by higher concentrations of N, P, K, Ca, and Mg in the leaves, stem, or the root. However, total contents of the elements were 1.8- to 3.7-fold higher in a D. lotus seedling due to its greater dry weight. Since D. lotus seedlings absorbed more inorganic elements on a tree basis and grew more vigorously than D. kaki seedlings, the level of fertilization for astringent persimmons should be adjusted depending on rootstocks to maintain the trees at the optimum vigor.

• Journal of Applied Biological Chemistry
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• v.43 no.2
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• pp.104-108
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• 2000

The plant growth-promoting activity of Acremonium strictum MJN1 isolated from roots of Panox ginseng was explored. The myceliaI extract of A. strictum MJN1 enhanced the rice seedling growth by 14.5 and 9.0% in the dried weight of shoots and roots, and the growth of red pepper by 54 and 85% in the top length and the dried weight in pot experiments, respectively. The plant growth-promoting substances in the myceliaI extract of Acremonium strictum MJN1 were identified as D-adenosine and glycerol. Both commercial D-adenosine and glycerol also promoted significantly the rice seedling growth but, unlike the mycelial extract of A. strictum MJN1, hardly affected the yields of plants grown in pots or field. Therefore, it is possible that other plant growth-promoting substances are produced by A. strictum MJN1. However, this study shows that A. strictum MJN1 has a great potential as a biofertilizer.

• 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.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.600-606
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• 2014

The objective of this study was to determine the effects of seedling ages of scions and rootstocks for grafting and light intensity during their cultivation in a closed transplant production system on the growth and development of grafted cucumber transplants. Cucumber scions and rootstocks were cultivated under 5 photosynthetic photon flux (PPF) levels: 100, 140, 180, 230, and $280{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in a closed transplant production system. The scions were grafted onto the rootstocks at 8, 9, 10, 11, and 12 days after sowing (DAS). Hypocotyl length of scions and rootstocks decreased significantly as PPF increased, and an increase in dry weight with increasing PPF was more pronounced in scions. After grafting, cucumber transplants were grown in a greenhouse until 22 DAS and were then transplanted for investigation of their growth and development. Plant height, leaf area, and fresh weight of cucumber transplants grafted at 8, 9, and 10 DAS were greater, but light intensity during cultivation of scions and rootstocks did not significantly affect the early growth of cucumber transplants after grafting. The number of female flowers in grafted cucumber after transplanting was highest when scions and rootstocks were cultivated under PPF 140 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and were grafted at 8 DAS. These results indicate that controlling environmental conditions in a closed transplant production system during the production of scions and rootstocks can advance grafting time and promote the growth and development of grafted cucumber transplants.