• 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.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.84-90
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• 1995

These experiment were conducted to know the seedling growth pattern and to deter­mine the appropriate seeding amount for producing the small and middle sized uniform seedlings of which known to have low bolting in the cultivation of Angelica gigas. Cotyledons of seedling were emerged by 18 days after seeding and the first and the second leaf appeared at 5.0 days and 9.8 days respectively after the anterior leaf emergence. Leaf development from the 3rd to the 6th in order needs about 13 days respectively after the emergence of anterior leaf. Growth of small and middle sized seedling of which required $60{\sim}87days$ were 3.0 to 7.0mm in root head diameter, 6.3 to 10.3cm in root length, 0.4 to 1.3g in fresh root weight per plant with 3.9 to 5.0 leaves. The highest production ratio of small and middle sized seedlings was shown in $15,000seeds/m^2$ of seeding amount as 52.8% respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.295-305
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• 1994

Greenhouse and laboratory studies were conducted to investigate the allelopathic potential of alfalfa and vetch residues on soybean and corn using various extract concentrations (0, 5, 10, 15 and 20%, w/v) and residue rates (0, 0.25, 0.5, 0.75 and 1%, w/w). Aqueous extracts of alfalfa (Medicago sativa L.) and vetch (Vicia spp.) exhibited an allelopathic effect on soybean and corn seed germination, seedling length and weight. The degree of inhibition significantly increased as the aqueous extract concentration increased. Alfalfa and vetch 20% extracts reduced soybean seed germination, seedling length and weight by 35%, 57%, 32% and 15%, 42%, 25% respectively, when compared to control. Corn germination, seedling length and weight was inhibited by 20%, 23%, 38% by alfalfa and 19%, 18%, 35% by 20% vetch extracts. Alfalfa and vetch extracts inhibited secondary root formation and branching as the extract concentration increased. Alfalfa and vetch 20% extracts inhibited by 41% and 32% secondary root numbers, respectively as compared to control. It was found that the aqueous extract of alfalfa resulted in greater reduction in germination, seedling length and weight of soybean than that of vetch. Alfalfa and vetch 1% residue rate inhibited soybean plant height by 30% and 10%, leaf area by 31% and 23%, and dry weight by 18% and 1%, nodule number by 27% and 20% also. Alfalfa and vetch residue significantly enhanced plant height, leaf area and dry weight of corn. The maximum stimulation occurred with 0.25% and 1% of alfalfa and vetch residue rates, respectively. Plant height, leaf area, and dry weight increased by 23%, 59%, 58% and 17%, 52%, 94% with alfalfa and vetch residues of 0.25% and 1%, respectively. This study demonstrates that there is an allelopathic potential resulting from alfalfa and vetch residues on soybean growth and yield. It also suggests that these residues may affect crop growth and development due to the inhibitory or stimulatory effects of allelochemicals existing in the residue.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.23-29
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• 2001

This study was carried out to develop a seedling raising method without nursery soils in automatic raising facility of rice seedlings for machine transplanting. Pre-germinated seeds were sowed on the seed trays with three different seats such as paper seat, corrugated board, and polyethylene film instead of nursery soils. The growth characteristics of the seedlings for 20 days after sowing were compared with that of a conventional standard raising method with nursery soils. There was no difference in plant height of 10-day old seedlings among the different nursery methods, but the plant height of seedlings grown for 15 days after sowing in the trays with fivefold newspaper and nursery soils was significantly taller than those on other nursery conditions. Dry weight of seedlings grown in the tray with fivefold newspaper bottom was heavier than those in nursery trays with a corrugated board and a piece of polyethylene film. The seedlings grown in a nursery tray with fivefold newspaper showed better seedling quality and root-mat formation compared with the other nursery trays. This result suggests that the healthy seedlings for machine transplanting can be raised in the paper-sheet tray without nursery soils. The labour hours and cost required for the soil-free method using paper was reduced by about 49.3% and 26.6%, respectively, compared with the semi-adult seedling on nursery soils.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.374-384
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• 2022

There is an increasing demand for Tetradium daniellii seedlings due to their uses as alternative energy, for ecological restoration, and as a honey plant. This study was conducted to determine the optimum container for superior seedling production of T. daniellii. Experiments were performed using five plastic container types (500, 350, 320, 300, and 250 ml) for forestry facility cultivation. The height and root collar diameter growth of T. daniellii seedlings were significantly high in the 350-ml container. High growth appeared primarily in the container with a larger cavity volume and lower growing density. Root development was most active in full sunlight. The maximum dry matter production was observed in the 350-ml container, which was similar to the results of height and root collar diameter growth. QI, an index showing the quality of a seedling, was maximum at 0.97 in the 350-ml container. In conclusion, the 350-ml container is optimum for superior seedling production of T. daniellii.

• Journal of Ecology and Environment
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• v.41 no.6
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• pp.152-164
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• 2017

Background: Natural regeneration of seedlings as well as saplings of Korean fir has been significantly impacted by the browsing from the early stages of their development, potentially, by roe deer for the last two to three decades at the study site since late 1980s. This study was carried out to investigate current status of the disturbance in the seedling development of Korean fir (Abies koreana) on Mt. Hallasan, Jeju Island, Korea. Methods: Field survey was carried out during June and August in 2016 to measure the characteristics of study site and understory vegetation by applying systematic sampling to 125 plots of $5m{\times}5m$ quadrat located on eastern slope of the mountain. Correlation and regression analyses were applied to the variables quantified from the data sets using the SAS software. Results: No saplings with their diameters at breast heights smaller than 5.0 cm were found at the study site indicating the serious disturbance in the natural regeneration of Korean fir at the study site. No seedlings with their heights taller than 36.0 cm were found at the study site indicating even more serious disturbance during earlier stage of the natural regeneration of Korean fir at the study site. A total of 616 individuals of the seedlings of Korean fir were found at 54 out of 125 sampling plots. One hundred thirty-eight seedlings (22.4%) out of 616 individual seedlings have the vestiges for being grazed, potentially, by roe deer. Conclusions: Due considerations should be given to the effects of browsing of the seedlings by roe deer to promote the natural regeneration of Korean fir, ultimately to restore Korean fir. It is needed for the managers of the forest to install fences around the forest area. Exclosure experiments as well as enclosure experiments of different densities of browsing should be carried out. In addition, treatment with different densities of Jeju dwarf bamboo should also be included in the experiment on Mt. Hallasan National Park, Jeju Island, Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.158-158
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• 2022

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.395-404
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• 1996

This experiment was to evaluate the growth characteristics of lodging resistance cultivated at sandbed in rice varieties. Five varieties were used in this studies. The leaf area, leaf dry weight, culm dry weight and total dry weight of cultivated rice seedling at sandbed showed the maximal values at heading stage, but decreased according to growth development. The number of newly developed roots of rice seedlings cultivated at sand pot were the most at the 30 days seedling stage, but those were decreasing at 40 to 45 days seedling stage. Cheongmyungbyeo and Dongjinbyeo showed the most vigor in newly developed roots. The bending moment at breaking of rice internodes were the largest at the 4th node, but decreased at the top internodes. Cheongmyungbyeo and Dongjinbyeo were proved lodging resistant varieties by the bending moment. The weight of culm base was positively correlated with bending moment at breaking of rice culm, but lodging index was negatively correlated weight of culm base and root dry weight, respectively.

• Current Research on Agriculture and Life Sciences
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• v.23
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• pp.1-8
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• 2005

The purpose of this study was carried out to determine the optimum sowing date and days after sowing (DAS) in automatic facility located at Uiseong of Gyeoungbuk province. The seedling height was rapidly increased with a delay of sowing time from April to May. The 10-day old seedlings with suitable plant height (> l0cm) for machine transplanting in the facility were obtained when the seeds sowed after May 20 at Uiseong in Gyeoungbuk province. The dry weight-height ratio of 10-day old seedlings was significantly decreased when the seeds sowed after June 20, and 15-days old seedlings did after May 10. No. of panicles/hill was reduced with increasing of days after seeding. But there were no significant difference among other yield components such as no. of grains/panicle, ratio of ripened grains, and 1,000 grain weight. The highest grain yield, 748kg/10a, was attained from the 10-day old seedlings transplanted at May 27 in comparision with those of 15-day and 20-day old seedlings. The grain yield of 10-day old seedlings transplanted at June 26 was also higher than that of 15-day old seedlings.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.130-130
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• 2017

Sorghum bicolor is considered as copper-tolerant species. The present study was conducted to understand the copper tolerance mechanism in Sorghum seedling roots. Morphological and effects of Cu on other interacting ions were observed prominently in the roots when the plants were subjected to different concentrations (0, 50, and $100{\mu}M$) of $CuSO_4$. However, the morphological characteristics were reduced by Cu stress, and the most significant growth inhibition was observed in plants treated with the highest concentration of $Cu^{2+}$ ions ($100{\mu}M$). In the proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis coupled with MALDI-TOF-TOF mass spectrometry was performed to explore the molecular responses of Cu-induced sorghum seedling roots. In two-dimensional silver-stained gels, a total of 422 differentially expressed proteins (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. A total of 21 protein spots (${\geq}1.5-fold$) from Cu-induced sorghum roots were analyzed by mass spectrometry. Of the 21 differentially expressed protein spots from Cu-induced sorghum roots, a total of 10 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of the most identified protein species from the roots that function in stress response and metabolism was significantly enhanced, while protein species involved in transcription and regulation were severely reduced. The results obtained from the present study may provide insights into the tolerance mechanism of seedling roots in Sorghum.