• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.126-132
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• 2010

A high sugar rice cultivar 'Danmi' which has been recently developed and released in the Functional Crop Resource Development Division, Department of Functional Crop, National Institute of Crop Science, has high glucose and sucrose contents but has a poor seed development. This defect poses some problem in ensuring stable seedling establishment in the nursery bed. We examined the germination and seedling emergence characteristics of 'Danmi' and determined an optimum seeding rate for seedling establishment. 'Danmi' seeds has a light 1,000-grain weight of 18.2g compared with Ilmibyeo's 26.7g. The 97.4% of 'Danmi' seeds has specific gravity below 1.0 while only 2.0% of seeds was fully developed with specific gravity above 1.12. However, the reverse is true in the Ilmibyeo seed used as a control cultivar. Although the seed germination of Danmi was 89-91% regardless of seed specific gravity but at a slower rate than Ilmibyeo regardless of water soaking temperatures of $20-30^{\circ}C$ because of high seed amount of specific gravity below 1.0 in 'Danmi'. It took 2～4 days longer of seed soaking in the Danmi seeds than Ilmibyeo before germination. 'Danmi' has low normal seedling emergence rate than Ilmibyeo in the seedbed soil due to high percentage of abnormal seedlings like stunting and incomplete growth. Normal seedling emergence rate of 'Danmi' in the seedbed was 62.6～64.9% for 10-day old seedling and 83.5～86.7% for 30-day old seedling which is lower by 29.6～30.0% and 11.3～12%, respectively than Ilmibyeo. Although 'Danmi' has low normal seedling emergence rate, but it has greater seed number per weight basis. Therefore, based on the normal seedling number per unit area of Ilmibyeo(control cultivar) for seedling rate of 10-day and 30-day old seedlings, the recommended seeding rate of 'Danmi' for transplanting rice is 220g seeds for 10-day old seedling and 130g for 30-day old seedling per nursery box, which is equivalent to 1.5 times seed volumes of Ilmibyeo.

• Journal of Environmental Science International
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• v.25 no.2
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• pp.289-294
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• 2016

In this study, we examined the impact of transplant timing of mother plants for seedling strawberry on growth and development of daughter plants and field stage. The leaf growth of treated mother plants and crown thickness were low when transplant was performed on April $10^{th}$. Based on the results collected until July $13^{th}$, the numbers of daughter plants with more than two leaves were 20.6 and 19.5 for March $10^{th}$ and March $25^{th}$, and these values decreased by April $10^{th}$ and April $25^{th}$ showing values of 15.1 and 11.8, respectively. After seedling growth was complete, leaf area and fresh weight of the saplings were remarkably low beginning from the transplant on April $10^{th}$. Crown thickness of saplings was generally lower when transplant timing was late. After 45 days of transplant leaf length and width were noticeably lower than the transplant on April $10^{th}$ and $25^{th}$. First cluster was 100% for both the March $10^{th}$ and $25^{th}$ transplant, followed April 10th and $25^{th}$ with values of 66% and 43%. The results revealed that transplant on March $10^{th}$ and $25^{th}$ had a greater positive impact on the growth and development of the strawberry cultivar 'Seolhyang'. A supplementary study will have to be conducted to determine the relationship between the harvest period of the first cluster and the yield of marketable strawberries depending on the transplanting time of mother plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.416-423
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• 1997

To obtain the basic information about the translocation of seed reserves of soybean[Glycine max(L.) Merrill] cultivars, 'Hill', 'Paldalkong' and 'Jangyeobkong' , the dry matter changes of emerging organs during the germination and seedling development were observed at the research farm of College of Natural Resources, Korea University, on May 26, June 5 and June 14. Mean fresh weight, dry weight and moisture content of three soybean cultivars were increased until the V2 stage in all seedling parts except cotyledons. Cotyledon dry weight was continuously decreased and the decreased amount at the V2 stage was about 80% of the cotyledon dry weight at the germination stage. Structural component of cotyledons was 22.2% of the cotyledon dry weight at the germination stage. Metabolic components of cotyledons were markedly decreased until V2 stage, and about 91% of cotyledon metabolic components at germination stage was utilized. However, those of whole seedling were increased after the V1 stage. Therefore, it appeared that role of cotyledons as nutrient supplier for germination and seedling growth was important until the V1 stage especially.

• Proceedings of the Malacological Society of Korea Conference
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• 2002.11a
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• pp.15-16
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• 2002

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.181-188
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• 2020

This study was conducted to identify the optimal conditions for seedling growth in Veronica rotunda var. subintegra (Nakai) T.Yamaz. which a endemic plant and can be development as ornamental plants. We sowed V. rotunda var. subintegra (Nakai) T.Yamaz. seeds, and exposed the seedling was different treatment conditions. We varied soil type and fertilizer concentration, shading ratio, additional fertilizer concentration, pretreatment light exposure and collection time of seeds. We found that seedling growth was good in horticultural substrate (with no additional fertilizer), but mixed soils supplemented with fertilizer inhibited growth, regardless of the fertilizer concentration. In the 55% shading treatment, seedling growth was greater than in the non-shading treatment. High concentration addition of fertilizer (Hyponex) promoted plant growth, in terms of both plant length and fresh weight. Exposure of seeds to a red light-source prior to germination had a greater effect on seedling growth than exposure to other light sources. Seedlings exhibited better growth when grown from seed collected in 2018, rather than 2017.

• Journal of Practical Agriculture & Fisheries Research
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• v.18 no.1
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• pp.93-100
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• 2016

This research was conducted to determine a pre-germinated herbicides with iron-coated seeds in water and wet hill seeded rice. Days of rice seedling emergence was the faster germination at the application of benzobicyclon > oxadiazon > thiobencarb > butachlor and the sealed iron-coated seeds with pre-germinated seeds> pre-germinated seeds> iron-coated seeds with pre-soaking. The seedling establishment was relatively high in untreated control and benzobicyclon among seed treatments by 63.7% and 75.7%. There was 100% seeds killed of pre-germinated seeds in terms of herbicide phytotoxicity and sealed iron-coated seeds with pre-germinated seeds in butachlor but benzobicyclon was of safe with 2% rice seeds killed. Infant rice seedling height was of 9.2-12.9cm in benzobicyclon and 11.9-16.3cm in untreated control and thus there was relatively normal development and growth at the initial rice seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.3
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• pp.256-264
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• 2021

Rapeseed (Brassica napus L.) is generally sown in late autumn and harvested in early summer in Korea, however, spring cultivation has also been attempted in some areas because frequent climate changes induce reducing productivity. Therefore, there is a need for a transplanting technology that is relatively easy to control of cropping season according to changes in cultivation conditions. In this study, to find out the optimal characteristics of seedlings for machine transplanting of spring cultivation, seedling morphological characteristics were investigated according to the seedling age of three varieties for 2020 and 2021. The hypocotyl length was less than 2 cm in both years and the 40-day-old seedling was the shortest among all seedling ages. The number and size of leaf were increased with longer seedling age in both years. To evaluate seedling quality, total seedling length, seedling weight, and impact resistance were measured before transplanting. Total seedling length was the longest in 40-day-old seedlings and the shortest in 25-day-old seedlings in both years. In the case of seedling weight, no significant differences were observed depending on the seedling age and the impact resistance increased with increasing seedling age. Finally, 'Jungmo7001', 'Naehan', and 'Tamla' showed a high transplanting rate in seedlings grown for more than 30 days, 35 days, and 40 days, respectively, in the field using a general transplanter. These results suggest that the proper seedling age for transplanting is limited depending on the rapeseed varieties. The suitable seedling cultivation method can be selected for different cultivation environments.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.395-398
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• 2002

Present paper showed allelopahtic effects of Tagetes minuta aqueous extracts on seed germination and root hair development. Allelopathy of aqueous extracts derived from T. minuta examined using two test plant species (Lotus comiculatus var. japonicus and Lactuca sativa). The seeds of test species were inoculated in petri dishes containing 0, 10,50 and 100% aqueous extracts from T. minuta. At day 5, the relative seed germination ratio to control was evaluated, and the development of seedling root hairs was observed through light microscopy. Seed germination of L. comiculatus var. japonicus was significantly inhibited proportional to the concentrations of aqueous extract, but that of L. sativa wasn't inhibited. The inhibitory allelopathic effect of T. minuta was found in the development and growth of seedling root hairs. It was concluded that the inhibitory allelophatic effects have been to be investigated using various bioassay, for the allelopathy of plant species shows species-specific and organ-specific.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.320-327
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• 1990

Experiments were conducted to investigate the method to raise seedling establishment rate and the optimum seeding dates and rates in direct seeding culture using transplanter under submerged field condition in Chuncheon area during 1986 to 1988. Direct seeding on submerged field using transplanting machine after sowing on seedling growing box contained with paddy or upland soil was possible. Higher rate of seedling establishment was obtained in case of sowing sprouted seed and intermittent irrigation after sowing. Seedling establishment rate was higher both in April 30 or May 10 seeding plot. Minimum daily average air and soil temperature to ensure more than 70 percent seedling establishment was 14.8$^{\circ}C$ and 16.3$^{\circ}C$ respectively. Optimum sowing date in the direct sowing was early May and optimum sowing rate was 200g per box, 6kg per l0a. In this case rice grain yield was 481kg per l0a and this is almost same yield level compared hand and machine transplanting.

• Journal of the Korean Professional Engineers Association
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• v.32 no.6
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• pp.120-129
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• 1999