• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.121-125
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• 1998

This experiment was carried out to investigate the effects of direct seeding and planting of seedlings in different ages on yield and yield characteristics of Cynanchum wilfordii $H_{EMSLY}$. Emergence date was three days earlier in direct seeding compared to May 14 in plots planted with one - or three - year - old seedlings. Petiole length was 16cm and 26cm longer in direct seeding and 1 - year - old seedlings, respectively, compared to 279cm in plot of 3 - year - old seedling. Root diameter was 0.4cm thicker in direct seeding and 0.5cm thicker in 1 - year - old seedlings compared to 1.0cm in seedlings of three years old. Root length was 7.2cm shorter in direct seeding, but was 0.6cm longer in 1 - year - old seedlings than 32.2cm in seedlings of three years old. Yield increased by 29 % in direct seeding and 55% in seedlings of one year old compared to 1,403kg/l0a in 3 - year - old seedlings. In cultivation of Cynanchum wilfordii $H_{EMSLY}$, the suitable planting methods were direct seeding or the use of 1 - year - old seedlings which were profitable at higher density as $50{\times}10cm$.

• Communications for Statistical Applications and Methods
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• v.18 no.3
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• pp.301-317
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• 2011

Statistical and probabilistic behaviors of fibers forming fiber webs of all kinds are of great significance in the determination of the uniformity and physical properties of the webs commonly found in many industrial products such as filters, membranes and non-woven fabrics. However, in studying the spatial geometry of the webs the observations must be theoretically as well as experimentally confined within a specified unit area. This paper provides a general theory and framework for computer simulation for quantifying the fiber segments bounded by the unit area in consideration of the "edge effects" resulting from the truncated length segments within the boundary. The probability density function and the first and second moments of the length segments found within the counting region were derived by properly defining the seeding region and counting region.

• Korean journal of applied entomology
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• v.27 no.2
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• pp.81-86
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• 1988

Experiments were conducted to investigate the locational and ovipositional preferences of the single and mixed populations of the brown planthopper(BPH), Nilaparvata lugens (Stal), and the whitebacked planthopper(WBPH),Sogatella furcifera (Hovath), with the different popula-tion densities at seeding, max-tillering, booting and heading stages of rice variety seonam by대. The WBPH showed a locational preference for the upper portion while the BPH was observed to stay generally on the lower portion regardless of rice growth stages, population density-levels and the single or the mixed populations of two species. At seeding, max-tillerinf, boo-tring and heading stage, the preference for the lower portion of the rice plants was found to be slighty reduced with the lapse of time, respectively, from the single or the mixed popula-tions of both the species. Ovipositional lication of both the species was found not to be affected by the different population densities at rice growth stage. Although the BPH prefered a ovi-positional location for the lower portion at seeding, booting and heading stages, its preference-was somewhat reduced with the developmental stages of rice plants, whereas the WBPH showed a ovipositional preference for lower portion at seeding stages, but prefered the same tendency of ovipositional preference for the upper and the lower portion, The location and ovipositional preferences were likely to be affected by the competition between species with the mixed populations rather than single.

• Korean Journal of Medicinal Crop Science
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• v.26 no.1
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• pp.64-71
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• 2018

Background: The cultivation of ginseng (Panax ginseng C. A. Meyer) in greenhouses could reduce the use of pesticides and result in higher yield; however, construction costs are problematic. The adaptation of direct-sowing culture in greenhouses could reduce the cost of ginseng production. Methods and Results: To improve seedling establishment in direct-sowing culture, effects of sowing density (SD), number of seeds sown per hole (SN), and thinning (TH) treatment on the root yield were investigated after 3 years of seeding. The emergence rate was significantly influenced by SD, but not by SN or TH. Damping-off and rusty roots increased with an increase in SN with diminishing effects of SN on seedling establishment. Root weight and diameter were affected by SD, SN, and TH, however, there were no statistical significances. The total number of roots harvested per unit area increased with increasing SD and SN, and the weight of roots was affected by SD, but not by SN or TH. Conclusions: Multi-seed sowing per hole and/or thinning might not be an efficient method for the direct-sowing culture of ginseng. The SD for direct seeding culture in greenhouses should be approximately $33-42seeds/m^2$ for an optimum yield of 3-year-old ginseng.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.64-69
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• 2008

The objective of experiment was to investigate the effects of planting density on growth and yield of vegetable soybean, and to clarify the optimum planting density of vegetable soybean in the middle west region of Korea. The field experiment with 4 levels of planting density was carried out at Yesan area in $2005{\sim}2006$. The days from seeding to flowering and the days from seeding to harvesting and lodging were not significantly different among planting distance. The stem length was increased as planting distance was shortened but the number of node, branch, pod per branch, pod per individual, weight of stem and pod, one hundred pod weight and rate of 2+3 seed per pod were decreased as planting density was increased. The size of vegetable soybeans was not significantly different among planting distance, but the harvest index of vegetable soybean was decreased as planting distance was shortened. Yield of vegetable soybean was increased as planting distance was decreased. However, the approriate densities for stem and pod weight per a plant, number of pod per a branch and the vegetable soybean yield of 2+3 seed per pod were different from that density. The optimal planting distance of varieties was $60{\sim}25\;cm$ in Sunheukkong and Ilpumgeomjeongkong and was $60{\sim}35\;cm$ in Galmikong.

• Development and Reproduction
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• v.12 no.1
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• pp.51-56
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• 2008

To optimize the cell culture conditions of zebrafish embryonic cells, we compared the efficiency of three types of medium, DMEM, K-NAC and D-NAC. In this study, we showed that the cells grown in K-NAC have better plating efficiency than DMEM, especially in the case of low cell seeding density. However, cells grew slower in K-NAC than those in DMEM in confluent cultures. The effect of 0.1% zebrafish embryo extracts was minimal. The presence of 1% trout serum in culture medium significantly increased the growth rate of cells(p<0.05). No difference was found at $2{\sim}3{\times}10^5$ cell seeding density(p<0.05). At $4{\sim}5{\times}10^5$ cell seeding density, cells grew better in DMEM than K-NAC (p<0.1). The results suggest that supplementation of NAC and A2P in Keratinocyte SFM may improves plating efficiency when cells are plated at low population. No difference was found for cell growth in either medium with 5%, 10% or 15% FBS supplemented (p<0.05). Cells culture in D-NAC grew significantly better than those in DMEM(p<0.05). Our results clearly showed that the use of NAC and A2P in the culture medium has a positive effect on cell growth regardless of the amount of FBS added.

• Plant Resources
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• v.3 no.3
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• pp.194-199
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• 2000

The result of this experiment which are conducted, to improve the cultivation technology of Alisma plantago, to increase its quantity and to contribute for stable production with Yongiun local group by examining the optimal planting density and transplanting period of double cropping of Alisma plantago in the southern region. The characters of plant height, leaf width and length tend to be reduced as the seeding period is later by the order of the 10th, 20th and 30th of July. The period required for flowering is reduced as the transplanting period is later and dense planting is applied. Plant height, the number of leaves and yield of dry root have much quantity at the dense planting density of 20$\times$ 15cm as they are transplanted later in the 30th of August or the 10th of September, but they are rather less in sparse planting density of 20$\times$25cm or 20$\times$35cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.1-9
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• 1972

For a measure against late transplanting, this experiment was conducted to investigate a reasonable seeding rate in nursery bed and a proper nursery size. The treatments applied to this experiment are as follows a) seeding rates: 0.2ι, 0.4ι and 0.6ι per 3.3$m^2$ b) nursery sizes. for 10a-field area: 39.6$m^2$, 49.5$m^2$ and 59.4$m^2$ c) transplanting dates: June 5, June 25 and July 15. The seeding date was April 26 and planting density was determined by the number of sound seedlings based on the combination of seeding rate and nursery size. The results may be summarized as follows: 1. In seedlings both increased nursery period and decreased seeding rate showed a remarkable-increase in plant height, number of leaves, dry matter weight and the ratio of dry weight to plant height. But their number of tillers and live leaves did not show such tendency. 2. Delayed transplanting date shortened culm length and panicle length as well as number of days from transplating to heading and it also delayed heading date. On the other hand the transplanting of 80-day seedlings resulted in premature heading. 3. As a result late transplanting reduced number of spikelets per panicle, maturing rate and 1000-grain weight. In the last analysis it linearly reduced grain yield. The decreasing rate of yield by late transplanting was 15.6% in June 25 plot and 41. 3% in July 15 plot, compared with the yield in June 5 plot. Such a remarkable decrease in yield of the extremely late transplanted plot was mainly due to markedly decreasing number of spikelets per panicle and 1000-grain weight. 4. Both increased seeding rate and nursery size gave a rise in number of tillers per unit area as well as number of transplanting hills but gave a fall in culm length and panicle length. 5. Accordingly, though thick seeded - dense planted plot increased number of panicles per unit area, decrease in number of spikelets per panicle and 1000-grain weight made no differences in yield between thick seeded - dense planted plot and thin seeded - sparse planted one. However, the yield in the thick seeded - dense planted plot transplanted on July 15 was reduced owing to the remarkable decrease in maturing rate and 1000-grain weight. 6. We came to the conclusion that as a measure against the extremely late transplanting the suitable seeding rate was 0.4ι per 3.3$m^2$ and the proper nursery size was 59.4$m^2$ for 10a-field area.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.24-25
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• 1990

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.67-71
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• 1997

Bupleurum falcatum is one of the oldest medicinal crop spontaneously generated as well as cultivated by man and successfully grown during the summer season in Korea. This study was conducted to examine the effect of planting density in the row spacing and hill spacing system using machine seeder on major agronomic traits, yield and labor saving. In 1993 and 1994, a spilt plot design was used with row spacing as the main plot and hill spacing as subplot. Labor saving efficency of the machine seeder reduced 96% than the hand seeding in sowing time required. Number of seeding stand increased, but stem height and number of nodes did not affect with different density in each row and hill spacing. There were reduced with narrow hill spacing on stem diameter, number of branches, shoot weight and root traits. There was no significant interaction between row and hill spacing for any major traits studied except shoot weight. Yield was more increase at 20cm than at 30cm row spacing. For these studies the optiomum density appears to be between drilling or 5cm hill spacing with 20cm row spacing. A highly significant positive correlation was appeared between number of seedling stand and root yield.