• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.30-39
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• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.174-179
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• 2005

Purpose: The 5-year survival rate is the most useful parameter for evaluating the effect of management on most malignant tumors. Recurrence after a curative resection for gastric cancer occurs mostly within 3 years of the operation, which caused us to evaluate whether a 3-year disease-free survival (3DFS) can be substituted for a 5-year overall survival (5OS). Materials and Methods: We reviewed the medical records of 656 consecutive patients who had undergone a curative resection for gastric cancer To assess whether 3DFS represents 5OS, we used a simple linear regression with survival probability calculated by using the survival function. Results: Recurrence was found in 175 cases during the follow-up periods. The accumulative frequencies of recurrence at postoperative 1 year, 3 years, and 5 years were 46% (81 cases), 89% (156 cases), and 97% (170 cases), respectively. The correlation coefficient (r) and the coefficient of determination $(r^2)$ between 3DFS and 5OS were 0.87 and 0.76, respectively, and the regression equation was $5OS=0.18+(0.80{\times}3DFS)$. The r and $R^2$ according to the type of recurrence were 0.89 and 0.80 in peritoneal seeding, 0.88 and 0.78 in hematogeneous metastasis, and 0.86 and 0.73 in local recurrence, respectively. The r (0.77) and $r^2$ (0.60) were relatively lower in low stages (stage I and II) compared to r (0.88) and $r^2(0.77)$ in high stages (stage III and IV). Conclusion: The 3DFS is an excellent predictor of 5OS. Therefore, if we use the former as the treatment evaluating method, 2-year time reduction in assessing and reporting treatment results is expected.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.365-372
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• 2011

This study aimed to examine foundational data for container seedling production with the subject of Daphniphyllum macropodum community in Mt. Naejang National Park. To achieve the goal, it investigated the growth characteristics of young tree seedlings growing in places with different light intensity environment. Regarding the growth environment of Daphniphyllum macropodum community, it was typical heavy rain summer climate, and the soil was silt loam with the organic content as 11.42~15.61%, total nitrogen as 0.50~0.76%, cation exchangeable capacity (C.E.C) as 18.92~23.32 cmol/kg, and pH as 4.85~5.58. About light intensity environment changed by research plots, relative transmittance of solar radiation was 71~76% in plot A, 37~42% in plot B, 65~70% in plot C, and 28~33% in plot D. The seedlings tended to be intensively distributed either under the crown of their mother tree or in the slope site, and plot A and C where light intensity environment is relatively more favorable showed 1,550 tree/ha and 1,250 tree/ha. Total biomass production of Daphniphyllum macropodum seedlings was 5.37 g in plot A and 5.29 g in plot C, so they were higher than 4.42~4.51 g in plot B and D with relatively less favorable light intensity environment. The T/R ratio was 1~2, leaf area rate was $139.71{\sim}183.50cm^2{\cdot}g^{-1}$, leaf area ratio was $39.68{\sim}60.66cm^2{\cdot}g^{-1}$, and leaf dry weight ratio grew higher in the range of $0.28{\sim}0.33cm^2{\cdot}g^{-1}$ as the intensity of radiation became less. It is thought that in the generation and growth of Daphniphyllum macropodum seedlings, the intensity of light has more effects than the organic content in soil. And it is also thought that in the application of container seedlings production, light environment management over 65~70% to full sun light intensity will affect significantly the initial growth of Daphniphyllum macropodum.

• Journal of Bio-Environment Control
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• v.27 no.3
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• pp.245-252
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• 2018

Yam bean (Pachyrhizus erosus) is a subtropical plant belonging to the Fabaceae family, and is a tuberous vegetable used as various food material with a crisp and juicy taste. This study was conducted to seek optimum sowing time of yam bean in Korea. For this, we surveyed germination properties by the different temperatures and compared the accumulation temperature (AT) and dry matter production (DMP) on growth stages of yam bean by the different sowing times. Two types of varieties cultivated mainly in Korea, Thailand local variety (TLV) and Cheongunmanma cultivar (CGMM), was used. The germination rate of yam bean was 86.0~94.0% at above $18^{\circ}C$, and germination days was longer at lower temperature. The times for flowering and tuber formation of CGMM were later than those of TLV, and the AT required for flowering, tuber formation and hypertrophy of CGMM were higher than those of TLV by $293^{\circ}C$, $280^{\circ}C$ and $108^{\circ}C$, respectively. Also, DMP of shoot and tuber in CGMM were greater than those in TLV. In sowing at April 25, tuber formation was slower than sowing after that time, and harvest index (HI) was relatively low due to delayed formation and hypertrophy of tuber. In sowing after June 9, DMP of shoot was relatively greater in early growth, but tuber was not sufficient to enlarge due to lack of growth days by cold and frost in late October. In sowing May 10 and 25, DMP of tuber and HI were the highest, because the change of day length and temperature gave an advantage to vegetable growth and tuber development. All above suggest that it was suitable to sow seeds on May for increment of tuber productivity in Korea.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.111-123
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• 1975

6 years data on the plant growth and grain yield of 13 rice varieties were investigated to define the relations between meteological conditions and plant growth of rice including grain yield. The results obtained are summarized as follows; 1. Variation of average temperature by years showed great number at early and middle July, middle August and early November, however smallest figure at late June and late July. And that of sunshine hours by years were least at late June and late July, and largest at middle July. 2. Among rice yield components variation of panicle number per hill by years was biggest and that of 1000 grain weight least. Rate of variation of plant growth and rice yield was different by rice varieties. 3. Direct effects on rice yield was greatest at maturing ratio and next at 1000 grain weight. The effects of yield factor on the rice yield wers different by years. 4. Higher temperature and longer sunshine delayed the miaxmum tillering stage but shortened the days from seeding to heading. 5. A significant negative correlation was recognized between the number of panicles per hill and average temperature of 11 to 40 days after transplanting, and number of grains per panicle was correlated with the average temperature of 11 to 70 days after transplanting. High temperature before heading time showed atime decreased maturing ratio. 6. Accumulated temperature was highly correlated with 1000 grain weight in all season. Highest positive correltaion was recognized between grain yield of rice and average temperature of 61 to 70 days after transplanting but correlations between rice yield and average temperature after heading stage were negative. 7. Highly significant correlations were confirmed between maturing ratio and sunshine hours of 31 to 50 days as well as 61 to 70 days after transplanting, and maturing ratio was highly correlated with accumulated hours of sunshine. Correlation between rice yield and hours of sunshine was significant at 51 to 60 days after transplanting.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.97-103
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• 1993

Relationships between crown diameter divided into the small$(0.3{\sim}0.5cm)$, the medium$(0.5{\sim}0.7cm)$ and the large seedling$(0.7{\sim}0.9cm)$ by the size of crown diameter of Angelica gigas and topdressed nitrogen level of 0, 50, 70 and 100% were conducted to study on growth and yield of two year-planted A. gigas in Suwon. The larger of the crown diameter, the better of the dry weight of leaf and root of A. gigas. Growth of the plane was rapidly increased on June and August, but slowly increased on July and that of root was increased until October while decreasing the aerial stem growth from September. Lower top dressed nitrogen level in the larger seeding was greatly increased the bolting rate compared to the medium or small seedlings. Yields of dried root weight per 10a were 441kg for the large, 373kg for the medium, and 378kg for the small seedling, and weight of the higher nitrogen per 10a were more increased than that of the lower dressed nitrogen treatment.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.183-189
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• 2000

This study was carried out to analyze ecophysiological responses for seedling of Quercus serrata, Quercus mongolica and Quercus variabilis that are the typical species of deciduous broadleaved forests in Korea. And executed experiments in the climatic control room to provide necessary information to ecological forest management and methods of natural regeneration through the analysis of seedling responses. The details of experimental analysis were growth processes of 4 months after seeding that vary with the condition of three light intensity[relative light intensity(RLI) 8%, 20%, 52%] and three soil moisture[water suction(WS) Ψ=100 hPa, Ψ=280 hPa, Ψ=330 hPa] gradient, growth factors after harvesting and the nutrition condition of leaves. The results of this study are followings: 1) Early growth was prosperous after germination for the species which have more weight of acorn. 2) The formation of lammas shoot was favourable with Q. variabilis and Q. mongolica. And the rate of the occurrence was the highest in the RLI 20%, and it was remarkably reduced in the RLI 8%. 3) As the height growth of seedling of all 3 species were greater in the RLI 20% and 8% than that of the RLI 52%, they showed strong shade tolerance. 4) The increase of light intensity promoted the diameter at root collar growth, and development of main and lateral roots with all 3 species. 5) It showed that the increase of light intensity in the experimental radiation condition raised special leaf area weight(mg/cm$^2$) and leaf area productivity(mg/cm$^2$). Consequently, these resulted in the increase of leaf thickness and total dry biomass per the unit area of leaf. 6) As the increase of light intensity, the minerals contents of leaves such as N, P and K were lowered, and the increase of soil moisture resulted in the increase of P, K, Ca and Mg.

• Research in Plant Disease
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• v.11 no.1
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• pp.28-34
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• 2005

This study was conducted to investigate the control possibility of garlic white rot causing severe yield losses of Allium species and cultivars using cultural practices such as optimal sowing date and burial depth, and lime application. Inoculum density in infested field soil was investigated at different soil depth, and that on the diseased plant debris was done. Inoculum density and recovery ratio of white rot pathogen of garlic was highly different between two species of Sclerotium cepivorum forming comparatively small sclerotia and Sclerotium sp. forming comparatively large ones. It was confirmed that S. cepivorum formed more sclerotia on bulbs of garlic than S. sp., and sclerotial recovery of S. cepivorum was higher than that of S. sp. Inoculum density of white rot pathogen in the infested field at garlic seeding period ranged from one to thirteen sclerotia per 30 g soil. Inoculum density of white rot pathogen decreased remarkably with increasing soil depth and above 95% of sclerotia were distributed within 5 cm of soil depth. Disease severity of white rot was higher on slightly planted garlics than deeply-planted ones. Garlic seed bulbs infected by white rot pathogens were confirmed to be one of main inoculum sources of white rot in the field and the disease incidences caused by garlic seed transmission showed big differences among garlic varieties. When nine garlic varieties harvested from infested plots were sown in the field, highly susceptible varieties, ‘Wando’, ‘Daeseo’, ‘Namdo’ and ‘Kodang’ showed high disease incidences, whereas other five varieties were not infected at all. It was confirmed that white rot occurred higher on early-sown garlics, before middle October, than on late-sown ones, after late October. Meanwhile, increasing application rate of lime ranged from 100 to 300 g reduced disease severity of white rot.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.124-128
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• 2016

The objective of this research was to determine the effects of harvesting frequency and fertilization levels on botanical composition, dry matter yield, and forage feed compositions of Alpine grassland at 800 m altitude. This research lasted for three years at National Alpine Agricultural Research Institute in Pyeongchang with two harvesting frequency schedules (two and three times annually) and two levels of fertilizer application (conventional level of fertilizer at 280-200-240 kg/ha and a lower level of fertilizer at 200-200-200 kg/ha for N, $P_2O_5$, and $K_2O$). Mixture combinations with seeding rate (kg/ha) were as follows: Orchardgrass 18, Tall fescue 9, Timothy 8, Kentucky bluegrass 3, and Ladino Clover 2. The gramineae ratio ranged from 93.2 to 95.3%. Therefore, gramineae forage was considered as the dominant plant in this experiment. No significant (p>0.05) difference was observed in forage dry matter yield between the two harvesting frequency treatments (two times at 9.8 ton/ha and three times at 8.6 ton/ha). However, forage dry matter yield in the two times of harvesting frequency tended to be greater than that in the three times of harvesting frequency. Significantly (p<0.05) higher forage dry matter yield in the standard fertilization level group than the lower fertilization level group (9.8 ton/ha vs. 8.7 ton/ha) was observed. However, there was no significant (p>0.05) difference in forage crude protein concentration between the two harvesting frequency treatment groups, although the concentration in the group with three times of harvesting frequency tended to be higher. In contrast, crude fiber concentration in the group with two times of harvesting frequency tended to be higher, although the difference was not statistically significant (p>0.05). Crude protein, ether extract, crude fiber, and organic matter concentrations were not significantly (p>0.05) different between the two groups with different fertilization levels. Based on these results, it was concluded that the group with two times of harvesting frequency with conventional fertilization level might be proper for obtaining better forage productivity for Alpine grassland at 800 m altitude.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.489-495
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• 1996

Seedling emergences of four rice varieties (Dongjinbyeo, Dadajo, Galsaekggarak-sharebyeo, and Italiconaverneco) and three barnyardgrass species(Echjnochloa oryzjcola, E. crus-gali var. crus gali E. crus-gali var. praticola) were evaluated in relation to soil strength. Soil strength was varied by compressing the entire volume of soil with a hydraulic jack so as to be 0.5, 1, 2, 3, 6kg /$\textrm{cm}^2$. Soil strength was measured with a penetrometer (Yamanaka type) and soil covering above the seed was 4cm deep. Experiments were conducted at two air temperature conditions of 17 and $25^{\circ}C$. At a soil strength of up to 2kg/$\textrm{cm}^2$, little or no decrease in seedling emergence occurred in all rice varieties and barnyardgrasses tested. Above that value, seedling emergence decreased progressively as the soil strength increased. The degree of decrease was greatest in Dongjinbyeo and smallest in Dadajo among tested rice varieties, and greatest in Echinochloa oryzicola among barnyardgrasses, being greater in barnyardgrasses than rice. Seedling emergence was delayed almost linearly as the soil strength increased. The delay was greatest in Dongjinbyeo among rice varieties and in Echinochloa oryzicola among barnyardgrasses. Mesocotyl length increased as soil strength increased up to 2 to 3kg / $\textrm{cm}^2$ in Dongjinbyeo and Dadajo in 17$^{\circ}C$ and $25^{\circ}C$, and up to 6kg/$\textrm{cm}^2$ in Galsaekggaraksharebyeo and Italiconaverneco in $25^{\circ}C$. Dongjinbyeo showed the least elongation of mesocotyl among rice varieties in any soil strength. The total length of mesotyl, first internode and incomplete leaf showed little variation with soil strength. The total length was longer than the 4cm covering depth in other varieties except Dongjinbyeo. This might have caused the lower emergence rate in Dongjinbyeo than other varieties in higher soil strength.