• Journal of Sericultural and Entomological Science
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• v.30 no.2
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• pp.84-87
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• 1988

Tow Soil fumigants, cylon and chloropiclin were examined for mulberry graftage growth on the nursery garden. Thirty ml/$m^2$ of each fumigants was injected and followed vinyl coverage 4 weeks before planting. Fumigants increased clearly diameter and branch length of graftages, and controled weeds occurance. These effects showed a little bit higher in chloropiclin than in cylon, but no difference statistically at 5% LSD.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.1
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• pp.33-44
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• 1988

For the purpose of examining the effects of simulated acid rain on the chemical properties of the experimental soil in Pinus densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils (nursery soil: forest soil of siliceous sandy loam = 1 : V/V)in the early spring of 1985. The regime of artificil acid rain, in terms of spray frequency per monthly and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain (pH 2.0, pH4.0, and pH 5.5 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (May 1 to August 31) in 1985. THe results obtained in this study were as follows; 1. Soil acidity was dropped, and exchangeable aluminum contents in the soil was dramatically increased in both species, with decreasing pH levels of acid rain. 2. Exchangeable potassium, clacium, magnesium contents, and base saturation degree of the soil were highly drcreased in two species as the pH levels of acid rain decreased. 3. In two species, sulfate concentrations in the soil were decreased of pH 4.0 treatment, and remarkably increased at pH 2.0 treatment of acid rain in comparison with control. 4. Total nitrogen and available phosphate contents of the soil were not affected by acid rain treatment in the both species, and Fe contents at pH 2.0 treatment were highest among three acid rain treatments.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.11-11
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• 2020

Background : The genus Cypripediums are typically adapted to the low temperature and cold climates of the high land in Korea. The species which were reported in Korean peninsula are C.japonicum, C.macranthos, C.calceolus and C.guttatum. We had already reported the successful germination of the C.macranthos and C.guttatum. The small spotted lady's slipper orchid(C.guttatum) is most endangered plants to extinction of which population was reported less than 100 in Korea. The objective of the present research is restoration of the C.guttatum in ex situ and adaptation in high land and nursery. Methods and Results : The 350 seedlings of C.guttatum were transplanted in soil at alpine area(altitude 750m) and the nursery of Korea National Arboretum(KNA) in YangPyeong city on May 2019 and 2020 in order to verify the possibility of ex situ restoration. The sprouted ratio of the seedlings were less than 10% in the alpine area and 83% in the nursery of KNA. The reasons of the diverse survival ratio are presumed as the low moisture content in the soil and heavy shade of the alpine area. The 15 cypripedium species and 29 hybrids were also effectively adapted in the KNA rare plant garden. Conclusion : These results demonstrated the difficulties of the restoration for small spotted lady's slipper orchid in the natural habitation. From the above results, we may conclude that the critical factors of the genus Cypripedium are intensive care for the fragile seedlings during the 1^st year acclimatization.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.73-78
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• 2017

Objective of this experiment was to evaluate efficiency of application of biochar pellet in case of application of soil carbon sequestration technology. The treatments were consisted of control as general agricultural practice method, pellet(100% pig compost), biochar pellets with mixture ratio of pig compost(9:1, 8:2, 6:4, 4:6, 2:8) for comparatives of pH, EC, $NH_4-N$ and $NO_3-N$ concentrations, and yields in the nursery bed applied biochar pellets after lettuce harvesting. The application rates of biochar pellet was 6.6g/pot regardless of their mixed rates based on recommended amount of application (330kg/10a) for lettuce cultivation. pH in the nursery bed applied different biochar pellets after lettuce harvesting was only increased in the treatment plot of pig compost pellet application, but decreased in 4:6 and 2:8 pellet application plots. However, EC was observed to be not significantly different among the treatments. $NH_4-N$ concentration was only increased in the treatment plot of pig compost pellet application, but $NO_3-N$ concentrations were decreased as compared to the control. Yields in the treatments of 9:1, 8:2 and 4:6 biochar pellet application plot were increased from 9.5% to 11.4%. Therefore, this biochar pellet application might be useful for soil carbon sequestration and greenhouse gas mitigation in the agricultural farming practices because it was appeared to be a positive effect on lettuce growth.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.189-196
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• 2015

This study was performed to identify the effect of mixed bed soil on growth of aerial parts and root zone of daughter plants for nursery field strawberry seedling raising with expanded chaff. The plant height and leaf area of daughter plants were highest or largest in the mixed soil of ERH +RH (100:0, v/v), followed by ERH+RH (75:25). The higher the mixing ratio of RH, the shorter the plant height or the smaller the leaf area. A similar tendency was observed in fresh weight. Within a root diameter of 0-0.4 mm and a root height range of 0.4-0.8 mm, root surface area and volume were statistically significantly better with treatment of ERH+RH (100:0, v/v) compared to those of roots treated with ERH+RH (75:25), ERH+RH (50:50) and ERH+RH (25:75). The growth rate of aerial parts and root zone of daughter plants were noticeably lower in two mixing ratios of 50:50 and 25:75. According to the mixing ratios of ERH+CD surface treatment, the number of roots was greatest in plants treated with ERH+CD (80:20, v/v) and ERH+CD (85:15) on August 1. However, the number of roots was highest in plants treated with ERH+CD (85:15, v/v) on August 15. Root length was longest in the plant with no treatment, and drastically shortened from ERH+CD (90:10, v/v) in both surface and mixed treatment. Although root weight showed a significant difference in ERH+CD (90:10, v/v) treatment, its increase was gradual. The rate of root growth was highest in ERH+CD (85:15). These study findings suggest that the content ratios of mixed soil ERH+RH (75:25, v/v) or below and ERH+CD (85:15) are thought to be desirable for the production of high quality seedlings.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.203-210
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• 2014

The purpose of this study was to investigate the effect of experimental warming using infrared lamps on seed germination and seedling survival rate of Pinus densiflora and Abies holophylla. The air temperature of warmed plots had been automatically maintained 3 higher than control plots. The percent germinations (%) of the two coniferous species were higher in warmed plots than in control plots, however a significant difference appeared only in A. holophylla. In addition, P. densiflora and A. holophylla showed the shorter mean germination time (days), higher germination rate ($seed{\cdot}day^{-1}$) and germination energy (%) in warmed plots than in control plots. A. holophylla showed a higher seedling mortality rate in the warmed plots than in control plots because of increased air and soil temperatures and decreased soil moisture. However, seedling survival rate of P. densiflora showed no significant difference by experimental warming. In the future, changed air and soil temperatures and soil moisture due to global warming will induce a variety of changes in seed germination and survival rate of tree species in nursery culture. Therefore, it is necessary to establish adaptation strategies that improve techniques in nursery culture against global warming.

• The Plant Pathology Journal
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• v.31 no.2
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• pp.140-151
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• 2015

Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of $0.96log_{10}ng/g$ to $2.39log_{10}ng/g$ was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of $2.91log_{10}ng/g$ to $3.36log_{10}ng/g$ at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field.

• Korean Journal of Medicinal Crop Science
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• v.22 no.5
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• pp.391-397
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• 2014

To control the disease of root rot in ginseng nursery, inorganic sulfur solution of 0.1%, 1.0%, and 2.0% were irrigated by amount of $10{\ell}$ per $3.3m^2$ before sowing. On the last ten days of July, Fusarium solani and F. oxysporum were similarly detected by 44.8% and 43.8%, respectively, while Cylindrocarpon destructans was low detected by 4.4% in the diseased seedling. The more sulfur's concentration was increased, the more soil pH was decreased. Soil pH was decreased from 5.87 to 4.59 by the irrigation of sulfur solution of 1.0%. The more sulfur's concentration was increased, the more electrical conductivity (EC) of soil was increased. EC was increased from 0.27 dS/m to 1.28 dS/m by the irrigation of sulfur solution of 1.0%. Irrigation of sulfur solution was effective on the inhibition of damping-off caused by Rhizoctonia solani in ginseng seedling. Control value for damping-off by the irrigation of sulfur solution of 1.0% and 2.0% were 75.7%, and 78.5%, respectively. Growth of leaf was inhibited by the irrigation of sulfur solution of 2.0%. Root weight per $3.3m^2$ showed the peak in sulfur solution of 1.0%, while survived-root ratio and root weight per plant were decreased in the level of 2.0%. Survived-root ratio of seedling in sulfur solution of 1.0% was distinctly increased by 4.7 times compare to the control, but control value for root rot was relatively low as 49.2%. Mycelium growth of C. destructans, F. solani, and R. solani were distinctly inhibited by the increase of sulfur's concentration in vitro culture using PDA medium.

• Research in Plant Disease
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• v.8 no.4
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• pp.234-238
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• 2002

In vitro and in vivo activities of a biocontrol agent, Bacillus stearothermophilus strain YC4194 was evaluated for the control of Pythium damping-off of cucumber. B. stearothermophilus YC4194 inhibited germination of cystospores and formation of zoosporangia of Pythium aphanidermatum in vitro. Incorporation of a bentonite and talc based formulation(10$^{9}$ cfu/g) of B. stearothermophilus YC4194 to the nursery soils (10 g/ι soil) resulted In a significant (p=0.01) reduction in the disease severity of cucumber damping-off after inoculation with P. aphanidermatum. The control efficacy of B. stearothermophilus YC4194 formulation was not different from that of the fungicides, dimethomorph, metalaxyl, ethaboxam. When the cucumber plants were transplanted to the soil inoculated with P. aphanidermatum zoospores, the B. stearothermophilus YC4194 maintained the high population density in rhizosphere soil upto 10$^{7}$ cfu/g until 15 days after treatment.

• Korean Journal of Medicinal Crop Science
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• v.17 no.6
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• pp.415-420
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• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.