• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.203-211
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• 2005

The experiment was conducted to investigate the nutrition absorption pattern in the growth stages and develope the optimal nutrient solution hydroponically grown the tomato in closed substrate culture system with the nutrient solution of National Horticultural Research Station in Japan into 1/2S, 1 S, and 2S. When plant was grown in 1/2 S, the growth and yield were high and the pH and EC in the rooting zone were stable. Suitable composition of nutrient solution for tomato was $NO_3-N$ 7.1, $PO_{4}$-P 2.1, K 4.0, Ca 3.1, Mg 1.2, and $SO_{4}-S\;1.2\;me{\cdot}L^{-1}$ in the early growth stage and $NO_3-N$ 6.5, $PO_4-P$ 2.3, K 3.4, Ca 3.1, Mg 1.1, and $SO_4-S\;1.1\;me{\cdot}L^{-1}$ in the late growth stage by calculating a rate of nutrient and water uptake. To estimate the suitability for the nutrient solution of tomato in a development of optimum nutrient solution of tomato developed by Wonkwang university in korea (WU), plant was grown in perlite substrate supplied with different solution and strengths(S) by research station for greenhouse vegetable and floricultuin in the Netherlands (Proefstation voor tuinbouw onder glas te Naaldwijk; PTG) of 1/2 S, 1 S and 2 S, respectively, The growth was good at the PTG and WU of 2 S in early growth stage, and at the WU 2S in late growth stage. The highest yield of tomato obtained in the WU of 2 S, although blossom-end rot was appeared in all treatments. pH and EC in root zone of WU of 2 S were stable during the early and late growth stage. Therefore when plant was grown in WU of 2 S, N and P content in the nutrient solution need to low, according N and P content of their leaves were high in WU of 2 S.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.125-128
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• 1968

The effect of number of leaf after heading time on the growth of residual part and translocation of carbohydrates were investigated with water culture condition. Mutual shading and root rot were prevented. The results may be summerized as follows; 1. The ratio of ripened grain in the plot of no-leaf, flag leaf, two-leaf(flag and 2nd leaf) and three-leaf (flag, 2nd and 3rd leaf) was 38.8, 74.7, 83.9 and 87.0% respectively. The thousand grain weight was 21.3g, as the lowest value in no-leaf plot and was 28.7g in all other plots. 2. The accumulation of carbohydrate translocated in culm was increased by increment of leave-cutting, whereas the weight of culm was decreased. 3. It was suggested that healthy flag and 2nd leaf can keep the ratio of ripened grain around 80 percent.

• Research in Plant Disease
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• v.8 no.3
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• pp.146-161
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• 2002

Incidence of soilborne diseases, as a major cause of failure of continuous monocropping becomes severe in recent years. For examples, recent epidemics of club root of chinese cabbage, white rot of garlic, bacterial wilt of potato, pepper phytophthora blight, tomato fusarium wilt and CGMMV of watermelon are the diseases that require urgent control measures. Reasons for the severe incidence of soilborne diseases are the simplified cropping system or continuous monocropping associated with allocation of major production areas of certain crop and year-round cultivation system that results in rapid degradation of soil environment. Neglect of breeding for disease resistance relative to giving much emphasis on high yield and good quality, and cultural methods putting first on the use of chemical fertilizers are thought to be the reason. Counter-measures against soilborne disease epidemics would become most effective when the remedies are seeded for individual causes. As long-term strategies, development of rational cropping system which fits local cropping and economic condition, development and supply of cultivars resistant to multiple diseases, and improvement of soil environment by soil conditioning are suggested. In short-term strategies, simple and economical soil-disinfestation technology, and quick and accurate forecasting methods for soilborne diseases are urgent matter far development. for these, extensive supports are required in governmental level for rearing soilborne disease specialists and activation of collaborating researches to solve encountering problems of soilborne diseases.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.74-80
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• 1993

Survey on the status of cultivation and production of medicinal crop was studied on 18 medicinal herbs and 5 medicinal trees in 66 major crop producing complexes. Native seeds or seedlings of the crops obtained from self-seed or neighbored farmer were cultivated and organic fertilizer was preferred to chemical fertilizer in the complexes. More than 60.7% of farmers were applied compost among the organic fertilizers, while 34.8% of them cultivated without any organic fertilizers. Both of using the compound chemical fertilizers and urea and urea only used were showed 51. 5% and 40.9%, respectively. Ostericum koreanum, Angelica gigas, Phellopterus littoralis, and Bupleurum fulcatum belonging to the family Umbeliferae and Aralia continentalis, Polygonatum sibiricum and Eucommia ulmoides in the complexex were not damaged by insect pests and plant diseases. Mite, aphid, grub, cutworm, onion magot fly and european corn borer were known to as major insect pests and anthracnose, powdery mildew, brown leaf spot, leaf blight and root rot as major plant diseases. Productivity and income of a farm by medicinal crops in the complex were greatly different from seeding time, planting distance, year yielded, and selling routes even in the same cultivation method and in the same cultivated area.

• Microbiology and Biotechnology Letters
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• v.27 no.6
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• pp.427-432
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• 1999

For the development of a multifunctional biocontrol agent, the siderophore-producing strain GL7 was isolated from a rhizosphere on chrome azurol S agar. The GL7 was identified as a strain of Pseudomonas fluorescents on the basis of their reactions to standard physicochemcial tests from Bergey's manual, API diagnostic test, and fatty acid analysis. P. fluorescents GL7 considerably inhibited spore germination and hyphal growth of phytopathogenic fungus Funsarium solani in a dual culture. In pot trials of bean with P. fluorescens GL7, the disease incidence was significantly reduced down to 5% from 70% of incidence in the untreated control. P. fluorescens GL7 also enhanced plant growth to nearly 1.5 times than that of the untreated control, promoting elongation and development of the roots. These results suggest that the plant growth-promoting P. fluorescens GL7 can play an important role in the biological control of soil-borne plant disease in a rhizosphere.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.29-34
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• 1994

A leading sweet pepper cultivar, Keystone Resistant Giant #3, was crossed with a line with resistance to Phytophthora capsici, PI201232, for incorporation of the resistance and to study the inheritance of resistance to the disease. Seedlings of parents, $F_1$, $F_2$ and backcross populations of a cross between Keystone Resistant Giant #3 and PI201232 were inoculated with zoospore suspension of P. capsici at 36 days after seeding. Most of the $F_1$ seedlings survied the inoculation and this suggested that resistance is dominant over susceptibility. The number of survived plants in $F_2$ population was, however, much less than the killed. All the plants in a backcross to Keystone Resistant Giant #3 were killed. Therefore, the observed numbers did not fit the expected ratio for segregation of one or two dominant alleles as previously reported. The resistance to P. capsici appeared to be inherited in a quantitative mode in evaluation of root rot. Resistant individuals in $F_2$ population were selected and a breeding program for incorporation of the resistance to P. capsici by backcross method is continued.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.255-269
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• 2018

Armillaria is a white-rot fungus that decomposes organics; it is also a root pathogen that kills trees. Recently, since the forest tending practice, the incidence of Armillaria infections on tree stumps has been increasing. Herein, we have examined the morphological features of Armillaria solidipes and A. gallica collected from 10 areas in Korea, and investigated the activities of the decomposing enzymes cellulase and laccase of these two Armillaria species. A. solidipes was found in eight host tree species including Pinus densiflora, Quercus serrata, and Castanea crenata at the altitude of 107~1,396 m, while A. gallica was found in three host species including P. densiflora and Fraxinus rhynchophylla at the altitude of 119~556 m. The fruiting bodies of A. solidipes are close with lamellae, and have brown to black hairs on the stipe, while those of A. gallica are distant with lamellae and clavate-shaped, and have yellow hairs on the base. The activites of cellulase of the two species were not different, but the activity of A. solidipes laccase was higher ($12.94{\pm}0.4U/mL$) than that of A. gallica laccase ($9.14{\pm}0.3U/mL$).

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.847-858
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• 2015

Bacillus amyloliquefaciens GR4-5 was isolated from the rhizosphere soil of Korean ginseng and displayed broad-spectrum suppression of ginseng root rot pathogens. The survivability of B. amyloliquefaciens GR4-5 in soil was investigated under three different conditions; indoor, outdoor - of which soil was put in 14 mL tube after treatment - and field environments. Soil samples were collected over a four-week period from three experimental designs, and assessed for 16S rRNA gene copy number by quantitative polymerase chain reaction (qPCR). In outdoor condition, the 16S rRNA gene copy number of Bacillus spp. was 8.35 log copies g $soil^{-1}$ immediately after the GR4-5 treatment. Two weeks later, the 16S rRNA gene copy number of Bacillus spp. (6.70 log copies g $soil^{-1}$) was similar to that of the control (6.38 log copies g $soil^{-1}$). In indoor condition, the 16S rRNA gene copy number of Bacillus spp. maintained in a certain level for a longer period than those in outdoor and field. The 16S rRNA gene copy number of Bacillus spp. in field experiment was reduced faster than that of outdoor condition. Our results show that B. amyloliquefaciens GR4-5 can survive in bulk soil for 1 week, indicating its potential use as a biocontrol agent following 7 day application intervals. This study presents that outdoor microcosm system design could be a useful method to assess easily the survivability of beneficial microorganisms.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.129-134
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• 1997

Effect of soil moisture level on the growth of ginger plant was investigated through a pot experiment. The soil used for this study was collected from a newly reclaimed hillside land. The soil was a silty clay loam(19% sand, 57% of silt and 24% of clay), acidic in soil rection(pH 4.7, in $H_2O$) and low in organic matter content(1.2%). Soil moisture levels selected for the experiment were 10, 15, 20, 25, and 30% on weight basis. Under the soil moisture of 20-25%, the emergence ratio was 80-100%, 25 days alter planting. The performance of above ground parts was best under 20-25% of soil moisture. When the soil moisture content was far from 25%, high or low, the die out of above ground parts of ginger tended to increase. Under 20-25% of soil moisture the growth of roots was best and the occurrence of root rot was minimal.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.112-117
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• 2013

Phytophthora capsici is one of major limiting factors in production of pepper and other important crops worldwide by causing foliage blight and rot on fruit and root. Increased demand for the replacement of fungicides has led to searching a promising strategy to control the fungal diseases. To meet eco-friendly agriculture practice, we isolated microorganisms and assessed their beneficial effects on plant health and disease control efficacy. A total of 360 bacterial strains were isolated from rhizosphere soil of healthy pepper plants, and categorized to 5 representative isolates based on colony morphology. Among the 5 bacterial strains (GJ-1, GJ-4, GJ-5, GJ-11, GJ-12), three bacterial strains (GJ-1, GJ-11, GJ-12) presented antifungal activity against P. capsici in an fungal inhibition assay. In phosphate solubilization and siderophore production, the strain GJ-1 was more effective than others. The strain GJ-1 was identified as Bacillus sp. using 16S rDNA analysis. Bacillus sp. GJ-1 was also found to be effective in inhibiting other plant pathogenic fungi, including Rhizoctonia solani, Pythium ultimum and Fusarium solani. Therefore, the Bacillus sp. GJ-1 can serve as a biological control agent against fungal plant pathogens.