• Applied Biological Chemistry
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• v.48 no.3
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• pp.296-300
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• 2005

Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.13-18
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• 2014

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was purified by bioactivity-guided fractionation. Based on mass spectroscopy and nuclear magnetic resonance spectral data ($^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopies, rotating frame nuclear Overhauser effect spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structure of this compound was elucidated as a cyclic lipopeptide composed of a heptapeptide (Gln-Leu-Leu-Val-Asp-Leu-Leu) bonded to a ${\beta}$-hydroxy-iso-hexadecanoic acid arranged in a lactone ring system.

• Research in Plant Disease
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• v.18 no.3
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• pp.210-216
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• 2012

Clubroot of Chinese cabbage by Plasmodiophora brassicae, was found to be high virulent to the Chinese cabbage, turnips and cabbage. It this study, the endophytic bacteria Flavobacterium hercynium EPB-C313, which was isolated from tissues of Chinese cabbage, was investigated the antimicrobial activity on the inactivation of resting spores and its control effect on clubroot disease by bioassay. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivate the resting spores of P. brassicae with 90.4, 36.8, and 26.0%, respectively. The clubroot was inhibited with 100% by dipping the seedlings of Chinese cabbage in culture solutions of F. hercynium EPB-C313 before planting, however the chemmical 'fluazinam' was 91.7% in pot tests. Complex treatment were highly enhanced control efficacy with 63.7% at field of 50% diseased plants by soil incorporation with the pellet contains organic matter and F. hercynium EPB-C313, seedling drench of culture solution of F. hercynium EPB-C313 and soil drench with 10 days after planting. These results imply that the F. hercynium EPB-C313 is a very useful biological control agent of clubroot disease of Chinese cabbage.

• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.21-26
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• 1979

To compare the effect of dikegulac (sodium 2,3 : 4, 6-di-O-isopropylidene-2-keto-L-gulonate) and ancymidol (${\alpha}$-cyclopropyl-${\alpha}$-(4-methoxyphenyl)-5-pyrimidinemethanol) on the growth and flowering responses of Salvia splendens cv. Bonfire, foliar spray of dikegulac at rates of 0.06 and 0.12% and ancymidol at rates of 50 and 100 ppm, and soil drench of ancymidol at rates of 0.1 and 0.5 mg/pot were treated. Dikegulac reduced the plant height and induced the lateral shoot development by disrupting apical dominance, and thus increased the number of inflorescences and retarded flowering date. Dikegulac treatment greatly increased chlorophyll content of leaf, especially chlorophyll a. Ancymidol reduced the plant height without disrupting apical dominance and retarding flower ing date, but did not increase inflorescence number except soil drench at rate of 0.1 mg/pct. Ancymidol treatment significantly increased chlorophyll content of leaf, especially chlorophyll a. Dikegulac can be effectively used as a pinching agent and branching agent for salvia.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.161-169
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• 1992

Studies were conducted to examine the effects of single or combined treatment of uniconazole [(E)-1-(4-chlorophenyl)-4, 4-dimethyl 2(1, 2,-4-triazol-1-yl)-1-penten-3-ol)] and silver thiosulfate (STS) on reducing ozone injury to snap beans (Phaseolus vulgaris L. 'Strike'). Two weeks after seeding, plants were given a soil drench of uniconazole(XE-1019) solution at concentrations of 0.001, 0.005 and 0.025 mg/pot, and then two days prior to ozone fumigation, 0.3 and 0.6 mM STS containing 0.01% Tween-20 were also sprayed. Uniconazole was effective in providing protection against ozone injury through increase activities of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) as well as the increase of chlorophyll content and stomatal resistance resulted from plant growth retardation. The phytoprotective effects of STS seemed to be related to its properly of blocking the ethylene action and increasing activities of SOD and POD. Even at low concentrations, a combined treatment with uniconazole drench, STS spray significantly reduced ozone injury compared to single application.

• Journal of Ginseng Research
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• v.22 no.4
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• pp.237-243
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• 1998

Three fungicides, Orbit (propiconazole), Benlate (benomyl) and ASC-66835 (fluazinam), were tested as soil drenches to control disappearing root rot (DRR) of ginseng (Panax quinquefolius) in gardens artificially infested with Cylindrocarpon dsstrutans. The incidence of DRR was low (0∼3.5%) in uninfected plots and significantly higher in infested plots (2.6∼19.9%). Significant reductions in the incidence of DRR were observed in 1-year-old and 2-year-old gardens that were treated and assessed for disease in the same year Significant control was not obtained in 3-year-old gardens treated and as secede in the same year, or in 1-year-old or 2-year-old gardens assessed in the year following information. Disease incidence was significantly reduced by 49-77% by low and high rates of benomyl (45 and 1,250 mg a.1./L) and propiconazole (10 and 40 mg a.i./L) and by fluazinam at 150 mg a.i./L. These fungicides seem to be worthy of further investigation as soil drenches to control DRR of ginseng.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.19-20
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• 2003

Helicobasidium mompa Tanaka and Resellinia necatrix Prillieux cause violet root rot and white root rot of various crops, respectively. Intensive cultural practices, such as the use of dwarf stock, glasshouse cultivation, etc., predispose plants to the diseases. The diseases can be controlled only by biennial drench of 50100L of chemicals for each tree. Biocontrol with soil microorganisms proved ineffective under field conditions. Long-term control may be hampered by the perennial growth of hosts and by the difficulty in the establishment of antagonists in soil. Crop rotation or soil amendment is not applicable, either. Fungal viruses with dsRNA genome (Buck 1986) are promising against root diseases of fruit trees since they exist within the cytoplasm of fungal hyphae and need no effort to help them persist in the field. The viruses are considered to spread though the network of fungal mycelia in the soil once they enter the fungal cytoplasm. Here, we present preliminary results from a project to control the root diseases of fruit trees with dsRNA.(중략)

• Applied Biological Chemistry
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• v.48 no.1
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• pp.48-52
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• 2005

Six stains of plant growth promoting rhizobacteria were selected through germinating seed assay and root colonization assay. Among them, SKU-78 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 60% reduction of bacterial wilt disease compared with the control. It was suggested that SKU-78 strain activated the host defense systems in plants, based on lack of direct antibiosis against pathogen. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, SKU-78 stain was identified as Bacillus sp. SKU-78.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.270-274
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• 2005

The aim of this study was to determine the effect of milk as one of the environmental friendly materials that substitute chemical fungicides for control powdery mildew (Sphaerotheca aphanis) of strawberries $(Fragaria{\times}ananassa\;Duch.)$. 'Maehyang' and 'Akihime' varieties planted in greenhouses were evaluated for the control of powdery mildew. Applications of $5\%,\;10\%\;and\;20\%$ milk had much better effects on controlling powdery mildew. In particular, $10\%$ milk showed a higher efficacy than other concentrations applied onto straw­berry in greenhouse experiments. Foliar spray application of $10\%$ milk was effective for powdery mildew, whereas drench application was not. Also, foliar spray of $10\%$ milk was able to accelerate more firmness and calcium contents of strawberry fruits than the non-treated. The $10\%$ milk applied with fertilizer salts $(Ca(H_2PO_4)_2-H_2O\;and KH_2PO_4)$ showed there was a similar efficacy to $10\%$ milk alone in greenhouse experiments. White crystals and cracks on strawberry fruits appeared by $20\%$ milk. This result indicated that $10\%$ milk was a useful substitute for fungicides to control powdery mildew of strawberry.

• The Plant Pathology Journal
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• v.37 no.1
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• pp.72-78
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• 2021

Various management systems are being broadly employed to minimize crop yield loss resulting from abiotic and biotic stresses. Here we introduce a Bacillus zanthoxyli HS1 strain as a potent candidate for managing manifold stresses on vegetable plants. Considering 16S rDNA sequence and biochemical characteristics, the strain is closely related to B. zanthoxyli. The B. zanthoxyli HS1's soil-drench confers disease resistance on tomato and paprika plants against infection with Ralstonia solanacearum and Phytophthora capsici, respectively. Root and shoot growths are also increased in B. zanthoxyli HS1-treated cabbage, cucumber, and tomato plants, compared with those in mock-treated plants, after application of high salinity solution. Moreover, the pretreatment of B. zanthoxyli HS1 on cabbage plants inhibits the degradation of chloroplast pigments caused by high salinity stresses, whereas the inhibitory effect is not observed in cucumber plants. These findings suggest that B. zanthoxyli HS1 stain inhibits disease development and confers tolerance to salinity stress on vegetable plants.