• The Plant Pathology Journal
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• v.24 no.2
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• pp.164-170
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• 2008

Carbon utilization by Chryseobacterium strain KJ1R5 was studied to enhance its biocontrol activity against Phytophthora capsid. Chryseobacterium strain KJ1R5 has previously been shown to control Phytophthora blight of pepper (Capsicum annuum L.). Strain KJ1R5 could utilize carbon sources such as L-arabinose, D-cellobiose, ${\beta}-lactose$ and D-galactose well. P. capsici could utilize D-glucose well, showing the absorbencies ranged from 0.577 to 0.767 at 600nm. When 2% L-arabinose, which could only be utilized by the bio-control strain KJ1R5, was amended into the bacterial suspension, the efficacy of biological control increased. Among the amendments of various carbon sources into bacterial suspension, L-arabinose and D-(+)-glucose significantly enhanced biological control activity, resulting in a reduction of disease incidence to 6.9%, compared to 21.9% for the strain KJ1R5 alone and 81.3% for P. capsici inoculation alone, indicating that amendment with specific carbon sources could increase the biological control activity.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.422-428
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• 2014

Endophytic bacterial strains from root tissue of strawberry were screened for their efficacy in growth improvement and control of Phytophthora blight disease of chili pepper plant under greenhouse condition. Plants treated with the strain EP103, identified as Pseudomonas fluorescens, showed growth improvement in terms of fresh weight and root length compared to the untreated control and other endophytic strains. When challenged with Phytophthora capsici, there was significant reduction of disease in EP103 treated plants with an efficacy of 78.7%. There was no direct inhibition of the target pathogen by EP103 when tested under in vitro antibiosis assay. Analysis of differential expression of selected marker genes for induced systemic resistance (ISR) in plants treated with EP103 and challenged with P. capsici showed up-regulation of PR1 and PR10 pathogenesis-related (PR) proteins. PCR analysis showed that EP103 produced secondary metabolites such as pyoluteorin, pyrrolnitrin, hydrogen cyanide and orfamide A. This study indicated the potential of endophytic P. fluorescens strain EP103 as an efficient biocontrol agent against P. capsici in chili pepper plant.

• Research in Plant Disease
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• v.12 no.3
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• pp.153-157
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• 2006

In 2005, average temperature was lower, and average rainfall was less than those of previous year. The diseases of rice, barley, pepper, chinese melon, apple and oriental pear were surveyed. Bacterial blight, bacterial grain rot, and panicle disease of rice, black rot of pear, and white rot and bitter rot of apple were severe. Especially, brown rot of rice occurred four times higher than those of previous year. Panicle blight of rice increased about 3 times, compared with the previous year, presumed that the higher rainy days, rainfall and RH promoted spread of the fungal pathogens to panicles of rice. The diseases of rice leaf blast, sudden wilt syndrome, downy mildew and powdery mildew of chinese melon in plastic greenhouse, and virus diseases of hot pepper occurred distinctly less than those of the previous year. Another diseases surveyed occurred similar or less.

• Applied Biological Chemistry
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• v.47 no.3
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• pp.339-343
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• 2004

Anionic surfactants such as sodium dioctyl sulfosuccinate (SDSS) and sodium dodecylbenzene sulfonate (NaDBS) and a nonionic surfactant, polyoxyethylene oleyl ether (OE-7) were tested for their protective, curative, and persistent activities on tomato late blight (TLB, Phytophthora infestans), red pepper blight (RPB, P. capsici), and cucumber downy mildew (CDM, Pseudoperonospora cubensis). They exhibited a strong protective activity on TLB, RPB, and CDM. Among them, $NaDBS\;(500\;{\mu}g/ml)$ showed the most in vivo antifungal activities(1-day protective activity) with control values of 99%, 100%, and 85% against TLB, RPB, and CDM, respectively. However, the three surfactants represented a weak disease controlling efficacy on TLB, RPD, and CDM in a 1-day curative application. SDSS and NaDBS exhibited a good persistent activities on TLB and RPB. Especially, NaDBS, at $500\;{\mu}g/ml$, showed control values of more than 88% on TLB and RPB in a 7-day protective application. The results indicate SDSS and NaDBS have a potential for the control of TLB, RPB, and CDM in the fields.

• Research in Plant Disease
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• v.8 no.1
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• pp.1-10
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• 2002

Climate in the year of 2001 could be summarized as severe drought from March to May, unusually high temperature in whole plant growth periods and clear weather condition especially in harvesting time of September and October without any typoons. In rice, major diseases such as leaf and panicle blast, bacterial blight, sheath blight and bacterial grain rot developed little due to unfavorable weather conditions, however, brown spot occurred severely due partly to the reduced use of N-fertilizer, Rice stripe virus infection was unusually high mainly in the west coast areas with four times more diseaseD area campared to the previous year, In pepper phytophthora blight was extremely severe in Cheonnam and Cheonbuk provinces, where had frequent rainfalls during growing period. Incidence of major diseases of tomato and cucumber in 2001 was relatively mild. In watermelon, penicillium fruit rot, one of the peculiar disease, spread over major production areas, whereas CGMMV, usually severe in every years was much reduced. Watermelon plants growing in open-fields were more severely diseased than those in plastic houses. Major diseases of chinese melon and strawberry occurred slightly and in particular, sudden wilt syndrome of chinese melon which was severe in 2000 showed mild infections in 2001. Incidence of white rot of garlic and onion was much lower unlike other years due mainly to spring drought and high temperature in the growing period. Infected area of potato bacterial wilt tended to increase in 2001 while fusarium wilt of sweetpotato was decreased. Apple diseases were generally mild, but powdery mildew of pear increased sharply. Barley scab was not severe as seen in other years.

• Research in Plant Disease
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• v.10 no.1
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• pp.21-24
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• 2004

A destructive stem rot of pepper (Capsicum annuum) was found from the often field sporadically in Jingyemyon, Hadong-gun in July 2002 and vinyl houses in Moonsan-eup, Jinju City in October 2003. The same fungus also caused collar and crown rot and systemic wilt or blight of whole plant. White mycelium spread over stems of infected plants and sclerotia formed on the old lesions and near the soil surface. The fungus showed maximum mycelial growth around 3$0^{\circ}C$. The mycelial color is white and width of hyphae ranges 3.6∼10.2 ${\mu}{\textrm}{m}$, and formed clamp connection. Numerous sclerotia were farmed in artificial media such as PDA at 3$0^{\circ}C$. The shape of sclerotia were sphere and 1.0∼2.1 mm in diameter, The fungus was isolated repeatedly from the infected tissues and the pathogenecity of fungus to pepper (Capsicum annuum) was confirmed, and identified as Sclerotium rolfsii. This is the first report on the stem rot of pepper (Capsicum annuum) caused by Sclerotium rolfsii in Korea.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.26-32
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• 2017

Antimicrobial activity of 6 phosphate compounds as $H_3PO_3$, $H_3PO_4$, $K_3PO_4$, $K_2HPO_4$, $KH_2PO_4$ and $NH_4H_2PO_4$ against Phytophthora capsici JHAW 1-2 and Colletotrichum acutatum JC24 was investigated in this study. Inhibitory effect on zoospore release, zoosporangia germination and zoospore germination was superior than mycelial growth. Among 6 compounds, $H_3PO_3$ and $H_3PO_4$ showed the best antimicrobial activity against P. capsici JHAW 1-2. Diseases controlling activity of the phosphate compounds tested on seedling and fruit of pepper against Phytophthora blight was also better than those against anthracnose. When $H_3PO_3$ was applied to the pepper seedlings at a concentration of $100{\mu}g\;mL^{-1}$, severe phytotoxicity was occurred. However, with applying $10{\mu}g\;mL^{-1}$ of $H_3PO_3$ showed 100% the disease control efficacy. In case of $100{\mu}g\;mL^{-1}$ $H_3PO_4$ application showed excellent antimicrobial activity against P. capsici JHAW 1-2, and 56.7% of the disease control efficacy with no phytotoxicity. To investigate the control efficacy against anthracnose, conidia suspension was inoculated with non-wound and wound inoculation method on pepper fruit. Among 6 compounds, only $100{\mu}g\;mL^{-1}$ of $H_3PO_3$ and $H_3PO_4$ had a activity of more than 70%, but the control activity on other treatments was minimal or unacceptable.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.66-76
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• 2014

Resistance of one hundred commercialized cultivars of chili pepper to four isolates of Phytophthora capsici was evaluated under controlled environmental conditions. The cultivars are commercialized as resistant (59%) and susceptible (41%) to Phytophthora blight in Korea. Mean disease severities of the cultivars on P. capsici MY-1, KPC-1, JHAI1-7, and KPC-7 isolates were 37, 55, 60, and 74%, respectively. In addition, 38 for MY-1, 48 for KPC-1, 56 for JHAI1-7, and 76 cultivars for KPC-7 showed susceptibility. To P. capsici MY-1, the weakest pathogenicity isolate among them, 59 cultivars represented high resistance. By contrast, only six cultivars showed high resistance to P. capsici KPC-7, the strongest isolate. Furthermore, resistance of most cultivars except for three cultivars was negatively correlated with the virulence of P. capsici isolates. And isolate-specific resistance of the chili pepper cultivars could not be found. Among them, six cultivars showing resistance to all the tested isolates were selected for further study. The development of Phytophthora blight on the six cultivars according to inoculum density ($5{\times}10^4$ to $1.5{\times}10^6$ sporangia/pot) and incubation temperature (25 to $30^{\circ}C$) after inoculation of P. capsici was tested. Resistance of the cultivars to P. capsici KPC-1 and JHAI1-7, moderately pathogenic isolates, was hardly affected. But to KPC-7 isolate, the highly resistant cultivars showed susceptiblility or moderate resistance when the seedlings were inoculated with inoculum density of $1.5{\times}10^6$ sporangia/pot and incubated at 28 to $30^{\circ}C$. From these results, it is likely that resistance of chili pepper cultivars to Phytophthora blight is affected by the virulence of P. capsici isolate.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.1-10
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• 1994

Biological control of plant disease has been considered a potential control strategy in integrated pest management in recent years. This paper reviewed the progress of research on the biological control of plant diseases in Korea during the last two decades and adopts some future prospects. The crop diseases included, red pepper, Phytophthora blight, ginseng root rots cucumber wilt, sesame damping-off, strawberry wilt and tobacco bacterial wilt and mosaic. Biological control of plant diseases requires a multi-disciplinary approach involving input from plant pathologists, ecologists, mycologists and molecular biologists. The author proposed to organize a group“Committee for Biological Control”including researchers, industries, growers and administrators.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.23-26
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• 1988

A severe blight disease of lily (Lilium spp.) caused by Botrytis elliptica was found in a vinyl house in Taejon for the first time in 1987. Initial symptom of the disease was brown spotting on leaves and stems of the plants. The spots gradually increased in size and coalesced to form bigger spots and blights on the leaves. Plants with severe damage became brown and sometimes died. In the inoculation experiments, the fungus was found to be pathogenic only to lily, but not to pepper, tomato, ginseng, onion and welth onion.