• Mycobiology
• /
• v.30 no.4
• /
• pp.244-246
• /
• 2002

A destructive stem rot of tomato(Lycopersicon esculentum) occurred sporadically some farmers' fields in Jinju City, Gyeongnam province in Korea. The infected plants also showed stem, crown rot or whole plant blight. White mycelium spread over stems of infected plants and formed sclerotia on the old lesions nearby soil surface. The fungus showed maximum mycelial growth around $30^{\circ}C$. The fungus formed white colony on PDA, usually with many narrow mycelial strands in the aerial mycelium and the width were $4.0{\sim}9.8{\mu}m$. The typical clamp connections were formed on the mycelium. Numerous sclerotia was formed on PDA at $30^{\circ}C$. The shape of sclerotia was globoid and $1.0{\sim}3.0$ mm in size. The fungus was isolated repeatedly from the infected tissues and the pathogenicity was confirmed to tomato and identified as Sclerotium rolfsii. This is the first report on the stem rot of tomato caused by S. rolfsii in Korea.

• The Korean Journal of Mycology
• /
• v.51 no.2
• /
• pp.141-146
• /
• 2023

Stem rot symptoms were observed in Gondre (Cirsium setidens) plants growing in a vinyl greenhouse in Taebaek, Korea during a disease survey in June 2022. The plants presented with dark brown to black rot on the stems at or above the soil line. Severely diseased plants displayed wilt and blight. Disease incidence among these plants ranged from 1 to 5%. Three isolates of Rhizoctonia sp. were obtained from the stem lesions of diseased plants. All isolates were identified as Rhizoctonia solani AG-2-2(IV) based on the morphological and cultural characteristics, results of the anastomosis test, and phylogenetic analysis. The pathogenicity of the isolates to Gondre plants was confirmed using an artificial inoculation test. The lesions induced by the inoculation test were similar to those observed in the investigated vinyl greenhouse. Here, we report a case of R. solani AG-2-2(IV) causing stem rot in Gondre.

• Korean Journal Plant Pathology
• /
• v.14 no.4
• /
• pp.294-298
• /
• 1998

Since 1995, boxthorn bight caused by Phytophthora spp. has occurred at Chongyang areas in Chungnam province. Infected plants showed yellows and wilt at early stage, but the symptom rapidly progressed into blight due to the decay of roots and basal stem tissues. The disease was relatively severe in poorly drained lowlands and incidence reached ca. 20% in some fields. Two species of Phytophthora were constantly isolated from freshly infected roots and asal stems. Among 39 isolates collected, 26 were identified as P. nicotianae and 13 as P. drechsleri based on their mycological characteristics. Both fungi showed strong pathogenicity to boxthorn cv. Chongyang No. 1. However, the former expressed stronger pathogenicity than the latter. Phytophthora blight of boxthorn caused by the fungi has not been reported n Korea previously.

• Mycobiology
• /
• v.32 no.2
• /
• pp.95-97
• /
• 2004

In July 2002, a destructive stem rot of tawny daylily(Hemerocallis fulva) was occurred sporadically in exhibition farm of Gyeongsangnam-do Agricultural Research and Extension Services located in Hamyang-gun, Korea. The fungus also caused collar and crown rot, and systemic wilt or blight of whole plant. White mycelium spread over stems and petioles of infected plants and sclerotia were formed on the old lesions and near the soil surface. The optimum temperature for mycelial growth and scierotial formations was $30^{\circ}C$ on PDA. The mycelial width ranged $4.2{\sim}10.4{\mu}m$ and the color was white, usually many narrow mycelial strand grew in the aerial mycelium and formed clamp connection. The shape of sclerotia was spherical and $1.0{\sim}3.2$ mm in diameter. The fungus was isolated repeatedly from the infected tissues and confirmed its pathogenicity to Hemerocallis fulva and identified as Sclerotium rolfsii. This is the first report on the stem rot of H. fulva caused by S. rolfsii in Korea.

• Korean Journal of Medicinal Crop Science
• /
• v.8 no.2
• /
• pp.151-156
• /
• 2000

Field experiments were conducted to investigate the yield and paeoniflorin content between healthy peony and blight plot of top part with every year during 3 years at June, July, August, September, separately. Stem length and diameter, No. of stem in the blight plot of peony were decreased in early in blight time compared with those in no blight growth. No. of flower buds per plant was 5.2, 4.6 in 3 year- grown and 4year-grown plots at late June blight compared with 11.5, 16.2 in no blight. No. of axillary flower was also similar to as above. Main root length and root diameter was most decreased in the plot of late June blight compared with healthy peony. No. of root more than 10mm of root diameter was small in order of blight time, namely Late June, July, August and September. The root dry yield of 4 year healthy peony was most high in 1,603kg per 10a, but it was lowed in 1,007kg in the plot lasted blight during 3years at late June. Paeoniflorin content was no different between 3year-grown and 4year-grown, but it was high in late June blight plot increased with the early in blight time.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2002.11a
• /
• pp.99.3-99
• /
• 2002

• Journal of Ginseng Culture
• /
• v.6
• /
• pp.51-79
• /
• 2024

In the 1970s and 1980s, during the nascent phase of ginseng disease research, efforts concentrated on isolating and identifying pathogens. Subsequently, their physiological ecology and pathogenesis characteristics were scrutinized. This led to the establishment of a comprehensive control approach for safeguarding major aerial part diseases like Alternaria blight, anthracnose, and Phytophthora blight, along with underground part diseases such as Rhizoctonia seedling damping-off, Pythium seedling damping-off, and Sclerotinia white rot. In the 1980s, the sunshade was changed from traditional rice straw to polyethylene (PE) net. From 1987 to 1989, focused research aimed at enhancing disease control methods. Notably, the introduction of a four-layer woven P.E. light-shading net minimized rainwater leakage, curbing Alternaria blight occurrence. Since 1990, identification of the bacterial soft stem rot pathogen facilitated the establishment of a flower stem removal method to mitigate outbreaks. Concurrently, efforts were directed towards identifying root rot pathogens causing continuous crop failure, employing soil fumigation and filling methods for sustainable crop land use. In 2000, adapting to rapid climate changes became imperative, prompting modifications and supplements to control methods. New approaches were devised, including a crop protection agent method for Alternaria stem blight triggered by excessive rainfall during sprouting and a control method for gray mold disease. A comprehensive plan to enhance control methods for Rhizoctonia seedling damping-off and Rhizoctonia damping-off was also devised. Over the past 50 years, the initial emphasis was on understanding the causes and control of ginseng diseases, followed by refining established control methods. Drawing on these findings, future ginseng cultivation and disease control methods should be innovatively developed to proactively address evolving factors such as climate fluctuations, diminishing cultivation areas, escalating labor costs, and heightened consumer safety awareness.

• Korean journal of applied entomology
• /
• v.20 no.2 s.47
• /
• pp.83-86
• /
• 1981

Experiments were carried out to study on control of stem blight of asparagas caused by Shoma asparagi Sacc. in Suweon, $1976\~1978$. Symptoms of the disease were found in the field from late of May and severe infection was shown thereafter. Plastic film mulching with foliage spray of Topsin 154g a.i. and Difolatan 220g a.i. per 10a at 10days interval during the growing season, gave significantly good control and high yield compared with other treatments. In addition to reduction of the disease, the treatment with mulching has maintained good soil moisture for asparagus growth when the soil moisture was measured at about loom under the soil surface from July to August.

• The Plant Pathology Journal
• /
• v.18 no.3
• /
• pp.152-155
• /
• 2002

Epicoccosorus nematosporus was detected in all 22 counties surveyed, but the frequency of occurrence of fingerprint stem blight disease (FSBD) on Eleocharis kuroguwai caused by the fungus varied with fields and regions. The disease occurred more frequently in mountain areas than in plain areas. E. nematosporus was detected in less than 20% of plain areas such as Cimjae and Milyang, whereas, it occurred in 40-60% of mountain areas such as Sangiu and Jangsoo. In Milyang, mean temperature in July to August 1993 ranged from 17 to $27^{\circ}C$ with 14.3 h of dew period. Meanwhile, in the mountain area such as Sangiu, Gyeongbook, temperature ranged from 17 to $24^{\circ}C$ with 16.1 h of dew period. Plant mortality was 61% in Milyang and 82% in Sangju. Underground tuber formation was highly suppressed at 16 and 33 tubers per plot in Sangju and Milyang, respectively. In 1992 and 1995, plants infected ranged from 40 to 78% in July to September. This sharply decreased to an average of 15% in 1999.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.2
• /
• pp.166-173
• /
• 1993

Seed infection to pod and stem blight (Diaporthe phaseolorum) is severe at summer type soybeans maturing at hot and humid conditions. In order to increase germination and plant stand, this experiments were evaluated the effects of fungicide Benoram(Benomyl 20% ${\pm}$ Thiram 20%) seed treatments with different seed sizes on emergence yield at field conditions, and with different infection degrees to pod and stem blight on germination in laboratory. Benoram treatment on seed was improved emergence rate and elongated hypocotyl not increased growth and yield. It was clearly improved length but germinations and germination speed by Benoram fungicide treatment on severely infected seed however was not improved germination rate at good quality of seeds and the effect was higher at large seed cultivar than small ones.