• Plant Disease and Agriculture
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• v.5 no.2
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• pp.119-121
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• 1999

A destructive collar rot of safflower occurred severely research farm of at Kyongsangnam-do Agricultural Research and Extension Services in 1999. Incidence of the disease at 3 fields in Chinju was ranged from 21.6 to 34.2% Upper parts of infected stems were mostly blighted and white mycelia were found on the lesions. The same fungus was isolated consistently from the infected tissues and confirmed its pathogenecity to safflower. The causal fungus of collar rot disease was identified as Sclerotium rolfsii by the examination of colony type sclerotium formation and pathogenicity test. This fungus also causes stem rot crown rot wilt or blight on the safflower. This is the first report on the collar rot of safflower caused by Sclerotium rolfsii in Korea.

• The Plant Pathology Journal
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• v.20 no.1
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• pp.75-80
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• 2004

In an attempt to develop effective biocontrol system for management of stem rot disease in groundnut, 57 bacterial isolates and 13 isolates of Trichoderma spp. were evaluated for their antagonistic activity against Sclerotium rolfsii. The antagonists were selected based on their ability to inhibit the external growth of S. rolfsii from infected groundnut seeds. Four isolates of Pseudomonas fluorescens, GB 4, GB 8, GB 10 and GB 27, and T. viride pq 1 were identified as potent antagonists of S. rolfsii. T. viride pq 1 produced extracellular chitinase and parasitized the mycelium of S. rolfsii. Under controlled environment conditions, P. fluorescens GB 10, GB 27, T. viride pq 1 and the systemic fungicide Thiram(equation omitted) reduced the mortality of S. rolfsii inoculated to groundnut seedlings by 58.0％, 55.9％, 70.0％ and 25.9％, respectively compared to control. In vitro growth of P. fluorescens GB 10 and GB 27 was compatible with T. viride pq 1 and Thiram(equation omitted). Integrated use of these two bacterial isolates with T. viride pq 1 or Thiram(equation omitted) improved their biocontrol efficacy. Combined application of either GB 10 or GB 27 with T. viride pq 1 was significantly effective than that with Thiram(equation omitted) in protecting groundnut seedlings from stem rot infection.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.661-663
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• 1998

Bipolaris stem rot of cactus severely occurred up to 77% at the field of Koyang and Kimcheon from 1996 to 1997. The symptom was initially light yellow, water soaked round lesion, subsequently turned light brown and dried to death. The causal fungus was identified as Bipolaris cactivora (Petrak) Alcorn. Conidia were obclavate to fusoid, rounded ends, light brown color, 1~4 septate, and conidial size was 23~42$\times$6~9 ${\mu}{\textrm}{m}$ (av. 32.5$\times$7.5 ${\mu}{\textrm}{m}$). Conidiophores were caespitose, straight, pale to golden brown and 67~280 ${\mu}{\textrm}{m}$ in length. When healthy cacti were inoculated with the isolates obtained form the lesion of diseased plants, the same characteristic symptoms as those in the field were produced. The symptom of four-month-old cactus was developed more rapidly than that of six-month-old cactus. The pathogen was reisolated from the artificially inoculated lesions.

• The Plant Pathology Journal
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• v.35 no.3
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• pp.219-233
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• 2019

Soybean cultivars susceptible to Phytophthora root and stem rot are vulnerable to seed rot and damping-off of seedlings and young plants following an infection by Phytophthora sojae. In this study, the disease responses of Japanese soybean cultivars including currently grown main cultivars during the early growth stages were investigated following infections by multiple P. sojae isolates from Japanese fields. The extent of the resistance to 17 P. sojae isolates after inoculations at 14, 21, and 28 days after seeding varied significantly among 18 Japanese and two US soybean cultivars. Moreover, the disease responses of each cultivar differed significantly depending on the P. sojae isolate and the plant age at inoculation. Additionally, the treatment of 'Nattosyo-ryu' seeds with three fungicidal agrochemicals provided significant protection from P. sojae when plants were inoculated at 14-28 days after seeding. These results indicate that none of the Japanese soybean cultivars are completely resistant to all tested P. sojae isolates during the first month after sowing. However, the severity of the disease was limited when plants were inoculated during the later growth stages. Furthermore, the protective effects of the tested agrochemicals were maintained for at least 28 days after the seed treatment. Japanese soybean cultivars susceptible to Phytophthora root and stem rot that are grown under environmental conditions favorable for P. sojae infections require the implementation of certain practices, such as seed treatments with appropriate agrochemicals, to ensure they are protected from P. sojae during the early part of the soybean growing season.

• Agrochemical news magazine
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• v.25 no.3 s.196
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• pp.41-43
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• 2004

• Korean journal of applied entomology
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• v.26 no.1 s.70
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• pp.25-30
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• 1987

An unusual disease syndrome, partial stem rot and final blight of the whole plants was observed in sesame, Sesamum indicum L., cultivar Pungnyeonkkae and Kwangsankkae grown in the field. Symptoms progressed from water-soaking continuous banding lesions on one side of stem to producing abundant Fusarium growth on the lesion at late stage of pathogenesis. Although wilting of plants was most frequently observed in sesame seedlings when infected with Fusarium oxysporum, reproduction of the partial stem discoloration and rot was possible by soil inoculation, and wound inoculation in old plants. The disease occurred from late July. Mycological characteristics of the isolate Fusarium oxysporum compared with those reported in sesame suggested that the isolate might be F. oxysporum f. sp. sesame.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.260-268
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• 1999

Crude extract of Coptis japonica root-stem was evaluated for antifungal activity against Phytophthora capsici, Fusarium oxysporum, Colletotrichum dematium, Colletotrichum truncatum, Botrytis cinerea, Botryosphaeria dothidea and Alternaria porri, and antifungal active compound from the extract was identified. In addition, the usefulness of the extract for some plants disease control was investigated. Crude extract of C. japonica root-stem exhibited antifungal activity against P. capsici, F. oxysporum, C. dematium, B. cinerea, B. dothidea and A. porri. Antifungal activity of the substance isolated from C. japonica root-stem was similar to a standard chemical berberine-Cl. Red-pepper fruit rot, sesame stem rot and welsh-onion alternaria leaf spot were effectively controlled by the crude extract of C. japonica root-stem. Phytotoxicity was not observed in the red-pepper and welsh-onion leaves and red-pepper and strawberry fruits with exogenous foliage application of the crude extract. Seeds germination and radicle growth of red-pepper and sesame were inhibited by the crude extract of C. japonica root-stem. 4.24g of yellowish compound per 100g of C. japonica root-stem was obtained. The compound was identified as berberine-Cl by HPLC.

• Research in Plant Disease
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• v.13 no.1
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• pp.6-14
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• 2007

Root and basal stem rot disease occurred on moth orchid (Phalaenopsis spp.), Pung-nan (Neofinetia falcata) and Nadopung-nan (Aerides japonicum) grown in the farmers' greenhouses located in Namyangju Kyonggi province, Korea during 2005 to 2006. Wilting symptoms occurred on these orchard plants at initial stage and the infected plant leaves turned yellow to red. The discolored leaves were fallen down to lead to eventual death of the entire plant. A total of 59 isolates of Fusarium spp. was obtained from roots and leaf bases of the diseased plants. The cultural and morphological characteristics of isolated Fusairum spp. were identified as Fusarium oxysporum, F. proliferatum and F. solani. F. oxysporum and F. proliferatum were isolated from all these orchard plants but F. solani was isolated only from Phalaenopsis spp. Pathogenicity of the three Fusarium spp. was confirmed by artificial inoculation. Although F. oxysporum, F. proliferatum and F. solani cusing root rot disease in Phalaenopsis spp. have been reported in Korea, the pathogens in N. falcata and A. japonicum were not reported yet. Therefore, this is the first report on the root and stem rot of N. falcata and A. japonicum caused by F. oxysporum and F. proliferatum in Korea.

• Research in Plant Disease
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• v.20 no.2
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• pp.126-128
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• 2014

This study was carried out to assay the disease incidence degree of Sclerotium rot caused by Sclerotium rolfsii in sixteen most popular commercial cultivars of sweet potato (Ipomoea batatas) in Republic of Korea. The degree of disease incidence was evaluated on pot experiments. In pot experiments using artificial inoculation, the Sclerotium rolfsii caused a stem rot on seedling of sweet potato plants and causes a crown rot on lower stems near or at the soil line at favorable environmental conditions. White mycelial mats and sclerotia were formed at the infection sites. Plants severely infected were fell over or died because lower stems near soil surface were rotten. The degree of disease incidence was varied according to cultivars. Two cultivars, Bio-mi and Deayumi, were very resistant, while five cultivars, Shinjami, Shingeonmi, Hongmi, Yeonjami, and Shinhung-3 were highly susceptible.

• The Plant Pathology Journal
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• v.40 no.1
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• pp.48-58
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• 2024

The oldest and most extensively cultivated form of millet, known as pearl millet (Pennisetum glaucum (L.) R. Br. Syn. Pennisetum americanum (L.) Leeke), is raised over 312.00 lakh hectares in Asian and African countries. India is regarded as the significant hotspot for pearl millet diversity. In the Indian state of Haryana, where pearl millet is grown, a new and catastrophic bacterial disease known as stem rot of pearl millet spurred by the bacterium Klebsiella aerogenes (formerly Enterobacter) was first observed during fall 2018. The disease appears in form of small to long streaks on leaves, lesions on stem, and slimy rot appearance of stem. The associated bacterium showed close resemblance to Klebsiella aerogenes that was confirmed by a molecular evaluation based on 16S rDNA and gyrA gene nucleotide sequences. The isolates were also identified to be Klebsiella aerogenes based on biochemical assays, where Klebsiella isolates differed in D-trehalose and succinate alkalisation tests. During fall 2021-2023, the disease has spread all the pearl millet-growing districts of the state, extending up to 70% disease incidence in the affected fields. The disease is causing considering grain as well as fodder losses. The proposed scale, consisting of six levels (0-5), is developed where scores 0, 1, 2, 3, 4, and 5 have been categorized as highly resistant, resistant, moderately resistant, moderately susceptible, susceptible, and highly susceptible disease reaction, respectively. The disease cycle, survival of pathogen, and possible losses have also been studied to understand other features of the disease.