Anthracnose disease caused by Colletotrichum horii (C. gloeosporioides), results in considerable economic damage to sweet persimmon in southern Korea yearly. This study deals with the life cycle of the pathogen in terms of seasonal fluctuations of spore dispersal and the development of disease based on field surveys, spore potential and fungal isolation. Anthracnose disease was observed first on twigs in the last week of May and reached an incidence of 1.2%. Subsequently, the disease increased rapidly and reached an incidence of 86% by the end of July. Infection of fruits started in mid‐June (2.8%) and increased gradually to 64.4% by the end of July. In severely infected orchards, 46.2% of diseased fruits were dropped. The pathogen began releasing conidia in the first week of May and continued until the end of September. The maximum release of spores was observed in mid‐July. To determine the optimal use of chemicals for control of anthracnose, the following spray programme was evaluated. Spraying two or three times resulted in 89.4 and 93% control, respectively, whereas spraying more than four times led to 100% control. In comparison, the disease rate of unsprayed trees was 89.8%. To control anthracnose effectively, it is recommended to take steps to eliminate inoculum sources in sweet persimmon orchards before spraying chemicals.

Farfugium japonicum (L.) Kitam (common name: Leopard plant) is known as a medical herb and belongs to family Asteraceae (1). In June 2012, a leaf spot disease was observed on the leaf surface of F. japonicum at a forest research plot Jinju, Gyeongnam province, Korea. More than 95% of F. japonicum plants were infected and leaf spot symptom appeared in the regions under our investigation. Light brownish symptoms initially developed and the spot size gradually increased and turned dark brown with an irregular shape as the disease progressed (spot size 1 to 10 mm in diameter). At the late stage of disease, spots became hollow and completely dehydrated. The infected leaves were easily crumbled, possibly due to dryness. To isolate the causal agent, the infected leaves were surface disinfected and pieces of leaves were placed on water agar (WA). Nine isolates were isolated from 10 pieces of the infected leaves. Fungi mycelia from the WA were transferred on potato dextrose agar (PDA) and incubated at 28°C for 7 days. The colonies were purple navy to black and conidia spores developed on the media. The morphological characteristics of spores were multi-septate, dark brown, pyriform, and 6.7 to 12.8 × 22.2 to 38.4 μm. The spores had 1 to 4 transverse and 0 to 3 longitudinal septa. The morphological characteristics of the isolates showed considerably similar to well-known Alternaria tenuissima (2). The leaf spot disease caused by A. cinerariae of F. japonicum was reported from Japan (3). Spores of A. cinerariae are golden brown to brown with 3 to 9 transverse and 0 to 6 longitudinal septa and are 87.5 × 28.7 μm (avg.) (3). To verify pathogenicity of the isolate, the pure cultured fungi on the PDA medium was taken (4 mm in diameter) and placed on healthy leaves of Leopard plant. The artificially inoculated leaves were placed on wet filter paper in Petri dishes and incubated at 25°C and 80% humidity. At 7 days after inoculation, similar disease symptoms developed on 8 out of 10 infected Leopard plant leaves. The pathogen was reisolated from artificially infected leaves. To identify in molecular biology level, genomic DNA was extracted and the ITS-rDNA region was amplified using universal primers ITS1 and ITS4. The amplified PCR product was purified and sequenced (528 bp) with ITS1 and ITS4 primers for both directions and then deposited in GenBank (Accession No. KC415611.1). The BLAST search showed that it matched previously reported A. tenuissima with 100% identity. To the best of our knowledge, this is the first report of Leopard plant leaf spot disease in Korea. References: (1) E. Y. Kim et al. J. Ethnopharmacol. 146:40, 2013. (2) E. G. Simmons. Page 1 in: Alternaria Biology, Plant Diseases and Metabolites. J. Chelchowski and A. Visconti, eds. Elsevier, Amsterdam, 1992. (3) T. Sakoda et al. Res. Bull. Pl. Prot. Japan 46:73, 2010.

Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of 48.5 × 15.2 cm. Black, half-rounded globular mound shaped stromata were associated with the cankers, and the asci of the fungi associated with the cankers were cylindrical shaped with their spore-bearing parts being up to 84 µm in length. The average fungal ascospores size was 7.59 × 4.23 µm. The internal transcribed spacer sequence for the canker causing fungus showed 99% similarity to the sequence of Annulohypoxylon truncatum. In this study, the isolated fungus was precisely described and then compared with fungi of similar taxa.

BACKGROUND: Some microorganisms extant in nature have ability to suppress various plant pathogens, and also can promote plant growth. Thus microorganisms are such great source of antimicrobial agents to develop antagonistic microorganism production and eco-friendly crop management. We isolated the microorganisms in various eco-friendly formulations. The suppressive abilities against plant pathogens have been characterized in vitro level. METHODS AND RESULTS:The indigenous microorganisms have been isolated from Cooked rice, Black sugar, Rice Bran, and Red clay using dilution plating method. Population of bacteria and fungi were above 10 7 in the all formulations. We isolated and pure cultured the microorganisms based on morphological characteristics. Three major plant pathogens (Fusarium oxysporum, Rhizoctonia solani, Phytophthora capsici) have been used to select antagonistic microorganisms. Total 20 bacteria and 9 fungi showed the pathogen growth suppression ability in vitro condition. The selected microorganisms were identified by ITS sequence similarity. CONCLUSION: All tested eco-friendly formulations contained high-density of the microorganisms. Among the isolated microorganisms, Bacillus spp. and Streptomyces spp. showed the most effective antifungal activity against the plant pathogens such as F. oxysporum, R. solani, and P. capsici. Among the selected fungi Trichoderma sp. demonstrated antifungal activity. Our results suggest that the currently adapted eco-friendly formulations might useful for sustain agricultural system.

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