• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.88.1-88
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• 2003

Antogonistic bacteria against Rhizoctonia solani and Pythium spp., causing serious damage to golf course grasses, were isolated from the top soil of several golf courses in Korea. The isolate of Limk0102 was selected as the biological agent by characterization of antifungal activity, large scale preparation, fungicides tolerance and ecological fitness to the targe environment. The isolate was identified as Bacillus subtilis by biochemical and physiological characterization, and 165 rDNA sequence analysis. The bacterial agent was formulated as a granule type by seeding it on fine sand. The formulated agent showed high recovery rate (more than 10$\^$8/ cells/g sand) even after 6 month-storage at room temperature with similar antifungal activity with that of original cells. In vitro, the biological agent successfully exhibited antagonistic performance on bentgrass inoculated with R. solani or Pythium spp. isolated from the diseased grasses on golf courses. Field evaluation on disease control activity and ecological fitness of the agent is now under going on several golf courses.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.295-306
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• 2009

We investigated the quality of 48 cultivar in 5 types, most popularly used in Korea golf courses. Only brown patch disease caused by Rhizoctonia solani AG1-1 was occurred naturally. While disease was developed seriously into tall fescue cultivar in spring time and into bentgrass cultivar in fall time, respectively, however, among species were not significantly different. Tall fescue and perennial ryegrass cultivar had higher chlorophyll contents in November and there were also significantly different between cultivar of tall fescue, kentucky bluegrass and fine fescue species. Turfgrass color also showed significant difference between grass species. Perennial ryegrass has the highest value of turf leaf color, followed by kentucky bluegrass and tall fescue species. Significant differences among cultivar were found in kentucky bluegrass, tall fescue and fine fescue. Although fresh weight of turfgrass was not statistically different between grass species, root length was significantly different between species. Tall fescue species had the longest root length. Fresh weight showed differences among cultivar in kentucky bluegrass, bentgrass and tall fescue species. Based on our results, growth and grass quality showed large differences among cultivar and each turfgrass species.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.157-164
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• 2017

Functional microorganisms decompose various organic matter by enzyme activity and suppress plant disease caused by pathogen. This study was conducted to isolate and select functional microorganisms with protein or carbohydrate degradation activities and antagonistic activity against turfgrass fungal pathogens for eco-friendly turfgrass management in golf course from compost containing livestock manure of poultry or swine. Totally 68 isolates collected from livestock manure compost strains were isolated and tested for their activities of amylase, protease and lipase and antagonistic activities against Rhizoctonia solani AG2-2, R. solani AG1-1, and Sclerotinia homoeocarpa. Among the isolates, 34 strains were selected as functional microbes showing higher activities of amylase and protease. Three isolates of ASC-14, ASC-18, and ASC-35 among the 34 strains were selected as antifungal bacterial strains repressing the above 3 turfgrass fungal pathogens. Analysis results of 16s rRNA gene sequence and phylogenic cluster indicated that ASC-14 and ASC-18 belonged to Bacillus amyloliquefaciens, while ASC-35 was B. subtilis, respectively.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.176-181
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• 2010

Brown patch (Rhizoctonia solani AG1-1), dollar spot (Sclerotinia homoeocarpa), pythium blight (Pythium spp.), anthracnose (Colletotrichum graminicola), yellow patch (Rhizoctonia cerealis) and Zoysia patch (Rhizoctonia solani AG2-2) are the major turfgrasses diseases in Korea. In this study, 23 medicinal plant extracts were tested for antifungal activities against turfgrass pathogenic fungi. In paper disk diffusion method, 12 medicinal plant extracts, including Sophora flavescens, showed antifungal activity. Also, in the test of antifungal activity on media contained the extracts of S. flavescens, Curcuma longa, Rheum undulatum, Coptis chinensis and Asiasarum sieboldi showed above 80% inhibitory effects on the mycelial growth in 110 mg/10 ml concentration of the extracts. S. flavescens, in particularly, showed antifungal activity against the six turfgrass pathogenic fungi. The inhibition rate of S. homoeocarpa was 100% in 10 mg/10 ml, 5 mg/10 ml and 2 mg/10 ml concentrations of C. longa extract. In case of Pythium spp., the extracts of S. flavescens, R. undulatum and C. chinensis showed 100 % inhibition rate on the test media.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.147-156
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• 2006

This study was initiated to evaluate the growth characteristics of seven creeping bentgrass cultivars in summer, 'Penncross' showed the worst visual quality, whereas 'Penn A-4' and 'Crenshaw' the best quality. 'Putter', which was maintained a fair quality during the test period, was regarded as a good cultivar because of no significant variation in summer as compared to the other caltivars. 'Crenshaw',' L-93' and 'Penn A-4' were greater in chlorophyll content and 'Penncross' lowest during the summer. Also, 'SR1020' had a low content of chlorophyll. 'Putter' greatly increased in chlorophyll content after fertilization. The highest shoot density($19.3/cm^2$) was found with 'L-93' in early August, followed by 'Crenshaw', 'Penn A-4', 'Putter', 'Dominant', and 'SR1020' in that order. However, 'Penncross' was lowest($15.7/cm^2$). As for a root length, 'L-93' was longest, being over an average 5.5cm. 'Penn A-4' and 'Putter' also showed good result in root growth. However, the root length considerably decreased with 'SR1020', 'Penncross' and 'Dominant' in summer. Brown patch was a serious disease for the most cultivars, except 'Penncross'. 'Dominant' had the most serious damage. 'Putter', 'L-93', 'Crenshaw', 'SR1020', and 'Penn A-4' were also greater in damage over the others. In regards of algae occurrence in summer, 'Penn A-4' had the least damage, while 'Dominant' the greatest. In conclusion, 'Crenshaw', 'Penn A-4' and 'L-93' were the best cultivars in terms of summer growth. Conversely, 'Penncross' was the poorest one. However, this study was conducted under the conditions of one-year old green. Accordingly, in-depth experiment should be done over several years to elucidate the characteristics of growth for the wide range of creeping bentgrass cultivars during the summer.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.1-7
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• 2007

This study was initiated to evaluate the qualitative characteristics of creeping bentgrass(Agrostis palustris Huds.) cultivars for the climate In Korea through the NTEP(Nat'l Turfgrass Evaluation Program) data. 'L-93' showed the highest rating in overall mean visual quality. It was also the most prominent cultivar in seedling vigors, ground cover, and genetic color especially in summer. In case of turf texture, 'Penn A-1' and 'A-2' were the finest group, but the poorest group in cold tolerance. Leaf density and thatch accumulation were lower with 'Penncross', 'Pennlinks', 'Crenshaw', and 'L-93' as compared with 'Penn A'-type and 'G'-type cultivars. Resistance to moss invasion was greater with 'Penn A'-type and 'G'-type cultivars, but 'Penncross' was the least. These observations indicated that leaf density was considered to associate with the characters of turf quality, thatch accumulation and resistance to moss invasion. 'Penn A'-type cultivars were highly resistant to snow mold. Greater resistance to brown patch was associated with 'Penn A' and 'Penncross'. Higher resistance to pythium blight was found with 'Penncross' and 'Pennlinks'. 'L-93' showed higher resistance to dollar spot, but not to pythium. Therefore, these results demonstrated that turf maintenance program for the new bentgrass cultivars should be different from a conventional management for the cultivar of 'Penncross'.