• Proceedings of the Turfgrass Society of Korea Conference
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• 2011.02a
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• pp.39-42
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• 2011

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.249-261
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• 2017

To prevent large patch disease, caused by Rhizoctonia solani AG-2-2, in zoysiagrass a fungicide, Tebuconazole and three microbial agents Streptomyces sp. Burkholderia sp. and Streptomyces sp. S8 were applied in commercial turfgrass cultivation field in Sanchung, Gyeongnam, Korea. All treatments showed 50% reduced the pathogen population in thatch layer throughout the yearly cultivation period. Not only reduced the pathogen population, Tebuconazole, Streptomyces sp. Burkholderia sp. and Streptomyces sp. S8 treatment also enhanced turfgrass growth, chlorophyll and proline content. Malondialdehyde contents in each treatment was reduced from 6.2~28.9% when compared with the control. Taken together, reduction of pathogen population in soil lowered the disease incidence or severity, and allowed the turfgrass developed as normal condition. The results suggested that the selected microbial agents may use as biological control and growth promotion agents for the Zoysia turfgrass.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.125-132
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• 2011

Drought is a major limiting factor in turfgrass management. Turfgrass responses to water deficit depend on the amount and the rate of water loss as well as the duration of the stress condition. This review paper was designed to understand responses such as photosynthesis, canopy spectral reflectance, plant cell, root, hormone and protein alteration when turfgrass got drought stress. Furthermore, mechanisms to recover from drought conditions were reviewed in detail. However, there are still many questions regarding plant adaptation to water deficit. It is not clear that the mechanism by which plants detect water deficit and transfer that signal into adaptive responses. Turfgrass research should focus on the best management practices such as how to enhance the ability of self-defense mechanism through understanding plant responses by environmental stress.

• The Plant Pathology Journal
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• v.16 no.3
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• pp.137-141
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• 2000

A causal fungus of turfgrass blight was isolated from the infected leaves of zoysiagrass (Zoysia japonica Steud.) and identified as Nigrospora sphaerica (Sacc.) Mason by using a light misroscope. Its conidia are large (14-20 ${\mu}{\textrm}{m}$ diameter), shiny, black, aseptate, and smooth-walled spheres. The fungus caused typical blighting symptoms on the two turfgrass plants of bermudagrass (Cynodon dactylon (L.) Pers.) and bentgrass (Agrostis palustris Huds.). The fungus was found to produce a phytotoxic subtance to be associated with the pathogenic mechanism. A phytotoxin was isolated from the liquid cultures of N. sphaerica by repeated silica gel column chromatography and its structure was determined to be 5, 6-dihydro-5-hydroxy-6-propenyl-2H-pyr-2-one (T-3 compound). It was not a host-specific toxin showing phytotoxic effects to various plants inclusing turfgrasses in the leaf-wounding assay, the whole plant test, and the cellular leakage test. The compound caused leaf tip dieback symptoms in turfgrass plants similar to those caused by the pathogen. Thus, T-3 compound is thought to be involved in the development of Nigrospora blight.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.383-395
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• 2016

This study investigated the effect of exogenous hydrogen peroxide ($H_2O_2$) on the antioxidant responses and growth of warm-season turfgrass (Zoysia japonica Steud.) and cool-season turfgrass (Poa pratensis L.) subjected to drought stress. Compared with control plants that were not pretreated with $H_2O_2$, plants pretreated with $H_2O_2$ had significantly greater fresh and dry weights of shoots and roots, and increased water content. $H_2O_2$ pretreatments before drought stress significantly decreased the concentrations of malondialdehyde and $H_2O_2$. DPPH radical scavenging and glutathione activities were significantly increased. The responsive activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase were also significantly enhanced. Our results suggest that exogenous $H_2O_2$ could improve the growth of warm-season and cool-season turfgrass under drought stress by increasing the activity of their antioxidant enzymes, while decreasing lipid peroxidation.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.161-175
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• 2005

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.95-99
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• 2013

To investigate the actual condition of production and management of sod, a questionnaire was ask to 57 farmers in major cultivated areas of turf sod in Korea in 2010 and 2011. The results of the turfgrass management situation analysis showed a mixed farming where the ratio of the principal work and the side work progress similarly, and for the landholding type depending on the management scale, the rental ratio was high for a scale over 0.5 ha. Sod production farmers has high-profile in new varieties of turfgrass, integrated management of the fertilization and soil or disease and insect pest however the future of the turfgrass industry does not seem optimistic due to the problems such as market stability or scarcity of worker. Obtaining of information on culture methods depended neighbor's experience (81.8%). Concerning the varieties preference analysis, the 32.1% of farmer answered that the reproductive rate was a key factor for the new variety. Sod production farmers want to receive financial support (28.1%), improvement of distribution structure of sod (26.6%), and spread of good variety turfgrass (23.4%).

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.322-332
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• 2017

Microbial fertilizer has been used to prompt turfgrass growth and quality and to prevent turfgrass diseases in turfgrass management of golf courses. This study was conducted to evaluate effects of microbial fertilizer containing Lactobacillus fermentum (MFcL) on changes of turfgrass quality and growth by investigating turf color index, chlorophyll index, clipping yield, and nutrient content in the turfgrass tissue. Treatments were designed as follows; non-fertilizer (NF), control fertilizer (CF), MFcL treatments [CF+$1.0g\;m^{-2}$(MFL), CF+$2.0g\;m^{-2}$ (2MFL)], and only MFcL treatment (OMF; $1.0g\;m^{-2}$ MFL). Chemical properties of soil by application of MFcL was unaffected. Turf color index, chlorophyll index, clipping yield and nutrient content and uptake of MFcL treatments were similar to CF. Furthermore, turfgrass shoot density of MFL was increased by 20% than that of CF, and that of OMF by 22% than NF. These results show that the application of microbial fertilizer containing L. fermentum increased turfgrass shoot density, which is not attributed to nutrient uptake in this study, but needs to be further investigated with other mechanisms such as biostimulant induction or phytohormone production.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.121-129
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• 2014

We investigated turfgrass diseases and inoculum density at nationwide turfgrass cultivation sites in year of 2013. Occurrences of large patch and rust disease appeared in September. Brown patch recorded in September to October at Namhea and Pythium blight disease occurred outbreaks in early July at Namhea site. Some sites in Namhea damaged 3% area of total cultivation field by Sclerotinia homoeocarp. In Daepyeong (Gyeongnam), Fairy ring and large patch were recorded. Severe takeall and fairy ring have been observed in Gochang-si. Multi-site in Cheongju-si, brown patch was observed in pandemic level. Interesting enough, a cool-season turfgrass cultivate sites in Pyeongtaek-si brown patch, leaf blast, summer patch, and Curvularia leaf spot were investigated during the surveys period. Inoculum densities (Rhizoctonia spp.) at turfgrass cultivations sites were increased as cumulatively in all survey sites. The investigation result indicated that the disease occurrence and pathogens are similar as diseases in golf courses.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.141-148
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• 2008

This study was conducted to investigate nutrient content at shoot and root(contained runner in zoysiagrass) in creeping bentgrass, kentucky bluegrass and zoysiagrass before turfgrass dormancy. The shoot ratio of dry weight in creeping bentgrass, kentucky bluegrass and zoysiagrass was 12%, 27% and 25% and root ratio was 88%, 73% and 75%, respectively. The orders of nutrients contained in turf-grass were N>K>Ca>P>Mg>Na in plant tissues. The proportion of nutrients in tissue of creeping bentgrass, kentucky bluegrass and zoysiagrass was 17%, 28% and 34% in shoot and 83%, 72% and 66% in root, respectively. These results showed that nutrients in turf-grass tissue was contained more than 70% in root before grasses dormancy. In turf grass management, all grasses were required to fertilize sufficiently N, $K_2O$, CaO and $P_2O_5$ before winter.