Inhibition of in Vitro Growth of Three Soil-borne Turfgrass Diseases by Antagonistic Bacteria from Composted Liquid Manure

This study was conducted to test in vitro the antagonistic effect of composted liquid manure (CLM) against soil-borne turfgrass pathogenic fungi, Rhizoctonia solani AG-2-2 (IIIB) (brown patch), R. solani AG-2-2 (IV) (large patch), and Sclerotinia homoeocarpa (dollar spot) for environmentally friendly turfgrass management. CLMs were collected from 9 livestock excretion treatment facilities around the country including Gunwi (GW), Hapcheon (HC), Hoengseong (HS), Icheon (IC), Iksan (IS), Muan (MA), Nonsan (NS), and Yeoju (YJ). CLMs of IC, GW, and IS showed significant (p < 0.05) mycelium growth inhibition that was 17.8%, 20.4%, and 48.0% against R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. A total of 110 bacterial isolates were obtained from the CLMs that showed antagonistic effects. Among them, 5, 4, and 10 microbe isolates showed promising antifungal activity against mycelium growth of R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. The bacterial isolates ICIIIB60, GWIV70, and ISSH20 effectively inhibited the mycelial growth of three soil-borne turfgrass pathogens. Selected bacterial isolates were identified as Alcaligenes sp., Bacillus licheniformis Ab2, and B. subtilis C7-3 through 16s rDNA gene sequence analysis. Among 5 fungicides, the most compatible fungicide with ICIIIB60, GWIV70, and ISSH20 was tebuconazol, toclofos-methyl and toclofos-methyl, respectively. These findings suggested that CLMs could be effectively used not only as organic liquid fertilizer sources but also as biological control agents for soil-borne turfgrass diseases such as brown patch, large patch, and dollar spot. Additional key words: Alcaligenes, Bacillus, brown patch, dollar spot, integrated pest management (IPM), large patch *Corresponding author: kisun@snu.ac.kr ※ Received 9 May 2014; Revised 23 July 2014; Accepted 2 August 2014. 2013 (No: PJ008456032013) . C 2014 Korean Society for Horticultural Science Rhizoctonia Pythium, Fusarium, Sclerotinia . Rhizoctonia large patch R. solani AG2-2(IV) brown patch R. solani AG2-2(III-B) . Sclerotinia dollar spot S. homoeocarpa , , (Shim and Kim, 2000). Kor. J. Hort. Sci. Technol. 32(6), December 2014 880 Fig. 1. Location of public livestock excretions treatment facilities for this study. , , (Lee et al., 1998). . , (Shim and Kim, 2000). , , , , . , . , (Garling and Boehm, 2001), 20-30% (Cheng et al., 2008), (Enterobacter cloacea) dollar spot (Boulter et al., 2002; Nelson and Craft, 1991). Brown patch 42% 39% (Nelson and Boehm, 2002), large patch 47% (Nakasaki et al., 1998). . SCB , , (Kim et al., 2011; Lim et al., 2008; Park et al., 2011; Seo et al., 2010), (Ham et al., 2009, 2010; Kang et al., 2010; Park et al., 2012), SCB (Kim et al., 2012) SCB (Lim et al., 2011) , . , (Boulter et al., 2002). , , (Liu and Baker, 1980; Moody and Gindrat, 1977; Ruppel et al., 1983; Tu, 1980). , brown patch large patch, dollar spot , (integrated pest management, IPM) .