Back R. J. Kremer1,2, E. H. Ervin3, M. T. Wood2,4 and D. Abuchar3
US Department of Agriculture, Agriculture Research Service1,
Department of Soil & Atmospheric Service2,
Department of Horticulture, Turfgrass Research Center3, University of Missouri and
Sustainable Community Development, Columbia, Missouri, USA4
Full Paper (PDF File: 101KB)
Abstract
Different species of turfgrass are widely used worldwide for golf courses, athletic fields, and landscaping. Sclerotinia homoeocarpa [(Lib.) Korf & Dumonf], causal agent of "dollar spot," is considered the most prevalent turfgrass pathogen in North America Fungicides are a major input for controlling this disease. To evaluate effective alternative control approaches, research was conducted to (i) determine effects of Effective Microorganisms (EM) on growth and development of S. homoeocarpa in bioassays and (ii) effects of EM on disease development by S. homoeocarpa in turfgrass and turf quality.
A laboratory bioassay (in vitro) was conducted on S. homoeocarpa isolated from various turfgrass species using EM on potato dextrose agar (PDA). For the greenhouse study (in vivo), standard golf course soil substrate was amended with various rates of EM Bokashi made with local organic wastes. The fungus, cultures on autoclaved millet seeds, was inoculated into golf course substrates in pots four weeks after seeding with Penncross creeping bentgrass. Developing turfgrass was evaluated for disease infection and turf quality (disease rating). Laboratory results showed that EM amended in PDA at 1.0 and 4.0% significantly inhibited hyphal growth of S. homoeocarpa. In the greenhouse study, the EM Bokashi treatments had significantly less disease during the 3 week period than the standard golf green substrate. Increased turf quality was observed with increasing EM Bokashi concentration. Results suggest that EM cultures can potentially inhibit in vivo S. homoeocarpa growth. Further investigations into potential beneficial uses may lead to adaptation of biologically based technology such as EM to develop more sustainable environmental systems.