Incorporating Organic Tools in Conventional Management Systems for Golf Course Fairways in the Mid-Atlantic.

Biological pesticides are generating increased interest from turfgrass managers who are exploring alternatives to conventional pesticides. Biofungicides are not commonplace in modern turfgrass management programs, as many superintendents question their efficacy and place in a conventional program. To address these concerns and further our understanding of currently available biofungicides, a study was initiated in Derwood, MD to evaluate available biofungicides when used in rotational programs and when combined with additional management tools (i.e., organic fertility) in a sustained IPM program. Our two year, 2 x 4 factorial study evaluated fertilizer source [Fish meal based (Organic) vs Sulfur Coated Urea (Synthetic)] and fungicide source [conventional fungicides (conventional) vs biofungicides (organic) vs alternated conventional and biological fungicides (hybrid), and none] as factors in dollar spot (Sclerotinia homeocarpa F.T. Bennett) and grey leaf spot [Magnaporthe grisea (T.T. Hebert) Yaegashi & Udagawa] control on perennial ryegrass (Lolium perenne L.) maintained as a golf course fairway. Turfgrass was visually rated for disease development and quality throughout each growing season. In the first year of the study, fertility treatments did not impact foliar disease when comparing area under disease progress curve (AUDPC) values. In the second year of the study, plots receiving synthetic fertility had significantly lower AUDPC values when compared to organic fertility. In both years of the study, disease control programs significantly impacted disease development. The conventional and hybrid programs reduced incidence of both pathogens compared to organic and none treatments while producing higher turf quality regardless of fertilizer source. Results support incorporation of organic pesticides into conventional programs as a viable option for extending application intervals on turfgrass fairways.