Utilizing organic amendments for general suppression of dollar spot on creeping bentgrass turf

Dollar spot (Clarireedia spp.) negatively impacts the aesthetic value and playability of golf course fairways. A 2-yr field trial was conducted to examine organic amendment effect on dollar severity fungicide residual efficacy for control creeping bentgrass (Agrostis stolonifera L. ‘007’). Treatments were arranged in a 7 × 5 split-plot factorial measuring fertilizer source (soil incorporated biosolids compost, soil biochar, surface applied vermicompost extract, standard fertilizer, or non-treated) by five treatments (fluazinam 14 d, fluxapyroxad fluazinam threshold, none) at product label rates. Nitrogen fertility levels all standardized ∼205 kg N ha–1 annually. Threshold when three more infection centers per area counted two four replicates. In 2017, significantly effective reducing disease than non-treated, but statistically similar. 2018, vermicompost, compost non-treated. Fungicides controlled every d. reduced number threshold sprays compared none, yet same effects not consistently observed 2018. Study results illustrate effectiveness nitrogen application mitigating during establishment no potentially allowing use disease.