Professor The Ohio State University Columbus, Ohio, United States
Abstract Text: Soilborne diseases are a major limitation to soil-grown cut flowers as they are challenging to manage, especially when adhering to sustainable farming practices. Anaerobic soil disinfestation (ASD) has been investigated over the last two decades as a sustainable soilborne disease management tool, mostly in vegetable crop production,but minimal testing has been conducted in ornamental crop systems. We explored the effectiveness of ASD in reducing disease in cut flower production using the Pythium root rot (P. sylvaticum) on ranunculus (R. asiaticus) model system.Topsoil was amended with a Pythium-colonized vermiculite mixtureat a rate of 17kg/m3and one of six carbon amendments (molasses, wheat midds, tomato pomace, compost, distillers dried grains, and spent mushroom substrate) at a rate of 2.02 kg/m2. Soil was saturated with water andsealed, then incubated for 4 weeks at 25° C in a RCBD.Unamended aerobic and anaerobic treatments were included as controls. Following incubation, 3-month-old ranunculus plugs were transplanted into soil. Incidence and severity of aboveground symptoms were significantly reduced in the molasses and wheat midds treatments compared to the anaerobic control. In run two, root rot severity was significantly reduced in the molasses and wheat midds treatmentscompared to both controls, whereas no differences between treatments were observed in run one. This study provides us with important information that is both immediately beneficial to growers andhelps inform the next phases of ASD research in different cut flowerpathosystems.
