%0 Journal Article %T Host Range and Virulence of a Fungal Pathogen for Control of Giant Salvinia (<i>Salvinia molesta</i>) %A Clyde D. Boyette %A Robert E. Hoagland %A Lawrence R. Higgenbotham %A H. Lynn Walker %A James A. Young %A Kenneth C. Stetina %J American Journal of Plant Sciences %P 444-454 %@ 2158-2750 %D 2021 %I Scientific Research Publishing %R 10.4236/ajps.2021.123029 %X A teleomorph of the fungus Botryosphaeria rhodina (Berkeley et Curtis) von Arx, (Br) was evaluated as a bioherbicide for control of giant salvinia (Salvinia molesta D.S. Mitchell) under greenhouse conditions and in small-scale field trials. We found that fungal mycelium was highly infective and could be rapidly produced (48+ h) in soy flour-cornmeal liquid media contained in shake flasks or fermenters. A dew period was not required to achieve infection and mortality of inoculated plants. A surfactant (Silwet L-77, a polyalkyleneoxide modified heptamethyl-trisiloxane) incorporated in the fungal formulation was required for Br to infect and kill plants. Infection and mortality occurred rapidly (within 48 h after treatment), and re-growth of treated plants did not occur. In replicated field trials, Br controlled giant salvinia ~95%. Br also infected other plants, such as common salvinia (S. minima Baker), and Azolla filiculoides Lam., as determined in ongoing host range research. However, no symptomatology was