Pathogenicity and Management of Olpidium bornovanus, a Root Pathogen of Melons

Abstract

Greenhouse studies document, for the first time, that Olpidium bornovanus, an obligate, holocarpic, root-inhabiting zoosporic fungus heretofore regarded as a nonpathogenic parasite, is a root pathogen. Significant browning of the roots and reductions in shoot and root growth were recorded within 28 days following inoculation of melons with the fungus. Amending the recirculating nutrient solution with either a nonionic surfactant (Agral 90) or a strobilurin fungicide (azoxystrobin) resulted in efficacious management of the disease caused by the fungus.