Control of root rot of peppers caused by Phytophthora capsici with a nonionic surfactant

Motile zoospores were identified as the sole infectious propagule of Phytophthora capsici responsible for spread of the pathogen in a recirculating rock wool cultural system.Amending the nutrient solution with a nonionic surfactant resulted in the elimination of zoospores 100% control of the spread of the root pathogen from a point source.In the absence of the surfactant all of the pepper plants within the cultural system irrespective of plant age died within 2 weeks following hypocotyl-inoculation of a single plant which served as the source of secondary inoculum. The potential significance of surfactants for the control of polycyclic soilborne diseases attributed to Phytophthora spp.other zoosporic pathogens is discussed.