Occurrence of Pythium root rot of Eustoma grandiflorum caused by Pythium irregulare and P. spinosum in Kanto District and its chemical control

Abstract

Two Pythium species were isolated from rotted secondary roots of collapsed plants of Eustoma grandiflorum during 1987-1992 in Kanto district and identified as P. irregulare and P. spinosum. An inoculation experiment showed that the fungi were the causal agents of the disease. Granular applications of metalaxyl were significantly effective for control of the disease. Soil drenches of benomyl, captan or hymexazol did not reduced the damage.