Papaw root rot caused by Phytophthora palmivora Butl.

Abstract

A severe root rot of papaw (Carica papaya Gaertn.) in Queensland is caused by Phytophthora palmivora Butl. Waterlogging is an important predisposing factor in the occurrence of the disease. In the Brisbane area, soil temperatures are favourable for growth and sporulation of P. palmivora, except during June, July and August. Field evidence suggests that crop rotation reduces the severity of attack. P. palmivora isolated from roots proved capable of rotting green papaw fruit, but a similar fruit rot has not been found naturally in Queensland.