Stem rot: A disease of cowpeas caused by an undescribed species of Phytophthora

Abstract

A stem rot disease of cowpeas which is the cause of serious losses in Queensland is described. A species of Phytophthora is shown to be the causal agent and is described in detail. The name Phytophthora vignae n. sp. is proposed. Field observations show that the disease is soil-borne and that there is a build-up of the pathogen in the soil as a result of growing successive crops of susceptible varieties.