Abstract

Podosphaera balsaminae was recorded for the first time in Argentina and apparently in the Americas, causing powdery mildew on Impatiens balsamina (balsam) and Impatiens × hawkeri (New Guinea impatiens). This is also the first record of P. balsaminae on New Guinea impatiens. In a preliminary test, results of cross inoculations suggest that a pathogenic specialisation of P. balsaminae for these two hosts is present.