Source of downy mildew (Plasmopara obducens) infections on Impatiens

HDC project PC230 (completed 2009) comprised research to investigate the biology and control of impatiens downy mildew with the aim of developing Good Practice Guidelines to assist growers in implementing effective disease management strategies.  Considerable progress in understanding of the epidemiology of the pathogen and confirmation of the conditions required for host infection was achieved within the latter stages of this project.  The techniques developed now allow investigations to be undertaken into the main sources of inoculum for host infection and disease spread, a key aspect of the epidemiology not elucidated in PC 230.  The aim of this project is to determine potential sources of downy mildew infections caused by Plasmopara obducens on impatiens crops.