white rust

White rust is a plant disease caused by funguslike organisms called oomycetes, specifically those in the genus Albugo. This disease affects many herbaceous plants, causing light yellow areas on leaves and chalky-white, waxy pustules that eventually darken on the underside of leaves and other aboveground parts. Symptoms can include wilting leaves, swollen stems and flower parts, and stunted growth.1

Control methods for white rust are similar to those used for true fungal rusts and include planting resistant varieties, destroying alternate host plants, maintaining sanitation, and using appropriate fungicides. It is important to distinguish this plant disease from the corrosion of metals, which is a chemical process.12