Chrysanthemum white rust in diameter, but may turn brown as the tissue becomes necrotic. On the underside of the leaf, the spots develop into pink or white pustules that become prominent as the teliospores develop. Chrysanthemum white rust Chrysanthemum white rust is a disease of plants caused by the fungus Puccinia horiana that infects species of the genus "Chrysanthemum". Chrysanthemum white rust was first identified in Japan, although it is now established throughout Asia, Europe, South America. It has been found in the United States, Australia, and New Zealand on several occasions, but early detection and eradication efforts have prevented the disease from
After-rust After-rust After-rust is a form of rust which sometimes develops on a non-ferrous metal surface when that surface has been finished, deburred, or cleaned with a carbon steel brush or steel wool. It is caused by microscopic deposits of the steel which become embedded in the metal surface and which over time begin to oxidize. This oxidation causes the surface to become dull and may impart a brown color to it. After-rust can be avoided by cleaning such surfaces only with non-ferrous brushes/ wools including rustless bronze, aluminum, and stainless steel wool and nonferrous wools such as those made of