Forage, Pasture Health Don’t let your pasture rust. Fight Puccinia. Franz Lichtner October 20, 2014 Have you noticed an orange or rusty look on the grasses in your pastures? It’s not grass changing colors for the fall. It’s actually a fungal pathogen called "Puccinia," also known as "rust." All the grazing management tips you need Subscribe to read this article and over 2,500 more! Subscribe today! If you're already a subscriber, log in here.