Fire is common in tallgrass prairie, but in this study at Konza Prairie Biological Station rust infection is still reduced by it.
Dendy, S. P., B. Tong, H. A. Alexander, P. A. Fay, L. Murray, Y. Xing, and K. A. Garrett. 2017. A long-term study of burning effects on a plant pathogen in tallgrass prairie. Plant Pathology 66:1308-1317. [link]