college of agricultural sciences

Stewart Lab - Pathogenic Fungi on Trees

The Stewart Tree Pathology Laboratory studies forest, shade and orchard tree pathology, with research spanning from molecular studies to applied biology. Our work focuses on understanding the fungi and other microorganisms that impact tree health, from canker and root diseases to needle casts and rusts, across forest, orchard, and urban tree systems.

Using tools ranging from population genomics and phylogenetics to amplicon sequencing and molecular diagnostics, we investigate the biology, evolution, and management of tree pathogens including Cytospora, Fusarium, Armillaria, Lophodermella, and Cronartium ribicola (white pine blister rust), among others. Our research also extends to the broader microbial communities associated with tree health, examining how soil and endophytic microbiomes shift in response to disease, fire, and reforestation efforts.

By combining foundational research with applied, field-based approaches, we aim to directly inform disease management and supports the long-term health of forest and orchard systems across Colorado and beyond.