Extended survival of Puccinia graminis f. sp tritici urediniospores: implications for biosecurity and on-farm management

Puccinia graminis f. sp. tritici (Pgt), the causal organism of stem rust, is of global importance across wheat-growing countries. However, some epidemics commence without the obvious presence of alternate' or green bridge' hosts, suggesting urediniospores can survive in the absence of suitable host plants for many weeks. Testing a range of inert material types, including metals, plastics, fabrics and woods, highlighted a significant effect of material type and temperature on urediniospore viability (P