Impact of crop management systems on diseases of spring wheat on the canadian prairies

Fusarium spp. (Fspp.) associated with crown/root rot of wheat are also responsible for Fusarium head blight (FHB), a disease of increasing importance on the Canadian Prairies. This study showed that tillage/input level (organic [01], reduced [RI] or high [Hl]) had a greater impact on common root rot (CRR) than cropping diversity (low diversity, diversified with annual grains, or diversified with annual grains/forage). Levels of CRR and Cochliobolus sativus were highest for 01 and HI, and lowest for RI. Higher disease levels were also observed under low cropping diversity where the frequency of cereals and fallow was highest. Fspp. were more common in 01 and RI than Hl, and in the more diverse systems, although the nature of these associations varied with the species. F. avenaceum and F. culmorum, two of the main crown/root rot and FHB pathogens, were most associated with RI systems and/or continuous diversified grain rotations, and least associated with 01 systems. Further work on crop management effects on Fusarium populations in wheat is warranted considering the increased development of important diseases caused by Fspp. in western Canada