Gossen, B.D.Bailey, K.L.Derksen, D.A.Watson, P.R.2018-09-022018-09-022000-02-22http://hdl.handle.net/10388/9916The current trend towards reduced tillage practices was expected to increase losses due to plant disease relative to conventional tillage; increased diversity in crop rotation was expected to reduce these losses. To test these widely-accepted hypotheses, diseases (incidence and severity) were monitored on spring wheat, lentil, and field pea grown in diverse crop rotations under zero and conventional tillage at Indian Head, SK from 1992-1995. Crop rotation and tillage practice had little effect on lentil diseases, but epidemics of Ascochyta blight [Ascochyta lentis] and botrytis blight [Botrytis cinerea] were most severe in the treatments with the densest plant stands. Leaf disease severity on wheat grown under zero tillage did not differ from wheat under conventional tillage, but root disease severity was lower. The importance of individual root pathogens of wheat changed under zero tillage, with Fusarium spp. increasing while Bipolaris sorokiniana decreased. Rotation did not affect disease severity or the incidence of pathogens causing root disease. However, leaf disease severity on spring wheat was slightly higher in the most diverse rotation than in two other diverse rotations. Regardless of the tillage or crop rotation practices used, the annual environment was the most important factor limiting the severity of disease and the losses incurred.enAttribution-NonCommercial-NoDerivs 2.5 CanadaPresentation