Marie-Eve Bérubé and
Anne Vanasse, Département de phytologie, Université Laval, Québec, Québec, G1V 0A6, Canada;
Sylvie Rioux, and
Nicole Bourget, Centre de recherche sur les grains, Québec, Québec, G1P 3W8, Canada; and
Yves Dion and
Gilles Tremblay, Centre de recherche sur les grains, Saint-Mathieu-de-Beloeil, Québec, J3G 0E2, Canada
Fusarium head blight (FHB) is a serious disease in the wet conditions of eastern Canada. Tillage practices and herbicide applications have been reported to influence disease intensity. This study aimed to determine the effect of glyphosate on FHB development in wheat and barley and on Fusarium graminearum inoculum production under different soil tillages. The experiment was performed during 2 years (2007 and 2008) at two different sites in Quebec, Canada. Six trials were set in both sites, combining two cereal species (wheat and barley) and three soil tillages: moldboard plow, spring tillage (minimum-till), and direct drilling. For each trial, glyphosate or other herbicides were applied on Roundup Ready soybean the year preceding cereal crops, constituting the main plots. The next year, three wheat and three barley cultivars were sown as subplots. FHB index, Fusarium-damaged kernels (FDK), deoxynivalenol (DON) content, and F. graminearum inoculum production were measured. Glyphosate had no significant effect on FHB index, FDK, or DON content, whatever the trial and the site. F. graminearum inoculum production was enhanced by glyphosate in only 1 of 12 trials. Cultivar effect was highly significant on DON content. The relationship between F. graminearum inoculum from soybean residues and DON content was weak.