The impact of row spacing, seeding rate, and fungicide timing on leaf disease and fusarium damaged kernel severity, deoxynivalenol, and productivity of spring wheat
T.K. Turkington, H. Klein-Gebbinck, K. Xi, B. Beres, R. Aboukhaddour, Prabhath Lokuruge, A. Mulenga, G. Peng, W. May, R. Mohr, G. Telmosse, D. Pageau, A. Foster, B. Blackwell, H. Kubota, B. Tidemann, and G. Semach. 2021. The impact of row spacing, seeding rate, and fungicide timing on leaf disease and fusarium damaged kernel severity, deoxynivalenol, and productivity of spring wheat. Proceedings of the 2021 National Fusarium Head Blight Forum, December 6-7, 2021. Page 30.
Plain language summary
Fusarium head blight of wheat, caused by the fungus Fusarium graminearum is a serious disease issue faced by Canadian wheat producers. Research was conducted in 2019 on spring wheat at seven research sites across Canada. The impact of row spacing, seeding rate and fungicide timing were evaluated. Fungicide timing impacted fusarium damaged kernel severity at three sites and mycotoxin (deoxynivalenol) levels at one site. Overall, FDK and DON levels were generally lowest for the dual fungicide application treatment, intermediate for single early or late applications and highest for the check no fungicide applied. Although dual post-head emergence applications did positively impact some parameters this treatment may be less economical, while also not being registered for use in Canada.
he impact of row spacing, seeding rate, and fungicide timing were assessed at seven Canadian spring wheat sites in 2019. Narrow and wide row spacings (RS) were only set up at four sites. Seeding rates (SR) of 200 and 400 seeds m-2 were used, while fungicide (Prosaro XTR) timings included: check no treatment; at the start of anthesis (early); a late application date 7-10 days after the start of anthesis (late); and a dual early and late application. Leaf spot levels were low at four sites, while low to moderate levels occurred at the remaining three sites. Overall in 2019, RS and its interaction with other factors generally had limited impacts on disease, crop productivity and kernel quality. Seeding rate and fungicide tended to have the most frequent impacts on leaf disease and crop productivity. Higher seeding rates (SR) at two of seven sites increased leaf spot severity. Seeding rate also impacted yield, and thousand kernel weight (TKW) at four and three sites, respectively. Yield was increased with increased SR at three sites and decreased at one site. By increasing the seeding rate TKW was decreased at two sites, but increased at the other. In 2019, fungicide timing impacted leaf disease and yield at three and two sites, respectively. Here the lowest leaf disease levels were similar for all fungicide treatments, while the highest yields occurred for early and dual applications. Fusarium damaged kernel severity was decreased by the increased seeding rate at one site only. Elevated deoxynivalenol (DON) levels only occurred at one site and were significantly impacted by RS, the interaction of RS and SR, and fungicide timing. At this one site DON was decreased with increased RS and SR, although there was an interaction whereby SR differences were only significant for the narrow RS. These observed impacts were likely due to more head emergence variability and perhaps a wider window for infection. Fungicide timing impacted fusarium damaged kernel severity at three sites and DON levels at one site. Overall, FDK and DON levels were generally lowest for the dual application treatment, intermediate for single early or late applications and highest for the check. Although dual post-head emergence applications did impact some parameters this treatment may be less economical, while also not being registered for use in Canada. The funding of the Canadian Agricultural Partnership Canadian National Wheat Cluster and Prairie producer/industry groups is graciously acknowledged.