Management of Root Rot of Soybean in Alberta with Fungicide Seed Treatments and Genetic Resistance

Root rot, caused by Fusarium spp. is prevalent in soybean crops in Alberta, Canada. To mitigate the risk to soybean crops caused by Fusarium spp., nine seed-treatment fungicide formulations were assessed for their efficacy in promoting seedling survival, reducing root rot symptoms and maintaining yield. Twelve soybean varieties were also assessed for resistance to seedling blight and tolerance to Fusarium root rot. All treatments except Vibrance + Apron XL improved emergence. All the fungicide formulations reduced root rot severity on Fusarium-inoculated soybean seedlings under field conditions and all treatments except Vibrance + Apron XL reduced root rot under greenhouse conditions. Among the varieties, ‘90M01’ showed lower reductions in emergence than all others except ‘900Y61’ and ‘900Y81’ under field conditions and emergence losses for ‘900Y71’ were greater than all other varieties. ‘LS003RR’ had a lower disease severity rating compared with ‘TH32004R2Y’, ‘27005RR’ and ‘900Y71’. NSC Portage had a higher nodulation rating compared with all other varieties except ‘90M01’. Yield losses were consistently low for ‘TH32004R2Y’ and ‘900Y71’. Under greenhouse conditions, ‘900Y81’ had lower seedling losses compared with all other varieties except Tundra and OAC Prudence. 900Y71 had a greater loss of emergence than all other varieties except NSC Portage and ‘LS005RR’. ‘900Y81’, ‘OAC Prudence’ and ‘Tundra’ had lower disease severity compared with all other varieties except ‘TH27005RR’ and ‘900Y61’. Shoot length and dry mass were lower for ‘900Y81’ compared with all other varieties, while root dry mass was lower for ‘OAC Prudence compared with ‘LS005RR, ‘90M01, ‘TH29002RR’ and ‘LS003RR’.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author