Management of root rot of soybean in Alberta with fungicide seed treatments and genetic resistance

• Published in: Canadian Journal of Plant Science
• Main Authors: R. Nyandoro, K.F. Chang, S.F. Hwang, H.U. Ahmed, G.D. Turnbull, S.E. Strelkov
• Format: Text
• Language: English
• Published: Canadian Science Publishing 2019
• Subjects: Canada; Tundra
• Online Access: https://doi.org/10.1139/cjps-2018-0266

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 the 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 the other varieties except ‘90M01’. Yield losses were consistently low for ‘TH32004R2Y’ and ‘900Y71’. Under greenhouse conditions, ‘900Y81’ had lower seedling losses compared with all the other varieties except ‘Tundra’ and ‘OAC Prudence’. ‘900Y71’ had a greater loss of emergence than all the other varieties except ‘NSC Portage’ and ‘LS005RR’. ‘900Y81’, ‘OAC Prudence’, and ‘Tundra’ had lower disease severity compared with all the other varieties except ‘TH27005RR’ and ‘900Y61’. Shoot length and dry mass were lower for ‘900Y81’ compared with all the other varieties, while root dry mass was lower for ‘OAC Prudence’ compared with ‘LS005RR’, ‘90M01’, ‘TH29002RR’, and ‘LS003RR’.