Disease reaction to Rhizoctonia solani and yield losses in soybean

• Published in: Canadian journal of plant science Vol. 98; no. 1; pp. 115 - 124
• Main Authors: Chang, K.F, Hwang, S.F, Ahmed, H.U, Strelkov, S.E, Harding, M.W, Conner, R.L, McLaren, D.L, Gossen, B.D, Turnbull, G.D
• Format: Journal Article
• Language: English
• Published: Ottawa Canadian Science Publishing 01-02-2018; Canadian Science Publishing NRC Research Press
• Subjects: baisse de rendement; fonte des semis; Genotypes; Glycine max; Inoculation; Inoculum; Nodulation; Plant sciences; resistance; Rhizoctonia solani; Root rot; résistance; Seedling blight; Seedlings; soja; soybean; Soybeans; Variation; yield loss
• ISSN: 0008-4220; 1918-1833
• DOI: 10.1139/cjps-2017-0053

Seedling blight and root rot caused by Rhizoctonia solani Kühn are important constraints to the expansion of soybean [Glycine max (L.) Merr.] production in Alberta, Canada. The reaction of 21 soybean genotypes to R. solani was assessed in inoculated field trials in Alberta in 2014–2016. Inoculation with R. solani resulted in a significant reduction in stand, nodulation, and yield and a significant increase in root rot severity for all of the soybean genotypes. The genotype P001T34R had lower reductions in stand establishment compared with NSC Portage RR, TH29002RR, TH27005RR, or LS003R22 and there were inconsistent variations in yield loss among the genotypes in two of the three site–years. No significant variation in disease severity or nodulation was observed among the genotypes. Stability analysis showed the soybean genotypes P001T34R, 23-60RY, NSC VitoRR, and NSC TilstonRR2Y had higher and more stable stand establishment, while 900Y01, 23-60RY, P001T34R, and P002T04R had higher and more stable seed yield in comparison with the other genotypes in this study. The study also revealed that R. solani caused a loss of 48% in stand establishment and 52% in seed yield. Root rot severity ranged from 0.38 to 2.36 on a scale of 0–4 among the genotypes but was not consistent over the trials. Root rot severity and yield loss increased with increasing inoculum density, while stand establishment, nodulation, and seed yield declined. Regression analysis showed that stand establishment, nodulation, and yield were strongly positively correlated but strongly negatively correlated with root rot severity.