Brown girdling root rot as a potential threat to canola production in North Dakota

• Published in: Phytopathology 2010-06, Vol.100 (6), p.S89-S89
• Main Authors: Nepal, A, del Rio Mendoza, LE
• Format: Article
• Language: English
• Subjects: Rhizoctonia solani
• ISSN: 0031-949X

Rhizoctonia solani was observed causing brown girdling root rot of canola plants in research plots in Langdon, ND in 2008 and 2009. Since R. solani is known to cause important yield reductions in other canola producing areas of the world, a study was conducted to assess the potential threat this pathogen represents to the canola industry in ND. To evaluate the protection provided by conventional seed treatment, seeds from four commercial canola cultivars were washed in running water to eliminate the chemicals from the seeds. Washed and non-washed seeds were planted in replicated trials in greenhouse soil mix infested or not with canola seeds colonized by an R. solani AG 4 isolate. Pots were maintained at 21C and 14 hours light daily. Germination and plant standing were quantified 14 and 20 days after planting, respectively. The experiment was repeated once. The seed treatment did not increase germination nor plant standing significantly (a = 0.05). Germination and plant standing were reduced from 90 to 70% and from 87 to 57%, respectively, when seeds were planted in R. solani-infested soils. Cultivars IX08-7121R and Hyclass 712 had significantly less germination (mean of 64%) than cultivars DKL30-42 and G75449 (mean of 77%). To get a better estimate of the potential impact of this disease on the canola industry in North Dakota, a larger study involving 59 commercial cultivars and R. solani isolates from three AG groups (4, 2-1, and 2-2) is under way.