ARS | Publication request: Depth at which Rhizoctonia solani causes infection fo sugar beet

Submitted to: American Physical Society
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2010
Publication Date: June 1, 2010
Citation: Desouza, S., Bolton, M.D., Khan, M.F. 2010. Depth at which Rhizoctonia solani causes infection of sugar beet [abstract.] American Physical Society North Central Division. p. 20.

Technical Abstract: Rhizoctonia solani (Kuhn) is the causal agent of Rhizoctonia root rot of sugar beet (Beta vulgaris L.). Typically, Rhizoctonia root rot symptoms appear to be initiated on the plant at the soil line. Recently, sugar beet plants were observed with Rhizoctonia root rot infections close to the root tips and R. solani AG 2-2 IIIB was identified as the causal agent. There were concerns that AG 2-2 IIIB may be causing infections lower on the roots which may make fungicide control difficult. Our objective was to dertermine the depth which is most favorable for infection. Plants were inoculated at the four-leaf stage using two grain of barley inoculated with R. solani AG 2-2 IIIB. Inoculum was buried at 2.54, 7.62, and 12.70 cm depth. Plants were rated for root rot disease severity using the 0-7 rating scale fourteen days after inoculation. Results indicated that infections by R. solani AG 2-2 IIIB occurred at all depths. However, R. solani appears to favor the area on the roots just below the soil line irrespective of the depth placement.