Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2000
Publication Date: N/A
Technical Abstract: Rhizoctonia root and crown rot of soybean, caused by Rhizoctonia solani, can be a problem wherever soybean is grown, and there are no known commercial soybean cultivars released for resistance. Seven hundred soybean cultivars were evaluated for resistance to Rhizoctonia solani (root and crown rot) in the greenhouse. Cultivars were planted into trays containing a 2:1 sand:soil mix. Each tray also had cultivars Bedford or Jack (susceptible) or Centennial or Savoy (resistant). Plants were inoculated at their bases with a mycelial suspension of Rhizoctonia solani (AG-2) at the VE growth stage and were rated for disease severity using a 0 to 5 scale after 21 days. One hundred forty cultivars had disease ratings one standard deviation below the mean (<2.5 disease rating) and were reevaluated in a replicated trial. Twenty of the 140 cultivars had disease ratings of <2.5 in this test and were reevaluated in another replicated trial. In this final trial, cultivars Savoy, Asgrow 2601, and Asgrow 3701 had the lower disease ratings and were classified as moderately resistant to infection by Rhizoctonia solani.