|POORAN-DESOUZA, SOMWATTIE - North Dakota State University|
|KHAN, MOHAMED - North Dakota State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/12/2010
Publication Date: 8/23/2010
Citation: Pooran-Desouza, S., Bolton, M.D., Khan, M.F. 2010. Timing and methodology of application of Azoxystrobin to control Rhizoctonia solani in sugarbeet [abstract.] 2010 American Phytopathological Society Abstracts. 100:S102. Available: http://www.apsnet.org/meetings/Documents/2010_Meeting_Abstracts/a10ma601.htm.
Technical Abstract: Rhizoctonia solani AG 2-2 is the causal agent of Rhizoctonia root and crown rot of sugar beet (Beta vulgaris) in North Dakota and Minnesota. This disease is a major limiting factor to sugar beet production. Management strategies currently include using partially resistant cultivars and fungicides. Azoxystrobin is the most widely used fungicide for disease control. Our objective was to determine the best time for application of azoxystrobin and to compare the efficacy of azoxystrobin in foliar and soil drench applications in greenhouse trials. Azoxystrobin was applied as a hypocotyl drench at 0, 3, 10, 14, and 21 days post-inoculation, at 0, 7, 14, and 28 days pre-inoculation, and applied to either foliage or soil of inoculated sugar beet hypocotyls at the four-leaf stage. Based on disease severity means, azoxystrobin applied at pre-inoculation was not significantly different from non-inoculated check. Post inoculation applications at 0 and 3 days had low root disease severity and at 21 and 28 days disease severity were similar to inoculated checks. In efficacy trials, foliar application of azoxystrobin was significantly different from soil drench application and had the highest disease severity that was similar to inoculated checks. Azoxystrobin application as a soil drench at the base of the hypocotyls and prior to infection was effective in controlling disease.