Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2004
Publication Date: October 31, 2004
Citation: Hanson, L.E., Miller, S.D., Panella, L.W. Response of glyphosate-tolerant sugar beet to fungal plant pathogens in the presence of glyphosate. ASA-CSSA-SSSA-CSSS Anual Meeting abstracts 6326. 2004. Technical Abstract: Recent efforts at improving crop plants have included the development of novel forms of herbicide resistance to enhance weed control efforts. One common type of herbicide resistance is to the herbicide glyphosate. Some herbicides can affect disease severity by direct effects on plant pathogens or by affecting the host's exudates or responses to pathogen attack. Glyphosate has been reported to affect the severity of some diseases, particularly those caused by Pythium or Fusarium, under experimental conditions. Glyphosate-tolerant sugar beet is available, but is not currently used commercially. To examine the effect of glyphosate treatment on disease severity, sugar beet that were tolerant to glyphosate were treated with glyphosate or control (standard herbicides in the field or surfactant in the greenhouse) and exposed to soil-borne plant pathogens. Disease severity is being determined for the different treatments. In preliminary tests, no significant differences in disease levels were observed with a F. solani isolate and two F. oxysporum isolates in the greenhouse (P greater than 0.05). However, for a third F. oxysporum isolate, disease levels were significantly higher following glyphosate use than in plants treated with surfactant alone (P less than 0.05). Potential interactions with other Fusarium isolates and other pathogens are being investigated.