Title: STRATEGIES FOR USE OF PATHOGENS IN WEED BIOLOGICAL CONTROL: SOME LESSONS FROM SIMILAR SYSTEMS
Widmer, Timothy - USDA-ARS-EBCL
Rayamajhi, Min B - USDA-ARS-IPRL
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: June 5, 2007
Publication Date: December 1, 2007
Citation: Widmer, T., Rayamajhi, M. Strategies for use of pathogens in weed biological control: some lessons from similar systems. Book Chapter.
Interpretive Summary: Biological control is being seriously investigated in weed management. The intentional release of plant pathogens to kill weeds is one component of biological control. The best chance to find a specific and effective pathogen is to look in the native habitat of the weed. This article outlines the steps necessary for isolation, screening, identification and pathogen improvement for safe release to manage invasive weeds. The concerns with the use of exotic pathogens are addressed with a specific emphasis on potential host range expansions. Previous studies involving local fungal applications for weed control, biological control of plant pathogens, and behavior of “agronomic” pathogens are examined. The impact of this review is to give an assurance that pathogens can be released safely for weed control and is a good option to chemical herbicides.
Biological control is an important component in weed management. When pursuing pathogens as a biological control agent, location is an important factor to consider where to search for an effective agent. Although there may be more risks and research to conduct, pathogens isolated from weeds in their native location may be the most efficacious. Ecological matching between invasive and native ranges will assist in finding more environmentally suited agents and assure that interactions in development between the host and pathogen are similar. Steps conducted for isolation, screening, identification and pathogen enhancement are addressed. The concerns with the use of exotic pathogens are addressed with a specific emphasis on potential host range expansions. To address this fear of host range expansions, past research and records of mycoherbicide applications, biological control of plant pathogens, and behavior of “agronomic” pathogens are examined.