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United States Department of Agriculture

Agricultural Research Service

Title: Novel Considerations in Biological Control of Plant Pathogens

Authors
item Lartey, Robert
item Conway, Kenneth - OKLAHOMA STATE UNIV

Submitted to: Plant Health Progress
Publication Type: Book / Chapter
Publication Acceptance Date: April 25, 2003
Publication Date: December 1, 2004
Citation: Lartey, R.T., Conway, K.E. 2004. Novel considerations in biological control of plant pathogens. In: Lartey, R.T., Caesar, A.J., editors. Emerging Concepts in Plant Health Management. Research Signpost. p. 141-157.

Interpretive Summary: Biological control of plant disease has not yielded the desired effects of complementing or replacing chemicals as the major means of disease control. Emerging technologies such as using transgenic plants to combat plant pathogens and diseases has been hampered by a range of concerns. In the meantime, the available chemicals for plant diseases control are dwindling because of rapid development of resistance by pathogens and environmental concerns. These have justified the need for reevaluation of the approach to biological control as a viable alternative to chemical control. As a novel approach is proposed in this review and suggests critical pre-evaluation of relationships between components of the target environs, namely the pathogen, the antagonist, resident microbial populations and the host plant. Understanding of interactions, such as growth promotion, growth inhibition and growth neutral relationships among the components is a key for developing a viable biological control system. Briefly, a successful pathogen needs to overcome antagonistic effects of potential competitors. While a successful antagonist (biological control agent) will require a growth promoting or neutral relationship with other potential antagonists in the pathogen's environs while neutralizing the defensive mechanisms of the pathogen

Technical Abstract: Decades of research on application of biological agents to control plant disease have not yielded the desired result of complementing or totally supplanting chemicals as the major means of disease control. The last two decades of the 20th century saw the emergence of transgenic plants that express foreign genes to control plant pathogens. Various concerns regarding practical application of this technology have put on hold any effective use of the technology, at least for the near future. Meanwhile, the number of chemicals that are available for control of plant diseases is dwindling due to rapid development of resistance by pathogens, or due to environmental concerns. Plant pathologists are therefore left with no choice but to reevaluate the whole approach to biological control as a viable alternative. We present in this review an approach that is based on pre-evaluation of relationships between four components of the target environs, namely the pathogen, the antagonist, resident microbial populations and the host plant. The approach focuses on understanding interactions such as growth promotion, growth inhibition and growth neutral relationships among the components of the target environs as basis for developing a viable biological control system. It is based on the idea that a successful pathogen needs to overcome antagonistic effects of potential competitors. For an antagonist (biological control agent) to be successful, it will require a growth promoting or neutral relationship with other potential antagonists in the pathogen's environs while neutralizing the defensive mechanisms of the pathogen.

Last Modified: 12/21/2014
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