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United States Department of Agriculture

Agricultural Research Service

Title: Risk Analysis: Case History of Puccinia Jaceae on Yellow Starthistle

item Bruckart, William

Submitted to: Proceedings USDA National Forum
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2003
Publication Date: December 1, 2003

Interpretive Summary: Before a pathogen from another country can be used in the United States, it must be tested to make sure it is safe and will not damage other plants where it is used. This is called "Risk Analysis". There are five parts to a risk analysis, and they concern: 1) awareness, 2) perception, 3) assessment, 4) management, and 5) communication of risk. A pathogen called Puccinia jaceae has been studied for use in controlling a weed known as yellow starthistle. Although it is probably not risky, it needs to be tested anyway, because we don't know everything about it. The first step is to see if a related plant might get sick or infected when it is inoculated by this pathogen. If the plant has some symptoms, then it is tested further to see if it really gets sick and damaged by the infection. If it does not get sick in the greenhouse, even though it gets infected, then the risk of the plant being hurt in the field is low and the pathogen is probably alright to use in the U.S. Once the study is complete, then the information is told to many others who can agree or disagree about the concludions of the study. If they agree, then permission is given to use the pathogen in the U.S.

Technical Abstract: Risk analysis has five components: Risk awareness, Risk perception, Risk assessment, Risk management, and Risk communication. Using the case with the foreign plant pathogen, Puccinia jaceae, under evaluation for biological control of yellow starthistle (Centaurea solstitialis, YST), approaches and procedures are given to illustrate how each of the components of risk analysis was addressed. Many of the issues concerned the advantages and challenges that come from conducting the evaluation in a containment greenhouse. Plant pathogens can be very damaging to plants (risk awareness) and, for various reasons, may be perceived as dangerous. P. jaceae was selected for evaluation because it is most likely safe to use in the U.S., a characteristic of the rust fungi. Risk assessment is based on the formula: risk is Hazard x Exposure (R = H x E). For release of classical agents such as P. jaceae, exposure is assumed. Risk Management involves controlling hazard by documenting a very high level of host specificity. Risk Assessment, therefore, begins with identification of potential hazards. An example with P. jaceae is limited infection of safflower. Research showed that P. jaceae could not be maintained using safflower as the sole source of inoculum, and P. jaceae teliospores did not initiate safflower seedling infections. Support of these findings came from direct, side-by-side greenhouse comparisons of safflower susceptibility to infection by North American isolates of P. carthami, the safflower pathogen, which is manageable in California. Field tests in Greece also supported these findings. Risk Communication included several meetings with safflower growers, California Department of Food & Agriculture plant pathologists and regulators, the Technical Adivsory Group, APHIS-PPQ personnel, and notice in the Federal Register about the proposed action to release P. jaceae in California.

Last Modified: 4/22/2015
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