A QUANTITATIVE RISK ASSESSMENT MODEL FOR THE IMPORTATION OF U.S. MILLING WHEAT CONTAINING TELIOSPORES OF TILLETIA CONTROVERSA

Authors: Peterson, Gary; STEFANSKI, ROBERT - USDA, WAOB

Submitted to: International Plant Protection Congress
Publication Type: Abstract Only
Publication Acceptance Date: 4/19/2004
Publication Date: 4/19/2004
Citation: Peterson, G.L., Stefanski, R.J. 2004. A quantitative risk assessment model for the importation of u.s. milling wheat containing teliospores of tilletia controversa. International Plant Protection Congress. Beijing, China, May, 2004 - p.308.

Interpretive Summary:

Technical Abstract: Dwarf bunt of wheat caused by the fungus Tilletia controversa Kuhn (TCK) is a pathogen historically limited in distribution by its very specific environmental requirements for establishment. Our objective was to develop a quantitative TCK pest risk-assessment model (TCK-PRA) to evaluate and communicate the potential risk of introduction, establishment and yield loss from the importation of U.S. milling-wheat containing teliospores of TCK. A TCK-PRA model was developed by a multi-national task force using new, historic and estimated data expressed as frequency distributions. These distributions were utilized in Monte Carlo simulations to quantify risk. The TCK-PRA model examines pathways of teliospore diversion from transport and milling processes, spore contamination levels, grain handling, and end-product usage. A geophytopathological sub-routine model was developed to identify and quantify potential regions of risk using weather data from the widely available UN World Meteorological Organization's telecommunications network. When the model was applied to the U.S. and Sweden, results correlated well with the known distribution of the disease. TCK-PRA model evaluation scenarios for China, Brazil, Mexico, India and Peru were conducted and results presented.