Technical report of EFSA prepared by the Assessment Methodology Unit on Quantitative pathway analysis of the exposure of the wheat production area with Tilletia indica M. teliospores one year after importation of US wheat for grain into the EU and desert durum wheat into Italy. Appendix B to the Scientific Opinion on a quantitative pathway analysis of the likelihood of Tilletia indica M. introduction into EU with importation of US wheat of EFSA Panel on Plant Health (PLH)

The EFSA Plant Health Unit asked the Assessment Methodology Unit to recalculate and update the Quantitative Pathway Analysis of the exposure of the EU wheat production area with Tilletia indica M. teliospores provided by USDA APHIS. Simulations were computed, for importations of US wheat into EU and desert durum wheat into Italy, based on original model and an updated model with revised parameter values. Model output was teliospores number per hectare on soil surface of each EU country. Simulated teliospores numbers entering EU were lower with the updated than with the original model. These results showed a high uncertainty, underestimated with the original model, over the number of teliospores entering each EU country. Sensitivity analysis showed several key parameters (proportion of bunted kernels in Arizona regulated counties, number of Arizona positive hectares and number of teliospores per bunted kernel) strongly influencing number of teliospores entering the EU. In addition, high sensitivity indices were obtained with the updated wheat model for several parameters related to EU country characteristics. Further research would be needed to refine parameter values and to reduce uncertainty. This technical report contains a full description of the calculations and results. The description and discussion of the scenario and model can be found in the Scientific Opinion on a quantitative pathway analysis of the likelihood of Tilletia indica M. introduction into EU with importation of US wheat of EFSA Panel on Plant Health (PLH) (EFSA 2010).