EPPO Global Database

EPPO Reporting Service no. 05 - 2002 Num. article: 2002/088

Model to quantify the probability of entry and establishment of Tilletia indica in Western Australia, and its consequences


A mathematical model has been developed to quantify the probability of entry and establishment of Tilletia indica (EPPO A2 quarantine pest) in Western Australia, and to simulate spread, containment and economic impact of the pathogen. Using this model, it was found that the most likely means of entry is through imports of bulk grain or fertilizer. Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travellers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. This could be diminished to one entry every 50 years and less than one establishment every 100 years by increasing funds dedicated to plant quarantine. Depending on the rate of pathogen spread used in the model, and the amount of resources allocated for detection, the time of first detection (after introduction) could range from 4 to 11 years, and the economic impact could range from 8 to 24 % of the total value of wheat production in Western Australia.


Sources

Stansbury, C.D.; McKirdy, S.J.; Diggle, A.J.; Riley, I.T. (2002) Modelling the risk of entry, establishment, spread, containment and economic impact of Tilletia indica, the cause of Karnal bunt of wheat, using an Australian context.
Phytopathology, 92(3), 321-333.