A reappraisal of the current status of Tilletia indica as an important quarantine pest for Europe

Abstract

Tilletia indica, the fungus responsible for Karnal bunt disease of wheat, is currently recognised as a quarantine pest by both the EU and EPPO. The evidence that has been used to justify this status is reviewed and found to be in need of reappraisal. Yield losses caused by the pathogen are insignificant and disease levels are rarely high enough to cause serious quality problems. The sole reason for its designation as an important quarantine pest would seem to lie in the serious implications for trade should the pathogen be detected in an exporting country. Since there is strong evidence to suggest that T. indica may not even establish in Europe, it would seem logical to reclassify the pathogen as the cause of a minor disease that is likely to have little quarantine significance for Europe. However, since most wheat-growing countries have strict quarantine regulations aimed at preventing the introduction of T. indica, this reclassification is unlikely to occur unless plant health authorities around the world can agree on a new status of reduced importance for T. indica that suits its actual potential as a pest.