Potential for entry and establishment in New Zealand of <i>Tilletia indica</i> the cause of Karnal bunt of wheat

Abstract

Karnal or partial bunt caused by the smut fungus Tilletia indica is a disease of wheat (Triticum aestivum and T durum) and triticale (x Triticosecale) It is listed as a quarantine pest in a large number of countries including New Zealand Strict phytosanitary measures are in place in New Zealand and offshore to prevent T indica from entering the country However they may not be strict enough to prevent undetected contamination of grain or other traded goods via potential entry pathways This study used climatic indices generated by two meteorological models to indicate that climatic conditions in wheatgrowing regions of New Zealand are suitable for the establishment of T indica Establishment of T indica on wheat may have a significant effect on grain quality and restrict trade of grain or grain products The exclusion of the pathogen through improved border measures is the most costeffective way to minimise the likelihood of T indica introduction