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Diseases caused by Botrytis spp are one of the major management issues in New Zealand vineyards These fungi are genetically diverse across New Zealands vineyards with this diversity being reflected in differences in pathogenicity and fungicide resistance between populations These populations are known to differ in their seasonal and regional distribution A basic understanding of this diversity and the factors governing its distribution are important in developing effective control strategies against Botrytis spp This study reviews knowledge on the phylogenetic seasonal and regional distribution of Botrytis spp in New Zealand vineyards It confirms earlier reports that populations associated with diseased fruit at harvest often differ from those most frequently detected at flowering This study also uses microsatellite data to show that the regional differences in diversity seen at flowering are not evident in the populations associated with diseased fruit at harvest

The accuracy of host range testing in weed biocontrol programmes using plant pathogens has been questioned prompting a research programme into the field safety record of pathogens used for weed biocontrol in New Zealand Nationwide disease surveys were conducted from 20002009 and focused on species closely related to target weeds and therefore potentially most at risk of attack These surveys identified pathogens associated with any disease symptoms observed on nontarget hosts Disease damage attributable to biocontrol agents was observed on two nontarget plants Pustules of the blackberry rust Phragmidium violaceum were found on the endemic Rubus species R cissoides (bush lawyer tataramoa) at one location This result was predicted from host range safety tests conducted prior to its arrival in New Zealand No nontarget damage was observed in the remaining case studies confirming to date that all biocontrol pathogens are highly host specific to their target weeds