Steinkellner


Die Bodenkultur - Journal for Land Management, Food and Environment

S. Steinkellner and H. Redl:

Sensitivity of Uncinula necator Populations Following DMI-Fungicide Usage in Austrian Vineyards

Summary

Monitoring of the development of Uncinula necatorstrains resistant to demethylation inhibitor fungicides (DMI) has been carried out in Austrian vineyards. After several years of unsuccessful attempts at control of grapevine powdery mildew in the field disease incidence and disease severity declined considerably from 1995 to 1996 and DMI application resulted in an evident reduction of the fungus from 1996 to 1998. Despite better results in the field, all Uncinula necatorpopulations showed reduced sensitivity to all tested DMIs in the laboratory study. Moreover, all samples showed cross resistance among all tested DMIs. In some cases this resistance level was even higher against DMIs which had never been used in the plots the samples came from.

Key words: Uncinula necator, grapevine powdery mildew, Oidium tuckeri, fungicide resistance, Demethylarien Inhibitor fungicide (DMI).