QoI resistance of Plasmopara viticola and Erysiphe necator in the mid-Atlantic United States.

  title={QoI resistance of Plasmopara viticola and Erysiphe necator in the mid-Atlantic United States.},
  author={Anton B Baudoin and Gilberto Olaya and François Delmotte and Jeneylyne F. Colcol and Helge Sierotzki},
  journal={Plant Health Progress},
Of 20 Plasmopara viticola isolates collected in four locations in Virginia and northwest North Carolina in 2005, 16 were resistant to QoI fungicides. The resistance factor was over 100, and label rates of formulated azoxystrobin and pyraclostrobin provided little or no control of these isolates. Additional sampling in 2006 revealed at least 15 additional vineyards with QoI-resistant P. viticola in Virginia, Maryland, and Pennsylvania. Of 22 isolates of Erysiphe (Uncinula) necator collected in… 

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