Characterization of Italian Plasmopara viticola populations for resistance to oxathiapiprolin.

Background: Oxathiapiprolin is a novel fungicide and the first of the piperidinyl-thiazole-isoxazoline class to be discovered. This fungicide has been reported to have high activity against Plasmopara viticola, the grapevine downy mildew agent, and other plant-pathogenic oomycetes. In this study, the baseline sensitivity of Italian P.

A time-course investigation of resistance to the carboxylic acid amide mandipropamid in field populations of Plasmopara viticola treated with anti-resistance strategies.

Background: Despite anti-resistance strategies being recommended to reduce selection pressure on insensitive strains, no information is available on fungal population dynamics following their application in real field conditions. In this study, the effects on Plasmopara viticola populations of two identical spray programs, differing only in including or not the carboxylic acid amide (CAA) mandipropamid in mixture and in alternation with an anti-resistance partner, were compared in terms of downy mildew control efficacy and mandipropamid sensitivity in two commercial vineyards for four seasons.

Results: Both programs effectively and similarly protected grapevine from downy mildew, despite different starting sensitivity levels of the P.

QoI resistance emerged independently at least 4 times in European populations of Mycosphaerella graminicola.

Background: QoI fungicides or quinone outside inhibitors (also called strobilurins) have been widely used to control agriculturally important fungal pathogens since their introduction in 1996. Strobilurins block the respiration pathway by inhibiting the cytochrome bc1 complex in mitochondria. Several plant pathogenic fungi have developed field resistance.