Recent developments in elucidating modes of resistance to phenylamide, DMIand strobilurin fungicides

Resistance risk assessment, analysis of resistance events and risk manageme nt are based on elements such as the mode of resistance in target organisms , similarity of inhibitors, detection methods for resistant individuals, an d design and validation of product use strategies. The mode of resistance m ay be analysed in several steps including the molecular, genetic, biochemic al, physiological, and population level. Historical and recent findings are described for phenylamide fungicides (PAFs), demethylation inhibitors (DMI s) in sterol biosynthesis and fungicides of the strobilurin-type action and resistance (STAR) group (Qo respiration inhibitors, QoIs) with regard to t he site of resistance in target pathogens and the presence of resistant ind ividuals in populations. (C) 2000 Elsevier Science Ltd. All rights reserved .