The major threat to crops posed by fungal diseases results in the use by growers of enormous amounts of chemicals. Of these, quinol oxydation inhibitors (QoIs) are probably the most successful class of agricultural fungicides. QoIs inhibit mitochondrial respiration in fungi by binding to the Qo site of the cytochrome bc1 complex, blocking electron transfer and halting ATP synthesis. Unfortunate...

Cover: Scanning electron micrograph of 7-day-old colony of powdery mildew (Blumeria graminis f.sp. tritici) on a wheat leaf. Insert shows a 2-day-old colony at higher magnification. Although the sensitivity of mildew populations towards certain fungicides has changed considerably over the years, implementation of resistance management strategies has helped to sustain an overall satisfactory deg...

There are two mildew diseases affecting cucurbit crops: powdery mildew and downy mildew. Both fungal pathogens produce wind-dispersed spores that can be moved long distances, thus they cannot be avoided. Fungicides and resistant varieties have been important for managing these diseases. Unfortunately, both pathogens have demonstrated ability to evolve new strains that are not controlled as effe...

Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola (Sacc.), is the most destructive foliar pathogen of sugarbeet worldwide. Control measures include the use of resistant varieties and crop rotation, but timely fungicide applications are essential for CLS management. Resistance to sterol demethylation inhibitor (DMI) fungicides (FRAC group 3) has been increasing in C. beticola ...

ABSTRACT Acquisition of resistance to sterol demethylation inhibitors (DMIs) by populations of Venturia inaequalis was investigated using a microscopical method developed by C. Siebels and K. Mendgen. Microscopical analysis of conidiophore formation enabled the earlier detection of resistance and a clearer distinction between DMI-resistant and DMI-sensitive populations than other in vivo method...

quinol oxidation inhibitors (qois) are one of the most important classes of fungicides used in agriculture. they block electron transfer between cytochrome b and cytochrome c1, thereby impeding the production of atp via oxidative phosphorylation. qoi fungicides are generally at high risk of provoking resistance in fungal phytopathogens. resistance has been reported in more than thirty species, ...

As the usage of fungicides catapulted with the onward march of the dial hour, fungicidal resistance by the pathogens emerged as a new constraint. This amalgamated with the growing demand by the farmers for crop protection agents with low use rates, a benign environmental profile and a low toxicity to human and wild life, further gave an impetus to the search of new molecule of fungicides with n...