Pest Management Science (2020) 76, 2198-2207

Silvia L. Toffolatti, Giuseppe Russo, Davide Bezza, Piero A. Bianco, Federico Massi, Demetrio Marcianò and Giuliana Maddalena (2020)
Characterization of fungicide sensitivity profiles of Botrytis cinerea populations sampled in Lombardy (Northern Italy) and implications for resistance management
Pest Management Science 76 (6), 2198-2207
Abstract:
BACKGROUND
Resistance to fungicides is one of the aspects that must be considered when planning treatments to achieve an optimal control of grey mold, caused by Botrytis cinerea , in vineyards. In this study, extensive fungicide resistance monitoring was carried out in Northern Italy (Lombardy region) to evaluate several aspects of fungicide resistance (frequency of resistance, effect of field treatments, mechanism of resistance and fitness) on 720 B. cinerea strains isolated from 36 vineyards.
RESULTS
Of the characterized strains, 12% were resistant to a single fungicide class (3% to the succinate dehydrogenase inhibitor boscalid, 4% to the anilinopirimidine cyprodinil; 5% to the phenylpirrole fludioxonil; 0.1% to the ketoreductase inhibitor fenhexamid) and 0.8% to two fungicide classes contemporaneously. Resistance was associated with mutations reported in the literature for boscalid (H272Y/R) and fenhexamid (P238S or I232M). Two new mutations in sdh C (A187F) and in sdh D (I189L) could be related to boscalid resistance. Strains resistant to fludioxonil did not show any known mutations. No significant differences were found in the fitness of sensitive and resistant strains.
CONCLUSION
Overall, field populations of B. cinerea showed a relatively low frequency of resistance, but the geographical distribution of resistance, genetic mechanisms of resistance and fitness of resistant strains suggest that management of resistance should be implemented, at local and regional levels. Particular attention should be given to the fungicide sprays planned before veraison, since they seem to be associated with a higher frequency of resistant strains in vineyards.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Silvia Laura Toffolatti, Piero Attilio Bianco

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea		Italy