High-Efficiency Control of Gray Mold by the Novel SDHI Fungicide Benzovindiflupyr Combined with a Reasonable Application Approach of Dipping Flower

In this study, a novel succinate dehydrogenase inhibitor (SDHI) fungicide benzovindiflupyr was found to have strong inhibitory activity against gray mold caused by Botrytis cinerea. The sensitivity of B. cinerea to benzovindiflupyr was determined by testing 103 pathogen isolates with mean values of 2.15 +/- 0.19 mg L-1 and 0.89 +/- 0.14 mg L-1 for mycelial growth and spore germination inhibition, respectively. Furthermore, benzovindiflupyr had excellent long-lasting protective activity. Unfortunately, there were positive correlations between benzovindiflupyr and boscalid (r = 0.3, P = 0.04) and between benzovindiflupyr and isopyrazam (r = 0.31, P = 0.04). In the field, cucumber flowers are susceptible to infection by B. cinerea. Benzovindiflupyr applied at 20 mg L-1 by dipping flowers could successfully control cucumber gray mold, with the benzovindiflupyr dose of dipping flower application less than 1% of that of spraying application. Benzovindiflupyr combined with dipping flower application showed significant control of gray mold.