Botrytis cinerea
Pers., the causal agent of gray mold, infects more than 200 plant species. This pathogen has traditionally
been controlled by fungicides. However, with the increasing demand for pesticide-free foods new control strategies are
needed. The objective of this study was to isolate and select grapevine (
Vitis vinifera
L.) epiphytic yeasts for the biocontrol
of
B. cinerea in table grapes. Of the total isolated yeasts (n = 256), 32 exhibited mycelial growth inhibition in dual cultures
with a halo > 4 mm, and eight of these isolates inhibited > 90% of conidial germination. When evaluating increasing
concentrations on conidial germination inhibition, a dose-dependent response was observed with EC
90 values from 0.45 ×
10
5 to 0.22 × 10
8 cells mL
-1. The antagonistic activity of six yeasts against
B. cinerea in table grape berries 'Flame Seedless'
increased as the yeast colonization time increased from 1 to 24 h on the berries, resulting in a higher biocontrol activity on
B. cinerea. These results show the effectiveness of grapevine epiphytic yeasts as biocontrol agents of
B. cinerea on table
grapes.
