Fig. 4. Ascorbic acid (A), dehydroascorbic acid (B), reduced (C) and oxidized (D) glutathione concentrations of leaves collected during the phenological phases of stretched-out leaves (SL), fruit setting (FS), cluster closing (CC) and bunch ripening (BR) from symptomless (filled bars) or symptomatic (banded histograms) cv. Italia healthy vines (), vines with brown wood-streaking () or with brown wood-streaking and white rot (). Data are means of fifteen replicates ± sd. For each parameter, values with the same letters are not significantly different according to Tukey post-hoc test P⩽0.05.