FIGURE 1.

Plant extract (PE) protects grapevine leaves against P. viticola. Plants grown in greenhouse conditions were treated by PE at 5 g L⁻¹, or equal volumes of conserving (cons.) agents or water, and inoculated at 48 hpt with a suspension of P. viticola sporangia (2.10⁴ sporangia mL⁻¹). At 6 dpi, 40 disks per condition (i.e., five disks per leaf, with two leaves per plant, and four plants per condition) were punched out. Leaf disk sporulating area was evaluated at 7 dpi by image analysis. Results correspond to the mean ± confidence interval of four independent biological repetitions. Significant differences (p ≤ 0.05) were identified with Kruskal–Wallis coupled with Dunn’s multiple comparison test. Conditions with different letters are significantly different.