Fig. 3.

(A) Lesion diameters and (B) populations of Diaporthe batatas SP-d1 on inoculated slices of sweetpotatoes treated with gaseous chlorine dioxide (ClO₂). (C) Populations of isolate SP-d1 in the surface layers of sweetpotato roots treated with ClO₂ gas. Slices were inoculated with isolate SP-d1 (10 μl of 5 × 10⁶ spores/ml) and then treated with various ClO₂ concentrations (5, 10, and 20 ppm) for 0, 10, 30, and 60 min. Roots were dipped in spore suspension (5 × 10⁶ spores/ml) for 10 min and then treated with different ClO₂ concentrations (20 and 40 ppm) for 0, 30, and 60 min. Different lowercase and uppercase letters on bars (n = 3) are significantly different between time at a given concentration and between concentrations at a given time according to the least significant difference test at P < 0.05, respectively. Repeated experiments are indicated as experiments 1 and 2.