4.3.3. Experiment II: Influence of Treatments

To evaluate the influence of different treatments on the effect of OSE on *V. dahliae*, olive plants of cv. Picual were treated with seven treatments, including three BCAs and four commercial products (Table 4). These treatments and the type of application (foliar and/or irrigation) were selected for this study because of their significant efficacy against *V. dahliae in vitro*, as well as against the progress of VWO in planta demonstrated in previous studies [3].

Plants were treated with the water solution or suspension of each commercial product or BCA (Table 4), respectively, at 6-, 5-, and 3 weeks before obtaining OSE. Additionally, non-treated but inoculated plants by cornmeal–sand mixture (CSM; sand, cornmeal and distilled water; 9:1:2, weight: weight:volume) colonized by *V. dahliae* isolate V180 (theoretical inoculum density of the final substrate = 10<sup>7</sup> CFU g−1) were included as a positive control; and non-treated and non-inoculated plants as negative control. Plant inoculation was conducted 4 weeks before obtaining the OSE. Treatments or plant inoculation were conducted following the protocols described by López-Moral et al. [3]. A randomized complete block design with three blocks and four replicated olive plants per treatment (*n* = 10; eight treatments and two controls) was used (120 plants in total).

This experiment was maintained for six weeks after the first treatment was applied. Subsequently, OSE was obtained from plants of each treatment, as well as from plants of both positive and negative control, joining all the plants of each block, i.e., there were three experimental units of OSE (≈20 mL) per treatment or control.
