*4.3. Effect of Olive Stem Extract (OSE) on Conidial Viability of Verticillium dahliae* 4.3.1. Obtaining Stem Extract

For obtain OSE, the main stem of the plants was cut at its base, and the entire main stem and shoots were used. Leaves and roots were discarded. Subsequently, most of the cortical tissue of stems and shoots was removed manually using sandpaper, and the peeled stems were sprayed with distilled water and kept at 4 ◦C in the dark to avoid desiccation until further processing. OSE was obtained by the analytical laboratory 'C+E Analítica' (San José de la Rinconada, Seville, Spain) following the protocol described by Cadahía [28]. Specifically, once in the analytical laboratory, the shoots and stems were cut into 0.5 cm fractions, immersed in ethyl ether, and kept at −20 ◦C for 2 h. As a consequence of the freezer step, the water contained in the plant tissues crystallised, breaking the cell walls, which later allowed a sap-like extract to be obtained. At the same time, the ether is able to extract the chlorophyll that could interfere with the analytical process. After this step, the plant material was defrosted, and the aqueous phase (endosphere contents) was separated from the ether to obtain OSE by means of a hydraulic press [28].
