Verticillium Wilt of Olive

The causative agent of the disease is the fungus Verticillium dahliae Kleb., which survives in the soil in the form of microsclerotia. Two main pathotypes are identified in pathogen populations: the highly virulent defoliating (D) pathotype, which causes mass leaf drop and rapid tree death, and the less aggressive non-defoliating (ND) pathotype, where dry leaves often remain attached to the branches.

Symptoms of the infection often appear asymmetrically on individual branches or parts of the canopy. Unlike other crops, vascular browning in olive wood is weakly expressed or absent during infection. The diagnosis of variety resistance is based on the results of field trials and phenotypic reaction, as specific resistance markers are limited in practical application.