Verticillium wilt of Olea europaea: A re-emerging pathogen threat under climate change and sustainable management

Verticillium dahliae, a soil-borne fungus, is responsible for Verticillium wilt, one of the most serious vascular diseases affecting olive groves worldwide.This disease is prevalent mainly in the Mediterranean region, causing significant economic damage to olive orchards, particularly among highly susceptible varieties.The fungus penetrates the xylem tissue of the trees, leading to leaf drop and wilting; in severe cases, it can even kill the trees.Controlling Verticillium wilt is challenging due to the pathogen's long-term survival in the soil and its complex biological nature.The pathogen's pathogenic mechanism is highly intricate, as the pathogen can survive as microsclerotia in the soil for many years and has the ability to spread through plants and irrigation water.This review aims to provide up-to-date information on the biology of V. dahliae, including its strains, infection cycle, and epidemiology.Chemical control has proven relatively ineffective, while intensive cultivation and irrigation exacerbate the conditions conducive to disease development.This highlights the urgent need for sustainable and integrated disease management techniques.These techniques may include planting resistant varieties, such as Frantoio; biological control using agents such as Trichoderma species; solar soil sterilization; and improved drainage practices.Recent developments have emphasized the role of ecology and biotechnology in managing this disease through the application of microbial biostimulants.In this review, climate drivers of the disease are analysed in a dedicated section, the level of evidence of diagnostic and control approaches is graded (olive-specific versus other hosts), and an integrative framework linking pathogen biology, diagnostics and management is proposed together with the main knowledge gaps.