Kiwifruit Vine Decline Syndrome: etiology, mechanisms, and management of a multifactorial disease

Kiwifruit Vine Decline Syndrome (KVDS) is becoming one of the most severe threats to kiwifruit cultivation in Italy, with potential to spread to other kiwifruit cultivation areas. KVDS is a complex, multifactorial disease induced by the combined action of abiotic stresses and biotic agents. Waterlogging, soil compaction, and high soil temperatures seem to be the main factors generating conditions that make roots highly vulnerable to colonization by soilborne pathogens, with Phytopythium vexans and other oomycetes playing a central role. Aboveground, impaired hydraulic function drives canopy collapse during periods of high evapotranspiration demand. Despite significant progress, major gaps remain in clarifying the precise etiology, identifying primary pathogens, and understanding the physiological mechanisms that lead to plant decline. This review is the first comprehensive report on the current understanding of KVDS, including the mechanisms behind its induction, and the first attempts to contrast its spread, discussing a path forward to identify strategies to safeguard kiwifruit production and manage other decline syndromes that may arise as consequence of global changes.