Adverse effects of grapevine trunk diseases on canes produced from infected rootstock mother blocks

Grapevine trunk diseases (GTDs) threaten vineyard longevity by reducing the yield and phytosanitary quality of propagation material from rootstock mother vines. The optimal age for replacing mother blocks to mitigate these risks is unclear. This study evaluated the effects of mother block age on the physiological, morphological, and infection status of mother vines and one-year-old canes produced by it.

Cane morphology and physiology were highly variable, influenced by rootstock and season, with no consistent association with mother block age. Grapevine trunk disease incidence was widespread in mother vine heads, dominated by Celotheliaceae and Botryosphaeriaceae, with incidences up to 84-90%. One-year-old canes generally showed lower infection rates, though Botryosphaeriaceae and Celotheliaceae reached 28% and 2%, with DNA concentrations up to 3171 and 1055 ng μL^-1, respectively. Diplodia seriata in mother vine heads directly contaminated one-year-old canes. Multivariate analyses revealed Botryosphaeriaceae negatively impacted cane morphology, Celotheliaceae and Diaporthaceae reduced starch content, and Botryosphaeriaceae and Hymenochaetaceae increased total phenolic index.

Mother block age minimally influenced cane physiology or morphology. However, high GTD prevalence in mother vine heads poses systemic infection risks and reduces cane quality. Monitoring and management of GTD pathogens in rootstock mother blocks are essential to maintain the health and productivity of propagation material and ensure vineyard longevity. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.