Field evaluation of six red grapevine cultivars inoculated with Neofusicoccum parvum

Botryosphaeria dieback (BD) is a serious grapevine trunk disease (GTD) that causes large losses in yield and shortens the productive life of vineyards. Neofusicoccum parvum is one of the main causal agents of BD. Currently there are no curative fungicides to eradicate this disease; therefore, the use of tolerant cultivars to BD could be considered an interesting and sustainable alternative for its control. For this purpose, rooted cuttings of six red Vitis vinifera cultivars were selected and inoculated with N. parvum, under field conditions, over 2 consecutive years. Eight months after inoculation, plants were collected and inspected for lesion development. The fungal incidence varied depending on the cultivar and ranged from 42.1% in “Monastrell” cultivar to 93.3% in “Tinto Velasco” cultivar, evidencing a lack of qualitative resistance to N. parvum. The severity of internal wood symptoms caused by N. parvum differed considerably amongst the cultivars, being “Bobal” and “Monastrell” more tolerant than “Tinto Velasco” cultivar.