The effect of grapevine leafroll and rugose wood sanitation on agronomic performance and berry and leaf phenolic content of a Nebbiolo clone (Vitis vinifera L.)

Phenolic concentrations in leaves and berries collected from both heat-treated and grapevine leafroll associated virus type 3 (GLRaV-3) and grapevine virus A (GVA) infected vines of the Nebbiolo clone 415 were analyzed throughout the growing season. Anthocyanins, hydroxycinnamoyltartaric acids, flavonols, and catechins were analyzed by HPLC and total anthocyanins by spectrophotometry. The results showed that virus elimination induced an earlier and higher accumulation of anthocyanins in berries, while a higher quantity of flavanols was found in leaf blades of infected plants whose photosynthetic activity was previously demonstrated to be reduced. Sanitation also induced an increase of vine vegetative vigor and juice soluble solids whereas yield and acidity were not affected.