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, hydroxycinnamoyl tartaric acids, flavonols, and catechins were analyzed by HPLC and tot al anthocyanins by spectrophotometry. The results showed that virus el imination induced an earlier and higher accumulation of anthocyanins i n berries, while a higher quantity of flavanols was found in leaf blad es of infected plants whose photosynthetic activity was previously dem onstrated to be reduced. Sanitation also induced an increase of vine v egetative vigor and juice soluble solids whereas yield and acidity wer e not affected.