ANALYSIS OF THE LOSSES DUE TO GRAPEVINE LEAFROLL DISEASE IN ALBARIÑO VINEYARDS IN RÍAS BAIXAS (SPAIN) ANÁLISE DAS PERDAS DEVIDO O ENROLAMENTO DA VIDEIRA EM VINHAS DE ALVARINHO NAS RIAS BAIXAS (ESPANHA)

SUMMARY Leafroll disease symptoms in grapevine white varieties are milder than in red ones and producers do not regard leafroll to be economically significant especially when yield is not consistently affected. However, the potential alcoholic degree (PAD) of Albarino grapes from Grapevine leafroll associated virus 3 (GLRaV-3) infected plants in two vineyards in Rias Baixas (Spain), was found to be an average of 1o lower than the virus free ones. To analyse the economic losses, two price scales and six vintages for each location were used: A) Grape Purchase Agreements (GPA) and B) bonuses or penalties depending on mean PADs of each year. Income was 8.7% lower with (A) and 13% lower with (B), that is more than 2000 ۥha -1 per year. Annual and accumulated losses during the 30 years of vineyard lifespan, with 5% discount rate, and an average