MONITORING GRAPES' INFECTION WITH Botrytis cinerea BASED ON LACCASE ACTIVITY

Botrytis cinerea causes grey mould and is one of the most damaging disease occurring in vineyards worldwide, resulting in loss of grape production and wine quality. Laccase enzymes produced following fungal infection are involved in the oxidation of phenolic substances during the development of grey mould and has been used as an indicator of the degree of infection. Between the laccase activity of resulting juice of Botrytis cinerea infected bunches and the severity of infection observed in the vineyard a moderate to good correlation has been highlighted over the measurements carried out over veraison (BBCH81 - 88), and a strong correlation has been highlighted for the measurements carried out over the full ripening growth stage (BBCH 89). As a consequence of the degradation of polyphenolic compounds and the intensification of laccase activity in the infected musts, the change of chromatic characteristics, in the sense of increasing the values of the ,,Hue" parameter and the yellow color of musts was highlighted, in direct correlation with the oxidative processes.