Cognac glossary - GRAPEVINE DISEASES

Black rot  is a fungal disease  explosive  of the vine . Initially affecting the Atlantic regions, it now rages in all vineyards. Black-rot affects all the organs of the vine in their active growth phase. The most visible attacks are on the leaves. The attacks on the bunches occur after flowering . The period of berry sensitivity goes from fruit set to bunch closure.  While leaf damage is not directly detrimental to the vine, attacks on the bunches can lead to significant yield losses as well as a deterioration in the quality of the berries that can compromise the harvest and vinification.