It sounds scary and it is not the nicest thing to catch. Black Dead Arm (BDA) is a new kind of disease first discovered in 1999. It is a fungus disease that attacks the vine when it is pruned – vines are pruned all year round, not just in winter. During the whole growing season the vigneron has to cut back the branches, if not the vine would grow uncontrolled into long lianas.
One of these prunings are technically (in French) called “épemprage” – when unwanted young shoots are removed; – and is sometimes done mechanically (with a tractor). It is this type of vineyard work that new research findings from the University of Nîmes (Bernard Mollot) has identified as the probable cause of Black Dead Arm. Vitisphere.com
