Lightning

• Distribution of vines in the plot

Lightning striking a vineyard plot is a rare event. The damage is spectacular but is only visible after a period of 24 to 72 hours. Generally, the affected strains are distributed in the plots, either in focus , or on one to several rows when the trellis wires play the role of conductor.

• Symptoms

After such stress, the foliage, the clusters and the inner nodes of the vine turn brown and dry out (figures 1 and 2), only the nodes and the buds remain green and turgid (figure 3). Note that the berries of the affected clusters end up shrinking. In fact, lightning destroys the bark of the collenchyma of rods and branches. A few days after the accident, the generator base will be able to reform bast and wood, which will cause cracks in the dead tissue (figure 3). The symptoms are more marked on the upper leaves of the vine shoots and do not prevent the budding of their lower part.

By making a longitudinal cut in the shoots, we see that they are dry and that the pith has browned and has retracted in places (Figures 4 and 5). Subsequently, shoots and clusters may completely wither away, and the vines may become defoliated.

Blasted stumps do not die in all cases and no symptoms are normally visible on the arms and trunks. The vegetative growth of the vine will then resume with the development of inter-hearts located at the base of the twigs.