The trade press is just beginning to talk about a topic that greatly concerns many winemakers here in France – the sharp increase in vine mortality due to what is euphemistically called “wood diseases.”
Every year, an average plot in France can lose between 1.5% and 3.5% of its population (in a decade that means 15 to 35% of an average vineyard dies off!). The first obvious consequence is the loss in yields. But more importantly, in the long term, this means the gradual disappearance of old vines, critical for making great wines.
Vineyard research today has very few certainties concerning these wood diseases, a general term that covers a range of symptoms that include Eutypa Dieback, Esca and Black Dead Arm.
It is widely believed that these diseases are caused by multiplying fungi populations that eventually block the vine’s sap channels. This leads to an “apoplectic” death much like a stroke due to a blocked artery in humans.
Today, there is no method, no “product” to cure or even slow down the development of these fungi and our vineyards have not been immune to this problem, so we’ve set in place a dramatic experiment.
A visit to Rafael Palacios in Valdeorras, Galicia, allowed us to discover what appears to be a barbaric technique of splitting the infected vine in two almost down to the graft. A large stone is then inserted to keep the two sides from touching one another. The logic goes that the fungi are then exposed to air and light and will dry out. The vine will then be able to heal and thus develop new sap channels.
The results in Rafael Palacios’ vineyards have been spectacular, so we’ve decided to test this ancestral practice at home. Up until now, all we’ve done is tag each infected vine with a ribbon to avoid contaminating the others while we work in the vineyards. That it made it easier this winter, while we systematically split the affected vines. But I have to admit it’s not for the faint of heart! Stay tuned ….