Rootstock impact on foliar symptom expression of esca on Vitis vinifera cv. Cabernet-Sauvignon

Trunk diseases and esca in particular, represent a major threat to the sustainability of the vineyards. The percentages of unproductive vines in a plot could vary from 4% to over 20 % depending on local conditions and vintages. 

This syndrome is characterized both by foliar symptoms of variable intensity and internal symptoms in the grapevine wood. These necroses induce vascular disorders on vine trunk. Most survey networks or other monitorings of plot generally show that the levels of leaf symptom expression of esca may depend on the cultivar and the soil x climate under which this crop is grown. It has been also shown that soil has a major effect on water status of grapevine. And the interface between ground and vine is provided by the rootstock. The study presents the results of an experiment carried out in a plot of Cabernet-Sauvignon in the Bordeaux region with twelve repeats of four different rootstocks over four vintages. Data suggest that one of the four rootstocks tested significantly led to less foliar symptoms of esca under these conditions. Among the three other rootstocks, there were some differences that could be reversed depending on weather conditions of the year. 

This breakthrough could be considered as an extra-element to add to all the criteria required for choosing a rootstock.