Partitioning of grapevine biomass in thinned shoots.

In the viticultural areas where appreciated wines are produced, it is very important to keep quantity production under control if better quality is to be achieved. The main cultivation techniques used to control the production are pruning and cluster or berry thinning. In this work the effects of cluster thinning on the biomass partitioning of grapevine are shown. Three theses have been compared: shoots with two clusters, shoots with one cluster, shoots with one cluster thinned at fruit set stage. The results pointed out that thinning reduced both vegetative and reproductive accumulation, but at the same time, altering the source-sink relationship, this technique also determined a modification in the proportion of carbon allocation.