This is an entirely manual and very time-consuming operation. Thinning should therefore be carefully considered on the basis of the criteria below.
A vine with a high leaf density and crowded vegetation could be thinned with the qualitative objective of improving the aeration of the foliage and the bunches, and thereby reducing phytosanitary risks.
Thinning is also implemented to avoid both an overload of fruit and to facilitate pruning. It is possible not to proceed with thinning and then to reduce the load by removing excess bunches, which is a less time-consuming practice but even more corrective, since it takes place later.
As a precautionary measure, and in the case of extreme weather conditions such as frost, when the primary buds have not emerged or have been damaged, the secondary buds can be left, in order to remain as close as possible to the forecast load calculated during pruning.