The desuckering: the characteristics and aims of the intervention
Suckers are shoots that arise on the roots of the vine (specifically, of the rootstock) and therefore their elimination is always recommended (except in the case of frosts, etc.). The removal of the shoots that arise on the stem and branches is understood (but improperly). The elimination of suckers, coming from latent buds of the old wood of the vine, is always useful and must be carried out early (when the buds are parasites) to avoid removing organs that have become positive exporters of carbohydrates and to resort to cutting. This is not only to speed up the operation, but above all to avoid the formation of basal buds capable of developing again. Sometimes it can be useful to keep a few suckers in order to use it later to keep the correct shape of the plant or to renew some cordon.
The various types of bleeding operations
The desuckering can be done mechanically (with pneumatic machines or equipped with flails) or by hand. A great deal of research has been published on chemical stripping, combining the characteristics of chemical agents with mechanical tools. The best results were obtained with the use of dipyridyls (diquat, paraquat) at a dose of 600 grams per hectare, sprayed on 30-40 centimeter suckers and with 2% glufosinate ammonium. Positive results were obtained with NAA (a-naphthalenacetic acid) in 1% solution on shoots of about 10-20 centimeters. Ammonium glufosinate has been banned and as substitute compounds Piraflufen-ethyl and Carfentrazone-ethyl have been positively tested in S. Michele all'Adige, with two operations on suckers of about 10 and 20 centimeters. The latest generation hormonal spollonante is carfentrazone, a very volatile molecule that must be addressed to suckers with recovery machines.