Dormancy release with alternative products for sustainable viticulture

Abstract

The grapevine needs some period of chilling to overcome the dormancy, thus the cultivation of this plant in subtropical and tropical regions is only possible with the use of synthetic products for bud break. Nevertheless, the most efficient product, the hydrogen cyanamide  is not  more available for use in Europe, and probably it will happen in other countries. Aiming to evaluate new formulations for dormancy release, two trials were carried out in commercial vineyards, one located at Rolândia, and another in Londrina, in Paraná State, Southern region of Brazil, with the grapevine cv. BRS Carmen. Soon after winter pruning, the following treatments were applied on the dormant buds: T1- control (no treatment); T2- Vegetable oil 2% (VO); T3- VO 4%; T4- Mineral oil 2% (MO); T5- MO 4%; T6- VO 2% + MO 2%; T7- VO 2% + MO 4%; T8- Garlic extract (GE) 18%; T9- Green onion extract (GOE) 18% and T10- hydrogen cyanamide 3%. The following variables were evaluated: sprouting percentage, number of clusters, cluster weight, yield, total soluble solids, titratable acidity and pH. In both trials, the treatment VO 2% + MO 2%, between the alternative products tested, was the most efficient for increasing bud sprouting (94.4-71.1%) and number of cluster per plant (40.8-31.8), and did not differ from the treatment with hydrogen cyanamide. The treatment using vegetable oil 2% and mineral oil 2% did not change clusters quality, keeping high level of soluble solids/titratable acidity ratio (30.6).