The lack of chilling for grapevines produces adverse effects such as the delay and unevenness of budburst; difficulties for phytosanitary procedures, extension of the harvesting period and low fruit quality. The work was carried out close to Garibaldi, at an altitude of 640 meters in the region of "Encosta Superior" Northern of the State of Rio Grande do Sul. The objective of this work was to test concentrations of hydrogen Cyanamid varying from 0; 0,5; 1,0; 1,5 ; 2,0 and 2.5% sprayed onto Cabernet Sauvignon and Pinot Noir cultivars. The best shoot growth results were obtained from sprays of 1.75% and 2.0% in Cabernet Sauvignon and Pinot Noir, respectively. Concentrations beyond to 1.5% promoted shoot growth uniformity, independent of the year. The highest productivity was obtained with 2.0% hydrogen Cyanamid in both cultivars, with an average increase of 5 ton/ha. There was a larger fertility in the cane buds than in the spurs. The qualitative aspects of the grapes were not affected by the hydrogen Cyanamid sprays except for the average weight of the Pinot Noir clusters in the 2004 harvest.
Vitis vinifera; dormancy break
