Evaluation of some new wine grape cultivars under São Francisco Valley conditions.

This study aimed to evaluate the performance and characteristics of the grapes as subsidies to the recommendation of new wine grape cultivars for the São Francisco Valley. An experiment was carried out in Petrolina, Pernambuco state, during four seasons in 2014 and 2015 and the treatments were represented by 10 cultivars and three breeding selections: Grenache, Tempranillo, Merlot, Cabernet Sauvignon, Malbec, Petit Verdot and Syrah for red wines and Sauvignon Blanc, Chardonnay, Chenin Blanc and breeding selections 46, 14 and 47 for white wines. The experimental design was a randomized block with four replicates and two useful plants per plot. The following variables were evaluated: sprouting, bud fertility rate, Ravaz index, production, number of clusters, weight, length and width of cluster, weight and volume of 100 berries, soluble solids and titratable acidity. A better balance between production and vigour was obtained in Grenache, Merlot and Tempranillo cultivars, presenting values of 7.56, 6.50 and 5.93, respectively, for Ravaz index. Grenache, Chenin Blanc and Tempranillo were the most productive cultivars with average yields estimated at 10.4, 8.7 and 8.4 ton/ha/season. Selection 14 had longer, wider and less compact clusters, which can reduce clusters rottenness. The percentage of sprouting ranged from 38.13% in selection 14 to 77.6% in cv. Chenin Blanc. The average index of bud fertility was 0.79 cluster/bud, with no significant differences among cultivars. Greater potential for sugar accumulation was found in the selections 14, 46 and 47, while the titratable acidity ranged from 0.63% in cv. Merlot to 0.89% in selection 47. Grenache and Tempranillo have showed potential to obtain adequate yield and balanced vines, while Sauvignon Blanc, Chardonnay, Cabernet Sauvignon, Malbec and Petit Verdot presented low yield being necessary to select clones more productive and well adapted to the tropical conditions. Further information about the quality of grapes and wines should be added to these results to allow the recommendation of new cultivars or breeding selections of wine grapes for the São Francisco Valley.