Dormancy release and enzymatic activity in buds of grapevine cv. Ives treated with Gallesia integrifolia hydrolates

The lack of more sustainable options for the bud break of grapevines in mild winter regions is a limiting factor due to restrictions on the use of agrochemicals. In this context, a trial was carried out in a vineyard located in Marialva, Paraná, Brazil, over two consecutive crop cycles. The treatments consisted of the following doses of Gallesia hydrolate (GH): 0, 100, 150, 200 and 250 mL L-1, as well as 30 mL L-1 garlic extract and 20 mL L-1 hydrogen cyanamide as positive controls. The following variables were evaluated: bud break, percentage, number of clusters, yield (t ha-1), catalase activity, peroxidase activity. The GH treatments improved sprouting in both crop cycles, presenting a quadratic effect in relation to applied dose. The same effect was verified for the number of clusters and yield. A quadratic effect for peroxidase and catalase activity was verified in relation GH doses applied. The most abundant compound found in GH was the dimethyl disulfide. Based on these results, the GH at 150 mL L-1 could be a promising alternative for the bud break of grapevines cv. Ives. Key words: Vitis labrusca, grapes, bud break, sustainability, organic production.