In tropical regions, with the help of applying chemicals to induce dormancy, it is possible to obtain two grapevine annual harvests. However the effectiveness of the use of these products is questionable because of its high toxicity is a concern. In this sense, the objective of this study was evaluate the effect of a hydrolate obtained from Gallesia integrifolia in the sprouting, yield and enzyme activity of peroxidase and catalase on grapevines 'Benitaka'. The experiment was realized in commercial vineyard in the city of Marialva, state of Paraná, Brazil, in two consecutive cycles: 2011, August to December and 2012, January to July. The treatments consisted of the following doses of Gallesia hydrolate: 0, 50, 100, 150, 200 mL L-1, besides the positive control with hydrogen cyanamid to 20 mL L-1. It was evaluated the following variables: percentage of sprouting, number of clusters, cluster weight, yield (t ha-1), activity of catalase and peroxidase and content of reducing sugars in the buds. For the percentage of sprouting, there was a quadratic effect depending on the doses of Gallesia hydrolate with budburst estimated maximum doses of 108.8 and 97 mL L-1 of hydrolate for the first and second cycle, respectively, with similar results to treatment with hydrogen cyanamid. Treatments with Gallesia hydrolate also increased the number and the mass of clusters and the yield, with a quadratic effect depending on the dose. It was also verified the reduced activity of catalase, peroxidase and for the reduced sugars in the buds for plants treated with Gallesia hydrolate, showing its mode of action via oxidative stress, similar to the effect of treatment with conventional hydrogen Cyanamid. Based on the results obtained the Gallesia hydrolate in the doses between 100 and 150 mL L-1 can be an alternative to break dormancy of grapevine 'Benitaka' in tropical regions for sustainable viticulture.
Vitis vinifera; grapes; sprouts; sustainability; dormancy
