Efeitos do thidiazuron e do ácido giberélico nas características dos cachos e bagos da uva de mesa 'Vênus' na região noroeste do estado de São Paulo

Abstract

The use of growth regulators is widely diffused in vine crops to improve grapes quality (Vitis vinifera L.), aiming mainly the increase of fruit size and set, loosening clusters, and elimination of seeds. In this context, a trial was carried out in a vineyard located at Urânia-SP, Northwestern São Paulo State, during two seasons. It was used thidiazuron at 5 or 10mg.L-1 and gibberellic acid at 30mg.L-1, combined or not. The following variables were evaluated: weight, length and width of clusters and berries; weight of rachis; number of berries; number of trace-seeds; and total soluble solids content, total titratable acidity, and TSS/TTA ratio of juice. Gibberellic acid applications increased weight, length, width and number of berries, and reduced number of trace-seeds. Association to thidiazuron potentiated gibberellic acid effects regarding the increase in the number of berries and reduction in the number of trace-seeds. Thidiazuron applications, associated or not to gibberellic acid, delayed fruit ripening, decreased total soluble solutes content and TSS/TTA ratio and increased total titratable acidity of juice. Growth regulators applications also increased weight of clusters and rachis.