Etefom e épocas de poda no crescimento de videira rústica

Abstract

In tropical regions, vine needs different care than those required in temperate regions because of its continuous growth. Techniques such as the application of growth regulators and the alternation of pruning become essential for a satisfactory exploitation of viticulture, providing two or more crops per year. The objective of this study was to evaluate the effect of different pruning times, coupled with Ethephon doses, on the growth of ‘Isabel’ grapevine in two production cycles. Two experiments were carried out using a randomized block design, composed of 16 treatments, arranged in a 4 × 4 factorial scheme, with four replications. Four pruning seasons were evaluated in two crops: Winter (March 08, March 22, April 05, and April 19, 2013) and Summer (August 25, September 08, September 22, and October 06, 2013). The second variation factor consisted of four doses of Ethephon (0, 720, 1440, 2160, mg L-1). The evaluated variables were the duration of the productive cycle of the vine, the diameter of the base of the branches, the length of prebranches, the sprouting percentage, and the number of shoots per bud. The pruning seasons factor was evaluated by the Tukey test, at 5% probability and the factor Ethephon concentrations by regression analysis. In the Winter crop, the Isabel vine presented the smallest cycles, while in the Summer crop the cycles were longer. In the Summer harvest, pruning performed in early October provided a longer length of branches, while in the Winter season this occurs in the pruning performed in April. Concentrations of Ethephon influenced vine growth only in the Summer crop, with positive linear effect for branch length and quadratic effect, increasing sprouting up to the dose of 1440 mg L-1.