Grapevine nutrition is a fundamental factor for quality production. Often, for physiological mainly nutritional reasons, problems of reduced bud break occur, reflecting in grapevine productivity. This experiment was carried out to evaluate the effectiveness of the foliar formulation of macro and micronutrients, activated with polihexose in grapevine production, during two years, in a vineyard of the cv. Merlot grafted in the rootstock R110, formed in lira system, located in Monte Belo do Sul (RS), Brazil. Eleven treatments were used, consisting of three foliar nutrition programs, each with three rates, one, a designed basic program (TB) and one control treatment (without leaf nutrition), and a designed producer treatment (TP). The experiment was arranged in a randomized block design, with three replications. Evaluations were performed using the variables: bud productivity, productivity, percentage of sprouted buds, production plant and area, grape quality (ºBrix, total acidity and pH), index of cluster diseases, and grapevine nutritional diagnostic and cost-benefit relation of the programs. The statistical analysis (orthogonal contrast) only showed significant effects between rates 2 and 3 of program 2, for percentage of the sprouted buds (1994/95). In the 1995/96 harvest, there were significant effects for leaf fertilization versus control and, for rates 2 and 3, in programs 1 and 2, as for bud productivity and percentage of sprouted buds. A cumulative effect of the programs occurred in the analyzed variables. The cost-benefit relations of the basic treatment were higher than those of other programs and, in relation to control, reached 1:12.8 and 1:16.0 in the 1994/95 and 1995/96 harvests, respectively.
leaf analysis; leaf fertilization; productivity; bud break