|Authors: ||A.F. Fagherazzi, A.E. Mario, A.G. Turmina, S. Lerin, R. Voss, M.A. Andriao, L. Rufato|
|Keywords: ||Vitis labrusca, grapes, plant growth regulators, yield, quality|
Due to the constant need for improvement in physicochemical characteristics of grape bunches, there is a growing use of bioregulators in worldwide viticulture.
These products are composed of plant hormones that act at low concentrations in plant physiology.
However, there is a lack of information about the doses and the effect on different grape cultivars, because of the different characteristics of each cultivar.
The aim of this study was to evaluate the effect of applying bioregulator Stimulate® in different doses on the physicochemical characteristics of bunches and productivity of 'Bordo'. The experiment was conducted during the 2011-2012 harvest in the municipality of Monte Alegre dos Campos, Rio Grande do Sul, Brazil.
The experimental design was a randomised block with six repetitions.
The treatments were: T1: control; T2: 0.1%; T3: 0.2%; and T4: 0.3% of Stimulate® was applied once when the sproutings reached a vegetative growth of 20 cm.
Adjuvant Natur'l Oil 0.1% was added to all treatments.
The variables analysed were soluble solids, mass of bunches, berries and rachis length and width of bunches, diameter and number of berries, and productivity.
The data were subjected to regression analysis using the statistical program WinSTAT. The variables soluble solids, length of the bunches, masses of berries and rachis were not adjusted significantly to the regression test.
In the variables of number and diameter of berries polynomial regressions with minimal points were set up, while for total acidity a positive quadratic polynomial regression was obtained.
The application of the bioregulator increased productivity, width and mass of the bunches linearly.
It can be concluded that the dose 0.3% Stimulate® positively alters the physicochemical properties of bunches, generating higher productivity in 'Bordo' vineyards.
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