|Authors: ||S. Lerin, A.F. Fagherazzi, A.E. Mario, A.G. Turmina, J. Gerber, C.E. Boff, L. Rufato, A.A. Kretzschmar|
|Keywords: ||abscisic acid, fruit quality, coloration|
The cultivar 'Rubi' has coloration problems during maturation that make it less attractive to the consumer.
The red color of the grapes is due to the presence of anthocyanins in the skin of berries, which can be promoted by applying abscisic acid (ABA). In this sense, the objective of this study was to evaluate the effect of ABA applications during the veraison at different concentrations in the cv. 'Rubi'. The study was conducted in 2011/12 season in Vacaria, Rio Grande do Sul, Brazil.
The treatments were: T1 NDASH control, T2 NDASH 1.0 mg L-1, T3 NDASH 2.0 mg L-1, T4 NDASH 3.0 mg L-1, and T5 NDASH 4.0 mg L-1 of ABA. The experimental design was a randomized block with five replications.
The variables evaluated were: weight of berries, soluble solids, total polyphenols, anthocyanins, total acidity, bunch length, weight and diameter of berry, red colour brightness (L), red colour purity (C), red colour tone (°h). The results were subjected to regression analysis with WinSTAT statistical program.
The variables weight of berries, soluble solids, the bunch length, width of the bunch, bunch weight, diameter of berries and red color purity (C) not adjust to a regression test.
The application of ABA has provided a linear decrease in total acidity and the red color (h°) (the smaller the angle the greater the red color). For variables brightness of red color (L) and anthocyanins were adjusted polynomial regressions with maximum (134 ppm) and minimum points (148 ppm) respectively.
The application of ABA alters positively the characteristics of color and acidity of 'Rubi', without changing the physical characteristics of the bunches.
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