Efecto del uso de reguladores de crecimiento y elicitores sobre la composición química y características físicas de la baya de 5 variedades de uva de mesa coloreadas durante la maduración

Abstract

Agronomic management to improve color in table grapes (Vitis vinifera L.), such as the application of the hormones abscisic acid and ethylene, seek to increase the concentration of soluble solids and phenolic compounds, such as anthocyanins and tannins. However, these traditionally applied growth regulators also influence the softening and shelling of the bunch berries, both undesirable effects at the time of table grape export, for this reason, it was proposed in this work to test the effect of the methyljasmonate, abscisic acid and ethylene hormones, as well as extracts of yeast walls that act as elicitors, in the traditional varieties of Crimson and Red Globe table grapes, as well as in the new varieties Sweet Celebration, Krissy and Timco, in Buin commune (Metropolitan region). For this work, the following treatments were applied: T0: control (without applications); T1 abscisic acid (Protone) 400 ppm + tween as surfactant (0.1% v/v) with a wetting volume of 200 mL/plant; T2: ethylene (ethrel) dose (1L/ha) with a wetting volume of 500 L/h; T3: methyljasmonate 10Mm + tween 80 as surfactant (0.1% v/v) with a wetting volume of 200 mL/plant; T4: hydrolyzate of dry inactive yeasts 2g/L+tween 80 as surfactant (0.1% v/v) with a wetting volume of 200 mL/plant. The applications were made when the bunches were at 20% veraison and samplings were carried out weekly until one week prior to harvest. The first sample was taken prior to the applications, followed by 6 additional samplings once a week throughout maturation. In each of these samplings, the following measurements were made: berry growth (equatorial diameter (mm), berry length (mm) and weight of 10 berries (g), soluble solids (°Brix), total acidity (g/ L H₂SO₄), pH, total phenols (mg gallic acid/g skin), color intensity, total anthocyanins (mg malvidin/g skin), total tannins (g catechin/g skin) and anthocyanins by high performance chromatography coupled with an aligned photodiode detector (HPLC-DAD).The anthocyanins identified by HPLC-DAD were mainly glycosylated anthocyanins and on occasions the presence of p-coumarylated anthocyanins was found.Glycosylated anthocyanins were quantified where the majority in all the treatments and varieties was peonidin-3-O-glucoside.