Phenological characterization and quality of fi ne ‘Black Star’ table grape

Abstract

The phenological behavior of grapevines depends on several factors such as weather conditions, rootstock and cultivation, among others. Therefore, it is important to study the phenological behavior of a certain cultivar, at a specifi c region, to provide growers with data that will allow them to program/plan their management and crop operations. Thus, the objective of this work was to evaluate the phenological characteristics and physical-chemical attributes of the ‘Black Star’ grapevine berries. The trial occurred in a commercial area located in Marialva-PR, during an off season crop and a regular crop, between 2012 and 2013, respectively. For the phenological behavior, the duration (number of days) of the following stadia was determined for 10 plants: prunning at the begining of sprouting (PR-BI), prunning at visible infl orescences (PR-VI), prunning at full fl owering (PR-FF), prunning at the beginning of the berries maturation (PR-MI) and prunning at harvesting (PR-HA). Regular crop cycle lasted 146 days and off season crop 121 days. In regards to the thermal demand for the grapevine to complete the prunning cycle until harvesting, it was verifi ed an accumulation of 2,125 degrees-day (DD) for the regular crop and 1,691 (DD) for the off season crop. Berries, with seeds, had an elongated, elliptical form and a dark purple-red skin coloration. Average contents for total soluble solids, titled acidity and maturation index were 14.8 °Brix, 0.6% of tartaric acid and 24.8 for the regular crop, and 14.0 °Brix, 1.0% of tartaric acid and 14.1 for the off season crop, respectively.