Biochemical profile of ‘Niagara Rosada’ grapes under different rootstocks and training system

Grapevines are used to be trained to different systems, while there is a paucity of literature on the main cordon disposition with regards to grape quality, especially grafted on to different rootstocks. Therefore, a field experiment took place in the city of Sao Manuel, state of Sao Paulo, Brazil. This study aimed to evaluate the quality of the ‘Niagara Rosada’ grapes by training them to vertical shoot position (VSP) system with unilateral and bilateral cordons grafted on to rootstocks during two crop seasons (2015 and 2016). To assess the data, a 22 factorial setup organized in a randomized complete block design was used, corresponding to two rootstocks (‘IAC 766 Campinas’ and ‘IAC 572 Jales’) and two cordons (unilateral and bilateral cordon).  The variables assessed were the content of soluble solids, titratable acidity, fruit-ripeness index, reducing sugars, total phenolic compounds, total flavonoids, anthocyanins, antioxidant activity via DPPH and FRAP. Results indicated that ‘IAC 766 Campinas’ rootstock and bilateral cordon improved the chemical quality in grapes, especially the contents of anthocyanins and sugars. This management practice should be selected when growing ‘Niagara Rosada’ grapes, provided that there is an influence in the quality of the final product.