The influences of rootstock and pruning seasons on productive and physicochemical traits of 'Niagara Rosada' grape

Abstract

The current study aimed to evaluate the effect of different rootstocks ('IAC 766', 'IAC 572', 'IAC 313', 'IAC 571-6' and '106-8 Mgt') on the physicochemical quality of 'Niagara Rosada' grape under Brazilian subtropical climate. In this study, a vineyard trellising system supported three years old vines at a density of 6536 plants ha-1. Therefore, evaluations consisted of three pruning seasons: two winter pruning (August 2011 and September 2012) and a summer pruning (January 2012). A complete randomized block design was conducted, subdivided into plots, with five replicates, the plots represented by 5 rootstocks and subplots by pruning seasons. We evaluated bunch number per plant; bunch, berry and rachis fresh mass; berries number per bunch; soluble solid, pH and titratable acidity content in the grape must. Results showed that 'Niagara Rosada' grafted onto 'IAC 572', presented the highest bunch mass (227g), rachis fresh mass (7.5g) and berries number per bunch (66); while 'IAC 313' rootstock performed the lowest values. Moreover, 'IAC 766' and '106-8 Mgt' rootstocks presented the highest soluble solid and titratable acidity content, due to these rootstock's precocity. Furthermore, the highest ratio between soluble solid and titratable acidity was found in 'Niagara Rosada' grafted onto 'IAC 313' and 'IAC 571-6' rootstock.