Rootstocks for table grape ‘BRS Clara’ in the São Francisco Valley, northeast Brazil

Abstract

The present work aimed to evaluate the influence of rootstocks on yield and fruit characteristics of table grape ‘BRS Clara’ under the tropical conditions of the Sao Francisco Valley, northeast Brazil. An experiment was carried out during six growing seasons from 2014 until 2017 in Petrolina, Pernambuco State, Brazil (9°09’S 40°22’W; average altitude 365.5m). ‘BRS Clara’ is a white seedless table grape released by the Genetic Grape Breeding Program of EMBRAPA. It was grafted on six rootstocks: ‘IAC 313’, ‘IAC 766’, ‘IAC 572’, ‘SO4’, ‘Harmony’ and ‘Paulsen 1103’. The results showed that yields were affected by rootstock. Higher yields were obtained for vines grafted onto rootstock ‘Paulsen 1103’ (13.7 t ha(‑1)) than those grafted onto ‘IAC 572’ (5.4 t ha‑1). The number and weight of bunches per vine were also significantly higher in vines grafted on ‘Paulsen 1103’ than on ‘IAC 572’. The physical and physico-chemical characteristics of the grapes, such as length and width of the bunch, weight and diameter of the berry, soluble solids content, titratable acidity and ratio were not influenced by the rootstock. Vines grafted on ‘Paulsen 1103’ presented average values of 21.1 °Brix for soluble solids content and 0.56 g tartaric acid 100 mL(‑1) for titratable acidity. The sugar/acid ratio of 39.8 shows that grapes of very good quality meet the requirements for consumption of different markets. In conclusion, the rootstock ‘Paulsen 1103’ is recommended for table grape ‘BRS Clara’ grown in the Sao Francisco Valley, northeast Brazil, for increasing yield without affecting other quality characteristics of the grape.