Photosynthesis, Biochemical and Yield Performance of Grapevine Hybrids in Two Rootstock and Trellis Height

Abstract

The interaction between variety, rootstock, and trellis height is important for grapevine management, mainly for producing new varieties of grapes for juice and wine in new wine-growing regions with high production potential. Then, this study aimed to evaluate the rootstocks and trellis height influence on photosynthesis, biochemical, and yield performance for grapevine hybrids. The experiment was carried out in a randomized block design using two factors, rootstocks (‘IAC 766’ and ‘106-8 Mgt’) and trellis height (until 1.6 and 2.0 m), evaluated for two grapevine hybrids (IAC 138-22 ‘Maximo’ and ‘BRS Violeta’). During grapevine flowering, it was evaluated photosynthesis and biochemical performance, for this, the gaseous exchanges were measured using the open system photosynthesis equipment with a CO2 analyzer and water vapor by infrared radiation, being net assimilation rate of CO2, stomatal conductance, transpiration rate, internal CO2 concentration, water use efficiency, carboxylation efficiency (Rubisco), and the flux density of photosynthetically active photons. At the stages of grapevine flowering and ripening berries were evaluated the antioxidant enzymes (peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT)), total soluble proteins, chlorophylls, and SPAD. The interaction between rootstock and trellis heigh influenced varieties’ photosynthesis, biochemical, and yield performance. In conclusion under subtropical conditions, better photosynthesis, biochemical, and yield performance were observed when both cultivars were grafted on the ‘IAC 766’ rootstock. The ‘IAC 138-22 Maximo’ was trained until 2.0 and grafted on the ‘IAC 766’ rootstock, increasing grape production and photosynthesis efficiency. In addition, this variety was more productive than ‘BRS Violeta’.