Evaluation of the agronomic performance of cvs. Syrah and tempranillo when grafted on a new series of rootstocks developed in spain

Abstract

Context and purpose of the study ‐ The choice of an adequate rootstock is a key tool to improve the performance of grapevine varieties in different ‘terroirs’, as rootstocks confer adaptation to soil characteristics such as salinity, acidity, lime content or drought. Moreover, it is well‐known that rootstocks also have a significant influence on the growth and vegetative cycle of the plants and, consequently, on yield and grape quality, and they can be a relevant adaptation tool of viticulture in a changing climate. Therefore, it is essential to have a sufficient supply of rootstock varieties in order that the winegrowers can choose the best suited to the different growing conditions. However, since the beginning of the 20th century, the development of new grapevine rootstocks has been very limited, despite growers’ needs have changed dramatically. The objective of this study was to evaluate the agronomic performance of cvs. Syrah and Tempranillo when grafted on eight new rootstocks belonging to the RG‐Series, obtained by the Spanish nursery Vitis Navarra.

Material and methods ‐ The evaluation was performed during 4 consecutive seasons in a vineyard located in Miranda de Arga (Navarra, Spain), where Syrah and Tempranillo are grown grafted on 10 different rootstocks (eight new rootstocks and the two parental, 41B and 110R). The vineyard was planted following a completely randomized experimental design, with three replicates of ten vines. During the study period (2015‐2018), parameters related to growth, yield, and industrial and phenolic quality were collected in order to evaluate their performance.

Results ‐ The different rootstocks significantly modified growth, yield and quality parameters in both varieties, some showing very promising features for higher yielding vineyards, and some not so productive but interesting for higher quality grape production.