Cultivar and rootstock interaction affects the physiology and fruit quality of table grape with different water management – preliminary results

Abstract

Vine rootstocks are known to have an influence on the vegetative growth and yield of the scion, and also can influence fruit quality in grafted vines with direct effects on the uptake of water and mineral elements, or more indirectly by affecting the balance between fruit and shoot growth. The adaptability of rootstocks to restrictive soil conditions, water and nutrient supply is variable. The impact of different rootstocks on vine performance and scion could be useful information for selecting which rootstock is more suitable for the soils with reduced water availability. This study was conducted in 2013 on three Vitis vinifera L. cultivars ('Summer Royal', 'Crimson seedless' and 'Autumn Royal') grown in Apulia region (southern Italy) and planted in the same trial site. All vines were grafted onto two rootstocks ('140 Ru' and '34 EM') and subjected to two different irrigation practices under controlled water deficit, in order to study the effect of grafting and water deficit on the whole vine growth and productive development. In particular, vine performance was assessed throughout the season by determining the leaf water potential and, at harvest, the crop yield and both the organoleptic and nutritional (organic acids, carbohydrates, flavonoid and non-flavonoid phenolic compounds) grape quality. From the preliminary findings, we can conclude that physiological responses, such as water relations, of table grape vines could be influenced by the rootstock type, whilst metabolomic characterization of mature grapes suggest that the fruit quality was mainly dependent on the cultivar genotype, even though the different size-controlling rootstocks exerted a relevant influence, especially on vines under restricted water regime.