ROOT HYDRAULIC CONDUCTIVITY IN THREE SELF-ROOTED AND GRAFTED TABLE GRAPE CULTIVARS

Aim : Root hydraulic conductivity is one of the main factors that control water flow in the soil-plant system and ultimately affect crop irrigation requirements. This work sets out to estimate root water conductivity for three self-rooted or grafted table grape cultivars. Methods and results : We evaluated root water conductivity of the cultivars ‘Black Magic’, ‘Matilde’ and ‘Victoria’ grafted onto 1103 Paulsen rootstock or self-rooted. Measurements were performed on two-year-old table grapes grown in pots filled with pumice. Root water conductivity was determined by placing the pots in a pressure chamber and increasing pressures from 0.05 to 0.30 MPa, at intervals of 0.05 MPa. Plant growth in terms of shoot and root dry matter was also evaluated, as well as leaf and root area. Conclusion : Root water conductivity differed according to cultivar and grafting. The ‘Victoria’ cultivar had higher root water conductivity than the other two, which differed little between them. The grafted plants showed higher root water conductivity than the self-rooted plants, except the plants of the cultivar ‘Matilde’, whose root water conductivity for the grafted and self-rooted plants was almost the same. It was also observed that the higher root water conductivity in relation to cultivar and grafting changed with increasing water flux and was constant for high water flux. Significance and impact of the study : Estimation of root hydraulic conductivity helps to determine the water consumption of the cultivars investigated, whether self-rooted or grafted, as well as the amount of irrigation water to apply to vineyards