Ten grapevine rootstocks: effects on vegetative development, production and grape quality of cv. Mencia in the d.o. Bierzo (Spain)

Grapevine rootstock is basic to achieve good adaptation of the vine to ground and environment. Given the low knowledge of the effects of different rootstocks in the agronomic behavior of cv. Mencia, an experimental trial was developed in the D.O. Bierzo during the period of 2009-2012, on a vineyard planted in 2002 in Pieros (Leon).

The vines were trained with vertical trellis, by means of bilateral Royat cordon pruning, to 3 two-bud spurs per arm, for a total of 12 buds per vine. Vine distances were of 3.0 m x 1.0 m (3,333 vines/ha) and row orientation is East-NE to West-SW. The rootstocks to study are: 110R, 140Ru, 1103P, 101-14M, 420A, 5BB, 41B, 161-49C, 333EM, SO4. The experimental design consisted of 4 randomized blocks, with an elemental plot of 30 vines.

The results showed a tendency of rootstocks SO4 and 420A to increase grape yield, and 101-14M and 5BB to reduce it, through the variation of number of clusters per vine and cluster weight. The vegetative development was clearly favored by rootstocks 5BB and 1103P, and reduced by 101-14M and 110R, which became the weakest rootstocks, mainly due to the variation of individual shoot vigor. The Ravaz index was higher in 110R, 41B and SO4 and lower in 5BB and 1103P.

The influence of the rootstock varied on several parameters of grape quality, which was partially dependent on the level of vegetative growth and grape yield achieved by each rootstock. Thus, 5BB, 101-14M and 1103P, the less productive rootstocks, increased the sugar concentration, whereas 41B and 110R reduced it. The acidity increased with 110R and 1103P, and was reduced with 333EM and 101-14M, whereas the pH value of 5BB, of highest sugar concentration, stood out from the rest. The tartaric acid in 41B and SO4 was the highest, and decreased in 333EM and 140Ru, whereas the malic acid got the highest values in 5BB and 1103P, the rootstocks of highest vegetative growth, and decreased in 101-14 M, as well as in 41B and 110R, the rootstocks of lower sugar concentration. The potassium concentration clearly increased in 5BB, a rootstock of very low production and high sugar content, and decreased in 41B, the rootstock of lowest sugar concentration, and 101-14M, whereas the total phenols index did not shown statistically significant differences between rootstocks