Abstract

VALOR G, Oswaldo  and  SANCHEZ L, José. Bud break, fertility of lateral shoots and location of clusters on the main shoot of grapevine ‘Tucupita’ under tropical conditions. Bioagro [online]. 2003, vol.15, n.3, pp.193-200. ISSN 1316-3361.

Six-year old plants of the table grape cultivar ‘Tucupita’ were selected to study total and fertile bud break, location and frequency of clusters on main and lateral shoots, and fertility of the lateral shoots, at the Instituto de la Uva, in El Tocuyo, Lara State, Venezuela (9°48’ N, 69°48’ W, 630 m.a.s.l). Plants were grafted on ‘Criolla Negra’, spaced 3 x 2 m, trained in double cordon and supported on arbor trellis system. Pruning was managed leaving on the average 10 to 12 spurs per plant with 1 to 3 nodes each. Four groups of plants were chosen with 32 main shoots that were tagged as fertile and non fertile shoots, and grouped as free growing or tipped to 10 nodes in an acrotonous way. Bud break on spurs was 54 ± 1.84 % and additional bud break on arms and basal part of spurs was 30 ± 1.75 %. Fertile bud break was 33 ± 1.78% averaging 1.17 ± 0.12 clusters per shoot. The clusters were located between node positions from 3 to 11, being the highest frequency in the position 5. Clusters on positions 9 to 11 showed an intermediate structure between clusters and tendrils. Total lateral bud break was present along positions 1 to 15 of the main shoot. Fertile lateral shoots were present in all those node positions except on the position 1 which was always infertile. The greatest frequency of fertile lateral shoots was observed in positions 2 to 8. The infertile main shoots always showed the highest lateral bud break. Tipping did not influence the development of fertile lateral shoots but stimulated a higher lateral break mainly in those buds located near the apical portion of the main shoot.

Keywords : Vitis vinifera; budbreak; tipping.