ROOTSTOCK, BUD FRUITFULNESS AND YIELD OF TABLE GRAPES VARIETIES

Abstract

The influence of rootstocks ‘Saltcreek’, 'Freedom’ and ‘Harmony’ on vigor, bud fruitfulness, bud necrosis, fruit yield and quality for table grapes (Vitis vinifera L.), was evaluated on the ‘Perlette’, ‘Flame Seedless’ and ‘Sugraone’ cultivars. On the rootstocks ‘Saltcreek’ and ‘Freedom’ scions induced higher shoot length, pruning weight and shoot weight. There was a negative correlation between these variables and bud fruitfulness (r=-0.632*; r=-0.77*; r=- 0.765*). There was a positive correlation between bud necrosis and shoot length and pruning weight (r=0.743*; r=0.572). Bud fruitfulness was lower in all cultivars when grafted on ‘Saltcreek’ and 'Freedom' than on 'Harmony’ or on their own root. Regressions analyses showed high determination coefficients between bud fruitfulness and number of clusters for ‘Perlette’ (R² =0.73) and ‘Flame Seedless’ (R² =0.80), while for ‘Sugraone’ it was low (R² =0.43). The combinations ‘Perlette’/‘Freedom’ and ‘Flame Seedless’/‘Freedom’ had lower number of clusters per vine, but had more cluster length and cluster weight and berries with more diameter than on their own root. Rootstocks did not produce any advantage to ‘Sugraone’; on the contrary, they delayed harvest, effect that was also found in ‘Perlette’ and ‘Flame Seedless’.