Effect of pruning intensity on bud fruitfulness, yield and quality of Punjab Purple grapes (Vitis vinifera)

The hybrid H-516 (Punjab Purple) grapevines trained on Y-trellis system of training were pruned at 2, 3, 4 and 5-bud level during last week of January to standardize the pruning technique. The maximum fruitful buds (69.38%) were recorded at 2-bud level followed by 3, 4 and 5-bud pruning level. The higher number of bunches per fruitful bud (1.94 at 4^th node) were found when pruning was done at 4-bud level. The yield per vine was found to be highest (11.2 kg yield per vine) in case of pruning treatment, where 4-buds were retained. The pruning treatment in which 4-buds per spur was retained had higher anthocyanin (90.0 mg/100g) and total soluble solids content (18.95%). Likewise, lower acid content (0.52%) were found in 4-buds pruning level. The bunch weight and size did not differ significantly with various pruning levels. In grape hybrid H-516 at time of pruning 4-buds per spur should be retained for higher yield and improved fruit quality.