Synergistic influence of rootstock and cane regulation on biomass accumulation in wine grapes under semi-arid conditions

An investigation was conducted to know the influence of rootstock and cane regulation on growth, yield, and quality of wine grapes during 2022-2024 at the grape orchard, MHREC-Block J1, University of Horticultural Sciences, Bagalkot, located in the northern dry zone of Karnataka. The experiment was laid out in a split-split plot design with two rootstocks (Dogridge and 110 R), five wine grape cultivars (Cabernet Sauvignon, Medica, Shiraz, Sauvignon Blanc, and Chenin Blanc), and three cane regulation levels (Control, 36 canes/vine, and 24 canes/vine). Observations were recorded for fresh and dry weight of cane after foundation pruning. Results revealed that rootstock 110 R significantly outperformed Dogridge in both fresh (1540.26 g) and dry weight (1113.43 g) of cane. Among varieties, Medica recorded the highest fresh (1461.07 g) and dry weight (1071.66 g), significantly higher than others. Cane regulation of 24 canes per vine (C₃) yielded superior fresh (1271.02 g) and dry weight (945.18 g), followed by 36 canes per vine (C₂), which was on par with Control. The interaction of 110 R × Medica × 24 canes per vine recorded the highest fresh (1904.30 g) and dry weight (1182.56 g) of cane, significantly surpassing other combinations. The improvement in growth parameters under these treatments is attributed to enhanced root system efficiency, better nutrient and water uptake, optimized canopy load, and superior varietal sink strength. These findings suggest that the synergistic effect of suitable rootstock, high-performing cultivar, and optimal cane regulation improves biomass accumulation, thereby enhancing vine vigour and potential productivity under semi-arid viticultural conditions.