2024, Vol. 7, Issue 2, Part D

author(s)
Abhilash K, Satisha J, Shivashankara KS, Laxman RH, Satisha GC, Venkat Rao and Ashok Alur

abstract
In grape, manipulation of the source-to-sink ratio through various canopy management practices plays pivotal role, particularly balancing the growth and yield of grape cultivars under mild tropical climatic condition is an major task where, double pruning single cropping system is followed. So it is very much necessary to standardize as well as identify the proportion of biomass to crop load especially in the commercial cultivars like Red Globe (seeded and less vigorous cultivar) and Crimson Seedless (seedless and more vigorous cultivar) and hence the same cultivars were selected for this study. The study includes three cane regulation (20, 30, 40 canes per vine) and three leaf regulation (8, 12, 16 leaves per canes) treatments. Among the different treatment combinations, growth parameters like inter nodal length and girth of the cane (vegetative and fruiting cane) were found to be maximum under lowest cane and leaf density (20 cane with 8 leaves) treatments. Similarly, days taken to bud sprouting and panicle initiation were found to be earliest in case of lowest cane and leaf density treatments. The maximum leaf area per vine was observed in Red Globe, moderate cane and leaf density (12 leaves with 30 canes per vine) whereas, in crimson seedless, increased leaf and cane density increased leaf area. But, movement of assimilates into the sink (bunch) showed different trend with increased berry weight, bunch weight, bunch volume, yield per vine in moderate to high leaf or cane density in Red globe and less to moderate leaf density in Crimson Seedless. Whereas, leaf area required for production of per gram berry was found very less in lowest cane and highest leaf density (20 cane with 16 leaves) in both cultivars. This showed that, even though both the cultivars were differed in their vigour but with respect to assimilates accumulation were found to be in lowest cane density with highest leaf density.