Achieving Vine Balance of Syrah with Mechanical Canopy Management and Regulated Deficit Irrigation

摘要

Canopy architecture, yield components, fruit composition, and vigor of Syrah were measured in response T_o four canopy management and three regulated deficit irrigation (RDI) treatments. The control consisted of dormant hand pruning T_o 22, two-node spurs (HP) with no further manipulation. Other treatments consisted of mechanically box pruning vines T_o 10 cm hedges and mechanically thinning the canopy T_o a density of 5 (CLL) or 7 (CLM) count shoots per 30 cm of row or mechanically box pruning T_o a 10 cm hedge with no shoot thinning (CLH). Control vines were irrigated T_o 70% of evapotranspiration (ET_o) from fruit set until harvest (RDIC). Other vines either received 70% of full vine ET_o until veraison and 50% of ET_o (RDIL) thereafter or received 50% of ET_o between fruit set and veraison (RDIE) and 70% thereafter. Mechanical shoot thinning (CLM) removed 25% of the T_otal shoots, exposing 70,600 shoots-ha~-1 with a distance of 4.6 cm between count shoots on the cordon, which translated T_o four leaf layers and 12.6 m2 leaf area. The combination of the CLM and RDIE decreased berry weight at harvest by 12% without decreasing yield compared T_o HP, resulting in 21.5 T_onsha~-1 yield. A combination of CLM and RDIE was needed T_o achieve vine balance with a crop load of 9.9 kg yield/kg pruning weight and a leaf area T_o fruit ratio of 0.75 m~2·kg~-1. The study identified a canopy management method that can be used in combination with regulated deficit irrigation that reduces input costs through mechanization and enhances berry composition with a vine balance that provides sustainable production.