Training Systems for Cold Climate Interspecific Hybrid Grape Cultivars in Northern Climate Regions

Abstract

Training systems influence grapevine (Vitis sp.) size, shape, and canopy architecture, which ultimately affects yield and fruit composition. Cold climate interspecific hybrid grapes (CCIHG) have propelled the creation of a new and fast-growing grape and wine industry in the northeast and upper midwest of the United States. This study evaluated the effect of three training systems: high cordon (HC), midwire vertical shoot positioning (VSP), and modified Scott Henry (SH) on vine growth, yield, and fruit composition of four CCIHG cultivars, Brianna, Frontenac, La Crescent, and Marquette, during two growing seasons. The divided canopy training system SH increased the crop yield per meter of row in all cultivars relative to HC and VSP, despite reduction in crop size imposed by crop thinning in vines trained to SH. VSP-trained vines had lower yields compared with HC, and this was most evident during the second year of the study, as vines were still being trained when the study commenced. Despite the higher crop size associated with vines trained in a SH system, there were minimal differences in fruit soluble solid concentration (SSC), titratable acidity (TA), and pH at harvest time. No differences were observed in vine size, expressed as dormant cane pruning weights, among training systems possibly because of the control of vegetative vigor, especially in VSP-trained vines, through shoot positioning and summer pruning. CCIHG cultivars appear to have the capacity to support higher yields under SH and HC systems without compromising fruit quality; however, labor requirements involved in establishing and maintaining more complex training systems should be considered when selecting a training system for CCIHG cultivars.