elektion Oppenheim 4, a.k.a SO4, is a hybrid of V.Berlandieri X V. Riparia created at the viticulture school of Oppenheim, Germany, in 1904 (Galet and Morton, 1979). The rootstock has resistance to Phylloxera and moderate resistance to many nematode species. Scion vigor is considered moderate and has adapted well to Michigan conditions. It appears to confer “medium to short-cycling” on scion varieties regarding fruit and canopy maturation period (Howell, 2005).