PERFORMANCE OF GEWURZTRAMINER (VITIS-VINIFERA L) ON 3 ROOTSYSTEMS

'Gewurztraminer' vines on three rootsystems [own-rooted (OR); self-grafted (GWZ); S.O.4 (SO4)] in a randomized complete block experiment were evaluated over a 8-year period (1989-91) for yield components, fruit composition, and weight of cane prunings. No significant differences in yield components or fruit composition were observed between the treatments in 1989. Weight of cane prunings were also not affected by rootsystem, and ranged from 0.93-1.20 kg/vine following the 1991 season. Yield, cluster weight, and berries/cluster were highest in SO4 vines in 1990, and both the SO4 and GWZ treatments contained highest berries/ cluster in 1991. The SO4 and GWZ treatments were also highest in degrees Brix in 1990 and 1991, but no effect of rootsystem was observed on either TA or pH. It was considered noteworthy that use of a rootstock had some beneficial effects on yield and fruit composition in the absence of biotic factors (phylloxera and nematodes), nutrient deficiencies, high pH soils or water stress. Use of rootstocks in areas with low phylloxera populations may therefore be beneficial for environmental adaptation, with potential for attendant vine devigoration, yield increases, or improvement in winegrape quality.