Gill Giese,* Kevin Lombard, and Ciro Velasco-Cruz
*New Mexico State University, 1036 Miller Road, Los Lunas, NM 87031 (ggiese@nmsu.edu)

Rootstock choice has been shown to influence scion phenological development, leaf senescence, timing of dormancy, vegetative growth, and berry maturation. Our research aim was to determine and describe the rootstock influence on scion mortality, vine development and vegetative growth, yield components, and berry composition in the high-elevation (>1700 m), semi-arid climate of northwest New Mexico. Nine different rootstocks in grafted combinations with Refosco and Gewürztraminer were field-planted in 2008 in a completely randomized design with six replications and four vines per plot. After nine years, Refosco vines grafted to 775 Paulsen (Vitis berlandieri × V. rupestris) had the lowest vine mortality (25%), whereas among Gewürztraminer vines, those grafted to 775 Paulsen had the greatest crop weight. Gewürztraminer vines grafted onto SO4 (V. berlandieri × V. riparia) exhibited the lowest vine mortality (13%), and Refosco vines grafted to SO4 had the greatest crop weight (8.25 kg/vine) relative to all other tested scion/rootstock combinations. The earliest berry maturity and greatest YAN (yeast assimilable nitrogen) was associated with Gewürztraminer vines grafted to 1103 Paulsen. Lowest crop weights were associated with vines grafted to either 110 Richter (V. berlandieri × V. rupestris) or 5C (V. berlandieri × V. riparia). Understanding how rootstock selection can impact scion performance in non-traditional winegrowing regions is of immediate practical importance to local growers and can provide insight by comparison to data from more established regions.

Funding Support: New Mexico State University