Performance of Zinfandel and Primitivo Clones in a Warm Climate

Abstract

Four clones of Zinfandel and one clone of Primitivo, all certified virus-tested, were compared in a warm, Region V, climate over a five-year period. Few significant differences were found among Zinfandel clones; however, Primitivo differed substantially from Zinfandel. Despite having significantly more clusters per vine, Primitivo had 15% lower yield due both to 14% fewer berries per cluster and 11% smaller berries. Primitivo's 10% heavier pruning weight and advanced maturity (about 1 °Brix) could both be accounted for by its lower yield per vine.