Evaluation of Winegrape Clones
Three clonal trials were reported on: Zinfandel/Primitivo/Sangiovese, Cabernet Sauvignon, and Pinot noir for sparkling. In the Zinfandel trial, the UCD materials remain indistinguishable with large, tight clusters and large berries; the Primitivo variety has consistently had looser clusters as a result of fewer berries/cluster. Sangiovese 3 continues to have fewer berries per cluster than Sangiovese 2. The Cabernet Sauvignon clones in the new hillside location are showing some of the same trends as in previous studies with one of the major differences being the fewer berries/cluster evident in clone 6. Differences in berry size which were generally not seen in previous studies must be followed for a few more years to establish a reliable trend. In Pinot noir for sparkling wine, differences were seen in most yield components, chemistry at harvest and duo-trio tests, despite the great influence of the cool weather at bloom and its effect on fruitset. Some year x clone interactions were seen indicating that clones were reacting with relative differences between the two years. Another year or two will be required to establish consistent trends.