Evaluation of Zinfandel Heritage Selections

We have continued to evaluate selections of Zinfandel from across California. Although the selections are planted in an unreplicated plot, we are taking data and trying to interpret them with appropriate caution. In 2002, apparent differences exist in virtually all measured yield components (pruning wts were not available for this report). Average yield was 4.1 kg vine-1 with a range of 6.8 to 1.9 kg. Cluster wt averaged 215 g and ranged from 308 to 119 g. Berry wt averaged 1.7 g and ranged from 2.1 to 1.3, leading to an average berry number per cluster of 126 and a range of 194 to 60. As in previous years, the Primitivo selections from UC Davis FPMS had lower yields than the plot average despite having slightly more clusters per vine. Primitivo clusters were 60 to 90 g lighter than the plot average and had 30 to 45 fewer berries. FPMS Zinfandel clones had yield components that were at or below the plot average for all selections in 2002. The only exception was berries per cluster of Zinfandel 01A which had 17 more berries per cluster than the plot average. As in the past years, they do not distinguish themselves, as their reputation in industry implies, for having larger clusters and larger berries. The relative differences among clones in 2002, and the relative values for Primitivo and FPMS Zinfandels, reflect the longer term averages (1999-2002) averages. Wines were made from ten selections again in 2002. Wine analysis data are given in the report but the wines have not been otherwise evaluated at this time.