Evaluation of Winegrape Clones
This project evaluates 20 Pinot noir and 13 Chardonnay clones for their viticultural and enological attributes in production of base wines for sparkling wine production and five Merlot and three Malbec clones for their viticultural and enological attributes for production of red wine. Replicated plots of Pinot noir and Chardonnay clones have been established at Gloria Ferrer in Sonoma and of Merlot and Malbec at the Department?s Oakville Experimental Vineyard.
Chardonnay mean harvest °Brix was 21.6 in 2000 and did not vary by more than 0.6 °Brix from the mean with the exception of the Wente clone that was harvested 1.2 °Brix above the mean. This compares with the three-year average that shows a mean harvest Brix of 20.8. The yield range was approximately 2x for the three-year data and in 2000. In 2000 clone 4 had a yield of 8.2 kg vine-1 and the Wente clone yield was 4.0 kg vine-1. For the majority of Chardonnay clones harvest date was correlated to vine yield with two notable exceptions. While clone 4 has the largest crop and latest harvest date, the harvest date appears to be delayed more than the yield would warrant when compared to the other clones. Likewise, the Wente clone with the lowest yield also has a much later harvest date than we would predict. These observations hold for both the 2000 and three-year data.
Mean Pinot noir harvest °Brix for 2000 was 19.9. Harvest was completed over a 21-day period in 2000 and the two-year data shows a 19-day span. In both instances clone 4 was the first harvested and clone 780 the last. Yield ranged from 5.7 (clone 870) to 9.4 (clone 666) kg vine-1 in 2000.
As in preceding years, Merlot clone FPMS 8 had the lowest yield (6.3 tons/acre) in the 2000 growing season compared to the other clones (9.2 to 10.3 tons/acre). The primary contributing yield component was berries per cluster (103 for clone FPMS 8 versus 151 to 164 for clones 1, 3, 6, 9) this was also consistent with past data. In 2000 clone FPMS 8 produced the smallest berries and second lowest number of clusters per shoot. Averaged over six years, clone FPMS 8 has produced approximately two thirds the yield of the other four clones due to smaller clusters caused by reductions in both number of berries per cluster and berry size.
Mean yield for all Malbec clones was 4.9 tons/acre for the 2000 crop and was 40%above the average of the preceding 4 years (3.5 tons/acre). Clonal differences were evident in all components of yield except berry weight. In 2000, clone FPMS 08 was again the most fruitful in all components and produced 9.7 tons per acre compared to 4.1 and 2.2 tons per acre for FPMS 04 and 06. In each of the last four years, FPMS 08 has consistently produced the greatest crop and FPMS 06 has produced the least. Averaged over five years, yields were 3.0, 2.2, and 6.2 tons per acre for FPMS 04, 06, and 08 respectively.