Qun Sun,* George Zhuang, Antonios Marinos, David Garcia, and John Wilson
*California State University, Fresno, 2360 E. Barstow Avenue, M/S VR89, Fresno, CA 93740 (qsun@csufresno.edu)

Cabernet Sauvignon is planted widely in California’s Madera AVA (crush district 13). However, the price per ton for Cabernet Sauvignon in this region is much lower than in other California wine regions. It is becoming progressively more challenging to maintain economic sustainability and competitiveness to grow Cabernet Sauvignon in this region. The overall goals for this study were 1) to understand the differences in characteristics of Cabernet Sauvignon grapes and wines between Madera AVA and other California wine regions and to determine which fruit traits drive the quality dif- ference; and 2) to investigate whether mechanical leafing and deficit irrigation could achieve the desired fruit quality, then guide Madera AVA grapegrowers to use appro- priate farming practice. Cabernet Sauvignon berries were harvested from commercial vineyards in the Madera AVA and five other regions (McFarland, Linden, Livermore, Paicines, and San Lucas). Cultural practices were carried out according to commercial industry standards for that area. In a Madera vineyard, the experiment was a two (deficit irrigation: 50% ETc and 80% ETc) × three (leaf removal at bloom or berry set and control) factorial trial with a split block design and five replicated blocks. Wines were made in triplicate for each location. Berries from the Madera AVA treated with deficit irrigation (50% ETc) combined with mechanical removal at bloom had more total berry anthocyanin, total phenolic compounds, and wine color intensity. These quality indicators were better than those from McFarland and close to Linden. Sensory evaluation indicated that the wine made from treated berries in Madera AVA was fruity, peppery, and balanced with sourness, bitterness, and astringency.

Funding Support: American Vineyard Foundation