Graduation date: 2007In 2003 and 2004 vigor zones were delineated in two commercial vineyard sites based on vine growth variation to assess fruit and wine phenolic chemistry. In 2004, the effects of shading on the accumulation of phenolic compounds were also investigated. Model extractions were done from the shading experiment and the vigor zones in 2004. Wine and extracts were analyzed by HPLC and spectrophotometry. Berry weight, dry skin weight, °Brix, pH and anthocyanin content were higher and titratable acidity and the proportion of malvidin-3-O-glucoside was lower in 2003 compared to 2004. High vigor zones had lower °Brix and higher titratable acidity and a trend for lower anthocyanin content per berry in both years. Site A had proportionally higher peonidin and lower malvidin than site B. While there were minimal differences in seed proanthocyanidin, large increases were found in low vigor zones for skin proanthocyanidin, proportion of (-)-epigallocatechin, and pigmented polymer content in fruit. In 2004, the shade treatment had lower accumulation of flavonols, lower skin proanthocyanidin, minimal differences in anthocyanins, a large proportional increase in peonidin glucosides, and proanthocyanidin compositional differences. The model extractions from the shade experiment paralleled treatment differences in the fruit except that skin proanthocyanidin percent extraction was found to be ~ 17% higher in the exposed treatment. For the vigor zone model extractions, there were no differences in pomace weight. Site A model extracts tended to have a higher anthocyanin concentration and a lower proportion of malvidin-3-O-glucoside than those from site B. The 2003 wines had a higher anthocyanin concentration and a lower proportion of malvidin-3- O-glucoside than in 2004. The same response was seen in the fruit. The medium vigor zone wines had higher anthocyanin concentrations than either high or low vigor zones. In both years, there were higher proportions of delphinidin and petunidin glucosides in wines made from low vigor zone fruit. Low vigor zone wines had ~ a two-fold increase in pigmented polymer concentration, a large increase in the proportion of skin proanthocyanidin, greater sulfite resistant pigments, higher color density and lower flavan-3-ol monomer concentration. Differences found in the wines magnified variation in the fruit.