Research will be conducted to determine interactions among environmental conditions (soil and climate), irrigation and N fertilization levels, and canopy management methods that influence wine grape quality. The goal of the research is to determine whether a decline in canopy performance due to stress resulting from water and N deficits delays maturation and reduces fruit quality. The research will be conducted at two or three commercial sites differing in climate and soil texture. Canopy growth and performance (photosynthesis), and fruit microenvironment will be monitored over the growing season. Yield and its components and fruit compositional quality, including methoxypyrazine, will be determined. Beginning in the second year, small-lot wines will be made from selected treatments and will undergo compositional and sensory analysis. Additional complimentary basic research on leaf and fruit ABA levels, fruit phenolics, and mesoclimate characterization will be conducted under our AAFC-funded program. The results will be used to make site-based recommendations for irrigation, N fertilization and canopy management that will optimize vine vigour and canopy performance.