The 2011 ASHS Annual Conference

To better understand the optimal canopy management techniques necessary to meet the demands of both vineyard and cellar, a study was conducted analyzing the interactions amongst canopy management steps for Pinot Grigio in the southern San Joaquin Valley.  The treatments were arranged factorially where two pruning methods (spur vs. mechanical box-pruning), three shoot density levels (low (23 shoots/m), medium (33 shoots/m), high (49 shoots/m)), and two leaf removal methods (east-side leaf removal, or none) were applied to alter the canopy microclimate in four randomized complete blocks.  Pruning method and shoot density interacted to affect the count shoots and total shoots retained per meter of row.  Canopy microclimate was affected by pruning method, shoot density, and leaf removal treatments.   Light interception into the fruiting zone was 49 % higher for spur pruned vines compared to mechanically box-pruned, and was  44% higher for low shoot density compared to high shoot density treatments.    A 17% decrease in leaf layer number was observed for vines with leaf removal.   Yield was impacted by both dormant pruning and shoot thinning methods where an increase of 42% in mechanically box-pruned vines was seen compared to spur pruned, and increase of 27% from low to high shoot density.  Crop load and vine vigor were impacted by the interaction of shoot density and leaf removal.  Leaf area to fruit weight ratio reached the desired range (0.8-1.2 m²/kg) for medium shoot density treated vines that were mechanically box-pruned.  Wine phenolics analysis indicated a three way interaction amongst pruning method, shoot density, and leaf removal indicating quantitative wine parameters were multi dependent on canopy management methods.