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United States Department of Agriculture

Agricultural Research Service

Research Project: EFFECTS OF CLUSTER ZONE LEAF REMOVAL ON NORISOPRENOIDS OF PINOT NOIR FRUIT AND WINE, PART 1: CANOPY MICROCLIMATE AND FRUIT QUALITY
2010 Annual Report


1a.Objectives (from AD-416)
1. Determine the impact of cluster zone leaf removal in modifying microclimate for fruit quality in both high and low vigor vines. 2. Evaluate impacts of microclimate on total phenolics and anthocyanins of Pinot noir. 3. Improve the understanding of leaf pulling on formation of norisoprenoids in Pinot noir grapes and wine in relation to inherent vine vigor. 4. Link vine vigor, leaf removal and composition to sensory characteristics of wines.


1b.Approach (from AD-416)
Study Pinot noir at two distinct locations in Oregon: a vigorous, dry farmed site (Willamette Valley) and a low vigor site (Southern Oregon). These vineyards will have the same cultivar and rootstock to reduce between site variability. The experimental vineyards will be monitored for vegetative growth, vine size and microclimate of treatments. Sunlight intensity measurements of the vine canopy in the cluster zone will be taken for all treatments concurrently. Vines will be monitored for photosynthetic efficiency. Vine microclimate will be monitored for light spectral quality and temperature throughout the season. At the end of the season, cluster weights and berry weights will be obtained to determine any treatment effects on fruit size. Shoot number per vine and cluster per shoot will be recorded during the growing season. Documents Grant with Oregon State University.


3.Progress Report

A graduate research assistant was hired in January 2010, and during the late fall 2009 and early 2010, we investigated trial sites to fit project objectives and were able to secure the commercial vineyard location for this three-year trial. Prior to imposing treatments into the field, trunk circumference was measured for all vines to facilitate change in trunk circumference over time (estimator of vine size increase). This data combined with early season shoot lengths, was used to determine the best fit method for blocking the vineyard treatments across the block. Treatments were applied in the field, beginning with flower cluster thinning on June 15, 2010 at EL stage 55-56 (extended BBCH). Thinning for the fruit set stage has been completed as of July 2010. Pre-bloom thinning treatments were monitored for shoot growth three times prior to hedging and compared to the controls. Data indicate no difference in shoot growth between the severely thinned or moderately thinned (flower stage) as compared to the control. Laterals were also measured just before hedging, and there were no differences in lateral number per shoot or lateral length. Field data collection is active this season and we will proceed with measurements and analyses.

Methods of ADODR monitoring included stakeholder meetings, phone calls, and e-mail.


Last Modified: 10/22/2014
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