|AVF Proj. ID:||599|
|Category:||Cultural Practices - Crop Yield|
|Investigators:||Patricia A. Skinkis|
Defining Crop Load Metrics for Quality Pinot Noir Production in Oregon
A three year study began in 2013 to determine the impact of varying crop levels on vine growth and balance. The project involves two components: 1) a large grower collaborator crop load study and 2) a study that monitors vine growth, nutrition and physiology measures within four sites from the larger study. A total of 13 vineyard and winery collaborators have participated in the research and completed two full growing seasons of data collection and wine production for the study in 2013 and 2014. The 2013 season results from the large grower collaborative study indicates few differences in vine size (pruning weight), vine nutrient status, or fruit composition at harvest. Data from for the 2014 season are still being gathered from collaborators and will be analyzed statistically in spring/summer 2015. Data obtained from the four detail sites during 2013 and 2014 show no difference in vine nutrition at bloom or véraison, vine photoassimilation rates, nor differences in vine growth and leaf area when comparing full crop (non-thinned vines) with those cluster-thinned to one cluster/shoot. Despite very high yields in 2014, cluster thinning did not drastically change ripeness parameters measured. The differences in vine productivity among sites within the two projects are valuable in understanding how crop load may be influencing fruit composition and quality in vineyards with different yield capacity. The data obtained from the first two years of this research suggests that the Pinot noir vines in the Willamette Valley of Oregon may reach vine balance on their own and do not require cluster thinning to adjust for fruit ripeness or to maintain vine growth. Further seasons of research are required to better understand the role of vine balance.