|CHOU, MING-YI - Cornell University - New York|
|VANDEN HUEVEL, JUSTINE - Cornell University - New York|
|BELL, TERRENCE - Pennsylvania State University|
|KAO-KNIFFIN, JENNY - Cornell University - New York|
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/3/2018
Publication Date: N/A
Interpretive Summary: Wine is a major global commodity the quality of which depends on many factors. The area and conditions under which wine grape vines are grown imparts differences to the finished wine that are collectively referred to as "terroir". This study seeks to understand the role of vineyard under-vine management practices and corresponding changes to the soil, grape, and wine microbial communities on wine quality. The results indicate that management changes do produce changes in the vineyard microbiome, but alteration of the wine microbiome and wine quality were not observed. A need for higher resolution tracking of microbes between soil, fruit, and wine is highlighted for future work.
Technical Abstract: The microbial component of terroir may play a critical role in fermentation processes and the resulting sensory analysis of wines, but little is known of how vineyard management practices influence this dynamic. We examined three under-vine soil management practices: 1) herbicide application, 2) soil cultivation (vegetation removal), and 3) natural vegetation (no vegetation removal) in a Riesling vineyard in New York over a three-year period. The microbial community of soil, grapes, and simulated spontaneous fermentations were profiled using high-throughput sequencing of the bacterial 16S rRNA gene and fungal ITS regions. Our results showed that soil fungal community structure under the natural vegetation treatment was distinct from other treatments, but this community shift did not extend to the grape microbiome or the simulated spontaneous fermentations. Soil bacterial communities were also impacted by management techniques. Sensory analysis of wine inoculated with the microbiome from grape washes showed no distinguishable patterns across treatments. Although this study revealed soil microbiome shifts based on under-vine management, there were no corresponding changes in fermentation communities and wine sensory analysis. The results revealed the need to track microbial transfer from soil to grapes, and grapes to fermentation processes, for better understanding of management implications on terroir.