Written by Dr. Harner, edited and compiled by Jess Trapeni
Research Updates from the Viticulture Lab at Virginia Tech
The growing season seemed to start with a bang, and we are now well into my first year of grape cultivation and field research as a new Assistant Professor of Viticulture and Viticultural Extension Specialist for Virginia Tech, based at the AHS Jr. AREC in Winchester. We have had a busy time so far putting in a small block of vines and setting up some new experiments while working to wrap up others that are ongoing. Our research themes for this year’s work mainly focus on grapevine nutrient management and Spotted lanternfly, although we are beginning a small canopy management trial with some of the interspecific hybrid varieties we have planted here, including Fleurtai, Soreli, Itasca, and Petra. These cultivars, along with another ten, are part of the Variety trial established in 2020 and supported by the Virginia Wine Board.
On the grapevine nutrition side of things, we are in our final year of data collection for a multi-vineyard project investigating the relationships between nitrogen fertilizer rate, vine growth and yield, and fruit nitrogen composition, with a particular focus on linking fruit amino acid composition to grapevine nitrogen status. This experiment was a collaboration between Dr. Tony Wolf, Dana Acimovic, and Dr. Amanda Stewart of Virginia Tech’s Department of Food Science & Technology, her graduate student Megan Mershon, and her postdoctoral associate, Dr. Marlon Ac Pangan. It’s part of a broader set of experiments investigating grapevine nutrient management, sampling, and related themes under research initiated by the National Grape Research Alliance (NRGA) and funded through the National Institute of Food and Agriculture’s Specialty Crop Research Initiative Coordinated Agricultural Projects (CAP) grant (project award number: 2020-51181-32159). Other participants in this larger project include members of Cornell University, Washington State University, Oregon State University, Rochester Institute of Technology, and others (more info can be found here: https://highresvineyardnutrition.com/). Additional funding for the extensive nutrient analyses we have planned for 2024 for this project was provided through the Virginia Wine Board and the Virginia Agricultural Council. Additionally, we are establishing the first year of a multi-year experiment that will assess the impacts of increasing rates of phosphorous on grapevine phosphorous status and root mycorrhizal colonization, when grown in deep, sandy soils. This is the focus of Gonzalo Ortiz’s M.S. project, and we are excited to see where the results lead us.
Aside from these projects, we’ll also be trying to get to the bottom of some lingering questions I have about how intensive Spotted lanternfly sap-feeding impacts grapevines. We’ll be looking at how SLF influences rates of photosynthesis throughout the grapevine canopy, which can help us better understand its potential impacts on fruit ripening and plant health—does infestation in one part of the canopy impact the functioning in the rest of the canopy? If so, how? A second project will be a preliminary look into whether SLF can impact concentrations of macro- and micronutrients in vegetative tissues. Overall, my goal is to try and hit the ground running and lay a foundation that we can build upon in the coming years. And, as always, I am curious and interested in questions or concerns that industry members may have and how our research and extension efforts can help. I’m hoping to send out updates on our work as we move through the projects. In the meantime, I can be reached through email at dharner@vt.edu, or through my office phone, at 540-232-6050.