Co-Cultivation of Grapevines and Transgenic American Chestnuts: Improving Water Relations through Niche Facilitation

View the project report

Commodities

• Fruits: grapes
• Nuts: chestnuts

Practices

• Crop Production: agroforestry, drought tolerance, multiple cropping
• Education and Training: demonstration, networking
• Sustainable Communities: sustainability measures

This project investigates the potential of co-cultivating grapevines and a new variety of blight-tolerant transgenic American chestnuts in Northeastern United States agroforestry settings to provide a novel product and diversify the agricultural practices of this region’s vineyards and orchards. Given the ecological and economic significance of chestnuts and grapes, this research explores the viability of their joint cultivation within the Northeast by building upon traditional agroforestry practices observed in other geographic regions. The pairing of these two crops with distinct water use strategies is premised on the hypothesized niche facilitation of grape for chestnut: Grapes have large xylem vessels that uptake vast quantities of water, which may enhance the physiological performance of moderately drought-tolerant American chestnut under conditions of excess soil moisture. American chestnut physiology remains under-examined, given this species’s extirpation prior to the emergence of physiological ecology as a discipline. To address this hypothesis and knowledge gap, I propose research which aims to examine how conditions of competition versus facilitation, induced by co-cultivation under varying grape densities versus standard monoculture plantings, influence light saturated photosynthetic rates, leaf water potential, and stomatal conductance of each crop, as well as chestnut basal diameter and height and grape harvest yield. This research and a coinciding outreach strategy to local orchardists, vignerons, nut growers, and other farmers and agricultural collaborators, will occur over the 2024 and 2025 growing seasons, providing insight into the feasibility and benefits of co-cultivating chestnuts with grapes in the Northeast.

1. Growth and Harvest Yield: To understand how grape planting density in this co-cultivation framework influences chestnut and grape growth performance compared to traditional monoculture systems, I will conduct a growth assessment of grapevines and chestnut trees and a harvest yield assessment of grapevines. I will measure and assess:
   1. Chestnut basal diameter 
   2. Chestnut height
   3. Grape harvest yield
   4. Growth and harvest yield differences among treatments
2. Photosynthesis and Water Relations: To determine the role of water usage as a driver of competition versus facilitation, I will evaluate the photosynthetic capacity and water relations of transgenic American chestnuts and grape. I will measure and assess:
   1. Leaf gas exchange measurements, specifically light saturated photosynthetic (Anet) rates and stomatal conductance (gs)
   2. Leaf water potential 
   3. Photosynthetic and water use differences among treatments
3. Agricultural Outreach: To promote the adoption of this regionally novel co-cultivation method within Northeastern vineyards–e.g. the wine region of the Finger Lakes–I will visit local vineyards and farmers and present my work to stakeholders and organizations within ESF’s existing network of outreach and communications. I will lead and participate in:
   1. External site visits
   2. Networking and professional engagement
   3. ESF site visits