A diagram representing the rootstock (the root portion of a single, healthy plant), scion (the young shoot of a different plant) and the junction where they are artificially united (graft union; diagram created by Heather VanVolkenburg).
Managing vineyards can be challenging to say the least, especially with the added complexity of extreme environmental changes, both between and within growing seasons. In order maintain a productive vineyard, growers have several key components that they must consider when planning for vine establishment and maintenance. The selection of rootstock is one such component. The types of rootstock may determine how the vines respond to the abiotic and biotic stressors that present-day vineyards face, especially those related to climate change.
Rootstock are an essential element in most vineyards, including vineyards here in Canada. To obtain a new vine, growers use the root system of one vine (i.e. rootstock) and combine it with a shoot from another one (i.e. scion). Each component can be from a different species of grapevine or even several species combined. Rootstock choices enable growers to select for grapevines that are more resistant to environmental adversities such as drought or disease, thus allowing for maintained or increased vine productivity Moreover, rootstock selection helps to overcome problems with soil such as texture, pH and density. While rootstock is normally selected for below-ground performance and resistance to challenges such as drought and disease (both of which occur more frequently due to effects of climate change), scions are usually chosen according to control above-ground aspects such as vine vigour, how quickly grapes ripen, fruit size, quality, and overall yield. In a simple way, the new plant has the best parts of two different plants!
The selection of a rootstock can be quite complex. For example, if the vineyard is located in an area prone to flooding, consideration should be given to a rootstock’s ability to survive in this condition. The type of soil will also influence this selection. Other considerations may be related to resistance to certain pests or viruses. Selection considerations must constantly evolve as agroecosystems are constantly changing according the environment in which they exist. With the changing climate, especially extreme weather events, selection becomes even more challenging.
Considering how closely existing rootstock choices interact with other management strategies (e.g. irrigation and cover cropping), defining good practices for local vineyards remains important. Here at Brock, we embrace the opportunity to work alongside vineyard growers to examine how integrated management techniques can help strengthen the sustainability of the industry. In our project, using organic vineyards as study locations, we are testing different combinations of three components of vineyard management, including irrigation, cover cropping and rootstock or their combined viability as local management techniques. By monitoring grapevine yields and growth, as well as disease and pest occurrence over consecutive seasons, we hope to evaluate how climate change may be affecting the different rootstocks and vine varieties present locally. Ultimately, we hope that results will contribute to maintain production of local grape growers in a sustainable way despite the challenges presented by climate change.
This blog will be ongoing throughout the duration of the project with monthly updates provided by Liette Vasseur, Heather VanVolkenburg, Kasia Zgurzynski, Habib Ben Kalifa, and Diana Tosato (see research team). We will be providing research activity updates as well as informative pieces that delve into agricultural concepts and important global issues as they relate to agricultural sustainability and climate change. Stay tuned for regular updates!