S20 - Session P3 - Impact of geotextile installation height on Vitis vinifera under cool-climate conditions of Québec, Canada

Authors: Caroline Provost *, Alexander Campbell

Growing grapes in cold climates have several challenges to overcome. Cold injury to grapevines is an important problem, especially at the northern limit of culture, where extensive damage to bud and cane tissues can result in severe economic losses. Winter protection methods were developed to use cultivars with lower cold hardiness (tender, semi-hardy) in cold regions. Several methods are available like wind machines, insulating with snow, mulch or soil, and geotextiles to reduce winter injury. However, the use of these methods needs to be matched to specific regions or improved for specific cultivars. Presently, geotextiles are used by Quebec producers though application methods and techniques vary, and little information is available concerning proper use and end results for grapevines. The main objective is to acquire specific knowledge on the installation height of geotextiles to optimize winter protection. Two parameters were evaluated for installing the geotextiles: the fruiting wire installation height at 8, 12 and 16 inches and insulation (padding) of the mid row posts. The trials were carried out on three grape varieties (Vidal, Pinot, Chardonnay) in four vineyards for three winter seasons (2019-2020, 2020-2021, 2021-2022). Results show that the installation height affects the temperature under the geotextile, but insulation does not. Moreover, snow cover also affected mean temperature under geotextile, higher mean temperature was observed for site with higher snow cover. Physiology and vine yields were not affected by the treatments either. Winter survival was most affected by the vineyard site and grape varieties rather than geotextile treatments. Several other projects are also currently underway at CRAM that assess several parameters (e.g. types of geotextile and their timing of installation and removal, fall vine pruning) which will help to optimize geotextile practices under the climatic conditions of Quebec, Canada.