Insulative effects of vine shelters may impact growth potential and cold hardiness of young vines

Abstract

Context and purpose of the study. The seasons immediately following planting are key growth stages where young vines are particularly susceptible to various forms of damage. Although vine shelters provide protection, with erratic temperature swings becoming more common, certain vine shelter types may directly or indirectly harm vines. The greenhouse effect provided by the insulative properties of shelters may increase heat injury potential during summer months. Conversely, the insulative effects of the shelters may increase the risk of cold injury during winter months. Vines acclimate at the start of winter into a state of dormancy and deacclimate entering spring, thereby providing protection from cold injury in a process that could be disrupted by shelter properties. The warmer environment provided by certain vine shelters may disrupt acclimation or promote deacclimation prematurely.

Material and methods. Five commonly used shelters were installed on a newly planted research vineyard block in Lubbock, Texas in April 2024. Investigated shelter types included waxed cardboard of two heights (18” and 30”), solid recyclable plastic (15”), opaque corrugated plastic (30”), and transparent blue polyester (30”). Watchdog 1000 series micro stations (Spectrum Technologies, Aurora, Illinois) were installed in each shelter type to measure temperature and relative humidity. Eichorn-Lorenz phenological stages were surveyed to assess growth rate. Beginning in November 2024, samples will be collected for measuring bud cold hardiness using differential thermal analysis (DTA).

Results. Waxed cardboard shelters had lower daytime temperatures than all other shelter types. Transparent blue polyester shelters had the highest daytime temperatures, followed by corrugated plastic shelters. Differences in recorded growth rate did not correlate with differences observed in temperature between shelter types. On the final date of assessment, vines housed in the blue polyester shelters, which provided the warmest growing environment, were the least developed. The question of whether shelter type may impact vine acclimation, dormancy, and deacclimation will be addressed using DTA from collected bud samples beginning in November 2024. This information will be of particular value as extreme and unpredictable late winter and early spring temperature swings become more common, increasing the risk of early vine deacclimation and susceptibility to cold damage.