Using UAV-based Remote Sensing to Assess Grapevine Canopy Damages Due to Fire Smoke.

BACKGROUND: Bushfires are becoming an increasing issue for the wine sector due to grape and vine losses and to smoke taint in wine. Smoke affects vine physiology and the smoke volatile phenols are absorbed by plant and berry, contaminating the wine. Our hypothesis has been that, for the first time, UAV (unmanned aerial vehicle)-based visible images can be used to study the physiology of the smoke-affected vines and to assess the compromised vines. RESULTS: Procanico vines were exposed to two smoke treatments, a week apart. Gas exchanges and leaf biochemical traits were measured in the short-term (30 min after smoke-exposure) and in the long-term (24 h after smoke-exposure). Canopy damages were assessed by conventional VIs (Vegetation Indices) and by an innovative index derived by UAV-based visible images, the Canopy Area Health Index (CAHI). Gas exchange showed a reduction after the first smoke exposure, but the vines recovered within 24 h. The second smoke exposure led to an irreversible reduction of functional parameters. VIs exhibited significant differences and CAHI presented a damage gradient related to bushfire nearby. CONCLUSION: The vineyard damage assessment by UAV-based visible images may represent a tool to study the physiological activity of smoke-affected vines and to quantify the loss of destroyed or damaged vines. This article is protected by copyright. All rights reserved.