Using UAV‐based remote sensing to assess grapevine canopy damage due to fire smoke

Abstract

BACKGROUNDBushfires are becoming an increasing issue for the wine sector due to grape and vine losses and smoke taint in wine. Smoke affects vine physiology and the smoke's volatile phenols are absorbed by plants and berries, contaminating the wine. Our hypothesis was that, for the first time, unmanned aerial vehicle (UAV)‐based visible images can be used to study the physiology of smoke‐affected vines and to assess compromised vines.RESULTSProcanico 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 damage was assessed with conventional vegetation indices (VIs) 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 in functional parameters. The VIs exhibited significant differences and CAHI presented a damage gradient related to bushfire nearby.CONCLUSIONThe 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. © 2020 Society of Chemical Industry

Techniques for Mitigating the Effects of Smoke Taint While Maintaining Quality in Wine Production: A Review

“…Although these sensors did not accurately quantify the levels of smoke exposure, they gave an indication of the duration of smoke exposure, which would enable winemakers to make informed decisions about whether or not they should invest in more costly compositional analysis of grapes, where smoke exposure is found to have occurred, i.e., to determine the level of taint [29]. Another recent study investigated a method of remote drone sensing to assess smoke damage of vine canopies [75], but perhaps, in the future, this drone sensing could be adapted for assessment (and eventually quantification) of smoke exposure of grapes as well.…”

Research trends in the oenological and viticulture sectors

“…Its innovative thrust was evident, mainly given by the evolution of the techniques of genetic analysis and improvement of the vine in response mainly to abiotic stress factors, such as global warming and water stress, and biotic stress factors, such as diseases and viruses, as well as the reuse and recycling of processing by‐products. Moreover, even if just 70 papers were retrieved from the Scopus database when searching the research terms ‘wine’ and ‘precision viticulture’ in the title and abstract research fields, the increasing adoption of digital technologies, including hyperspectral imaging, in grape growing might help to improve its sustainability because of the use of drones, robots, satellites and sensors to capture aerial images of the vines informing about soil quality, unwanted weeds, vine diseases, and smoke‐affected vines (Brunori et al 2020), and thus pilot‐targeted application of fertilisers and pesticides.…”

Field survey and UAV remote sensing as tools for evaluating the canopy management effects in smallholder grapevine farm

“…The digital number (DN) values for the red, green, and blue channels of each treatment plot were extracted for calculating the vegetation indices (VIs). Three VIs have been selected in the visible light spectrum, including Visible Atmospherically Resistant Index (VARI), Normalized Difference Greenness Vegetation Index (NDGI), and Red Green Ratio Index (RGRI) [25].…”