GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Monitoring vineyard canopy structure by aerial and ground-based RGB and multispectral imagery analysis

Monitoring vineyard canopy structure by aerial and ground-based RGB and multispectral imagery analysis

Abstract

Context and purpose of the study – Unmanned Aerial Vehicles (UAVs) are increasingly used to monitor canopy structure and vineyard performance. Compared with traditional remote sensing platforms (e.g. aircraft and satellite), UAVs offer a higher operational flexibility and can acquire ultra-high resolution images in formats such as true color red, green and blue (RGB) and multispectral. Using photogrammetry, 3D vineyard models and normalized difference vegetation index (NDVI) maps can be created from UAV images and used to study the structure and health of grapevine canopies. However, there is a lack of comparison between UAV-based images and ground-based measurements, such as leaf area index (LAI) and canopy porosity. Moreover, most vineyard 3D model studies provide limited details on how they can be used to guide vineyard management. This study evaluated the accuracy of UAV-based canopy measurements, including canopy volume and NDVI and compared them with ground-based canopy measures, such as LAI and canopy porosity.

Material and methods – Throughout the 2017-18 growing season, UAV flights were performed to collect RGB and multispectral images in the research vineyard at the Waite Campus, University of Adelaide, South Australia. Using these images, canopy volume and NDVI were calculated. Ground-based measurements for LAI and canopy porosity were also carried out for comparison.

Results – LAI measured from budburst to harvest showed a peak at around veraison, before starting to decline. Similar trends were also observed in canopy volume and NDVI. Using linear regression, canopy volume of Shiraz and Semillon blocks showed a strong positive correlation with LAI (R2 = 0.75 and 0.68, respectively). NDVI was also positively correlated with LAI (R2 = 0.75 and 0.45 for Shiraz and Semillon, respectively). Canopy volume extracted from UAV-based RGB imagery could be used to monitor canopy development during the growing season. However, canopy volume has limited capacity to inform on important canopy architecture properties such as leaf density, total leaf area and porosity, known to affect yield and fruit quality. The accuracy of NDVI was also found to be strongly affected by the presence of vegetation on the vineyard floor at early development stages.

DOI:

Publication date: September 28, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Jingyun OUYANG1, Roberta DE BEI1, Bertram OSTENDORF2, Cassandra COLLINS1*

1 The University of Adelaide, School of Agriculture, Food and Wine, Waite Research Institute, PMB 1 Glen Osmond, 5064, South Australia. Australia
2 The University of Adelaide, School of Biological Sciences, Adelaide, 5000, South Australia. Australia

Contact the author

Keywords

remote sensing, unmanned aerial vehicle, leaf area index, canopy architecture, canopy volume, NDVI

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Some applications come from a method to concentrate proteins

All techniques usually used to assay proteins was not reliable in vegetable extract due to interferences with the components included in extracts like polyphenols, tanins, pectines, aromatics compounds. Absorbance at 280nm, Kjeldhal assay, Biuret and Lowry methods, Acid Bicinchonique technique and Bradford assay give the results depending on the composition of extract, on the presence or not of detergent and on the raw material (Marchal, 1995). Another difficulty in these extracts for the quantification of proteins comes from the large amount of water included in vegetable and the low concentration of proteins. Thus in red wines, proteins are usually not taken into account due to their low concentration (typically below 10 mgL-1) and to the presence of anthocyanis and polyphenols.

Prospects of thermal imaging as a non-invasive tool to assess water status for irrigation scheduling in commercial vineyards

Aim: Irrigated viticulture is expanding worldwide mainly as a short-term adaptation strategy to climate change. Plant-based methods are increasingly being used for irrigation scheduling in commercial vineyards. Canopy temperature (TC) has long been recognized as an indicator of plant water status. TC, but also the thermal stress indices, e.g. crop water stress index (CWSI) and stomatal

Impact of chitosan treatment on the physico-chemical features of a sangiovese red wine

Chitosan is gaining interest in red winemaking thanks to its ability to inhibit the development of Brettanomyces spp. yeast, or other undesired wine microbial threats. However, little is known about potential side-effects of its addition on the physico-chemical parameters of red wines.

Armenia: historical origin of domesticated grapevine

The Armenian highlands are located on the northern border of western asia and stretch up to the caucasus from the north. Throughout human history, country has played an important role in connecting the civilizations of europe and the near east. The recent large-scale study about the dual domestication origin and evolution of grapes approved that in the Armenian highlands human and grapevine stories are interlaced through centuries and roots of grapevine domestication are found deep in the pleistocene, ending 11.5 thousand years ago. Findings of this study confirmed that glacial episodes distinguish wild grapes into eastern and western ecotypes around 200-400 ka.

Soil, vine, climate change – what is observed – what is expected

To evaluate the current and future impact of climate change on Viticulture requires an integrated view on a complex interacting system within the soil-plant-atmospheric continuum under continuous change. Aside of the globally observed increase in temperature in basically all viticulture regions for at least four decades, we observe several clear trends at the regional level in the ratio of precipitation to potential evapotranspiration. Additionally the recently published 6th assessment report of the IPCC (The physical science basis) shows case-dependent further expected shifts in climate patterns which will have substantial impacts on the way we will conduct viticulture in the decades to come.
Looking beyond climate developments, we observe rising temperatures in the upper soil layers which will have an impact on the distribution of microbial populations, the decay rate of organic matter or the storage capacity for carbon, thus affecting the emission of greenhouse gases (GHGs) and the viscosity of water in the soil-plant pathway, altering the transport of water. If the upper soil layers dry out faster due to less rainfall and/or increased evapotranspiration driven by higher temperatures, the spectral reflection properties of bare soil change and the transport of latent heat into the fruiting zone is increased putting a higher temperature load on the fruit. Interactions between micro-organisms in the rhizosphere and the grapevine root system are poorly understood but respond to environmental factors (such as increased soil temperatures) and the plant material (rootstock for instance), respectively the cultivation system (for example bio-organic versus conventional). This adds to an extremely complex system to manage in terms of increased resilience, adaptation to and even mitigation of climate change. Nevertheless, taken as a whole, effects on the individual expressions of wines with a given origin, seem highly likely to become more apparent.