Vineyard of the Future Initiative
New and emerging technologies
In a warming climate scenario, accompanied by increasing frequency and severity of climatic anomalies such as heat waves, water use might increase in an attempt to reduce heat and water stress.4,14 A double warming effect can also be produced due to a compression of phenological stages in grapevines, resulting in early harvest during hotter months.23 An increased need for irrigation could also be exacerbated due to reductions in precipitation in grapegrowing regions such as California, Chile, Europe and Australia.17,18,23
Furthermore, the most worrying effects for the viticulture industry around the world are the global geographic shifts in land and climate suitability for agriculture, which in the Southern Hemisphere would be southward.13,22
Some adaptive responses already have been identified, such as yield compensation strategies to account for reductions in quality, shifting sites of vineyards and variety substitution.23 However, there are many irrigation and canopy-management techniques that can be applied to ameliorate the effect of climate change on existing varieties and winegrowing regions.
Traditional monitoring of plant growth and physiological variables involves discrete frequency in sampling (for irrigation scheduling). This method will likely miss important processes in the viticulture crop cycle, especially in the event of climatic anomalies, which reduce the response time of amelioration management techniques.
Developing and testing new and emerging technologies are the main focuses of the Vineyard of the Future (VOF) initiative led by the University of Adelaide in an effort to use novel techniques to find efficient mitigating or adaptive tools to manage the effects of climate change on grapevines. VOF technologies are based on the intensive monitoring of spatial and temporal variations of soil, plant and atmosphere factors.
A great volume of data collection also requires more robust and complex analysis methods to explain the effects of climate change on plant physiology, phenology, growth, water status and balance between the reproductive and vegetative organs, which are critical for quality grapes. Within this system, management strategies such as irrigation techniques, canopy management, canopy sprays, shading materials and new varieties can be tested to find the most effective adaptation.
The VOF initiative has spread to other viticulture regions around the world. Countries such as Spain (professor Javier Tardaguila, University of La Rioja), the United States (California, E. & J. Gallo Winery) and Chile (professor Samuel Ortega-Farias and Dr. Carlos Poblete-Echeverria, University of Talca) are now participating in the VOF initiative.
This article discusses some techniques developed within the VOF framework that will soon be available to growers to assess spatial and temporal changes in soil moisture, canopy growth, architecture and plant water status.
The techniques are mapping 2D and 3D soil-wetting patterns, cover photography for leaf area index (LAI) and architecture assessment, infrared (IR) thermography and near infrared (NIR) spectroscopy. This work in relating the short-range remote-sensing techniques constitutes an additional step forward in implementation of these technologies as an automated routine technique for physiological vineyard assessment from proximal sensing and unmanned aerial vehicles (UAV) platforms, such as drones and robots.
Description of new technologies for the vineyard
Research currently being undertaken within the international VOF uses the Advanced Integrated Monitoring and Logging System (AIVMSL) approach (see Figure 1).
New in-soil monitoring techniques
Soil wetting and nutrient patterns
A wetting pattern analyzer (WPA) program has been created by the Australian arm of the VOF to characterize 2D and 3D soil wetting and nutrient patterns (Figure 2) within the root zone.5,10,11 This tool has recently been incorporated into the Irrimax software from Sentek Pty. Ltd. Australia (capacitance soil moisture and salinity probes). The software will be presented and released in late 2013 and will help growers target irrigation and fertigation to areas within the root zone of maximum water and nutrient uptake, avoiding excessive irrigation and loss of fertilizer for more economically and environmentally efficient management.
New plant-based technologies and techniques
Infrared thermography and automated analysis
Infrared thermography applied to vineyards has been proposed as a tool to estimate plant water status since 2002.16,19,20 Some research has also focused on the use of IR to assess the incidence of diseases in grapevines.21 However, the bottleneck of this technique was the lack of automated infrared thermal image analysis programs.
The Australian VOF group proposed an automated analysis method to assess plant water status (Figure 3) that can be applied to analyze changes within canopies due to environmental factors, disease incidence6 or smoke contamination from bushfires.6 This new analysis method can be used on images and videos obtained from an unmanned aerial vehicle such as octocopters being tested by the Chilean arm of the VOF (Figure 4).
Near infrared (NIR) spectroscopy
The University of Adelaide has demonstrated that grapevine water status can be measured non-destructively using near infrared (NIR) spectroscopy techniques. The Australian VOF combined NIR spectra of leaves (in which the regions around 1200 nm, 1450 nm and 1930 nm are associated with the presence of water in the sample) and more established techniques of measuring plant water status using mid-day stem water potential to develop models for prediction of water potential based on the spectral signature of leaves only.3
Results have shown good agreement between both techniques offering a new tool for irrigation scheduling (Figure 5). Current research has undertaken the use of this technique in an automated fashion through short-range remote sensing on a vehicle.
Canopy architectural assessment using cover photography
The cover photography technique to measure canopy architecture parameters using gap analysis algorithms does not require expensive instrumentation, but it does offer accu rate results comparable to techniques that use expensive instrumentation (AccuPAR Ceptometers, LiCOR 2000 – 2200).8 Our research at University of Melbourne has applied this technique to grapevines, and an automated video analysis method has been developed. This method allows the use of this technique with robots.9
The gap analysis algorithm also has been applied for development of a smartphone and tablet application that allows obtaining images, analysis of them and sends canopy architecture and leaf area index information to be mapped (Figure 6).7 Further developments of imaging techniques use high-end security cameras attached to extendable towers that can be attached to an unmanned terrestrial vehicle (UTV) or permanently installed in a vineyard. These can be used to detect disease, growth rate and grape maturity remotely.
Grape berries’ living tissue assessment
A novel berry tissue assessment technique discloses the link between grape berry living tissue and shrivel (Figure 7).12 This technique can be used to investigate the link between cell death and development of flavors and aromas in berries that might be favored in certain grapevine cultivars by mesocarp cell death. This technique has also been used to assess the effects of elevated temperatures at the onset and rate of berry cell death in cultivars such as Shiraz and Chardonnay.2
Further research has been conducted to develop in-field technology to assess berry cell death non-destructively using hyperspectral cameras and impedance spectrometry (Dr. Roberta De Bei, Sigfredo Fuentes, professor Tyerman and professor Javier Tardaguila).
New techniques resulting from these VOF initiatives are currently being tested in commercial vineyards in Australia and Chile as part of a beta testing stage. Some of these techniques will soon be commercially available to growers to be applied in the field (WPA and Canopy LAI).
In the meantime, the international VOF is currently working on other emerging technologies with exciting preliminary results that will add to newly developed tools.
This text was edited from first publication in the May/June 2013 Wine & Viticulture Journal with permission of the publisher, Winetitles. We acknowledge important funding contributions to the Australian VOF from the Waite Research Institute (WRI) of the University of Adelaide and the Wine2030 program from the same university.
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