Category: Projects

VitiCanopy: A new smartphone and Tablet PC App to assess vigour and canopy architecture of Horticultural Trees

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Download the App from iTunes by clicking HERE

Android version soon to be released, please keep an eye to new posts at the VoF webpage.

Authors:

Roberta De Bei 1, Sigfredo Fuentes 2, Matthew Gilliham 1,3, Steve Tyerman 1,3, Everard Edwards 4, Nicolò Bianchini 4,5, Jason Smith 6,† and Cassandra Collins 1,*

1School of Agriculture, Food and Wine, Waite Research Institute, the University of Adelaide,
PMB 1 Glen Osmond 5064, South Australia, Australia; roberta.debei@adelaide.edu.au (R.D.B.); matthew.gilliham@adelaide.edu.au (M.G.); stephen.tyerman@adelaide.edu.au (S.T.)
2Faculty of Veterinary and Agricultural Sciences, the University of Melbourne, Parkville 3010, Victoria, Australia; sigfredo.fuentes@unimelb.edu.au
ARC Centre of Excellence in Plant Energy Biology, Waite Research Institute, PMB 1 Glen Osmond 5064, South Australia, Australia
3CSIRO Agriculture, Waite Campus Laboratory, Private Bag 2, Glen Osmond 5064, South Australia, Australia; Everard.Edwards@csiro.au (E.E.); nicolo.bianchini@gmail.com (N.B.)
4Dipartimento di Scienze Agrarie (DipSA), the University of Bologna, Area Colture Arboree, Viale Fanin 46, 40127 Bologna, Italy
5National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, 6Wagga Wagga 2678, New South Wales, Australia; Jason.Smith@hs-gm.de
Correspondence: cassandra.collins@adelaide.edu.au; Tel.: +61-08-8313-6813
Current address: Hochschule Geisenheim University, Department of General and Organic Viticulture, Von-Lade-Str. 1, 65366 Geisenheim, Germany.

Abstract: 

Leaf area index (LAI) and plant area index (PAI) are common and important biophysical parameters used to estimate agronomical variables such as canopy growth, light interception and water requirements of plants and trees. LAI can be either measured directly using destructive methods or indirectly using dedicated and expensive instrumentation, both of which require a high level of know-how to operate equipment, handle data and interpret results. Recently, a novel smartphone and tablet PC application, VitiCanopy, has been developed by a group of researchers from the University of Adelaide and the University of Melbourne, to estimate grapevine canopy size (LAI and PAI), canopy porosity, canopy cover and clumping index. VitiCanopy uses the front in-built camera and GPS capabilities of smartphones and tablet PCs to automatically implement image analysis algorithms on upward-looking digital images of canopies and calculates relevant canopy architecture parameters. Results from the use of VitiCanopy on grapevines correlated well with traditional methods to measure/estimate LAI and PAI. Like other indirect methods, VitiCanopy does not distinguish between leaf and non-leaf material but it was demonstrated that the non-leaf material could be extracted from the results, if needed, to increase accuracy. VitiCanopy is an accurate, user-friendly and free alternative to current techniques used by scientists and viticultural practitioners to assess the dynamics of LAI, PAI and canopy architecture in vineyards, and has the potential to be adapted for use on other plants.

Keywords: canopy vigor; LAI; PAI; computer application; light extinction coefficient; image analysis; cover photography

Digital Viticulture Seminar: A success

The seminar was organised by the Melbourne Networked Society Institute (MNSI)

The Digital Viticulture seminar was a success with around 45 attendants from the academia, research and industry. In that occasion it was presented project advances so far and potential applications in the viticultural industry using sensor network and unmanned aerial systems (UAS).

However, all the technology and algorithms developed are not only applicable to viticulture, but also to a variety of other Horticultural and Agricultural crops and beyond. Some of the techniques related to visible and infrared thermography developed has been applied to assess biometrics in humans for sensory analysis of food and brewages and in animals to assess stress levels in productive processes, such as in the dairy industry.

According to Dr Sigfredo Fuentes, new and emerging technologies are easy to implement in precision agriculture, obtaining meaningful and repeatable interpretations of the data is where the applied science plays a big role. He mentioned the case of the newly developed smartphone and tablet PC App: VitiCanopy that can be downloaded from iTunes. “The VitiCanopy App was developed three years ago from technology that has been studied since 2007, its release to the public was last October 2015 after several trials to validate it in Chile, Spain and Australia. The beauty of the App is that it has been applied successfully in Apple orchards, Eucalyptus forests, Cherry trees, Cocoa orchards and Olive trees.

It was also shown in the seminar a prototype UAS made with 3D printed parts using a 3D metal powder printer (Titanium). The objective of this technology according to Dr Richard Collmann is to decrease the weight of UAS to increase payload for remote sensors and obtain more information per flights. Dr Collmann also discussed prototypes to change batteries automatically to increase flight time of UAS.

The seminar will be available as a podcast soon and posted in this webpage.

VoF

New Paper: Plant water stress detection based on aerial and terrestrial infrared thermography: a study case from vineyard and olive orchard

Authors: C. Poblete-Echeverrı́a1,a, D. Sepulveda-Reyes2, S. Ortega-Farias2, M. Zuñ iga1 and S. Fuentes3

1Escuela de Agronomı́a, Pontificia Universidad Católica de Valparaı́so, Quillota, Chile; 2Research and Extension Center for Irrigation and Agroclimatology (CITRA), Universidad de Talca, Chile; 3The University of Melbourne, Melbourne School of Land and Environment, Victoria 3010, Australia.

Abstract: 

Irrigation scheduling is critical for vineyards and olive orchards, since it directly affects yield and fruit composition. Regulated deficit irrigation (RDI) strategies have been applied on both crops with positive results in the past. However, to successfully regulate stress levels, it is necessary to have accurate measurements of plant water status, which is usually achieved using a pressure chamber. In this regard, canopy temperature (Tc) has been shown to be an accurate indicator of plant water stress. Therefore, the objective of this study was to evaluate the accuracy of water stress detection based on aerial and terrestrial infrared thermography for a vineyard and an olive orchard. Lateral infrared thermal images were obtained using a handheld infrared camera and nadir-view infrared thermal images were obtained using an unmanned aerial vehicle (UAV). In addition, measurements of midday stem water potential (Ψstem) from olives trees (Olea europaea L. ‘Arbequina’) and grapevines (Vitis vinifera L. ‘Carménère’) were taken under different RDI strategies during the 2013- 2014 growing season. The image analysis was performed using a customized code written in Mathlab® defining thresholds to exclude non-plant elements. Results showed that the use of infrared thermal images aided in recognizing the differences in the water availability for irrigation treatments when the plants were under stress conditions.

Keywords: unmanned aerial vehicle (UAV), lateral infrared thermal images, nadir-view infrared thermal images

Irrigation scheduling is critical for vineyards and olive orchards, since it directly affects yield and fruit composition. Regulated deficit irrigation (RDI) strategies have been applied on both crops with positive results in the past. However, to successfully regulate stress levels, it is necessary to have accurate measurements of plant water status, which is usually achieved using a pressure chamber. In this regard, canopy temperature (Tc) has been shown to be an accurate indicator of plant water stress. Therefore, the objective of this study was to evaluate the accuracy of water stress detection based on aerial and terrestrial infrared thermography for a vineyard and an olive orchard. Lateral infrared thermal images were obtained using a handheld infrared camera and nadir-view infrared thermal images were obtained using an unmanned aerial vehicle (UAV). In addition, measurements of midday stem water potential (Ψstem) from olives trees (Olea europaea L. ‘Arbequina’) and grapevines (Vitis vinifera L. ‘Carménère’) were taken under different RDI strategies during the 2013- 2014 growing season. The image analysis was performed using a customized code written in Mathlab® defining thresholds to exclude non-plant elements. Results showed that the use of infrared thermal images aided in recognizing the differences in the water availability for irrigation treatments when the plants were under stress conditions.

Keywords: unmanned aerial vehicle (UAV), lateral infrared thermal images, nadir-view infrared thermal images

New Paper: Seasonal variation of night-time sap flow of a young olive orchard: the unconsidered process for evapotranspiration estimations

Authors: R. López-Olivari1, S. Fuentes2 and S. Ortega-Farı́as3

1Instituto de Investigaciones Agropecuarias, INIA Carillanca, km 10 camino Cajón-Vilcún s/n, Temuco, Chile; 2Department of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, 3010, Australia; 3CITRA-Facultad de Ciencias Agrarias, Universidad de Talca, Av. Lircay s/n, Talca, Chile.

Abstract: Night-time sap flow (Sn), with transpiration as an important proportion of it at moderate to high vapor pressure deficits (VPD), is an important unconsidered factor that contributes significantly to total evapotranspiration (ET) of horticultural and fruit tree crops. This nocturnal process will be likely increased in a climate change scenario, with increases in night-time temperatures at higher rates compared to diurnal temperatures. The aim of this study was to characterise night-time water consumption over a commercial drip-irrigated young olive orchard (Olea europaea L. ‘Arbequina’) located in Pencahue valley, Maule Region, Chile (35°23’LS; 71°44’LW; 96 m a.s.l.) and its dynamics within the 2010/11 season. Four olive trees were selected for sap flow measurements using the Compensated Heat Pulse Velocity technique (CHPV). The canopy conductance (Gc) was calculated by inverting a modified PenmanMonteith equation. The aerodynamic conductance (ga) was calculated using an algorithm of the two-layer model proposed by Shuttleworth and Wallace (1985). An eddy covariance system was installed in the orchard to measure real ET. Results showed that Sn varied between 1.79 and 3.09 L tree-1 night-1 depending mainly of the atmospheric demand. The diurnal sap flow (Sd) measured was from 7.1 to 18.2 L tree-1 day-1. Parabolic shape curves described the relationship between Sn and Gc. Furthermore, the Sn/Sd ratio changed between 16 and 25% depending on the weather conditions, which it is not currently considered in ET models. It is clear that there is a nocturnal flow of water from soil to plant and water movement within the plant, but it is not yet clear the partition between the transpiration process and hydraulic redistribution. However, the former could be more likely due to the highly significant correlations found between VPD and Sn. Keywords: transpiration, canopy and aerodynamic conductance, two-layer model, Olea europaea L., eddy covariance system.