Contribution of thermal imaging to fertigation in soilless culture

Abstract

Thermography is a tool used in many scientific disciplines, including agriculture. This paper describes the application of thermography as a rapid diagnostic method of adequate watering. Two experiments were conducted. In experiment 1, Philodendron erubescens and Anthurium andraeum were transplanted to pots in a greenhouse in Almeria (Spain). The vegetative growth parameters of these plants were measured. In experiment 2, two areas of vegetative cover were established on green walls: one with a combination of aromatic plants and another with ornamental indoor plants. The thermographic images were recorded using a compact infrared camera, which had a spectral infrared range of 7.3-13 lm, microbolometer of 320 9 240 pixels, and the resolution was 0.01°C at 30°C. Three irrigation treatments were applied in both experiments, consisting of a control treatment (CT), a deficit irrigation [1/3 less volume, deficient irrigation (DI)] treatment, and an excess irrigation [1/3 greater volume, excess irrigation (EI)] treatment. In both experiments, the sample temperatures were recorded by thermography for each irrigation treatment. In experiment 1, the vegetative growth parameters were greater under CT than under DI or EI. The data of the reference thermographs over the leaves of the potted plants were significantly correlated with the superior growth parameters under the optimal irrigation treatment. A continuous vegetative canopy was formed on both of the green walls in experiment 2, and the average temperatures were correlated with the irrigation treatments in this experiment. The temperatures reflected in the reference thermographs allowed for the determination of the most appropriate irrigation treatment. These results suggest that thermography can be a useful method to provide an early diagnosis of water stress in potted plants and green walls.

The Effect of Organ Temperature on Total Yield of Transplanted and Direct-Seeded Rice (Oryza sativa L.)

“…With the development of agricultural thermal imaging technology, infrared thermal imaging system can quickly acquire the characteristics of crop temperature distribution, and can distinguish the temperature of different organs of crops through images. Therefore, infrared thermal imaging has also become the main tool for measuring plant temperature at present [15,16]. The infrared thermal imager could measure the temperature of crop organs and canopy accurately and quickly, and monitor the change of crop growth in real time, which provided an effective measurement method and technical basis in this study.…”

Non-Invasive Monitoring of the Thermal and Morphometric Characteristics of Lettuce Grown in an Aeroponic System through Multispectral Image System

“…The main image-based techniques for plant stress detection [29] (water stress and other stress types) are thermography [30][31][32], visible reflectance (VIS) [33], shortwave and near infrared (SWIR/NIR) [34], far infrared (FIR) and fluorescence [35]. These techniques evaluate the plant water content [36], being one of the most common biochemical parameters limiting the photosynthesis efficiency and crop productivity [37]. Water stress is one of the most critical abiotic factors restricting crop development.…”

The Use of Thermography Images in the Description of the Humidification Bulb in Soilless Culture

“…It is well known that infrared thermography is used in many aspects of science and technology (Grinzato, Cadelano, and Bison 2010), including agriculture (Inagaki and Nachit 2008;Jones et al 2002; Krapez and Olioso 2011;Möller et al 2007), plant physiology (Glenn 2012;Pearce and Fuller 2001), fertigation systems (Fernández-Bregón, Valera, and Urrestarazu 2013;Morales, Alvaro, and Urrestarazu 2014), or saline stress detection (Urrestarazu 2013a). As a technology, it can be used to monitor the efficiency of water resource use for in-field applications (Antonucci et al 2011) or potted plants in a soilless culture (Urrestarazu 2013b).…”