Non-invasive 'Electroplantogram' (EPG) of greenhouse crops for real-time detection of water deficit

摘要

By analogy with the electrocardiogram (ECG), the proposed term "Electroplantogram" (EPG) is a graphical representation of the digitized electrical activity of the plant In the present study, non-invasive EPG of tomato and eggplant have been recorded and analyzed to detect water deficit of plants in real-time. Such perspectives open the possibility to improve crop management efficiencies (water, nutrient supply). The key innovations of the study are 1) monitoring directly at plant level to manage thecrop and 2) performing monitoring of electrical signals of plant outside a Faraday cage. Two case studies have been carried out Firstly the long-term monitoring was done using electrical signals in eggplant at nursery stage and analysis of the electricalsignals in the case of water deficit. In this experiment, we simulated a breakdown of the irrigation system. The results showed that it was possible to record a non-noisy EPG over several days. The electrical signal presented strong positive peaks eachmorning (10 mV) at sunrise and at each irrigation (3 to 10 mV). When an irrigation was lacking, a strong negative peak has been observed (-30 mV). The experiment was repeated two times with similar results. In the second case study, electrical signals oftomato plants in a greenhouse were monitored again for water deficit Similarly to eggplant, an irrigation breakdown resulted in a strong negative peak of the electrical signal (-40 mV). After re-watering, the EPG recovered its normal level the followingday. A second irrigation breakdown resulted in a second strong negative EPG peak of (-60 mV). Such a novel approach needs to be developed and adapted to professional greenhouse conditions. If future developments are successful the management of greenhouse inputs could be made more efficient because interventions would respond directly to plant behavior and could be made in real-time.