Table 1.
Plant characterization methods for which EIS holds promise as a competitive or complementary method.
| Category | Method | Application(s) | Strengths | Weaknesses |
|---|---|---|---|---|
| Molecular | (RT-)(q)PCR | disease (Korimbocus et al., 2002) | reliable | invasive, laborious |
| DNA hybridization | disease | reliable | invasive, laborious | |
| Serological | ELISA | disease | reliable | expensive, invasive, complex, laborious |
| Chemical | Kjeldahl digestion | nutrition | reliable (Muñoz-Huerta et al., 2013) | invasive, slow, ex situ |
| Dumas combustion | nutrition | reliable (Muñoz-Huerta et al., 2013) | invasive, slow, ex situ | |
| soluble solid content | sugar content and fruit maturity | reliable | invasive, ex situ | |
| Optical | VIS/IR spectroscopy/imaging | water content (Zhang et al., 2012; Jin et al., 2017), nutrition, disease (Sankaran et al., 2011) | non-invasive | environment-sensitive |
| quantum cascade lasers | disease (Mur et al., 2011) | reliable, quantitative | complex, expensive, ex situ | |
| FT-IR spectroscopy | disease (Abramovic et al., 2007; Liaghat et al., 2014), abiotic stress (Yu et al., 2018), nutrition (Butler et al., 2017) | in situ (Abramovic et al., 2007) | environment-sensitive, expensive | |
| thermal imaging | disease (Chaerle et al., 2006; Xu et al., 2006), drought stress (Hashimoto et al., 1984; Cseri et al., 2013), nutrition (Chaerle et al., 2007) | non-invasive, large-scale | environment-sensitive (Humplík et al., 2015) | |
| soil-plant analyses development | nutrition (Yue et al., 2020) | fast, non-invasive | limited applicability, environment-sensitive | |
| hyper-/multispectral imaging | water content (Kovar et al., 2019), disease (Schubert et al., 2001), fruit maturity (Gutiérrez et al., 2019), osmotic stress (El-Hendawy et al., 2019; Mishra et al., 2019; Pieters et al., 2020) | non-destructive, broadly applicable | complex, expensive | |
| Quickbird satellite | nutrition (Wu et al., 2007; Bausch et al., 2008), disease (Jacobi et al., 2005) | large scale | environment-sensitive, expensive | |
| colorimetry | nutrition (Hytönen and Wall, 2006; Sahrawat et al., 2016), ripeness (Gonçalves et al., 2007), sugar content (Buysse and Merckx, 1993), stress (Bacci et al., 1998) | fast, cheap | environment-sensitive, invasive | |
| digital image analysis | disease (Mohanty et al., 2016; Tm et al., 2018; Singh et al., 2019; Liu and Wang, 2021; Nirmal et al., 2022), fruit quality (Benalia et al., 2016), nutrition (Chen et al., 2019) | non-invasive | environment-sensitive | |
| fluorescence spectroscopy/imaging | disease (Lins et al., 2009; Bürling et al., 2012; Granum et al., 2015; Pérez-Bueno et al., 2015; Montero et al., 2016), mechanical stress (Belasque et al., 2008; Pérez-Bueno et al., 2019), nutrition (Agati et al., 2015) | non-invasive | non-robust (Li et al., 2014) | |
| Electrical | ion-selective sensors | nutrition | fast | invasive |
| electronic nose | fruit maturity (Di Natale et al., 2001; Li et al., 2009), disease (de Lacy Costello et al., 2000) | portable, real-time, fast, non-invasive | non-robust, environment-sensitive | |
| conductivity | nutrition (Bodale et al., 2021) | cheap | invasive, qualitative | |
| resistance measurements | abiotic stress (Mancuso, 2000) | quick, easy and non-destructive | non-robust | |
| capacitance measurements | water uptake (Afzal et al., 2017; Cseresnyés et al., 2022), biomass (Dietrich et al., 2013; Cseresnyés et al., 2018) | in situ, fast, non-invasive | environment-sensitive | |
| resistivity tomography | biomass (Paglis, 2013), water content | non-invasive, broad applicability, in situ | complex, expensive | |
| Sonic | sonic tomography | disease (Ishaq et al., 2014) | in-field, non-invasive, reliable | complex |
| Physical | pressure bomb | water potential | reliable | invasive |
| penetrometry | fruit maturity | quantitative | invasive |