{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T13:52:46Z","timestamp":1782568366378,"version":"3.54.5"},"reference-count":45,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2019,11,6]],"date-time":"2019-11-06T00:00:00Z","timestamp":1572998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Water availability is a major limiting factor in plant productivity and plays a key role in plant species distribution over a given area. New technologies, such as terahertz quantum cascade lasers (THz-QCLs) have proven to be non-invasive, effective, and accurate tools for measuring and monitoring leaf water content. This study explores the feasibility of using an advanced THz-QCL device for measuring the absolute leaf water content in Corylus avellana L., Laurus nobilis L., Ostrya carpinifolia Scop., Quercus ilex L., Quercus suber L., and Vitis vinifera L. (cv. Sangiovese). A recently proposed, simple spectroscopic technique was used, consisting in determining the transmission of the THz light beam through the leaf combined with a photographic measurement of the leaf area. A significant correlation was found between the product of the leaf optical depth (\u03c4) and the leaf surface area (LA) with the leaf water mass (Mw) for all the studied species (Pearson\u2019s r test, p \u2264 0.05). In all cases, the best fit regression line, in the graphs of \u03c4LA as a function of Mw, displayed R2 values always greater than 0.85. The method proposed can be combined with water stress indices of plants in order to gain a better understanding of the leaf water management processes or to indirectly monitor the kinetics of leaf invasion by pathogenic bacteria, possibly leading to the development of specific models to study and fight them.<\/jats:p>","DOI":"10.3390\/s19224838","type":"journal-article","created":{"date-parts":[[2019,11,7]],"date-time":"2019-11-07T06:52:36Z","timestamp":1573109556000},"page":"4838","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["THz Water Transmittance and Leaf Surface Area: An Effective Nondestructive Method for Determining Leaf Water Content"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1495-8108","authenticated-orcid":false,"given":"Mario","family":"Pagano","sequence":"first","affiliation":[{"name":"CREA\u2014Research Centre for Plant Protection and Certification, Via di Lanciola 12\/A, 50125 Firenze, Italy"},{"name":"CREA\u2014Research Centre for Viticulture and Enology, Viale Santa Margherita 80, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lorenzo","family":"Baldacci","sequence":"additional","affiliation":[{"name":"NEST, CNR\u2014Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Ottomaniello","sequence":"additional","affiliation":[{"name":"NEST, CNR\u2014Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy"},{"name":"Dipartimento di Fisica \u201cE. Fermi\u201d, Universit\u00e0 di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0289-1727","authenticated-orcid":false,"given":"Giovanbattista","family":"de Dato","sequence":"additional","affiliation":[{"name":"CREA\u2014Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5688-2060","authenticated-orcid":false,"given":"Francesco","family":"Chianucci","sequence":"additional","affiliation":[{"name":"CREA\u2014Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luca","family":"Masini","sequence":"additional","affiliation":[{"name":"NEST, CNR\u2014Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7067-4970","authenticated-orcid":false,"given":"Giorgio","family":"Carelli","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica \u201cE. Fermi\u201d, Universit\u00e0 di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4400-8808","authenticated-orcid":false,"given":"Alessandra","family":"Toncelli","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica \u201cE. Fermi\u201d, Universit\u00e0 di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7534-5634","authenticated-orcid":false,"given":"Paolo","family":"Storchi","sequence":"additional","affiliation":[{"name":"CREA\u2014Research Centre for Viticulture and Enology, Viale Santa Margherita 80, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alessandro","family":"Tredicucci","sequence":"additional","affiliation":[{"name":"NEST, CNR\u2014Istituto Nanoscienze and Scuola Normale Superiore, Piazza San Silvestro 12, 56124 Pisa, Italy"},{"name":"Dipartimento di Fisica \u201cE. Fermi\u201d, Universit\u00e0 di Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8105-0792","authenticated-orcid":false,"given":"Piermaria","family":"Corona","sequence":"additional","affiliation":[{"name":"CREA\u2014Research Centre for Forestry and Wood, Viale Santa Margherita 80, 52100 Arezzo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,6]]},"reference":[{"key":"ref_1","first-page":"1051","article-title":"The effects of drought stress on yield, relative water content, proline, soluble carbohydrates and chlorophyll of bread wheat cultivars","volume":"8","author":"Keyvan","year":"2010","journal-title":"J. Anim. Plant Sci."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1186\/s13007-015-0054-x","article-title":"Non-invasive assessment of leaf water status using a dual-mode microwave resonator","volume":"11","author":"Dadshani","year":"2015","journal-title":"Plant Methods"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"30","DOI":"10.2307\/1310175","article-title":"Plant water balance","volume":"37","author":"Schulze","year":"1987","journal-title":"BioScience"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/S0098-8472(01)00074-0","article-title":"Water transport in trees: Current perspectives, new insights and some controversies","volume":"45","author":"Meinzer","year":"2001","journal-title":"Environ. Exp. Bot."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1111\/pce.12136","article-title":"Acclimation to humidity modifies the link between leaf size and the density of veins and stomata","volume":"37","author":"Jordan","year":"2014","journal-title":"Plant Cell Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1890\/05-0710","article-title":"Leaf structural diversity is related to hydraulic capacity in tropical rain forest trees","volume":"87","author":"Sack","year":"2006","journal-title":"Ecology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1890","DOI":"10.1104\/pp.107.101352","article-title":"Leaf maximum photosynthetic rate and venation are linked by hydraulics","volume":"144","author":"Brodribb","year":"2007","journal-title":"Plant Physiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1007\/s10867-009-9161-0","article-title":"Evaluation of leaf water status by means of permittivity at terahertz frequencies","volume":"35","author":"Scheller","year":"2009","journal-title":"J. Biol. Phys."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"10343","DOI":"10.1073\/pnas.0904209106","article-title":"Maximum leaf conductance driven by CO2 effects on stomatal size and density over geologic time","volume":"106","author":"Franks","year":"2009","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1104\/pp.110.162834","article-title":"Leaf extraction and analysis framework graphical user interface: Segmenting and analyzing the structure of leaf veins and areoles","volume":"155","author":"Price","year":"2011","journal-title":"Plant Physiol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"567","DOI":"10.1007\/s11099-016-0238-2","article-title":"Image analysis of the leaf vascular network: Physiological considerations","volume":"54","author":"Pagano","year":"2016","journal-title":"Photosynthetica"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1007\/s40415-017-0430-z","article-title":"A possible role of leaf vascular network in heat dissipation in Vitis vinifera L.","volume":"41","author":"Pagano","year":"2018","journal-title":"Braz. J. Bot."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1007\/s00425-014-2093-3","article-title":"Quantitative neutron imaging of water distribution, venation network and sap flow in leaves","volume":"240","author":"Defraeye","year":"2014","journal-title":"Planta"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1590\/S2197-00252013005000001","article-title":"Leaf Equivalent Water Thickness assessment using reflectance at optimum wavelengths","volume":"25","author":"Mobasheri","year":"2013","journal-title":"Theor. Exp. Plant Physiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"328","DOI":"10.1270\/jsbbs.66.328","article-title":"The effect of drought stress on the leaf relative water content and tuber yield of a half-sib family of \u2018Katahdin\u2019-derived potato cultivars","volume":"66","author":"Plich","year":"2016","journal-title":"Breed. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1111\/ppl.12380","article-title":"Apoplastic water fraction and rehydration techniques introduce significant errors in measurements of relative water content and osmotic potential in plant leaves","volume":"155","author":"Arndt","year":"2015","journal-title":"Physiol. Plant."},{"key":"ref_17","unstructured":"Taiz, L., and Zeiger, E. (2002). Plant Physiology, Sinauer Associates. [3rd ed.]."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/0378-4290(83)90033-3","article-title":"Field use of in situ leaf psychrometers for monitoring water potential of a soybean crop","volume":"7","author":"Oosterhuis","year":"1983","journal-title":"Field Crops Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1134","DOI":"10.1016\/j.jplph.2012.04.006","article-title":"Predicting leaf gravimetric water content from foliar reflectance across a range of plant species using continuous wavelet analysis","volume":"169","author":"Cheng","year":"2012","journal-title":"J. Plant Physiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"710","DOI":"10.1111\/pce.12429","article-title":"Combining quantitative trait loci analysis with physiological models to predict genotype-specific transpiration rates","volume":"38","author":"Reuning","year":"2015","journal-title":"Plant Cell Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1111\/j.1365-3040.2006.01600.x","article-title":"Anisohydric but isohydrodynamic: Seasonally constant plant water potential gradient explained by a stomatal control mechanism incorporating variable plant hydraulic conductance","volume":"30","author":"Franks","year":"2007","journal-title":"Plant Cell Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"756","DOI":"10.3389\/fpls.2018.00756","article-title":"Effects of light quality and intensity on diurnal patterns and rates of photo-assimilate translocation and transpiration in tomato leaves","volume":"9","author":"Lanoue","year":"2018","journal-title":"Front. Plant Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1146\/annurev.py.30.090192.003005","article-title":"Modeling leaf wetness in relation to plant disease epidemiology","volume":"30","author":"Huber","year":"1992","journal-title":"Annu. Rev. Phytopathol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1109\/22.744288","article-title":"Measurements of leaf water content using terahertz radiation","volume":"47","author":"Hadjiloucas","year":"1999","journal-title":"IEEE Trans. Microw. Theory Tech."},{"key":"ref_25","first-page":"27","article-title":"Review of theoretical methods and research aspects for detecting leaf water content using terahertz spectroscopy and imaging","volume":"11","author":"Qu","year":"2018","journal-title":"Int. J. Agric. Biol. Eng."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1002\/lpor.201000011","article-title":"Terahertz spectroscopy and imaging\u2013Modern techniques and applications","volume":"5","author":"Jepsen","year":"2011","journal-title":"Laser Photonics Rev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"21924","DOI":"10.1364\/OE.20.021924","article-title":"Terahertz confocal microscopy with a quantum cascade laser source","volume":"20","author":"Xu","year":"2012","journal-title":"Opt. Express"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1186\/s13007-017-0197-z","article-title":"Non-invasive absolute measurement of leaf water content using terahertz quantum cascade lasers","volume":"13","author":"Baldacci","year":"2017","journal-title":"Plant Methods"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"555","DOI":"10.1364\/AO.12.000555","article-title":"Optical constants of water in the 200-nm to 200-\u03bcm wavelength region","volume":"12","author":"Hale","year":"1973","journal-title":"Appl. Opt."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1186\/s13007-015-0057-7","article-title":"Monitoring leaf water content with THz and sub-THz waves","volume":"11","author":"Gente","year":"2015","journal-title":"Plant Methods"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Zahid, A.T., Abbas, H., Imran, M.A., Qaraqe, K.A., Alomainy, A., Cumming, D.R., and Abbasi, Q.H. (2019). Characterization and Water Content Estimation Method of Living Plant Leaves Using Terahertz Waves. Appl. Sci., 9.","DOI":"10.20944\/preprints201907.0125.v1"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Nie, P., Qu, F., Lin, L., Dong, T., He, Y., Shao, Y., and Zhang, Y. (2017). Detection of water content in rapeseed leaves using terahertz spectroscopy. Sensors, 17.","DOI":"10.3390\/s17122830"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Smart, K., Du, J., Li, L., Wang, D., Leslie, K., Ji, F., Li, X., and Zeng, D. (2016). A practical and portable solids-state electronic terahertz imaging system. Sensors, 16.","DOI":"10.3390\/s16040579"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2910","DOI":"10.1038\/srep02910","article-title":"Leaf water dynamics of Arabidopsis thaliana monitored in-vivo using terahertz time-domain spectroscopy","volume":"3","author":"Palomar","year":"2013","journal-title":"Sci. Rep."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"404","DOI":"10.3389\/fpls.2015.00404","article-title":"Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status","volume":"6","author":"Santesteban","year":"2015","journal-title":"Front. Plant Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1571","DOI":"10.1104\/pp.113.233601","article-title":"Monitoring plant drought stress response using terahertz time-domain spectroscopy","volume":"164","author":"Born","year":"2014","journal-title":"Plant Physiol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"827","DOI":"10.1093\/jxb\/erl115","article-title":"Use of thermal and visible imagery for estimating crop water status of irrigated grapevine","volume":"58","author":"Alchanatis","year":"2006","journal-title":"J. Exp. Bot."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1016\/j.compag.2016.07.028","article-title":"Temporal dynamics of maize plant growth, water use, and leaf water content using automated high throughput RGB and hyperspectral imaging","volume":"127","author":"Ge","year":"2016","journal-title":"Comput. Electron. Agric."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"036101","DOI":"10.1063\/1.2151267","article-title":"Absorption spectra of liquid water and aqueous buffers between 0.3 and 3.72 THz","volume":"124","author":"Xu","year":"2006","journal-title":"J. Chem. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1007\/s10658-009-9566-4","article-title":"Relation between leaf rust (Melampsora epitea) severity and the specific leaf area in short rotation coppice willows","volume":"126","author":"Toome","year":"2010","journal-title":"Eur. J. Plant Pathol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1016\/j.eja.2011.03.004","article-title":"High throughput phenotyping of canopy water mass and canopy temperature in well-watered and drought stressed tropical maize hybrids in the vegetative stage","volume":"35","author":"Winterhalter","year":"2011","journal-title":"Eur. J. Agron."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"67","DOI":"10.1016\/S0168-1923(01)00218-0","article-title":"Non-steady-state modelling of water transfer in a Mediterranean evergreen canopy","volume":"108","author":"Lhomme","year":"2001","journal-title":"Agric. Forest Meteorol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.agwat.2014.08.011","article-title":"Ecosystem water use efficiency for a sparse vineyard in arid northwest China","volume":"148","author":"Li","year":"2015","journal-title":"Agric. Water Manag."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1111\/j.1755-0238.2010.00117.x","article-title":"Non-destructive measurement of grapevine water potential using near infrared spectroscopy","volume":"17","author":"Cozzolino","year":"2011","journal-title":"Aust. J. Grape Wine Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1155\/2012\/276795","article-title":"Rapid determination of leaf water content using VIS\/NIR spectroscopy analysis with wavelength selection","volume":"27","author":"Zhang","year":"2012","journal-title":"J. Spectrosc."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/22\/4838\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:32:25Z","timestamp":1760189545000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/22\/4838"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,11,6]]},"references-count":45,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2019,11]]}},"alternative-id":["s19224838"],"URL":"https:\/\/doi.org\/10.3390\/s19224838","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,11,6]]}}}