Santesteban García, GonzagaPalacios Horcajada, InésMiranda Jiménez, CarlosIriarte Galarregui, Juan CarlosRoyo Díaz, José BernardoGonzalo García, Ramón2018-09-042018-09-0420151664-462X (Electronic)10.3389/fpls.2015.00404https://academica-e.unavarra.es/handle/2454/30444Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if terahertz (THz) time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years-old plant, using a general purpose THz emitter receiver head. Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.9 p.application/pdfeng© 2015 Santesteban, Palacios, Miranda, Iriarte, Royo and Gonzalo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.DendrometerPhloemTHz spectrometryVitis vinifera L.Water relationsXyleminfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess