Author: Victor Blanco-Montoya
First FruitCREWS e-seminar took place on December 12, 2023, titled Plant-based Sensors for Continuous Monitoring of Tree Water Status. The speakers of the seminars, Alan Lakso and Martin Thalheimer are two renowned scientists with broad experience in horticulture, irrigation, and water relations. They explained and discussed two new plant-based sensors that can continuously assess tree water status and will help growers and researchers to better understand tree physiology and water relations, and to manage irrigation to reach their goals.
Dr. Alan Lakso is an Emeritus Professor of Horticulture at Cornell University (USA). He has
emphasized carbon and water physiology to improve cultural practices, yields, fruit quality and
sustainability in apples and grapes. In addition to the Cornell research, he co-invented a
microtensiometer to embed inside plants to continuously monitor stem potential. After
prototype development, Lakso and colleagues Dr. Abe Stroock and Dr. Michael Santiago
founded FloraPulse Co. to further develop and commercialize the sensor. This sensor is
embedded in the trunk of the tree and measures its water potential. His results showed a
strong relationship between the measurements recorded by the sensor and the stem water
potential measured with the pressure chamber in different tree crops and locations and
related it to fruit growth.
Martin Thalheimer graduated in Agricultural Science at the University of Padova in 1989 and
obtained a MSc in Management of Soil Fertility at the University of Reading (UK) in 1992. Since
1993 he has been employed at Laimburg Research Centre in Italy, where his activities are
mainly focused on topics related to soil, fertilization, and irrigation. He developed a leaf-
mounted capacitance sensor for continuous monitoring of foliar transpiration. He successfully
related the daily pattern of the transpiration measurements recorded by the sensor to the
diurnal course of solar irradiance under the influence of varying climatic conditions and soil
water content in several species of fruit trees.
During their talks, both speakers were passionate about their work and encouraged the
audience to test these sensors i.e. to test their potential for irrigation scheduling based on
continuous, real-time information of tree water status. Almost 100 people attended the
seminar and there was a great Q&A session after the talks, which highlighted the importance
and interest in the development, validation, and use of new sensing devices for understanding
how fruit tree crops respond to drought stress, which is one of the goals of the FruitCREWS
action. This seminar is related to the information that Work Group 1 is currently compiling on
physiological parameters and sensing technologies for monitoring tree water status.