Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non‐invasive, online monitoring leaf patch clamp pressure probe

Abstract

Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so-called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P(p) that is highly correlated with the turgor pressure. Real-time recording of P(p) values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic-based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P(p) values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non-invasive turgor pressure sensor system for elucidating the dynamics of short- and long-distance water transport in higher plants.

Spatio‐temporal water dynamics in mature Banksia menziesii trees during drought

“…The minor variations seen in the normalized P p traces of the ZIM probes indicate stomatal oscillations in response to small, transient changes in microclimate, which have been reported previously (Rüger et al , Zimmermann et al ). Picking up such minor changes demonstrates the high sensitivity of the magnetic leaf turgor probe and highlights its suitability for detailed studies of stomatal responses and functioning.…”

Plant-Based Methods for Irrigation Scheduling of Woody Crops

“…Other effects of the environmental conditions and plant hydraulic functioning on the performance of the ZIM probe, were detailed by Zimmermann et al [163]. The ZIM system has been tested in a variety of forest tree species [165], grapevines [166,167], and grapefruit [167], banana [168], persimmon [169] and olive trees [49,[170][171][172], as well as in herbaceous crops such as tomato [173], canola [174] and wheat [175,176]. Also, comparative studies of the ZIM system vs. Scholander-type chambers have been made by Westhoff et al [166] for grapevines, by Rüger et al [165] for eucalyptus, avocado, grapefruit, beech and oak, and by Ben-Gal et al [170] and Fernández et al [49] for olive.…”

Film antitranspirants increase yield in drought stressed wheat plants by maintaining high grain number

“…However, this technique is costly, time consuming and destructive, which limits the number of samples and results in temporal and spatial quantification errors (O'Toole et al, 1984). There is increasing evidence that the recently developed, non-invasive leaf patch clamp pressure (LPCP) has promise for precisely measuring plant leaf water status in real time (Bramley et al, 2013;Westhoff et al, 2009;Zimmermann et al, 2010). The LPCP probe consists of two pads equipped with magnets, one of which contains a pressure sensor chip (Ruger et al, 2010).…”