Monitoring the greenhouse transpiration for control purposes is currently a difficult task. The absence of affordable sensors that provide continuous transpiration measurements motivates the use of estimators. In the case of tomato crops, the availability of estimators allows the design of automatic fertirrigation (irrigation + fertilization) schemes in greenhouses, minimizing the dispensed wat...

Plant transpiration is considered one of the most important physiological functions because it constitutes the plants evolving adaptation to exchange moisture with a dry atmosphere which can dehydrate or eventually kill the plant. Due to the importance of transpiration, accurate measurement methods are required; therefore, a smart sensor that fuses five primary sensors is proposed which can mea...

Previous studies on cytokinin (CK) and drought have suggested that the hormone has positive and negative effects on plant adaptation to restrictive conditions. This study examined the effect of CK on transpiration, stomatal activity, and response to drought in tomato (Solanum lycopersicum) plants. Transgenic tomato plants overexpressing the Arabidopsis thaliana CK-degrading enzyme CK oxidase/de...

It is well known that rootstocks can have an effect on the vegetative growth and development of the tree; however, there has been no clear explanation about the physiological mechanism involved in this phenomenon. Evidence indicates that the rootstock effects on tree vegetative growth may be related to hydraulic limitations of the rootstock. The objective of these experiments was to investigate...

In a world of diminishing water reservoirs and a rising demand for food, the practice and development of water stress indicators and sensors are in rapid progress. The heat dissipation method, originally established by Granier, is herein applied and modified to enable sap flow measurements in date palm trees in the southern Arava desert of Israel. A long and tough sensor was constructed to with...

The use of modern gas analysis instrumentation makes it possible to obtain continuous recordings of transpiration (3, 6, 8, 12, 13, 23) and photosynthesis (4, 5, 16, 19) from intact portions of higher plants. The high sensitivity and rapid response of these instruments permits one to determine rather subtle effects of various internal or environmental factors on physiological processes involvin...

Fifty-one genotypes of sugarcane (Saccharum spp.) or closely related germplasm were evaluated in a pot experiment to examine genetic variation in transpiration efficiency. Significant variation in whole plant transpiration efficiency was observed, with the difference between lowest and highest genotypes being about 40% of the mean. Leaf gas exchange measurements were made across a wide range of...

Thermal transpiration is a rarefied gas flow driven by a wall temperature gradient and is a promising mechanism for gas pumping without moving parts, known as the Knudsen pump. Obtaining temperature measurements along capillary walls in a Knudsen pump is difficult due to extremely small length scales. Meanwhile, simplified analytical models are not applicable under the practical operating condi...

Factors that affect water loss rates (WLRs) are poorly known for organisms in natural habitats. Seed-harvester ant queens provide an ideal system for examining such factors because WLRs for mated queens excavated from their incipient nests are twofold to threefold higher than those of alate queens. Indirect data suggest that this increase results from soil particles abrading the cuticle during ...

The growth equation for the rate of water uptake is augmented with a transpiration term. The obtained augmented growth equations are used to develop methodology which employs the pressure probe to measure transpiration rates from single plant cells. Experiments are conducted on the sporangiophores of Phycomyces blakesleeanus to demonstrate this technique.