Chronica Horticulturae volume 49 number 2 ... - Acta Horticulturae

A
B
C
Calibrating the compensation heat-pulse method. (A) Set up for olive. (B) Perfusion experiment for orange. (C) Excision experiment for orange.
Photo Dr. J.E. Fernández (see Fernández et al. 2006. Tree Physiol. 26:719-728 for details).
Some components of the CRP, an automatic
irrigation controller based on sap flow
measurements. Photo Dr. J.E. Fernández (see
Fernández et al. 2008. Aust. J. Agr. Res.
59:589-598 for details).
methods, used alone or in combination with
other techniques, to quantify and understand
how plants of different species use water, especially
in the long term.
The second Section was opened by Dr. Green,
who discussed the potential of combining
measurement and modelling techniques to promote
environmentally safe and sustainable agricultural
practices. He showed a variety of examples
in which sap flow measurements and
model exercises were used together as a useful
tool to irrigate wisely, i.e. to achieve the maximum
crop productivity at the same time that
the risk for soil and groundwater contamination
by agrochemicals is reduced. The contributions
of this Section showed the potential use
of sap flow measurements for quantifying
water use in a variety of species, and for the
development of scheduling irrigation strategies,
some based on fully automatic, telecontrolled
irrigation devices.
In the last Section, Prof. Čermák related the
experience of his team with the Trunk Heat
Balance method and the Heat Field
Deformation (HFD) method for characterizing
the tree architecture and functioning, including
the root system. Measurements with the HFD
method can provide data not only on the
dynamics of the sap flow in trunks, branches
and roots, but also on its radial pattern. The
effective structural and architectonical parameters
of crowns or roots can then be derived. The
rest of the contributions within this Section
addressed a variety of mechanisms related to
the hydraulic characteristics of the xylem in different
organs, and how they vary depending on
time, phenological stage and environmental
conditions.
The outstanding standard of most presentations
created interesting discussions after each
oral contribution, which were completed in the
open forum at the end of each Section. This,
Prof. M.I. Ferreira (right) and Dr. J.E. Fernández (left) during the Welcoming Address.
Section. Complementing the plenary sessions
was a display room in which main manufacturers
showed the latest advances in sap flow and
related equipment.
In his lecture to open the first Section, Dr.
Clothier gave an overview of how new
advances in the measurement and modelling of
water fluxes in the soil-plant-atmosphere system,
complemented with biophysical modelling,
enable us to develop within-enterprise
practices and resource management policies to
protect water quantity and quality across
diverse landscapes. The rest of contributions
within this Section gave us a detailed picture
both of recent advances in sap flow techniques
and new methods to improve the analysis of
the recorded values. Special attention was paid
to evaluate to which extent the mentioned
advances avoid or reduce limitations of the
existing sap flow methods. There was a discussion
on the potential of the existing sap flow
CHRONICA HORTICULTURAE •VOL 49 • NUMBER 2 • 2009 • 43