During the test years, the two vegetated units were found to
have ETcvalues which were different and much higher compared
to the ET0values based on other authors (Fig. 8). Giant reed-unit
was found to have average 10-day ETaru (evapotranspiration A.
donax) values ranging from 47.1 (1st 10-day period of August 2012)
to 1.4 mm/d (3rd 10-day period of November 2013). Average
maximum 10-day ETcyp(evapotranspiration C. alternifolius) values
for umbrella sedge-unit were recorded in 2nd 10-day period of
August 2012 (41.9 mm/d) and average minimum values in 3rd 10-day period of November 2013 (1.2 mm/d). Seasonal trends of
average ETaruand ETcyp10-day values were found to be very similar
to each other. Taking into consideration the different growth stages
of the two macrophytes, in 2012, from initial stage to crop
development stage (April–July), ETcvalues of both species showed
the same trend, with a constant 10-day and monthly increase.
During the first half of the mid-season stage (August), ETcvalues
increased rapidly in both planted units, reaching maximum values.
In this phase, during which maximum vegetative growth of the
two species was also reached, ETaruwas found on average to be
higher than ETcypby 11%. During the second half of the mid-season
stage (September), which coincided with initial apical senescence
of the two macrophytes, a progressive fall in ETcvalues was found,
despite the fact that the giant reed-unit was found to have average
ETc values which were even higher than the umbrella sedge-unit.
During the late-season stage (October–November), ETc
fell
progressively in the two units as leaf and stem senescence rose