Abstract:
In this research, some of the echo-physiological ch
aracteristics of pistachio trees were
studied to understand crop response to drought stre
ss and determine the best irrigation
interval. This experiment was carried out in an orc
hard with a sandy loam textured soil
and a commercial cultivar of pistachio named Ouhadi
grafted on
Pistacia vera L.
rootstock for three years. The irrigation system se
lected was surface flooding with
intervals of 30, 50, 80, and 110 days. These interv
als were chosen so as to resemble
common irrigation intervals of pistachio orchards i
n the region. This enabled a
comparison between the best and worst conditions of
trees in respect to drought stress.
Total irrigation water received was a constant dept
h of water to all treatments.
Quantitative and qualitative yield such as weight o
f fresh and dry nuts, percent of blank
and split nuts, and number of nuts per ounce, veget
ative and echo-physiological
characteristics were considered and measured. In te
rms of yield quantity and quality, the
results showed vegetative and echo-physiological at
tributes to be significantly different
between the treatments of 30, 80 and 110 days irrig
ation intervals. This means that with
an increase in irrigation intervals and considering
soil water holding capacity, soils were
not able to provide enough moisture for the plant t
o carry out its normal metabolic
activities. However, in the prolonged irrigation in
tervals, there were not much differences
between treatments i.e. the pistachio tree could ad
apt itself to the naturally occurring
environmental stress conditions.
Keywords:
Drought stress, Relative water content, Water use
efficiency.
