MOHAMMAD ALI SHAHROKHNIA* AND MOHAMMAD HADI JORENUSH
Agricultural Engineering Research Department, Fars Agricultural and Natural Resources Research and Education
Center, Agricultural Research, Education and Extension Organization (AREEO), Shiraz, Iran
*(e-mail : mashahrokh@yahoo.com; Mobile : 98 91771 09159)
(Received : February 5, 2022; Accepted : February 24, 2022)
ABSTRACT
Citrus is one of the most important trees in the semi-arid regions of southern Iran. Water is a limiting
factor in these regions. In the present study, five irrigation scheduling tools were used and compared
with conventional irrigation in Fasa region. The irrigation scheduling was based on the national document
of crop water requirement (NDCW), canopy temperature measurement by an infrared thermometer, soil
moisture monitoring, soil moisture tension measurement with Tensiometer and soil electrical conduction
by gypsum block. Two thousand and five hundred orange trees in silty clay loam soil were irrigated by
drip irrigation system during two years study periods. Applied water, fruit production and fruit quality
were measured at the end of the first and second year. Results showed that irrigation scheduling
treatments saved applied water from 23 to 40% and 41 to 51% in the first and second year compared to
the conventional irrigation. In both irrigation seasons, the maximum fruit yield was obtained in the
treatment scheduled based on canopy temperature. Irrigation scheduling increased water productivity
57 and 98% compared to conventional irrigation in the first and second year, respectively. The fruit
quality characteristics and economical income were not decreased in irrigation scheduling treatments.
Therefore, irrigation scheduling can be used to save applied water and cost with improving the fruit
quality of the citrus orchards in a semi-arid region.
Key words : Water productivity, canopy temperature, tensiometer, gypsum block