Evapotranspiration by Young Florida Flatwoods Citrus Trees

Abstract

Twenty‐one drainage lysimeters were installed in 1988 to measure water balance parameters for citrus trees. The lysimeters were designed to simulate the high water‐table conditions that exist for the more than 150,000 ha of citrus grown in the Florida Flatwoods. The lysimeters were constructed from 3.5‐m diameter by 1.0‐m deep polyethylene tanks. Young trees were transplanted into the lysimeters in 1988. Four experimental treatments consisting of constant water tables at depths of 0.61 m, 0.76 m, and 0.91 m plus a fluctuating water‐table treatment were included in the study. Trees were watered with a microirrigation system and all irrigation and drainage water was metered. Water‐table levels were maintained by float‐controlled pumps. Annual evapotranspiration (ET) averaged 16,030 L tree−1 for March 1989 to March 1990 and 11,733 L tree−1 for March 1990 to March 1991. ET rates were not significantly different among water‐table treatments. Tree growth, yield, and juice quality were not affected (p=0.05) by the water‐table treatments.