2nd UF Water Institute Symposium Abstract

   
Submitter's Name Isaya Kisekka
Session Name Poster Session: Optimal Use of Integrated Water Supplies 1
Category Optimal use of integrated water supplies
Poster Number 413
 
Author(s) Isaya Kisekka,  University of Florida, Agricultural and Biological Engineering Department
  Kati Migliaccio,  University of Florida, IFAS Tropical Research and Education Center
  Michael Duke, University of Florida, Agricultural and Biological Engineering Department
  Bruce Schaffer, University of Florida, IFAS Tropical Research and Education Center
  Jonathan Crane, University of Florida, IFAS Tropical Research and Education Center
   
  Evaluation of Evapotranspiration-Based Irrigation Scheduling Technologies in a Tropical Fruit Orchard in South Florida
   
  Evapotranspiration (ET)-based irrigation scheduling technologies were investigated in a carambola orchard irrigated with micro-jets. The objectives of this study were to: 1) evaluate water savings with ET-based irrigation technologies using real-time and historical weather data to schedule irrigation, and 2) evaluate the effect of ET-based irrigation scheduling on net CO2 assimilation (A), transpiration (E), stomatal conductance (gs), stem water potential ( ) and fruit yield, Four treatments namely: 1) real-time ET-based irrigation scheduling operated through a Toro-Intelli-Sense-612 controller (T1), 2) historical ET-based irrigation scheduling operated through a Rain-bird ESP-12-LX-plus timer (T2), 3) typical irrigation schedule for carambola in south Florida (76 mm/ week) (T3), and treatment 4 (T4) a non irrigated treatment were replicated three times and evaluated for differences in water applications and physiological plant responses. Results indicate T1 and T2 applied 68% and 70% less water compared to T3 respectively. Treatment 1 maintained the highest average weekly soil water content (?) of 29% while T4 maintained the lowest ? of 24%. There were no significant differences in among treatments, all treatments averaged -0.8 MPa. There were also no significant differences in carambola fruit yield among treatments. However, there were some significant differences in E and gs among treatments with T2 registering the highest E and gs while T4 registering the lowest. Across treatments, there were no significant differences in A, all treatments averaged 4.7 ┬Ámol m-2 s-1. Results suggest that adopting ET-based irrigation scheduling technologies could provide tropical fruit growers with several benefits including: reduced water volumes applied and consequently reduced energy inputs without negatively affecting the physiology of the plants.