Crop Water Requirements of Mature Blueberries in Florida

Climate-specific measures of crop water use of mature blueberry plantings could offer growers improved irrigation management. In contribution to improved irrigation management practices for Florida blueberry growers, this paper presents a crop coefficient for mature Southern highbush blueberry plants. Measures of crop water requirements were made using a water balance enabled by drainage lysimeters. Grower-controlled irrigation management is compared with a shorter, researcher-managed, timer-controlled schedule. A researcher-managed plot on a commercial blueberry farm is irrigated independently of the grower's fields, enabling comparison of crop ET and beneficial evaporated fractions, the ratio of water used for crop development to the gross irrigation diversion between grower-controlled and researcher-managed timer-controlled irrigation management. Four lysimeters in the researcher-managed plot and four lysimeters in a six acre plot of the grower's field were used to measure crop water use. Water balance durations range from 7 to 10 days. Lysimeter area corresponds closely to crop canopy area of mature plants. Irrigation inputs are measured by flowmeters, and precipitation inputs are measured by an onsite weather station that is also used to determine reference ET.