Evaporative Cooling of Apples by Overtree Sprinkling

Research has shown water application rates = 6 L s–1 ha–1 (38 gpm/acre) are more effective than lower rates in reducing fruit temperatures by evaporative cooling (EC). Applications at about 6.25 L s–1 ha–1 (40 gpm/acre) were sufficient to hold core temperatures close to the selected temperature range during a 40° C (104° F) day with clear skies and sunny conditions. Automated control of EC-based on-core temperatures worked well in this project. The management of EC systems should pulse water applications on and off so free water is continually evaporating, hydro-cooling is minimized, and water is conserved.