Impact of overhead irrigation on fruit quality of ‘Scifresh’ apples

Overhead sprinkler irrigation in orchards modifies the plant microenvironment which can affect fruit quality. The objective of the present study was to evaluate the effect of overhead sprinkler irrigation on fruit sunburn incidence, coloration, maturity parameters and the development of physiological disorders in ‘Scifresh’ apples. The overhead sprinkler irrigation system was activated when the air temperature reached 27 °C, with constant pulses maintained to ensure that the air temperature never exceeded the critical values of 29 °C for three months prior to harvest. The treatments were: (1) control without evaporative cooling; (2) microsprinkler irrigation with 0.6 L/h discharge rate; (3) sprinkler irrigation with 2 L/h discharge rate. The results indicated that overhead sprinkler irrigation reduced sunburn incidence by up to 90% as well as its severity, although there was no significant improvement in fruit color. In postharvest, both irrigation systems decreased the incidence of bitter pit and lenticel breakdown, without affecting fruit ripening. However, fruit under sprinkler irrigation had a 10% increase in soft scald incidence.