Oleocellosis Damage of Fruitlets In Late Season Mechanical Harvested 'valencia' Trees Does Not Affect Fruit Quality

Oleocellosis or oil spotting of citrus fruit, is a common injury on the flavedo caused by mechanical damage during harvesting and handling. Physical injury of oil glands of the peel allows the phytotoxic oil to injure the surrounding cells. Using ‘Valencia’ orange trees, we evaluated the effects of winter time drought stress and late season mechanical harvesting (MH) with a canopy shaker on oleocellosis of green fruitlets of next year’s crop. MH removed about 20-50 % of fruitlets depending on previous drought stress treatments and harvesting date. Beginning one week after harvesting (June 13^th), oleocellosis injury was evaluated on 240 fruitlets based on visual estimations of the percentage of surface injured. Tagged fruit were evaluated about every other month until late season harvest in May. In April, mature fruit quality including fruit size, juice content (%), total soluble solids (°Brix) and acidity, was not affected by previous drought stress treatments. Fruit surface injury decreased as fruit expanded and injuries healed but blemishes did not disappear. Thus, fruitlet oleocellosis in late season mechanical harvested trees did not increase fruitlet drop nor alter fruit quality.