Cycloheximide (CHI) at 20 to 30 ppm caused olive fruit abscission, and at higher concn, leaf abscission. Water potential in the tree was a strong factor influencing CHI-induced abscission. Reducing water loss by the prior application of antitranspirants (AT) greatly increased abscission due to cycloheximide. In addition, AT stimulated ethylene production resulting from CHI application. Prior application of a wax-type antitranspirant reduced fruit injury from cycloheximide. Increasing temp, from 4.5°C to 29.5°C (40° to 85°F), stimulated abscission due to cycloheximide. Up to 25% leaf abscission was tolerated without interfering with subsequent flower formation.