In order to clarify the role of leaves in ethylene evolution from fruit of Japanese persimmon, the effect of defoliation and wound applied to fruit skin on ethylene evolution and fruit drop were determined at immature stage of fruit growth in Japanese persimmon 'Hiratanenashi'.
Although little ethylene evolution from fruits and fruit drop occurred in controls, defoliation stimulatedits evolution and all fruits dropped until 12 days after the treatment. Defoliation plus wounding induced those phenomena more rapidly than defoliation or wounding only.The increase in ethylene evolution and the calyx drop in detached fruit occurred 2 to 7 days earlier than those in intact fruit receiving the defoliation treatment. It seems that etylene inhibitor remaining in the defoliated shoot is supplied to the intact fruit. The data may support the concept that fruits receive ethylene ithibitor from the leaves.