EPSTEIN, E., Institute of Horticulture, Agricultural Research Oranization, Volcani Center, Bet Dagan, Israel
KLEIN, I., Institute of Horticulture, Agricultural Research Oranization, Volcani Center, Bet Dagan, Israel
LAVEE, S., Institute of Horticulture, Agricultural Research Oranization, Volcani Center, Bet Dagan, Israel

The translocation and metabolism of ethephon at pH 7.0 and its effect on abscission of olive fruit, were studied in attached and detached fruits. In detached olives, the lowest fruit removal force values were achieved when the fruits were treated at their proximal cavity and kept under humid conditions. Following application of 14C‐ethephon to the proximal cavity 63% of the label was absorbed within 4 h; evolution of 14C‐ethylene proceeded at a slow rate, mainly from 14C‐ethephon remaining on the olive surface, totaling 37% of the applied ethephon in 20 days. 14C‐ethephon disappeared rapidly after its application to olive on the tree. More 14C‐ethephon could be extracted from olives on the trees after distal application than after proximal application. Since the response of detached olives to treatments with ethephon was similar to that of attached olives in regard to fruit removal force reduction, the former can be used for the study of many aspects of ethephon and ethylene metabolism in olives. In our study no ethephon metabolites other than 14C‐ethylene could be detected after 14C‐ethephon application to attached or detached olive fruits. 1977 Physiologia Plantarum