Klein, I., Institute of Horticulture, Agricultural Research Organization, The Volcani Center, Bet DaganIsrael
Epstein, E., Institute of Horticulture, Agricultural Research Organization, The Volcani Center, Bet DaganIsrael
Lavee, S., Institute of Horticulture, Agricultural Research Organization, The Volcani Center, Bet DaganIsrael
Ben-Tal, Y., Institute of Horticulture, Agricultural Research Organization, The Volcani Center, Bet DaganIsrael

Inconsistent results of ethephon in field experiments in olive (Olea europaea L.) are attributed to climatic differences and irrigation regimes. Physical measurements, using 14C-2-chloroethyl phosphonic acid (14C-CEPA) at pH 6.3 indicated 60% degradation within 5 h at 40° C. Rate of degradation at 20, 30, 40 and 50° C at relative humidities of 37 or 70% was higher than at similar temperatures at 3 or 93% relative humidities. Temperature-dependent degradation of ethephon was similar on the surface of detached leaves, intact plants or in the glass test tube. Non-irrigated trees responded better than irrigated trees to ethephon treatment. Uptake and translocation of 14C-CEPA as a function of the water content was measured in a model system of detached branches. Uptake of 14C-CEPA was increased and translocation decreased in partially desiccated branches. The increased uptake and decreased translocation in desiccated branches is in accordance with the response of non-irrigated trees in the field. © 1978.