ABSTRACTProtein synthesis inhibitors (Actinomycin D and cycloheximide) were infiltrated into banana slices by contact or under vacuum. Drastic reduction of the climacteric period was observed in both types of infiltration when cycloheximide was infiltrated into slices, compared to the Actinomycin D group and to a control group infiltrated with water. Ethylene production was stimulated when both protein synthesis inhibitors were used, in comparison to the water control group irrespective of the type of infiltration adopted. Ethylene production was higher in the vacuum infiltrated groups. It is suggested that cycloheximide and Actinomycin D affect the equilibrium of ripening differently, giving rise to the distinct responses observed.