Abstract: | Knee, M., Hatfield, S. G. S. and Bramlage, W. B. 1987. Responseof developing fruits to ethylene treatment.J. exp. Bot.38: 972979. Fruits of apple (Malus domestica Borkh. cv. Cox's Orange Pippin)were treated with various concentrations of ethylene usuallyfor 48 h to determine their response in relation to stage ofdevelopment. The main response recorded was the reduction byethylene of the delay in onset of rapid ethylene production(DEP) in individual fruits. Early in development low concentrationsof ethylene had little effect but DEP was progressively reducedby concentrations up to 107 mm3 m3. As the fruit approachedthe natural onset of rapid ethylene synthesis concentrationsof 102 and 103 mm3 m3 became increasingly effective.Increasing the duration of treatments with a fixed concentrationreduced DEP proportionately. Delay after harvest in applyinga 48 h treatment had little effect on the relation between DEPand concentration of ethylene applied. Although resistance todiffusion of gas in fruits increased during fruit developmentthis resistance was never large enough to affect the relationof concentration and response. Key words: ethylene, fruit ripening, Malus domestica |