Abstract
The effect of Ag+, applied in aqueous solution as AgNO3, on respiration, ethylene evolution and softening (three of ripening parameters) of Japanese persimmon (Diospyros kaki Thunb. cv. Fuyu) at various stages of development was studied at 25°C.
Immediately after the calyx portion was cut away from the fruit, various concentrations of Ag+ was vacuum-infiltrated through the scar of the fruit.
The results were summarized as follows.
In stage I fruits (harvested July 20), at 0.1mM Ag+ inhibition was almost complete on all of three ripening parameters. At higher concentrations (0.5mM and 2.5mM), however, inhibition was far less on respiration and ethylene evolution than at 0.1mM. On the contrary, fruit softening was accelerated at higher concentrations.
In stage II fruits (harvested August 16), the inhibitory effect of 0.1mM Ag+ on these three parameters decreased.
In stage III fruits (harvested October 23 and November 13), 0.02mM Ag+ was effective on all of three parameters. On the other hand, 0.1mM and 0.5mM Ag+ accelerated the respiration, ethylene evolution and softening of the fruit.
