Exogenous polyamines and gibberellic acid effects on peach (Prunus persica L.) storability improvement

Peaches (Prunus persica L., cv. Babygold 6) harvested at the stage of commercial ripening were pressure-infiltrated with putrescine (1 mM) or GA(3) (100 mg L-1) and then stored at 2 degrees C for 14 d. Both treatments increased fruit firmness, putrescine-treated peaches being significantly firmer than control ones. Treatments were also effective in reducing the susceptibility of the fruit to be damaged by mechanically compression with lower volume and surface of the damage zone. Ethylene emission and the respiration rate were reduced in treated fruits, which reflects a delay of the ripening process. The effects of the mechanical stress could be related to increased spermidine levels, rather than ethylene emission and respiration rate during storage.