Plant growth regulator effects on the storage and shelf-life 'triumph' persimmons

The plant growth regulators gibberellin (GA(3)) and paclobutrazol (PBZ) were applied to 'Triumph' persimmon orchards, in order to extend the harvesting and marketing season's of the fruit. PBZ, when applied to the roots in the spring advanced fruit ripening by 2-3 weeks without any detrimental effect on fruit size. However, the postharvest rate of fruit deterioration was accelerated. GA(3), when sprayed at least 10 days prior to harvest, delayed fruit ripening on the tree and the rate of postharvest fruit deterioration decreased. PBZ-enhanced fruit deterioration was inhibited by subsequent GA(3) application, thus enabling precocious harvesting followed by an extended shelf-life. The minimum period after GA(3) application for harvesting PBZ-treated fruit, was reduced to one week-the fruit maintaining its firmness without a delay in colour development. The time lag required for the GA(3) treatment to be effective in the harvested fruit, is apparently related to its effect on cell wall metabolism.