The objective this research was to evaluate the effects of preharvest spraying with plant regulators and harvest date on the fruit maturity of 'Laetitia' plums. The treatments evaluated were: control (untreated), aminoethoxyvinylglycine [AVG; at 125mg (a.i.) L-1], giberellic acid [GA3; at 100mg (a.i.) L-1] and 1-Methylcyclopropene [1-MCP; at 70µg (a.i.) L-1], combined with two harvest dates (01/11/2007 and 01/25/2007). The GA3 was sprayed 14 days before the first harvest, while AVG and 1-MCP were sprayed 7 days before the first harvest. The experiment followed the randomized block design with four replications. In general, the plant regulators delayed changes in skin color and preserved fruit texture, providing the highest resistances values for flesh compression and fresh penetration. The force for skin rupture was highest in treatment with 1-MCP. The control treatment showed the highest levels of soluble solids content (SSC). The treatments had no affect on red color of the fruit. Delays in harvest reduced fruit texture, titratable acidity and SSC, and increased fruit red color, however, treatment with plant regulators delayed changes in fruit maturity.
1-methylcyclopropene; gibberellic acid; aminoethoxyvinylglycine; ethylene; harvest date
