effects of gibberellic acid and putrescine treatments on marketable and some quality attributes certains of citrus fruit (citrus sinensis cv. hamlen)

Citrus fruit quality preserve the post harvest cause marketability increased. In this research, the effect of putrescin and gibberellic acid concentrations on storage life of sweet orange fruit (Hamlen cultivar) was studied to in factorial design (3*3*6=54)based on randomized complete block with six replications. Putrescin at three concentrations( 0, 1 and 2 mM) and three level of gibberellic acid (0, 50 and 100 mg/L) were sprayed on the tree at the physiological maturation stage and two weeks pre harvest. Fruit firmness, marketability, vitamin C, total acidity, total soluble solids (TSS) and ratio of total soluble solids (TSS) to total acidity were evaluated. The results showed that putrescin spraying at 1 mM significantly prevented fruit softening and preserved fruit firmness. Also putrescin treatment (1 mM) preserved ideal marketability and was superior than other treatments. Gibberellic acid significantly preserved total acidity and total soluble solids. The interaction of gibberellic acid and putrescine also preserved significantly vitamin C. Therefore, the application of putrescine at 1 mM and gibberellic at 100 mg/L was recommended for preserve marketability, appearance and quality of citrus sinensis cv. Hamlen.