Combinations of GA3 and AVG delay fruit maturation,increase fruit size and improve storage life of `Feicheng' peaches

Summary

Different concentrations of aminoethoxyvinylglycine (AVG) and gibberellic acid (GA₃) and their combinations, applied at two stages of fruit growth, were evaluated for prolonging the marketing season of `Feicheng' peaches. GA<sub>3</sub> applied at the end of pit hardening, or AVG applied two weeks before commercial harvest, inhibited fruit maturation on the tree, delayed harvest and reduced flesh browning after cold storage in a concentration-dependent manner. A synergistic effect was found when both GA<sub>3</sub> and AVG were used, with the combination of 100 or 150.mg l<sup>±1</sup> GA<sub>3</sub>, applied at the end of pit hardening, and 100 mg l<sup>±1</sup> AVG, applied two weeks before harvest giving the best results. These combinations retarded the change in ground colour, loss of firmness, and reduction in acidity by 2±3 weeks. Since harvest was prolonged by 2±3 weeks, soluble solids content (SSC) in fruit increased compared with the control (harvested earlier). Fruit size was significantly greater on treated trees compared with the controls when fruit set was controlled to the same level by hand thinning. After four weeks of storage and 4.d at 208C, 83% of control fruit developed tissue browning, but only 5% of AVG + GA<sub>3</sub>-treated fruit developed browning after six weeks of storage and 4 d at 208C. Thus, the marketing season of `Feicheng' peaches was prolonged by at least four weeks by 100 or 150 mg l^±1 of GA₃ and 100 mg l^±1 of AVG. Fruit treated with 150 mg l^±1 GA₃ plus 100 to 150 mg l^±1 AVG showed similar results but failed to ripen properly after cold storage.