Continuous spraying of putrescine during peach fruit development increased fruit size and postharvest fruit firmness

Putrescine (PUT) was applied at 0 (control), 3.5 and 7.0 mM to ‘CP-0019’, ‘CP-0036’ and ‘Diamante’ peach trees (Prunus persica L. Bastch) at 23 d after full bloom, and then every 25 d till 25 d before harvest. PUT at 3.5 mM increased fruit weight (P≤0.05) and diameter among all three cultivars at harvest relative to controls. ‘CP-0019’ peaches treated with 3.5 mM PUT also contained higher (P≤0.05) levels of phenolic compounds than controls throughout all the fruit growth period. At harvest, the ‘CP-0019’, ‘CP-0036’ and ‘Diamante’ peaches treated with 3.5 mM PUT demonstrated increased (P≤0.05) flesh firmness, in relation to control, by 40, 18 and 30%, respectively. At postharvest, the ‘CP-0019’, ‘CP-0036’ and ‘Diamante’ peaches at 3.5 mM PUT had 23, 13 and 31% increased (P≤0.05) flesh firmness compared to control fruit.