Chilling of Endodormant Peach Propagules: IV. Terminal Shoot Growth of Cuttings, Including Gibberellic Acid Treatments

Abstract

Cuttings from peach (Prunus persica (L.) Batch cv. Johnson Elberta) trees were subjected to five chilling durations (20 to 76 days) at seven temperatures (0 to 14C) and five concentrations of gibberellic acid [GA, (0.0 to 1 mm)]. There was a significant increase in terminal shoot length with longer chilling treatments. Cuttings treated at 2 to SC had the longest shoots, and shoot length decreased, in order, following treatment at 10, 0, and 14C. Treatment with the highest concentration of GA, resulted in the longest terminal shoots. Interactions between GA and chilling durations indicated that either higher concentrations of GA, or longer chilling treatments increased terminal shoot growth. Thus, endogenous promoters, like GA, are evidently produced or released during chilling. Sensitivity to GA, was also important. Chemical name used: Gibberellic acid (GA3).