Growth of Peach [Prunus persica (L.) Batsch] Fruits After Treatment With Ethephon During Successive Periods of Fruit Development

Abstract

During the first stage of dry weight increase (DW I) of peach fruit, ethephon inhibited growth but stimulated the short-term uptake of 14C-labelled assimilate as well as the natural abscission of the fruitlets. Abscission appeared to be the primary effect, while inhibited growth was a secondary effect of ethephon. This stage of growth DW I) includes the first half of the lag phase of fresh weight increase (FW 11). During the remainder of FW I1 (after the start of DW 11), ethephon did not affect growth except at the highest concentration, which inhibited growth. After commencement of FW 111, which is the final stage of rapid fresh weight increase, ethephon stimulated fruit growth. The data indicated that growth could be stimulated with ethephon during periods when the rate of fresh weight growth was rising but not when it was falling. Thus, endogenous ethylene appears to limit growth of peach fruit during the stages of rapid increase in fresh weight.