EFFECTS OF GIBBERELLINS ₄₊₇ AND SHOOT PINCHING ON HORMONAL LEVELS IN “CONFERENCE” PEAR

Foliar application of gibberellins enhances shoot elongation /10/, promotes setting of parthenocarpic and seeded pears /2/7/9/11/13/14/19/20/ and inhibits flower initiation /3/8/20/. The growth retardant PP 938 (J.F. 3900 – dyallyl-succinate) /18/; applied to "Conference" pear trees, retardes shoot growth, prevents June drop and induces fruit set.
These effects indicate that this compound can interfere with the biosynthesis of gibberellins, or their mode of action, much like daminozide (SADH) /4/ 21/.

The question that then arises is whether the exogenous GA affects both the shoots and fruits equally as sinks for food or whether the growth retardant modifies the hormonal and nutritional competition between both these organs.

This experiment has been designed to separate those effects on GA-treated trees.

Symposium on Production and Preservation of Pears

P. MONTALTI, G. CRISTOFERI, S. SANSAVINI

https://doi.org/10.17660/ActaHortic.1984.161.10