APPLICATION OF GROWTH REGULATORS TO PEACH AND APPLE TREES GROWING UNDER STRESS CONDITIONS IN SHALLOW AND STONY SOILS
Restriction of apple and peach root systems due to shallow and stony soils, or due to raising the trees in undersized containers reduced shoot and fruit growth severely. Growth and yields in stressed trees were increased considerably by the infusion of benzyladenine or kinetin into the tree trunks. Gibberellin (GA3) applied in the same way promoted the fruit growth of apples, but tended to induce biennial bearing. The application of mixtures of synthetic cytokinins and gibberellins by infusion or spraying was in most cases ineffective, however in severly declining apples trees it increased the number of laterals and their elongation.
Bioassays for cytokinins and gibberellins in treated trees pointed to a mainly acropetal transport of both growth regulators. The gibberellin level in peach roots and leaves raised not only due to application of gibberellin but also of kinetin.
Gur, A. and Sarig, P. (1983). APPLICATION OF GROWTH REGULATORS TO PEACH AND APPLE TREES GROWING UNDER STRESS CONDITIONS IN SHALLOW AND STONY SOILS. Acta Hortic. 137, 153-168