Correlative Inhibition of Axillary Buds in Apple Nursery Trees in Relation to Node Position, Defoliation, and Promalin Application

Abstract

Abstract Sprouting of axillary shoots was studied in nursery apple trees (Malus domestica Borkh) following defoliation and Promalin application. Both Promalin and defoliation stimulated lateral bud outgrowth. Promalin was more effective when applied to buds without the inhibition imposed by the subtending leaf. In the absence of the subtending leaves there was a decreased tendency for buds to sprout at lower node positions. Buds most responsive to Promalin were between those subtended by small, partially expanded leaves and those subtended by fully grown leaves.