EFFECTS OF DEBUDDING AND DEFRUITING ON ALTERNATE BEARING IN PISTACHIO (PISTACIA-VERA L)

Dormant and swelling inflorescence buds, inflorescences and infructescences were removed from both whole and half the canopy of cv. 'Bianca' pistachio female trees in order to investigate their role on alternate bearing. Summer inflorescence bud drop was almost totally avoided in the whole-canopy treated trees whereas in the non-bearing side of the half-canopy treatments, removing after full bloom still promoted a low percentage (about 20%) of inflorescence bud abscission. The latter treatment showed that the influence of the bearing half-canopy on the non-bearing one depended on the stage of the reproductive organs (inflorescence bud, inflorescence, infructescence) at removal time. The research also pointed out the importance of studying alternate bearing in pistachio by whole-tree treatments, because results from scaffold treatments can be affected by the crop load of other parts of the tree.