EFFECT OF BUD POSITION AND PRUNING ON AVOCADO STOCK PLANTS INTENDED FOR CLONING

Abstract

Etiolation and layering techniques currently represent the main alternative implemented for plant propagation in the world of commercial multiplication of avocado clones (Persea americana Mill.). Rooting stage is considered most critical and needs to be optimized. In this study, an assessment of the effect of bud position inside the shoot to be used during the cloning process was carried out, along with an evaluation of the pruning management in ‘Hass’ avocado trees and the ‘Duke 7’ clonal root stocks, in two stages: grafting and growth of the etiolated sprout. Results showed that grafts from the basal buds inside the sprout originated thicker etiolated sprouts (P ≤ 0.05) than those located in the apical or middle buds. The shortest time for obtaining rooted etiolated sprouts in ‘Duke 7’ rootstocks occurred on buds located in the middle and basal sections, than on sprouts from buds at the apical section. Histological analysis performed on etiolated sprouts of ‘Hass’ indicated an effect from bud position and pruning management of stock plants on anatomical aspects like in the continuity of sclerenchyma fibers and thickness of the fascicular and interfascicular cambium. Finally, scions from apical sections had higher total soluble carbohydrate content than middle and basal sections.