Morphological Effects of Paclobutrazol on the Regrowth of Rejuvenated Coffee (Coffea arabica L.) Trees

Abstract

This study was conducted to determine the morphological response of the regrowth of rejuvenated coffee (Coffea arabica L.) to varying timing and levels of application of Paclobutrazol (PBZ) [2RS, 3RS)-1-4 (-chlorophenyl)-4,4-dimethyl-2-1, 2, 4-triazol-1-yl-penten-3-ol]. Plants applied with PBZ two months before cutting had delayed shoot emergence, were shorted and had bigger lateral brances but with comparable percent plant survival, vertical shoot stem characteristics, lateral branch morphology, leaf morphology and root volume and dry weight compared to those applied with PBZ one month before cutting. Regardless of timing of application, plants given 0.5 and 1.0 g a.i.PBZ/ m canopy span had shorter vertical shoots with shorter internodes, fewer and shorter lateral branches, smaller leaves, and bigger root volume but comarable plant survival, days to shoot emergence, vertical shoot stem diameter, number of nodes of lateral branches, number of leaves, LAI and root dry weight with the untreated plants.