EPICORMIC SPROUTING FROM DETACHED BRANCHES OF Ilex paraguar-iensis: EFFECTS OF DISPOSITION SENSE AND BRANCH DIAMETER ON PROPAGATION POTENTIAL

Abstract

Background: Epicormic sprouting represents a promising strategy for vegetative rescue and propagation of mature trees; however, factors influencing sprout productivity and viability remain insufficiently understood for Ilex paraguariensis. This study evaluated the epicormic sprouting potential of detached branches according to disposition sense (horizontal and vertical) and branch diameter (thin and thick), as well as the rooting performance of cuttings derived from epicormic and canopy sprouts. Detached branches were maintained under controlled mini tunnel conditions and assessed over a 120-day period for survival, sprouting percentage, number of sprouts and sprout length. Subsequently, cuttings from both material sources were evaluated for survival, callus formation, rooting and sprout development.

Results: Disposition sense was the main factor influencing sprouting dynamics. Vertically disposed branches exhibited faster initial sprouting but reduced longevity, whereas horizontally disposed branches showed slower development combined with extended survival. Branch diameter had secondary effects, mainly influencing early sprouting responses. Epicormic cuttings showed lower survival compared to canopy-derived material; however, rooting percentages were statistically similar between sources.

Conclusion: These findings demonstrate that detached branches constitute a viable ex situ source of epicormic sprouts, allowing flexible management strategies depending on production goals. Nevertheless, improvements in environmental conditions and propagule physiological status may be required to enhance survival during vegetative propagation. Overall, detached branches represent a promising alternative for the propagation and conservation of I. paraguariensis, supporting clonal propagation programs while minimizing damage to mother trees.