The role of rootstock in citrus dwarfing: A review

The future of the citrus industry is contingent upon the achievement of sustainable cultivation practices in the face of numerous challenges, including the enhancement of citrus product value, the streamlining of orchard management, the enhancement of resilience to climate change, and the mitigation of pest and disease pressures. A central strategy to meet these challenges involves increasing productivity and reducing costs through more intensive orchard systems, which rely strongly on effective tree size control. The impact of dwarfing (canopy reduction > 60%), semi-dwarfing (40%–60%), and sub-standard (20%–40%) rootstocks on citriculture has been the subject of extensive research over several decades. However, the commercial application of these rootstocks remains limited to specific varieties and geographical regions. Substantial progress has been made in elucidating the molecular and physiological mechanisms that underlie dwarfing in citrus scion–rootstock combinations. Concurrently, breeding programmes worldwide have been developing and evaluating improved genotypes over the past two decades. This review revisits the topic by examining both the potential and limitations of a broader adoption of dwarfing rootstocks to support a new paradigm in citrus production. The present study provides a comprehensive overview of the currently available dwarfing rootstocks and their agronomic performance across contrasting soil and climatic conditions.