Citrumelo

Citrumelo is a citrus hybrid used primarily as rootstock for grafted citrus trees. It results from crossing grapefruit (Citrus × paradisi) with the trifoliate orange (Poncirus trifoliata). The term can refer to several related F1 hybrids developed for use in grafting, rather than a single standardized cultivar.

Characteristics include a vigorous, evergreen, and often thorny tree with a dense canopy. Citrumelo is generally more cold-tolerant than many sweet citrus varieties, though it is less hardy than Poncirus trifoliata alone. It tolerates a range of soil conditions better than some other rootstocks and can contribute to overall vigor in grafted trees. The fruit of citrumelo is typically small to medium with a thick rind and a very tart, acidic flesh. It is not commonly eaten fresh, though it may be used for juice or preserves in some cases.

Cultivation and use: In commercial citrus production, citrumelo is valued as a rootstock for its tolerance to certain soil-borne diseases and for supporting vigorous growth of the scion in cooler or marginal climates. It is commonly propagated by grafting or budding onto the rootstock and then grafting the desired citrus variety onto the citrumelo roots. Performance can vary with climate, soil, and the specific graft combination.

Limitations and management: The tree’s thorns and vigorous suckering can complicate orchard management. Pests and diseases affecting citrus can impact citrumelo as a rootstock, requiring standard integrated pest management practices.