Selenicereus megalanthus

Yellow pitahaya (Selenicereus megalanthus)
Scientific name	Selenicereus megalanthus
Common names	Yellow pitahaya; yellow dragon fruit
Family	Cactaceae
Order	Caryophyllales
Genus	Selenicereus

Selenicereus megalanthus, commonly called yellow pitahaya or yellow dragon fruit, is a climbing cactus cultivated for its yellow-skinned fruit. The accepted name is Selenicereus megalanthus; Hylocereus megalanthus is a historical combination that remains common in horticultural and research literature.^[1]

Description

This species is a vine-like, epiphytic or climbing cactus with segmented green stems and aerial roots. Crop-level pitaya production uses a strong support because the long stems need to be trained upward and then allowed to hang over the top of the trellis.^[2] Yellow pitahaya is not uniform in production: measurements from selected farms in Miraflores, Boyacá, Colombia showed meaningful differences among genotypes and between open-field and covered systems.^[3]

Cultivation

Soil and water

As a pitaya crop, it is reasonable to begin with a sharply drained soil and a site where irrigation can be controlled; this is a genus-level cultivation inference rather than a species-specific soil prescription.^[2] Keep the root zone from remaining saturated, provide organic matter where the native soil is poor, and use a sturdy trellis before the stems become difficult to train. Water deeply during active growth, then allow excess water to drain freely. Reduce irrigation during cool or dull periods when the plant is using water more slowly.

Sun and humidity

As a member of the pitaya crop group, it is reasonable to start with bright light, good airflow and protection from extreme exposure while the plant is establishing; confirm the final light level for the local clone and climate.^[2] UF/IFAS describes pitayas as tropical and subtropical cacti that can be injured by extreme sunlight and cold or freeze conditions. A sheltered position with ventilation is preferable to a stagnant, constantly wet canopy. In hot climates, gradual acclimation and some protection during the most intense afternoon exposure can reduce sun injury.

Seasonal changes

Pitaya production is most active during warm, frost-free growth. The practical genus-level inference is to increase irrigation and training as new stems extend, maintain airflow through the wet season, and protect the plant from frost or freezing weather rather than treating it as a hardy outdoor cactus.^[2] Flowering and fruiting depend on the local crop cycle and genotype; avoid transferring a calendar from a different pitaya species or climate. Covered production can change stem growth and fruit traits, as shown by the Colombian comparison of open-field and covered systems.^[3]

Propagation

Vegetative propagation by stem cuttings is practical crop-level guidance for pitaya. Use mature, healthy stem pieces, allow cut surfaces to dry in shade, and root them in a well-drained medium before planting out; the UF/IFAS crop guide gives a general curing and pot-rooting procedure, but its cutting dimensions and timing should not be treated as fixed values for this species.^[2] Support newly rooted plants promptly and avoid overwatering before a strong root system has formed.

Seed propagation is useful for breeding and genetic diversity but does not preserve a selected fruiting type as reliably as a cutting. The Miraflores evaluation found substantial variation among genotypes and identified genotypes 3 in open field and 7 under cover as outstanding within that local evaluation; those results are selection leads for that production context, not named cultivars or universal recommendations.^[3] A breeding-program review places the historical combination Hylocereus megalanthus in crossing, cytology and embryo-rescue work, including viable intergeneric hybrids, but those program records do not establish a general propagation protocol for this species.^[4]

Flowering, fruiting, and harvest

Pitaya flowers open at night. Some cultivated pitayas are self-incompatible, so growers should not assume that every clone will set fruit alone; planting compatible genetic types or using hand pollination is a crop-level strategy when natural fruit set is poor.^[2] Species-specific compatibility among yellow-pitahaya clones is not established here, so pollination results should be recorded by clone and flowering date rather than generalized.

In the Miraflores study, covered systems averaged 3.70 fruits per cladode and 121.24 cm cladodes, while average largest-fruit weight was 219.04 g in open fields and 186.48 g under cover. These are means from selected Colombian farms and genotypes, not yield or fruit-size targets for every plant.^[3] The same evaluation used 75% pericarp coloration and easy thorn detachment at physiological maturity as practical maturity indicators. Its measured soluble-solids means were 15.20 °Brix in open-field fruit and 14.66 °Brix under cover.^[3]

Harvest carefully to avoid bruising the skin and keep fruit cool after picking. Crop-level guidance supports harvesting mature fruit, allowing any desired finishing of color under appropriate conditions, and short-term refrigerated storage; exact storage life depends on maturity and handling.^[2]

Fruit and uses

The fruit has yellow skin and pale flesh containing numerous small edible seeds. It is eaten fresh, commonly halved and spooned, and can be chilled before serving. Fruit quality varies with genotype and production system: the Colombian evaluation measured soluble solids and fruit size rather than establishing a single species-wide flavor standard.^[3]

Pests and diseases

A farm census in Miraflores recorded basal rot, bacteriosis, flower-bud fly and potato bug among locally observed production problems. These observations identify issues encountered in that Colombian production area; they are not a universal pest and disease list or a basis for assuming that every yellow pitahaya planting will experience them.^[3] Good drainage, airflow, clean propagation material and removal of damaged tissue are sensible crop-level preventive measures, while diagnosis should be based on the actual symptom and local pest pressure.^[2]

References

• ↑ [1] GBIF species match: Selenicereus megalanthus.

• ↑ [2] Pitaya (Dragonfruit) Growing in the Florida Home Landscape, UF/IFAS Extension.

• ↑ [3] Morphoagronomic Evaluation of Yellow Pitahaya (Selenicereus megalanthus) in Miraflores, Colombia, Agronomy 12(7), 1582 (2022), DOI 10.3390/agronomy12071582.

• ↑ [4] Breeding an underutilized fruit crop: a long-term program for Hylocereus, Plant Methods 18, 61 (2022), DOI 10.1186/s13007-022-00899-5.