Starfruit

Averrhoa carambola

1. Identification and origin

The carambola tree (Averrhoa carambola L.) is a tree species of the Oxalidaceae family, originating from South-East Asia and widely cultivated in tropical and subtropical regions. The fruit, known as carambola or “star fruit”, is appreciated for its sweet-sour flavour and ornamental value.

2. Economic importance

Carambola is marketed fresh, processed (juices, jams, dried) and used in gastronomy for its characteristic shape. The crop has growing relevance in tropical and subtropical markets, including production for export.

3. Botanical characterisation

A small to medium-sized tree, generally between 5–10 m in height, with a rounded crown. The leaves are compound, alternate, with leaflets sensitive to touch and intense light. The flowers are small, pink to purple, gathered in panicles. The fruits are elongated berries with five prominent ribs, forming star-shaped sections when cut transversally.

4. Soil and climate requirements

It prefers warm and humid climates, with temperatures between 20–32 °C. It is sensitive to cold and strong winds. It adapts to well-drained, deep soils, with a pH between 5.5 and 6.5. It tolerates some salinity, but does not withstand prolonged waterlogging.

5. Main pests

• Fruit flies (Anastrepha spp., Ceratitis spp.): direct damage to the fruits.
• Scale insects (Coccidae, Pseudococcidae): sap sucking and sooty mould.
• Mites (Tetranychidae): chlorosis and reduced vigour.
• Defoliating caterpillars (Lepidoptera): leaf damage.

6. Main diseases

• Anthracnose (Colletotrichum gloeosporioides): leaf spots and fruit rot.
• Powdery mildew (Oidium spp.): white mycelium on young leaves.
• Root rots (Phytophthora spp.): decline and death in poorly drained soils.
• Bacterial spot (Xanthomonas spp.): lesions on leaves and fruits.

7. General crop management

Management includes formative and aeration pruning, removal of infected fruits and branches, balanced fertilisation and maintenance of good drainage. Regular monitoring is essential for the control of fruit flies and anthracnose. Harvesting should be carried out carefully to avoid mechanical damage to the fruits.

Bibliographic references

• EPPO Global Database – Averrhoa carambola.
• CABI Crop Compendium – Averrhoa carambola.
• Morton, J. (1987). Carambola. Fruits of Warm Climates.
• Crane, J. H. (2016). Carambola Growing in the Florida Home Landscape. University of Florida IFAS Extension.