Papaya

Carica papaya

1. Identification and origin

The papaya (Carica papaya L.) is a herbaceous arboreal species of the Caricaceae family, native to Central America and the north of South America. Its spread occurred through tropical trade routes, and it is currently cultivated in tropical and subtropical regions throughout the world. In Portugal, production occurs mainly in greenhouses or protected environments in Madeira and the Algarve.

2. Economic importance

The papaya is a crop of high commercial importance in tropical regions, standing out for the production of fresh fruit, local consumption and export. The fruit is valued for its flavour, nutritional value and the presence of papain, an enzyme used in the food, pharmaceutical and cosmetic industries. The growing demand for tropical fruit has increased interest in the crop in protected systems.

3. Botanical characterisation

A fast-growing perennial plant, with a size between 2–10 m, presenting a succulent and unbranched stem. The leaves are large, palmate, inserted in a spiral at the top of the stem. The flowers may be male, female or hermaphrodite, depending on the type of plant. The fruit is a large berry, ovoid or elongated, with orange pulp and black seeds surrounded by a mucilaginous aril. The plant is sensitive to cold and to excess moisture.

4. Soil and climate requirements

The papaya requires a hot and humid climate, with ideal temperatures between 21–33 °C. It is very sensitive to temperatures below 10 °C and to strong winds. It prefers well-drained, deep soils, with a loamy to sandy-loam texture and a pH between 6.0 and 6.5. Waterlogging is highly harmful, favouring root diseases. The crop responds well to regular watering and balanced fertilisation, especially in nitrogen and potassium.

5. Main pests

• Fruit fly (Ceratitis capitata): oviposition and rotting of the fruit
• Papaya fruit fly (Toxotrypana curvicauda): internal damage to the fruit (in regions where it occurs)
• Aphids (Aphididae): sap sucking and transmission of viruses
• Thrips (Thysanoptera): leaf lesions and scarring on the fruit
• Scale insects (Coccidae and Diaspididae): sap sucking and sooty mould
• Mites (Tetranychus spp.): chloroses and reduction of photosynthesis

6. Main diseases

• Papaya ringspot virus (PRSV): mosaics, deformations and decline
• Powdery mildew (Oidium caricae): white spots and reduction of photosynthesis
• Anthracnose (Colletotrichum gloeosporioides): post-harvest rots
• Root rots (Phytophthora spp.): wilting and sudden death
• Black spot (Asperisporium caricae): leaf lesions and reduction of productivity

7. General crop management

The management of the papaya includes the choice of cultivars adapted to the production system (hermaphrodites are preferred for the uniformity of the fruit). Planting should be carried out in well-drained soils, avoiding waterlogged areas. Watering should be frequent but moderate. Fertilisation should be regular, with emphasis on nitrogen, potassium and micronutrients. The control of pests such as fruit flies and aphids is essential to ensure commercial quality. Harvesting occurs when the skin begins to change colour to yellow, depending on the commercial destination.

Bibliographic references

• EPPO Global Database – Carica papaya
• CABI – Crop Protection Compendium – Carica papaya
• Paull, R. E., Duarte, O. (2011). Tropical Fruits. CABI.
• Chan, Y. K., et al. (2016). Papaya breeding and production. Acta Horticulturae.
• FAO (2020). Papaya Production Manual.
• Ventura, J. A., et al. (2019). Diseases of papaya. Plant Pathology Journal.