Okra

Abelmoschus esculentus

1. Identification and origin

Okra [Abelmoschus esculentus (L.) Moench] is an annual horticultural species of the Malvaceae family, native to East Africa and widely cultivated in tropical, subtropical and Mediterranean regions. It is valued for its immature fruits, eaten fresh or processed. In Portugal, cultivation occurs mainly on small farms and specialized vegetable gardens, in warm-climate areas.

2. Economic importance

Okra is a crop of growing interest due to demand in ethnic markets and its diverse culinary use. The fruits are rich in fibre, mucilage, vitamins and minerals. The crop shows good productivity in warm climates and can be integrated into intensive or semi-intensive horticultural systems. The fresh market is the main destination, but it is also used in canned and frozen products.

3. Botanical characterization

Okra displays the typical characteristics of the Malvaceae:

• Annual, erect plant, 1–2 m tall
• Large, palmate leaves, with 5–7 lobes
• Large, yellow flowers, with a purple centre
• Fruits are elongated capsules, pentagonal or octagonal, harvested immature
• Spherical seeds, rich in oil
• Deep root system, conferring moderate drought tolerance

The mucilage present in the fruits is a distinctive and valued characteristic.

4. Soil and climate requirements

Okra is a warm-climate crop:

• Optimum temperature: 25–35 °C
• Sensitive to cold and frost
• Prefers well-drained soils, of loamy to sandy-loam texture
• pH between 6.0 and 7.5
• Requires good light
• Moderate drought tolerance, but responds well to regular irrigation

In Mediterranean climates, cultivation takes place in spring-summer.

5. Main pests

• Aphids (Aphididae): leaf curling and transmission of viral diseases
• Whitefly (Bemisia tabaci): sap sucking and viral diseases
• Thrips (Frankliniella occidentalis): floral damage and fruit scarring
• Mites (Tetranychus urticae): leaf chlorosis and necrosis
• Caterpillars (Helicoverpa armigera, Spodoptera spp.): boring and defoliation
• Nematodes (Meloidogyne spp.): root galls and vegetative decline

6. Main diseases

• Powdery mildew (Erysiphe spp.): white spots and reduced photosynthesis
• Downy mildew (Peronospora spp.): angular spots and necrosis
• Root rots (Fusarium spp., Rhizoctonia solani, Pythium spp.): wilting and developmental failures
• Leaf spot caused by Cercospora spp.: circular lesions and leaf drop
• Viruses transmitted by aphids and whitefly (e.g.: BYMV, CMV): mosaics, deformations and reduced productivity

7. General crop management

Okra management is based on integrated practices that include sowing in warm soil or the production of seedlings in a greenhouse, followed by a suitable crop rotation to reduce the pressure of nematodes and soil fungi. Irrigation should be regular, avoiding waterlogging, and fertilization balanced, with special attention to nitrogen to prevent excessive vegetative growth. Frequent monitoring of aphids, whitefly and mites is essential, as well as the removal of basal leaves to improve ventilation and reduce the incidence of diseases. Harvesting should be frequent, daily or every two days, to avoid lignification of the fruits, and the use of cultivars adapted to the local climate contributes to greater productivity and crop health.

Bibliographic references

• EPPO Global Database – Abelmoschus esculentus
• CABI – Crop Protection Compendium – Abelmoschus esculentus
• FAO (2020). Tropical Vegetable Production Manual.
• Sharma, B. R., et al. (2017). Okra production and protection. Acta Horticulturae.
• Singh, V., et al. (2014). Diseases of okra and their management. Horticultural Reviews.
• Kumar, R., et al. (2015). Insect pests of okra and control strategies. In: Vegetable Crop Protection. Springer.