African eggplant, Solanum aethiopicum, is a deciduous shrub in the family Solanaceae which is grown for its edible fruits which are cooked and eaten as a vegetable. African eggplant is a highly branching plant which can grow up to 2 m (6.6 ft) in height. The leaves of the plant are arranged alternately on the stems and have smooth or lobed margins. Leaf blades may reach up to 30 cm (11.8 in) in length and 21 cm (8.3 in) in width. The leaf petioles are oval or elliptical in shape, reaching up to 11 cm (4.3 in) in length. Plants produce clusters of up to 12 white flowers which develop into egg or spindle-shaped berries which are red to orange in color with a smooth or grooved surface depending on variety. African eggplant may also be referred to as scarlet eggplant, bitter tomato, mock tomato, garden egg or Ethiopian nightshade and is native to Africa, likely resulting from the domestication of a related species, S. anguivi.
Scientific Name: Solanum aethiopicum
Common Name: african scarlet eggplant,bitter tomato (En); aubergine amère, aubergine africaine, aubergine écarlate, tomate amère, djakattou (Fr); 非洲紅茄 (Cn); nakati etíope, berenjena escarlata (Sp).
African eggplant is grown primarily for its bitter orange-red fruit, which may be eaten boiled, steamed, pickled or in stews with meat and other vegetables. Young leaves are also often used in soups.
African eggplants are a source of fiber, potassium, and offer traces of beta-carotene, ascorbic acid, iron, and calcium.
African eggplants, scientifically known as Solanum aethiopicum, vary in color and shape based on the cultivar. The species is divided into four main groups: Gilo, Shum, Kumba, and Aculeatum. Each group has unique characteristics:
Gilo: Edible fruits that vary from spherical to oval shapes.
Kumba: Has a primary stem with edible leaves and fruits, which can be green or red.
Shum: A short plant with small, smooth leaves. Its shoots are edible, but its small fruits are bitter and less preferred.
Aculeatum: Recognized for its flat fruits, often grown for ornamental use.
Growth requirements for African eggplant vary with variety. All types grow best in full sun and well-draining, deep soils with a pH between 5.5 and 6.8. Gilo types grow best at daytime temperatures between 25 and 35°C (77 and 95°F). Kumba types can grow in hotter temperatures of up to 45°C in low humidity, whereas Shum types require warm and humid conditions in order to thrive. No varieties of African eggplant tolerate very cold or water-logged conditions.
Growing from Seed
African eggplant seeds can be collected from fully ripe fruits. Once the seeds have been extracted, they should be laid out on a piece of paper to dry in a place where they are not exposed to direct sunlight. Once dry, seeds can be stored for many years and still remain viable. Seeds should be planted in a prepared nursery bed and should be sown 15 cm (6 in) apart with a further 20 cm (8 in) between rows. Seedlings are ready for transplanting when they reach 15 to 20 cm (6–8 in) in height and have 5–7 leaves. Plants should be hardened prior to transplanting by gradually reducing the amount of water they receive. Plants should be spaced 50 cm (20 in) apart allowing 75 cm (30 in) between rows.
General Care and Maintenance
African eggplants will benefit from frequent irrigation during the dry season, particularly when fruiting, to ensure high yields. The crop should be weeded as required to prevent competition. Addition of fertilizer in the form of cattle or chicken or cattle manure or compost will improve yields.
African eggplant is typically ready for harvest 100 to 120 days after planting. The fruit should be harvested before the skin changes color from white to pale yellow when the skin becomes tough. Fruits should be harvested regularly to encourage maximum fruit production. Young leaves may be harvested from 45-60 days of growth.
James, B., Atcha-Ahowé, C., Godonou, I., Baimey, H., Goergen, G., Sikirou, R., and Toko, M. (2010). Integrated pest management in vegetable production: A guide for extension workers in West Africa. International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Available at: teca.fao.org/technology/integrated-pest-management-vegetable-production-guide-extension-workers-west-africa. [Accessed 30 June 2015, but note Teca.fao is down, so the whole link not placed here Nov. 1, 2018]. Free to access.
Ojiewo, Chris. (2013). African Nightshades and African Eggplants: Taxonomy, Crop Management, Utilization, and Phytonutrients. 10.1021/bk-2013-1127.ch011