Treculia africana
| African breadfruit (Treculia africana) | |
|---|---|
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| Common names | African breadfruit, ukwa |
| Scientific name | Treculia africana |
| Family | Moraceae |
| Genus | Treculia |
| Order | Rosales |
| Native range | Tropical Africa and Madagascar |
| Tree size | Usually 10–30 m, sometimes to 50 m; trunk to about 3 m girth |
| Fruit | Compound syncarp 20–39 cm across, 8–19 kg, borne on trunk and main branches |
| Propagation | Fresh seed (sow at once), patch budding, cuttings |
| Years to fruit | About 3–4 years when budded onto flowering scions |
| Uses | Edible seeds (ukwa), flour, oil; timber; folk medicine |
African breadfruit (ukwa in Nigeria) is the common name for Treculia africana, a large evergreen tree of the mulberry family (Moraceae). The species name was first published in 1847; the accepted native range covers tropical Africa and Madagascar, with the tree belonging to the wet tropical biome and growing mainly in riverine forest near streams and swampy ground.[1] The seeds of the enormous compound fruit are a traditional staple in south-eastern Nigeria, where the tree is called ukwa, and seed preparations appear in local food and medicine.[2]
Description[edit | edit source]
The tree is evergreen (semi-deciduous in parts of Nigeria), usually 10–30 m tall and up to 40–50 m in good forest, with a dense crown and a fluted trunk to about 3 m girth. The grey bark exudes white latex that turns rusty-red on exposure. Leaves are simple and alternate, about 30 × 14 cm (to 50 × 20 cm), and young leaves flush red or yellow.[3] For the typical variety africana, leaves measure 17–37 × 7.5–18 cm and mature trees reach about 40 m with a 3 m girth.[4] Earlier names for the species include Treculia madagascarica, T. mollis and T. perrieri.[5]
Kew's taxonomy accepts five varieties — africana, inversa, mollis, ilicifolia and sambiranensis — of which the three West and Central African forms (africana, inversa, mollis) are keyed below.[6]
Flowers are unisexual. Trees are usually dioecious, sometimes monoecious; male flower heads are 2.5–10 cm across (4–10 cm at anthesis), borne in leaf axils or on older wood.[3][4] Flowering continues almost throughout the year with a lean period in August–September in Nigeria.[4]
The fruit is a compound syncarp borne directly on the trunk and main branches, 20–39 cm across (to about 40 cm) and 8–19 kg, with a rough surface of pointed outgrowths.[3][4] It is green while juvenile and turns greenish-yellow when ripe. The many seeds, about 1 cm across (about 1.3 cm in var. africana), are embedded in a fibrous, spongy mesocarp; the seed coat is brown over a milk-white cotyledon.[7]
Cultivation[edit | edit source]
Soil and water[edit | edit source]
Native stands grow in riverine forest along streams and in swampy ground of the wet tropical biome.[1][3] The species tolerates a wide range of soils and climates and is recommended for home gardens and intercropping across most tropical and subtropical regions.[3] Seedling media trials at Nsukka showed that ricehull-based mixes (1:2:3 and 2:3:1 ricehull:poultry manure:river sand by volume, composted six weeks) gave the highest emergence (up to 57% by week 8 versus 18% in a soil-based 1:2:3 topsoil:poultry manure:river sand mix), the best seedling growth, and the longest turgor under induced water stress; water-holding capacity across the media ran 28–74%, highest in the 2:3:1 ricehull mix.[8] In a 12-year field trial at NIHORT Okigwe, budded trees were irrigated by sprinkler for about 3 hours every two days and given 5 kg of animal dung per tree in each of the first two years, with weeding twice yearly.[9]
Sun and humidity[edit | edit source]
The species is not strongly light-demanding; in the wild it belongs to the shade of wet forest near water, so young plants are raised under partial shade. Nursery work at Nsukka used blue polyethylene shade with watering every two days,[8] and the seed-origin trial at Nsukka germinated fresh seed under partial shade in a 2:1:1 topsoil:sawdust:poultry-manure medium.[7] Mature trees are comfortable in the humid atmosphere of the wet tropical biome rather than in dry open savanna.[1][3]
Seasonal changes[edit | edit source]
Flowering and fruiting are spread widely through the year in the humid lowlands. Long-running Nigerian observations record flowering almost year-round with a lean period in August–September, fruit maturity about three months after set, a fruiting peak from April to July and a lean fruiting period around November–December.[4] A three-year study across five south-eastern Nigerian towns found the species semi-deciduous with two alternating fruiting periods: dry-season flowering and fruit formation from November to late March with fruit drop in February–March, and heavy wet-season flowering in May–June with fruit formation, maturity, ripening and dropping from July to September; the wet-season periods were shorter.[10] An earlier regional account placed heavy fruiting from February to August and a light period from September to January.[9] Seasonal peaks therefore shift with site, region and year; in cultivation the main crop should be expected in and just after the wet season, with irrigation protecting the out-of-season flush.
Propagation[edit | edit source]
Seed is the normal route, and freshness decides success. In a controlled trial, freshly collected seed sown in medium or fine sand reached 87.5% germination, while no seed stored beyond two weeks germinated at all; the authors recommend sowing immediately after fruit harvest, preferably in medium sand.[11] The agroforestry profile likewise lists no seed pretreatment and records orthodox storage behaviour with 4500–5000 seeds per kg.[3] Germination is epigeal with a pair of thick, elongated dimorphic cotyledons;[4] radicles appear 4–6 days after sowing, germination peaks in weeks 2–3 and finishes at 16–18 days. In poly pots under partial shade (2:1:1 topsoil:sawdust:poultry-manure, seed 2.5–3 cm deep, watering every two days), emergence began in 6–9 days, was complete within 28–31 days, and reached up to 96.8% for the best seed lot.[7]
Patch budding is the proven route to early cropping. In the Okigwe trial, seedlings raised for three months in polyethylene bags were patch-budded six months after planting using budwood from flowering parent trees; 8 of 20 trees flowered 3–4 years after budding and the rest a year later, nearly all first-phase flowers aborted, and commercially useful seed yields began about three years after first fruiting. Per-tree seed yield then rose with age from roughly 1.2–2.6 kg in 1998 to 12.4–12.9 kg in 2005.[9] The agroforestry profile reports budded trees with adult scions producing viable seed within 2–4 years.[3]
Stem cuttings root readily from juvenile material — 69% rooting in the agroforestry record[3] — and a 2021 trial at Akungba-Akoko, Ondo State found up to 79.7% survival with the best shoot and root growth when cuttings were quick-dipped in a mix of 75% Moringa leaf extract and 50% orange juice and set in sterilised river sand under mist; the untreated control performed worst.[12]
Flowering, fruiting, and harvest[edit | edit source]
Trees are usually dioecious but sometimes monoecious; male heads measure 4–10 cm at anthesis and are produced in leaf axils or on older wood.[3][4] The syncarps form on the trunk and main branches, and fruit maturity takes about three months.[4] Ripe fruit turns greenish-yellow; traditionally the fruit is not harvested from the tree but allowed to ripen and drop, and trees are planted away from residences because a falling head is dangerous.[7][9][2] Before seed extraction the fruit is commonly left two to three weeks to ferment, which loosens the seeds; extracted seeds are sun-dried, about two hours in the market trade.[9]
Yield develops slowly and is strongly age-dependent. The only long-term measured record (Okigwe, 1994–2005) shows per-tree seed yields rising from about 1.2–2.6 kg per year shortly after first cropping to 12.4–12.9 kg per year by year twelve.[9] Database and review-level estimates of 120–200 kg of dried seed per tree per year under favourable conditions (5–10 t/ha), with up to 30 fruits per tree each yielding up to 10 kg of seed after pulp removal, are best treated as optimistic, well-managed figures rather than typical production.[3][2]
Fruit and uses[edit | edit source]
The edible part is the seed. Seeds are extracted after the fruit is macerated in water (or fermented), then boiled as a porridge (ukwa, often with maize or beans), roasted as a snack, dried and fried, or ground into flour for baked goods; an edible oil is pressed from them, and powdered seed is used in Nigeria for a non-alcoholic 'almond milk' breakfast drink.[3][7][2] Dried seed keeps in the market trade as a staple of Igbo cuisine.[9]
In one proximate analysis of seeds from five ripe fruits collected in Calabar (dry-matter basis): moisture 8.0%, crude protein 12.27%, carbohydrate 73.26%, fat 4.23%, ash 2.26% and crude fibre about 1.6%. Potassium (587 mg/100 g) and magnesium (186 mg/100 g) dominated the minerals, and toxicants measured low — hydrocyanic acid 0.06, oxalate 3.0 and phytate 0.7 mg/100 g dry matter — which the authors judged non-toxic for food use.[13] An earlier Nigerian analysis of var. africana seeds recorded about 17.23% crude protein, so protein content varies roughly 12–17% with provenance and method.[4] A review notes that anti-nutrients in the seed are easily detoxified by processing and cites feeding studies of extruded seed products in rats as safe; those are reported findings from the review, not a universal guarantee for raw seed.[2]
The species appears in West African folk medicine: a root decoction as anthelmintic and febrifuge and a caustic sap on carious teeth (Ghana), a bark decoction for cough, and recorded uses in leprosy treatment and as a laxative;[3] in Nigeria a leaf decoction is used for hypertension or gastro-intestinal infection, latex and wood are used in bone setting, and aqueous extract of the boiled seeds and root decoction in ulcer and inflammation remedies.[7] These are traditional uses, not demonstrated efficacy; a review notes that many perceived medicinal properties remain without scientific investigation even though laboratory antimicrobial and antihyperglycaemic findings have appeared.[2]
The yellow heartwood is used for furniture and carving, and the tree also supplies firewood and pulp.[3]
Cultivars and selections[edit | edit source]
Named selections are essentially the three field varieties; no formal cultivar releases with published trial data were found. Kew accepts five varieties — africana, inversa, mollis, ilicifolia and sambiranensis — and the West and Central African literature keys three of them on fruit-head size, seed size and hairiness:[6][4]
- var. africana — fruit heads over 20 cm, seeds large, rounded to elongated, about 1.3 cm long, mesocarp more than 5 cm thick; the standard choice for seed yield.
- var. inversa — fruit heads usually under 20 cm, knobbly and wrinkled, seeds about 1 cm or less; bears more numerous, smaller heads and roughly twice as many branches, so it crops heavily at a smaller fruit size.
- var. mollis — persistent spreading hairs on branchlets, petioles and leaf undersides, oblong-elliptic leaves, heads under 20 cm, seeds about 1 cm.[4][3]
For growers, africana-type trees are valued for seed size and weight, while inversa-type trees suit heavier cropping of smaller heads; the two also differ in slash colour (pinkish versus brownish) and branchlet gloss.[4]
One commercial claim stands alone: a Cameroon nursery (Nutrecul Agroforestry) reports growing many selections and using for most of its reforestation projects a large-fruited line it markets as the 'Nutreculia' or 'gigantica' cultivar of T. africana var. africana, with fruit 'above 15–25 kg'. No independent trial data or propagation details were retrieved; this is an attributed nursery claim, not a formal cultivar release.[14]
Photos[edit | edit source]
References[edit | edit source]
- ↑ [2] Ojimelukwe, P.C. & Ugwuona, F.U. (2021). The traditional and medicinal use of African breadfruit (Treculia africana): an underutilized ethnic food of the Ibo tribe of South East, Nigeria. Journal of Ethnic Foods 8: 21.
- ↑ [4] Okafor, J.C. (1981). Delimitation of a New Variety of Treculia africana Decaisne subsp. africana (Moraceae). Bulletin du Jardin botanique national de Belgique 51(1/2): 191–199.
- ↑ [7] Amujiri, A.N., Eze, P.C., Amadi, C.C. & Njoku, E.U. (2020). Effects of seed origin on the germination, seedling development and morphology of African Breadfruit (Treculia africana Decne, Moraceae) seeds. Bioscience Research 17(4): 3060–3068.
- ↑ [8] Baiyeri, K.P. & Mbah, B.N. (2006). Effects of soilless and soil-based nursery media on seedling emergence, growth and response to water stress of African breadfruit (Treculia africana Decne). African Journal of Biotechnology 5(15): 1405–1410.
- ↑ [9] Nzekwe, U., Ojeifor, I.M. & Nworie, H.E. (2010). Assessment of the gestation period and economic yield of African breadfruit, Treculia africana var. africana Decne, Moraceae. Agro-Science 9(1): 18–23.
- ↑ [10] Amujiri, A.N., Nwosu, M.O., Nzekwe, U., Osayi, E.E. & Sani, M.B. (2018). Studies on the Phenology of African Breadfruit (Treculia africana Decne) in South Eastern Nigeria. Environment and Ecology Research 6(4): 248–258.
- ↑ [11] Dolor, D.E. (2013). Propagation of Treculia africana as influenced by seed storage and propagation media. Agricultura Tropica et Subtropica 46(2): 52–57.
- ↑ [12] Ojo, M.O., Asinwa, I.O., Oluwadare, J.J., Fawole, O.A. & Adelakun, K.M. (2021). Effects of natural growth hormones on the vegetative propagation of Treculia africana A. Trecul. Ethiopian Journal of Environmental Studies & Management 14(3): 319–327.
- ↑ [13] Osabor, V.N., Ogar, D.A., Okafor, P.C. & Egbung, G.E. (2009). Profile of the African Bread Fruit (Treculia africana). Pakistan Journal of Nutrition 8(7): 1005–1008.
Image credits[edit | edit source]
- File:Treculia africana (breadfruit tree).jpg — African breadfruit (Treculia africana) tree bearing fruits, Nigeria (subject from file-page description). Creator: NiferO (Wiki Loves Africa 2025, Nigeria), CC BY-SA 4.0 (license). File page: Wikimedia Commons. Attribution: NiferO, CC BY-SA 4.0, via Wikimedia Commons.
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- File:Treculia africana - Fruit and Spice Park - Homestead, Florida - DSC09007.jpg — Treculia africana at Fruit and Spice Park, Homestead, Florida, USA (subject from file-page description). Creator: Daderot, CC0 1.0 (license). File page: Wikimedia Commons. Attribution: Daderot, CC0, via Wikimedia Commons.
- File:Treculia africana.jpg — 1872 Curtis's Botanical Magazine illustration of Treculia africana (plate by Joseph Dalton Hooker, vol. 98 ser. 3 nr. 28 tabl. 5986). Creator: Joseph Dalton Hooker (1817–1911), public domain (PD-old-70-expired / CC-PD-Mark). File page: Wikimedia Commons. Attribution: Joseph Dalton Hooker, public domain, via Wikimedia Commons.
