Scientific name
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Trifolium burchellianum Ser. Subordinate taxa: Trifolium burchellianum Ser. subsp. burchellianum Trifolium burchellianum Ser. subsp. johnstonii (Oliv.) J.B. Gillett Trifolium burchellianum Ser. subsp. johnstonii (Oliv.) J.B. Gillett var. johnstonii Trifolium burchellianum Ser. subsp. johnstonii (Oliv.) J.B. Gillett var. oblongum J.B. Gillett
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Synonyms
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Trifolium basileianum Chiov. Trifolium johnstonii Oliv.
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Family/tribe
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Family: Fabaceae (alt. Leguminosae) subfamily: Faboideae tribe: Trifolieae. Also placed in: Papilionaceae.
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Common names
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burchell's clover, cape clover; musa-pelo/moroko (Sesotho).
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Morphological description
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A creeping (sometimes ascending), stoloniferous/rhizomatous, taprooted perennial with glabrous or glabrate stems. Leaves trifoliolate, glabrous or glabrate; leaflets cuneate-obovate, cuneate-oblong or cuneate-elliptic, less often oblong, emarginate or less often, truncate or rounded at the tips, up to 25 (-50) x 19 mm, margin serrulate. Inflorescence many-flowered, globose, up to 3 cm across; peduncle longer than the subtending leaf, pilose towards the top; pedicels stout, 2-2.5 mm long, more or less erect in fruit, glabrous; calyx glabrous except for a few hairs at the margin; corolla purple, standard 8-13 mm long. Pods about 5 mm long and 3 mm wide. Seeds, dark brown, irregularly oval, about 2.1 x 1.8 mm; c. 700,000 seeds/kg. Subsp. johnstonii has larger flowers and leaflets than subsp. burchellianum. Var. oblongum has stout ascending stems, becoming almost woody, up to 3 mm thick, and up to 1 metre high.
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Distribution
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Native to: Africa: Angola, Ethiopia (south), Kenya, Lesotho, South Africa, Tanzania, Uganda. Subsp. burchellianum occurs in lightly grazed coastal and high altitude sites (including roadsides) in southern Africa and Angola. Subsp. johnstonii, the most common subspecies, occurs in upland grasslands, openings in evergreen forests, bamboo forests and moorland in Uganda, Kenya, Tanzania and southern Ethiopia. Var. oblongum occurs in the undergrowth at forest margins, less commonly in tall grass where it is more upright, in Kenya and southern Ethiopia.
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Uses/applications
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Potential as a permanent component of mixed grass-legume pastures in more intensive systems. May have a role as ornamental/ground cover in moderately shaded situations in the subtropics and upland tropics. Also considered to have medicinal value by tribal people in southern Africa.
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Ecology
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Soil requirements
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Found on sands, loams and clay loams, mostly with a slightly acid pH (ca. 6).
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Moisture
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Grows in moist situations (vleis and riverbanks) in lower rainfall (625-800 mm), coastal lowland subtropics, and in well-drained soils in higher rainfall upland tropics (1,000-2,500 mm). Drought tolerance fair, but poorer than that of T. semipilosum .
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Temperature
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Occurs from near sea level to 3,700 m asl (rarely in the alpine zone), and from 34ºS to 8 (-11)ºN, in areas with average annual temperatures from about 12-20ºC, and often subject to frost. T. burchellianum is less frost tolerant than T. repens, but is still not affected by grass temperatures as low as -9º C.
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Light
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It has moderate shade tolerance, reportedly better than that of T. repens, partly by virtue of its ability to grow up to the light when growing in taller grass .
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Reproductive development
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Flowering response patterns are unclear. In a controlled environment study, subsp. burchellianum proved to be a long day plant, but influenced by the need for low night temperatures. Subsp. johnstonii did not flower in response to any daylength or night temperature treatment. In the field in the subtropics, both subspecies exhibit generally similar response, commencing flowering in mid-spring, and continuing through to mid-summer. Quantitative short day types have been identified.
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Defoliation
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Although irregularly distributed in grazed lands in its native range, it is common in areas regularly mowed as low as 1-3 cm.
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Fire
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No information available.
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Agronomy
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Establishment
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High levels of hard seed are encountered in this species, sometimes >90%. Mechanical or concentrated acid scarification can be used to improve germination. T. burchellianum requires a different rhizobium strain (e.g. CB 727 in Australia) from those used for T. repens and T. semipilosum . While establishment is very slow, it has been successfully established from late summer to mid-winter. In the absence of firm establishment data, a similar approach to that used for T. semipilosum could be used: "It is best sown in autumn into a well-prepared, fine, firm, weed-free seedbed, either onto the surface or with minimal soil cover, followed by rolling. Late-season planting results in less competition from warm season grass during establishment. In the upland tropics, sowing immediately after the start of the wet season is best, minimising grass competition by heavy grazing or mowing once the ground is covered. Sowing rates of 2-3 kg/ha of seed are used."
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Fertiliser
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T. burchellianum is often found growing in low phosphorus soils. It may still respond to P applications as does the other perennial African clover, T. semipilosum . The addition of calcium on some very acid soils has been necessary for effective nodulation.
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Compatibility (with other species)
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Combines effectively with other species, particularly lower sward -forming grasses.
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Companion species
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Pests and diseases
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Red spider (Tetranychus spp.) and root knot nematodes (Meloidogyne spp.) have been the two main pests in artificial cultivations in southern Africa. It is less susceptible to the effects of rugose leaf curl disease caused by a phytoplasma than T. semipilosum .
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Ability to spread
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It has failed to naturalise in most areas where it has been introduced.
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Weed potential
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No indication of weediness.
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Feeding value
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Nutritive value
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In vitro DM digestibility is slightly lower than for T. repens (74% vs 80%), but is still satisfactory. N and P contents are similar to those of T. repens.
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Palatability/acceptability
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Toxicity
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T. burchellianum contains no prussic acid and has a low level of fraction I or 18S protein, a protein which, in high levels, is often associated with stable foam in bloat.
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Production potential
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Dry matter
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DM yields of 1-2 t/ha have been measured in sown stands, compared with about 3 t/ha for T. semipilosum , each with a similar amount of grass .
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Animal production
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No information available.
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Genetics/breeding
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Subsp. burchellianum 2n = 6x = 48; subsp. johnstonii var. johnstonii 2n = 48, 96; subsp. johnstonii var.oblongum 2n = 48. It is a cross-pollinating species.
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Seed production
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Seed yields may be as high as 390 kg/ha, varying among ecotypes and averaging from 100-150 kg/ha/yr. Year to year variation can be greater than ecotype differences.
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Herbicide effects
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No information available.
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Strengths
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- Tolerant of low to moderate fertility soil.
- Frost tolerant.
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Limitations
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- Low productivity.
- Susceptible to root-knot nematode.
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Other comments
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Selected references
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- Bogdan, A.V. (1956) Indigenous clovers of Kenya. East African Agricultural Journal, 22, 40-45.
| - Garden, D.L. (1977) A comparison of African clovers and temperate legumes on the north coast of New South Wales. Tropical Grasslands, 11, 125-131.
| - Gillet, J.B. (1971) Trifolieae. In: Milne-Redhead, E.E. and Polhill, R.M. (eds) "Flora of Tropical East Africa". (Part 4). pp. 1027-1028. (Crown Agents for Overseas Governments and Administrations: London.).
| - Jones, R.M., Strijdom, B.W. and Theron, E.P. (1974) The indigenous South African clovers (T.africanum Ser. and T. burchellianum Ser.) and their potential as pasture legumes. Tropical Grasslands, 8, 7-16.
| - Mannetje, L. 't and Pritchard, A.J. (1968) The effects of photoperiod and night temperature on flowering and growth in some African Trifolium species. New Phytologist, 67, 257-263.
| - Pritchard, A.J. and Mannetje, L. 't (1967) The breeding systems and some interspecific relations of a number of African Trifolium spp. Euphytica, 16, 324-329.
| - Ryding, O. (1991) A study of the variation in Trifolium burchellianum ssp. johnstonii (Fabaceae). Nordic Journal of Botany, 10, 317-321.
| - Wilson, G.P.M. and Bowman, A.M. (1993) Trifolium species on the New South Wales north coast: 2. African species. Genetic Resources Communication No. 19. (CSIRO Division of Tropical Crops and Pastures, St Lucia, Queensland, Australia).
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Internet links
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Cultivars
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Cultivars | Country/date released | Details | | None released to date. | | |
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Promising accessions
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Promising accessions | Country | Details | | CPI 24132 | Australia | Subsp. burchellianum (origin Langebosch, South Africa). | | CPI 22163 | Australia | Subsp. johnstonii (origin Kenya). |
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