Tephrosia vogelii (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Tephrosia vogelii J.D. Hooker

Protologue: Niger fl.: 296 (1849).

Family: Leguminosae - Papilionoideae

Chromosome number: 2n= 22

Synonyms

• Cracca vogelii (J.D. Hooker) O. Kuntze (1891).

Vernacular names

• Vogel's tephrosia, fish-poison bean (En)
• Papua New Guinea: pilawa
• Laos: hu: kata:yx (Vientiane).

Origin and geographic distribution

T. vogelii is native to tropical Africa. It was introduced to tropical America and South and South-East Asia as a cover crop. It was introduced into Java in 1908 and is now found throughout Malesia.

Uses

In Indonesia T. vogelii is cultivated as a green manure, wind-break, and temporary shade crop in cocoa, coffee, tea, rubber and cinchona plantations. In Central Africa, the Philippines and Peninsular Malaysia it is used as green manure e.g. in coconut plantations. T. vogelii grows taller than T. candida (Roxb.) DC. and is thus a good wind-break and shade plant. Because of its dense growth, it is a suitable hedge plant, while its variously coloured flowers make it also suitable as ornamental. In Africa and elsewhere it is cultivated for fish and arrow poison. The poison stupefies the fish, which is then easily caught. Dry crushed leaves are used as an insecticide against lice, fleas, and ticks, and as molluscicide. Medicinally, T. vogelii is used as an abortifacient, as a cure for skin diseases, schistomiasis, as a bactericide, emetic, and purgative, while a weak infusion of the leaves is taken as an anthelmintic. It is not used as a fodder because of its toxicity.

Properties

Grown as a green manure in Indonesia, the nitrogen content per 100 g dry matter is 3.7 g for 2-3 months old plants, falling to 1.2 g for 10 months old material, while the phosphorus content drops from 0.8 g to 0.2 g. The leaves of T. vogelii contain the toxins rotenon and several of its isomers: deguelin, tephrosin, iso-tephrosin and hydroxydeguelin-C. Per 100 g dry matter the leaves contain 0.7-4.3 g rotenoids; the stems, roots and seed also contain rotenoids, but in smaller quantities. As deguelin is closely related to rotenon, T. vogelii can be used like Derris spp. as fish poison. The weight of 1000 seeds is 31-37 g.

Description

• A softly woody, branching herb or small tree with dense foliage, 0.5-4 m tall, with velutinous to sericeous indumentum. Stem and branches tomentose with long and short white or rusty-brown hairs.
• Leaves arranged spirally, imparipinnate; stipules 10-22 mm × 3-3.5 mm, early caducous; rachis 5-25 cm long, including petiole of up to 3 cm, pulvinate; petiolule 1.5-5 mm long; leaflets in 5-14 pairs, narrowly elliptical to elliptical-oblanceolate, up to 7 cm × 2 cm, base acute to obtuse, apex rounded to emarginate, venation most distinct on lower surface, silky tomentose.
• Inflorescence a terminal or axillary pseudoraceme, 8-26 cm long, rusty tomentose; basal bracts leaf-like; peduncle stout, as long as pseudoraceme; flowers in fascicles of 2; bracts to fascicles orbicular to obovate, cuspidate, about 1.5 cm long, bracts to flowers narrowly elliptical to spatulate, about 1 cm long.
• Flower 18-26 mm long, fragrant when fresh, white, violet, purple or blue; pedicel up to 23 mm long; bracteoles sometimes present on calyx; calyx campanulate, tube 4-6 mm × 6.5-10 mm, pale greenish brown, outside sometimes sericeous, usually 4-toothed, teeth puberulous to sericeous within, vexillary tooth broadly ovate, 5-12 mm × 8-12 mm, lateral teeth oblong, 4.5-10 mm long, apex rounded, the carinal one narrow, boat-shaped, 6-15 mm long, acute; standard suborbicular, 20-28 mm × 24-32 mm, auricled at base, apex emarginate, the apical half and the margins puberulous to sericeous within, claw 3-5.5 mm long; wings 17-22 mm × 11-13 mm, auricled, inside sericeous, clawed; keel 15-20 mm × 10-12 mm, slightly auricled, clawed, hairy only on carinal side; stamens 10, staminal tube 19-20 mm long, glabrous, vexillary filament free at base and connate halfway, 22-26 mm long, glabrous, free parts of the other stamens alternately longer (6-11 mm) and shorter (4-7 mm); style bent through 70°, 11-15 mm long, bearded on both sides, stigma glabrous.
• Pod linear, slightly turgid, 5.5-14 cm × 0.8-1.8 cm, brown or green, woolly to sericeous, 6-18-seeded.
• Seed ellipsoid to reniform, 5-7 mm × 3-5 mm, dark brown to black.
• Seedling with epigeal germination; cotyledons rather thin, leaf-like, green, long persistent; first leaf simple, second leaf usually 3-foliolate.

Growth and development

Under favourable conditions, T. vogelii grows rather fast, usually exceeding the growth rate of other green manure legumes, such as Crotalaria micans Link, C. trichotoma Bojer and Mimosa diplotricha C. Wright ex Sauvalle. In Java, initial growth is slow, plants attaining only 8 cm at 6 weeks after planting. Subsequent growth, however, is rapid and plants may reach 36 cm at 3.5 months and 2 m or more at 1 year after planting. In Java, flowering and fruiting starts 10-12 months after planting and T. vogelii does not live much longer than one year. In Sri Lanka, however, it may grow for at least two years, and under favourable conditions even longer. T. vogelii is tolerant to repeated pruning only under favourable conditions; drought often stops resprouting.

Other botanical information

T. vogelii is closely related to T. nana Kotschy ex Schweinf. The latter is a native of Africa but is cultivated and naturalized in Java and can be distinguished by its 3-4 flowers per fascicle, smaller flowers and large number of seeds in relatively short pods. T. vogelii also greatly resembles T. candida, but is easily distinguished by its generally more luxuriant foliage and larger, more hairy pods. It yields a larger amount of green material when young than T. candida, but its life cycle is shorter. African specimens of T. vogelii usually have smaller calyx teeth. In East Africa, a white-flowered form predominates, in West Africa a purple-flowered form.

Ecology

T. vogelii is found in widely varying habitats, including savanna-like vegetation, grassland, forest margins and shrubland, waste land and fallow fields. It is tolerant to drought, strong wind and grazing. Burning has little effect on T. vogelii, as it resprouts readily due to its deep root system. It occurs in climates with an annual rainfall of 850-2650 mm and an annual mean temperature of 12.5-26.2 °C and is found up to 2100 m altitude. It grows well on andosols not subject to flooding and on well drained loams with pH 5.0-6.5 and is also tolerant to poor soils with low pH. In acid soil, it grows much better than Leucaena leucocephala (Lamk) de Wit and forms root nodules and fixes atmospheric nitrogen where the latter does not. On poor soils, however, growth of T. vogelii is slow and more prone to diseases.

Propagation and planting

T. vogelii is commonly propagated by seed. Air-dried seed can be stored in sealed containers for at least 1.5 year. Fresh seed should preferably be stored for 2 months before planting. Without treatment, the germination percentage is 65% and the seedling survival rate about 60%. Soaking in warm water (45 °C) for 5 minutes stimulates germination. For a green manure crop, the recommended spacing is 40 cm × 40 cm, with 2-3 seeds per hole, when planted in hedges the spacing should be 1.5 m between the rows. For large plantings, sufficient seedlings should be available for replanting in case of a low survival rate. When sown in rows, the recommended sowing rate is 5 kg/ha and when broadcast 8-13 kg/ha. Planting should be done at the beginning or in the middle of the rainy season.

Husbandry

Maximum biomass yield of green manure is obtained before flowering starts. To obtain tangible results, the plant material should be dug in towards the end of rainy season immediately after it has been cut. If the plants are weakly branched, they should be lopped to promote branching. Results of experiments in Indonesia have indicated that soils into which a 3-month-old T. vogelii crop had been incorporated showed an increase in organic matter (from 8% to 10%), nitrogen (from 0.4% to nearly 0.5%), phosphorus and potassium. The increase is larger when 2-month-old material is incorporated. In Indonesia and Sri Lanka, a 5-month-old crop was found to yield about 27 t/ha of green material. About 40% of the material was provided by the leaves and twigs alone, and the remainder by the stalks and roots. In Central Java T. vogelii may yield 4.4-4.8 t/ha green material about 110 days after planting. The use of T. vogelii green manure was found to increase yields of subsequent maize or rice crops by about 0.5 t/ha per planting season.

Diseases and pests

In Java, stems of T. vogelii are liable to serious attacks by Corticium salmonicolor , especially after lopping. When tested in the United States as a pesticide-producing crop, root-knot nematodes caused very serious damage. In Central Java, Helopeltis spp., a serious pest of cocoa, can also heavily attack T. vogelii. Because of this, T. vogelii is no longer recommended for planting in Java.

Handling after harvest

To make fish poison, leaves and small branches are gathered as needed; the leaves are macerated in water or beaten to a pulp and then thrown into the water. After about 10 minutes, stupefied fish float to the surface and can be easily collected. Pounded roots are used similarly.

Genetic resources and breeding

No germplasm collections of T. vogelii and its relatives are known to be maintained and no breeding programme is known to exist.

Prospects

The prospects of T. vogelii as a green manure, temporary shade or wind-break are not promising compared to T. candida, Crotalaria spp., or Leucaena leucocephala. However, T. vogelii may be useful if suitable alternatives are absent. Efforts should be made to select strains that are promising for use as green manure or to restore soils.

Literature

• Bosman, M.T.M. & de Haas, A.J.P., 1983. A revision of the genus Tephrosia (Leguminosae-Papilionoideae) in Malesia. Blumea 28: 421-487.
• Chiu, S.F., 1989. Recent advances in research on botanical insecticides in China. American Chemical Society Symposium Series 387: 69-77.
• Duke, J.A., 1981. Handbook of legumes of world economic importance. Plenum Press, New York, United States. pp. 232-233.
• Minton, N.A. & Adamson, W.C., 1979. Response of Tephrosia vogelii to four species of root-knot nematodes. Plant Disease Reporter 63: 514.
• Niyungeko, M.R., Ngurale, A., Ngoic, M. & Sanginga, N., 1990. Early nodulation and growth of Tephrosia and Leucaena on an oxisol at Yangambi, north-eastern Zaire. Nitrogen Fixing Tree Research Report 8: 85-87.
• Wargadipura, R., 1973. Macam-macam tanaman pupuk hijau untuk merehabilitasi tanah perkebunan teh [The use of some green manures for soil rehabilitation in tea plantations]. Menara Perkebunan 41(1): 7-11.

Authors

• B. Sunarno