Tephrosia candida (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Tephrosia candida (Roxb.) DC.

Protologue: Prod. 2: 249 (1825)

Family: Leguminosae - Papilionoideae

Chromosome number: 2n= 22

• Kiesera sericea Reinw. (1828),
• Robinia candida Roxb. (1832),
• Xiphocarpus candidus (Roxb.) Endl. ex Hassk. (1843).

• White tephrosia (En). White hoary pea (Am).
• Indigo sauvage (Fr)
• Indonesia: enceng-enceng (Javanese), kapeping badah (Sundanese), poko tom (Sumatra)
• Papua New Guinea: pis pea (Pidgin).

T. candida is native to the tropical foothills of the Himalayas in India, and is cultivated and naturalized throughout South-East Asia, from India and Sri Lanka through Burma (Myanmar), Indo-China, Malaysia, Indonesia, the Philippines and Papua New Guinea to the Solomon Islands, New Zealand and Hawaii. It has also been introduced in the West Indies and South America and has been tested in Africa.

T. candida is grown for many auxiliary purposes. It rehabilitates degraded land and controls erosion. During the first few years after planting it is used as a green manure crop; when it becomes woody with age it provides fuelwood. In newly planted perennial crops such as citrus, coconut, coffee, rubber and tea, it is grown as a temporary shade crop and later for filling in gaps for erosion control. It is said to improve the quality and yield of tobacco. In Vietnam, it is planted as a green manure in rotation or intercropped with annual crops. It is suitable for making hedges along contours, around fields and home gardens, as it is not eaten by domestic animals such as buffaloes and goats. There are unconfirmed reports of the bark and roots being used as fish poison. Powdered leaves are used as insecticide. T. candida is occasionally grown as an ornamental.

The approximate composition of dry leaves of T. candida per 100 g is: N 2.4-3.8 g, P 0.12 g, K 1.15 g, Ca 0.3 g; of the roots: N 1.18 g, P 0.07 g, K 0.47 g, Ca 0.14 g. The seeds and leaves contain small amounts of rotenoids, tephrosin and flavonoids.

• Herb, shrub or small tree, erect with straggling branches from base, up to 3.5 m tall.
• Leaves spirally arranged, imparipinnate; stipules 5-11 mm × 0.8-1.5 mm, often caducous; rachis (including the petiole) up to 22.5 cm long, with brown indumentum, pulvinate at base; petiolule 1.5-4 mm long, pulvinate; leaflets 6-13 pairs, opposite, narrowly ovate, elliptical to narrowly obovate, 1.3-7.5 cm × 0.5-1.7 cm, glaucous green, soft, with silvery indumentum, base acute, apex acute, long-mucronate, venation distinct below.
• Inflorescence a terminal, axillary or leaf-opposed pseudoraceme, 2.5-40 cm long; basal bracts few, leaf-like, upper bracts narrowly triangular, 2.2-6 mm × 0.5-1.5 mm, often caducous; flowers in fascicles of 5-13; bracteoles triangular, smaller than bracts, sometimes caducous; pedicel 9-16 mm long.
• Flower 13-26 mm long, white, silky, with dark brown hairs on the outside; calyx campanulate, unequally 4-toothed, cup fleshy, 3-4 mm × 4.5-7 mm, green, sericeous, teeth deltoid, sericeous outside, glabrescent, pubescent to sericeous inside; standard broadly ovate to obovate, 13-25 mm × 11-25 mm, apex rounded to emarginate, acuminate, claw 1-5 mm long; wings 12-20 mm × 5.5-13 mm, glabrous, claw 1-4.4 mm long; keel 11-20 mm × 3-10 mm, glabrous, lateral pockets sometimes bulging, claw 1.5-5 mm long; stamens 10, auricled, staminal tube 8-20 mm long, glabrous, vexillary filament free at base, connate halfway, other filaments alternately longer and shorter, free part 3 mm long; pistil with bearded style of up to 11 mm long, stigma penicillate at base.
• Pod linear, 7-12 cm × 0.5-1 cm, green or brown with silky hairs, slightly convex around the 10-15 seeds.
• Seed broadly ovoid, 4-5.5 mm × 3-4 mm, brown or greyish-brown with dark patches.

T. candida is deep-rooting. It is slow to establish, but grows steadily thereafter. It forms root nodules with Bradyrhizobium and fixes large amounts of atmospheric nitrogen. In Malesia, flowering occurs year-round; in Vietnam, flowering takes place from August to early September and pods can be harvested from October until February. Over-mature pods will shatter their seed. Maximum growth normally takes place in the second year after planting, but with regular pruning a dense cover can be maintained for many years.

T. candida grows in the seasonally dry tropics with an annual rainfall of 700 mm to over 2500 mm and a dry season of up to 4 months. It is cultivated in northern Vietnam, growing well under a rainy season of only 4 months and some showers during the rest of the year. It occurs from 0-1600 m altitude with an annual mean temperature of 18-27.5 °C, and does not tolerate frost. T. candida is grown on sandy soils in coastal areas and on very poor, eroded upland soils and mine spoils where few other crops can grow. It tolerates a pH range of 3.5-7; the more acidic soils seem to be more suitable. Waterlogging is not tolerated. The habitat of T. candida is primary and secondary forest, higher locations in sago palm swamps and disturbed places such as roadsides, river banks, steep slopes and fields.

Prior to sowing, seed is soaked in water for 4-5 hours. It is sown just before or during the rainy season. The germination rate of fresh seed is 95-100%, but decreases rapidly unless stored in a cool dry place. The optimum time for sowing in Vietnam is March-May. When broadcasting, a plant density of 50 000-60 000 per ha is aimed at, requiring 15-20 kg seed. Spacings of 40-90 cm × 10 cm are reported for intercropping, depending on the associated crop. Young plantings should be kept free from weeds.

In Papua New Guinea, it takes about 4 months for T. candida to cover the soil, but once established it forms a dense cover keeping the soil weed-free. It responds well to regular pruning. In Vietnam, three cuts for green manure can be made in the first year after planting and 2-3 cuts in subsequent years. In India, 3-4 cuts are made annually during 4-5 years. Cutting should be done 20 cm above the ground. When grown for ground cover, T. candida should be pruned lightly and frequently. T. candida has been tried as an alley crop with cassava planted in 7 m wide interrows. Preliminary results indicate a greatly increased yield of cassava and a considerable reduction of erosion. On poor soils T. candida responds well to fertilizers, especially phosphate. Fertilizer recommendations in Vietnam are: P₂O₅120 kg/ha, K₂O 12 kg/ha, CaO 400-600 kg/ha. As no suckers are formed, it is easy to remove when land is to be cleared, but older plants with thick woody stems may be more difficult and costly to uproot.

T. candida is susceptible to the root fungi Ganoderma spp. and Rosellinia spp. and to the nematode Heterodera radicola. Therefore, care should be taken when growing it in rotation or association with susceptible crops. When weakened by shade and woody with age, T. candida becomes liable to attack by Fomes spp. It should therefore be replanted at regular intervals. In Indonesia, the Tephrosia beetle (Araeocerus fasciculatus) attacks young pods. It used to be a serious pest making seed of T. candida difficult to obtain, but it can now be controlled easily with insecticides.

Seed yields vary between 350-500 kg/ha. T. candida can yield well on acid soils where Leucaena leucocephala (Lamk) de Wit does not grow at all. On such soils in Vietnam it realizes an annual green matter production of 10-18 t/ha, increasing the organic matter content of the soil from 1.7% to 4% in 2 years. On fertile soils, 25-30 t/ha of green matter can be harvested annually in 3 cuttings.

A small collection of Tephrosia germplasm is maintained at the Centro Internacional de Agricultura Tropical (CIAT) in Cali, Colombia and at the Southern Regional Plant Introduction Station of the United States Department of Agriculture, Griffin, Georgia. There is no known breeding programme with T. candida.

The ability of T. candida to grow well on poor, acid soils makes it an excellent temporary shade and green manure crop and a valuable alternative for Leucaena leucocephala on such soils. It has been little studied in research programmes and deserves further attention.

• Bosman, M.T.M. & de Haas, A.J.P., 1983. A revision of the genus Tephrosia (Leguminosae-Papilionoideae) in Malesia. Blumea 28: 421-487.
• Duke, J.A., 1981. Handbook of legumes of world economic importance. Plenum Press, New York, United States. pp. 230-232.
• Gichuru, M.P., 1991. Residual effects of natural bush, Cajanus cajan and Tephrosia candida on the productivity of an acid soil in southern Nigeria. Plant and Soil 134: 31-36.
• Le Van Lanh, 1994. Establishment of ecological models for rehabilitation of degraded barren midland land in northern Vietnam. Journal of Tropical Forest Science 7: 143-156.
• Nguyen, T.S. & Thai, P., 1993. Tephrosia candida - a soil ameliorator plant in Vietnam. Contour 5: 27-28.

• L.P.A. Oyen