Tephrosia candida Seeds | White Tephrosia
LATIN NAME: Tephrosia candida
COMMON NAME: White Tephrosia
Plant Profile
White tephrosia earns its keep not as a flower but as a soil builder. It is a short-lived legume that throws a wall of upright white pea-flowers, then drops a heavy leaf and stem mass that feeds the ground it grew on. On a cleared or eroded slope where little else will stand, a single sowing lifts the nitrogen and the organic matter enough to bring the next crop through, which is why it is planted as green manure from South Asia to the Pacific.
The bloom is a dense terminal spike of small white, pea-shaped flowers carried above pinnate leaves made of many narrow leaflets, and the slender, hairy pods that follow are the easy field mark against other white-flowered tropical legumes. The whole plant is softly hairy, which is the ‘candida’ of the name, and the stems stand 1 to 2 m in a good season before they lean and mat.
The timing that matters is the cut-in. Turn the growth under while it is still soft and green, before the stems wood, because a mature, seedy stand is harder to break down and can shed seed you did not want. As a rotation it fits the gap between a cereal crop and the next, filling the bare months with living cover instead of weeds.
The nitrogen comes from nodules on the root, small swellings packed with rhizobia that trade fixed nitrogen for plant sugar. Inoculate the seed with the right strain where the soil has never grown tephrosia, or the first sowing may sit green but hungry; once a field has the bacteria the nodulation comes free. The root also binds the topsoil, which is the other reason it is chosen for slopes.
Unlike legumes that sulk on sour ground, white tephrosia tolerates acid, low-fertility soils and even light shade, which is why it fits the slash-and-mulch systems of the humid tropics. It asks for sun and warmth and a frost-free window, and it returns the favour with growth where a clover would fail.
Science & Biotechnology
Tephrosia is the plant that gave rotenone its name, and the roots and leaves carry rotenoids that fish, and the larvae of many insects, cannot tolerate. That is the old fish-poison and botanical-insecticide story: crushed root in a stream stills the fish, and the same chemistry made the genus a source of garden dust before synthetics took over. The compound is real and the caution is real.
Uses & Benefits
Farmers sow it into a field after the main harvest, let it cover the ground through the off season, then cut it in and turn it under before the next sowing. The biomass is high for a legume of its size, and because the roots nodulate freely the nitrogen fixed stays in the soil rather than being carted off. In southern China it is the living fence and fodder row as much as the green manure, a single plant serving three jobs at once.
Use the plant as fodder only where the local practice is established and the dose is known, because the rotenoids that kill pests also worry a grazing animal at high intake. Keep livestock and pets off a fresh, heavy stand, and never treat the seed or leaf as a human food. The value is the soil, not the plate.
Growing from Seed
The seed has a hard coat, so chip or hot-water treat it before sowing so water reaches the embryo, then broadcast into a clean, firm seedbed and rake light. It emerges best on a warm soil and a moist surface, and the seedlings should be thinned or slashed to a 30 to 50 cm stand so the row does not smother itself. Water only to get it up; once established it runs on rain.
Scarify every batch, because unscarified seed can sit a full season and then appear in the wrong crop. A firm, fine tilth and a roll after broadcasting gives the best close, and a first cut when the stand is knee high yields the most biomass per square metre before the stems harden.
On smallholdings the plant does triple duty as a green-manure row, a living fence, and a fodder crop, because the leafy growth that feeds the soil also makes a readily eaten browse once it is cut and dried. The stems are too coarse to graze straight, but wilted and mixed with grass they carry the legume protein that lifts a thin herd through the dry months, and the fence line of it keeps stock in without posts. That multi-job habit is why it spread from its home range across the tropical smallholding belt, carried by farmers who valued one plant that built the ground and fed the stock at once. Keep the sowing to a managed line rather than a field, because a free stand seeds itself into the next crop and the rotenoid content argues against casual grazing of the fresh leaf, so the safer use is the turned-in green matter and the dried, measured fodder.
Our Take
For other tropical soil-builders compare Tephrosia apollinea, Crotalaria pallida, and Sesbania cannabina. I sow white tephrosia where the ground is spent and the season is short; it is the fastest way I know to hand a tired field back to the next crop in better shape than I found it.
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