Pachyrhizus tuberosus
| Pachyrhizus tuberosus | |
| Light: |  |
| Moisture: |  |
| Hardiness: | 10 |
| Soil pH: | 5.6-8.4 |
| Height: | 20' |
| Blooms: | Mid Summer |
| Native to: | |
| Nitrogen Fixer | |
| Edible Rating: |  |
| Tea: | Yes |
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Pachyrhizus tuberosus (common name: jicama)
Propagation: Pre-soak the seed for 12 hours in warm water and then sow in early spring in a warm greenhouse. Germination should take place within 2 weeks. As soon as they are large enough to handle, prick out the seedlings into individual pots of rich soil and grow them on fast. Plant them out after the last expected frosts. Give the plants some protection, such as a cloche, until they are growing away well.
Division of the root tubers in the autumn. Store the roots in a cool but frost-free place over the winter, planting them into pots in the greenhouse in early spring and planting them out after the last expected frosts. Give the plants some protection, such as a cloche, until they are growing away well.
Cuttings.
Cultivation: Prefers a light rich sandy soil[1].
Often cultivated for its edible root and seedpods in tropical areas[2], this plant is not hardy outdoors in Britain and requires greenhouse treatment[3] but could possibly be grown as a half-hardy annual. When grown for its root the flowers should be removed[1]. Plants are unlikely to form a tuber when grown in Britain due to their photoperiodic requirements[3]. This means that the plants require between 11 - 13 hours of daylight hours per day in order to initiate tuber production[K].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[3].
Range: S. America - Peru.
Habitat: Growing into trees and shrubs, often in disturbed areas and usually near the coast, from sea level to 500 metres.
Edibility: Root - raw or cooked[4]. Thirst quenching and nutritious[1]. A source of starch, it is used in custards and puddings[2][5]. Individual roots can weigh up to 20kg[3].
Young seed pods - cooked and used like French beans[1][2][5]. The pods must be thoroughly cooked in order to remove the toxic principle rotenone[3].
Usage: The plant contains rotenone, the active ingredient in the insecticide 'derris', and it has the potential to be used as an insecticide[3]. Derris is a relatively safe insecticide in that it does not affect warm-blooded animals and also breaks down into harmless substances with 24 hours of being used. It does, however, kill some beneficial insects and is also toxic to fish and amphibians[K].
Pollinators: Insects
Soil: Can grow in light and medium soils.
Flower Type: Hermaphrodite
Known Hazards: The seed might be poisonous[1].
Links
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Chittendon, Fred. RHS Dictionary of Plants. Oxford University Press, 1951.
- ↑ 2.0 2.1 2.2 Uphof, Johannes. Dictionary of Economic Plants. Weinheim, 1959.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 Huxley, Anthony. The New Royal Horticultural Society Dictionary of Gardening. MacMillan Press, 1992.
- ↑ Hedrick, Ulysses. Sturtevant's Edible Plants of the World. Dover Publications, 1972.
- ↑ 5.0 5.1 Usher, George. A Dictionary of Plants Used by Man. Constable, 1974.