Hevea brasiliensis (Bekele-Tesemma, 2007)
| Hevea brasiliensis (Bekele-Tesemma, 2007) |
Hevea brasiliensis Euphorbiaceae The Amazon Region, South America
Common names
- English: Hevea
- Amargna: Yegoma zaf
Ecology
A tree of moist and hot lowlands, widely cultivated in the tropics and commercially most valuable in Malaysia, Indonesia and Thailand. There is production on a commercial scale also in West Africa and South America. In Ethiopia, it grows well in Wet Kolla agroclimatic zone. Because of the extended root system, the soil should be deep. The optimal pH is 5 to 6. Hevea stands brief waterlogging but it will only produce well on well-drained soil.
Uses
Latex (white sap is tapped to obtain rubber).
Description
A large tree that grows up to 20 m, all parts producing white latex when cut.
- BARK: Smooth, light grey.
- LEAVES: Compound with three oval leaflets on a long stalk, each leaflet smooth and sharp tipped.
- FLOWERS: Small, in branched heads by leaves, female flowers at the tip, male at the base.
- FRUIT: Woody three-part capsules, about 4 cm long. The dry capsule splits explosively to set free the seeds, each grey and patterned, to 3 cm long.
Propagation
Seedlings, budding for good varieties. Germinate seed in seed beds and then transplant into pots. Bud after 3-6 months (green budding) or after 1-2 years (brown budding).
Seed
About 300 seed per kg.
- Treatment: None.
- Storage: Fresh seeds are recommended, the viability decreases rapidly after 1 month.
Management
In commercial production, planting densities in the stand vary between 150 and 400 trees per ha. Other crops can be grown between rows of trees. Weeding and use of leguminous and shade-tolerant cover crops also recommended. Under favourable conditions, tapping can begin 4 years after planting but often only after 6-9 years. Expert advice is recommended for any larger-scale planting.
Remarks
Several botanical varieties have been described. The cultivated forms belong to var. brasiliensis. Latex can be tapped every few days and may continue from the same trees for many years. Fertilisers containing phosphorous may be essential for good growth of leguminous cover crops.