Asia's rubber empire grew from seeds smuggled out of the Amazon in 1875
In 1875 Henry Wickham carried about 70,000 rubber tree seeds from Brazil to London's Kew Gardens. Only around four percent sprouted, but those seedlings went to Ceylon and Singapore and seeded plantations across British Asia. Today the Amazon's own rubber trade is long gone, and Southeast Asia's cloned trees face a fungus from the tree's homeland.
The Pará rubber tree, Hevea brasiliensis, is a member of the spurge family native to the Amazon basin. In the wild it can reach 43 metres. Its latex, white or yellow, flows in vessels in the bark that spiral up the trunk in a right-handed helix at about 30 degrees. Tappers cut across those vessels just deep enough to release latex into small buckets without harming the tree. Harvests begin seven to ten years after planting, and because yield falls with age, plantation trees are felled at 25 to 30, their wood now often used for furniture rather than burned.
People used rubber long before industry did. The Olmec made rubber from a related tree, Castilla elastica, some 3,600 years ago, including balls for the Mesoamerican ballgame. The discovery of vulcanisation in 1839 triggered an Amazon boom that enriched Manaus, Belém and Iquitos between 1840 and 1913. A first British attempt to transplant the tree in 1873 produced just 12 seedlings that died in India; Wickham's larger haul two years later succeeded, and by 1898 there were plantations in Malaya worked largely by Chinese labourers.
The Amazon lost its trade partly to disease. South American leaf blight, caused by the fungus Pseudocercospora ulei, is native to the basin and among the most aggressive crop diseases on the continent, so cultivation shifted to places free of it. By 2011 the top producers were Thailand, Indonesia, Malaysia, India and Vietnam. The tree is also fussy about climate, needing roughly 1,200 mm of rain a year, and a single frost can make a plantation's rubber brittle once refined.
Historian Charles C. Mann warned in his 2011 book 1493 that most Asian rubber trees are clones highly vulnerable to that blight, raising the prospect of a disaster for global industry if it ever arrives. Oddly, the tree's cyanide-based chemical defence seems to worsen its reaction to this fungus.
Source: Hevea brasiliensis
