Supply glut, slowing demand leave rubber tappers in a sticky place

Bangkok

AS rubber prices slumped towards a six-year low, 20 of 30 workers who drained the sticky latex from trees on Winai Chaikunanant's plantation in Thailand quit. Even with income sharing, they earned less than the minimum wage.

Mr Winai isn't faring much better. The 70-year-old loses money on every kilogramme produced on the farm he's tended for five decades because government subsidies aren't big enough to make up the difference. Half his trees were left untapped this season, and he plans to raze about 100 rai (16 hectares) to grow cassava or pineapple instead. And the market may only get worse for rubber growers.

Global demand for natural rubber, used mostly in tyres, is slowing as the economy cools in China, the world's largest buyer of new cars. Supplies are expanding after a decade-long rally in prices to a record in 2011 encouraged top producers such as Thailand, Indonesia and Vietnam to plant more trees. Output will exceed use for two more years, with the surplus quadrupling in 2016,…