Grain South Africa chairman Bully Botma said there was growing enthusiasm for the ethanol scheme, which will produce biofuels seen as much more environmentally friendly than conventional petrol or diesel.

"I think there's a lot of excitement," he said. "Some people say 14 months but I don't think it will happen that quickly. I think 18 months for production -- it depends on the support of the farmers."

Grain SA would ballot the farmers shortly, he said. Growers will be expected to donate some of their surplus -- part of the maize mountain that has kept prices low -- to be used as collateral to borrow money to fund eight plants.

Botma said the plants would have to consume about two million tonnes of maize a year if they were to boost prices.

Talk of the ethanol plants has yet to have significant impact on Johannesburg SAFEX maize prices. Traders are more worried about short term overproduction and poor exports and are sceptical the farmers will agree to cooperate on the project.

Botma said current low prices meant some farmers would not be able to afford to plant all their land this year, and that some banks were encouraging farmers to leave up to a third of their fields fallow to cut overproduction.

Farmer Johan Hoffman, involved in drawing up the detailed plans for the plants, said each would likely consume 370,000 tonnes of maize a year, totalling 2.96 million tonnes if all eight plants were built, and producing 1.2 billion litres of ethanol.

The plants, likely to be built in rural maize-producing areas in the Free State, North West and Mpumalanga provinces that suffer high unemployment, would each cost around 350 million rand.