Farmers in North Queensland are doing their bit to be environmentally friendly by investing in a tree that produces diesel.Over 20,000 trees have been sold to farmers in the tropics by the man who introduced the diesel tree from Brazil.

The tree produces an oil that can be extracted, filtered and used to power vehicles and farm machinery.

Because, the Brazilian Copaifera langsdorfii can be tapped much like a rubber tree, but instead of yielding rubber it gives up a natural diesel. According to the nurseryman selling the trees, one acre will yield about 1250 gallons annually compared to about 30 gallons of ethanol produced from an acre of corn.

Once filtered no complex refining is required it can be placed straight into a diesel tractor or truck. A single Copaifera langsdorfii will continue to produce fuel oil for an impressive 70 years, with the only negative being that its particular form of diesel needs to be used within three months of extraction.

It is estimated a one-hectare crop could produce enough fuel for an average-sized family farm.

Mike Jubow, a former cane farmer and now a nursery wholesaler, says diesel-producing trees are a long-term investment.

"If I'm lucky enough to live that long enough - I'm 64 now - it is going to take about 15 to 20 years before they are big enough to harvest the oil so that I can use them in a vehicle," he said.

"Principally, they are an ideal plantation tree for a family farm where, from generation to generation, you will harvest this oil so that your grandson and your great-grandson can still be virtually getting free fuel from these trees 30 to 50 years in the future."