AN Air New Zealand jet thundered through the sky on a two-hour flight this week — on a 50-50 blend of ordinary fuel and one made of seeds from the African desert.

The successful flight was promising for the airline industry, and truly exciting for the environment and the hope for national fuel autonomy.

Tuesday's test was the first commercial air flight to use fuel from the jatropha weed. It performed "well through both the fuel system and engine," Air New Zealand's chief pilot told the BBC.

The flight lasted more than twice as long as the first flight using biofuel, performed by Virgin Atlantic in February 2008. That plane used a 20-percent mixture of coconut oil and babassu oil in one of four engines.

But jatropha, unlike coconut or corn, sidesteps several problems now linked to biofuels.

Combined with pressures such as high gas prices, production of corn-based ethanol helped aggravate global food shortages last year.

Using food for fuel also harms the environment. Several European governments recently ended subsidies for palm oil diesel production. Their Asian suppliers, cutting rainforests to grow the palms, were actually boosting overall atmospheric carbons.

Finally, most food crops use great swaths of land and heavy fertilizer. Runoff from ethanol production has already compromised parts of the Mississippi River.

Jatropha, by contrast, is a sturdy weed that thrives in arid, low-producing land in India, Malawi and Mozambique. The oil in Air New Zealand's Rolls Royce engines came from environmentally sustainable farms.

It's also efficient: Each seed produces between 30 and 40 percent of its mass in oil.

No one expects jatropha to replace jet fuel, in part because it lacks the important hydrocarbon rings that help seal jet engines in flight.

But the humble seed oil does reflect the exciting quest for new biofuels — energy that can reduce the need for petroleum with less environmental stress and more bang for the production buck.

This is key for the airline industry; its emissions produce only 3 percent of greenhouse gas but do more damage at high altitudes.

In the long run, however, Tuesday's flight over Auckland is even more meaningful for combating climate change from the ground.

Jatropha, noted Jim Marston of the Environmental Defense Fund, shows the rewards of investing in new, clean energy sources. "Yes, yes, yes, yes," Marston said, of the possibility of jatropha being refined one day for car engines. To encourage such breakthroughs, the federal government should accelerate research into new and efficient alternatives.

Texas should be leading this research. Already, the University of Texas is developing algae as a fuel source. And Continental Airlines is set to test an algae-and-jatropha fueled flight on Jan. 7.

One century ago, Texas oil helped determine how the whole world would travel by land and air. Texas' creativity should now drive the fuel alternatives for the new millennium.