Looking to reduce its carbon footprint and cut its fuel bill, Air New Zealand on Tuesday tested a passenger jet that was powered partially with oil from a plum-sized fruit known as jatropha. The airline is the latest carrier to experiment with alternative fuels, partly due to the threat of rising oil prices but also to reduce carbon dioxide emissions from aviation, which are projected to rise 90 percent by 2020. Air New Zealand said the two-hour flight from Auckland International Airport was the first to use what are known as second-generation biofuels to power an airplane. Second-generation biofuels typically use a wider range of plants and release fewer emissions than traditional biofuels like ethanol. One engine of the Boeing 747-400 airplane was powered by a 50-50 blend of oil from jatropha plants and standard A1 jet fuel. "Today, we stand at the earliest stages of sustainable fuel development and an important moment in aviation history," Air New Zealand CEO Rob Fyfe said shortly after the flight. Along with investing in new technology to replace outdated fleets and new designs that reduce weight and air resistance, the International Air Transport Association says airlines are experimenting with a range of plant materials in an effort to find the jet fuel of the future. The association, which represents 230 airlines, said it wants 10% of aviation fuel to come from biofuels by 2017 as part of a broad climate-change plan. Air travel now generates only 2% of global carbon emissions that are believed to contribute to global warming, but the industry's high growth rate has raised concern about future emissions. "There are very promising biojet fuels, and jatropha is one of them," association spokesman Anthony Concil said Tuesday, adding that the industry is also looking at switch grass, algae and salt-tolerant plants called halophytes. Jatropha is a bush with round, plum-like fruit that has been found in parts of South America, Africa and Asia. Seeds from jatropha are crushed to produce a yellowish oil that is refined and mixed with diesel. Tuesday's flight was a joint venture by Air New Zealand, airplane maker Boeing, engine maker Rolls Royce and biofuel specialist UOP Llc, a unit of Honeywell International. In February, Boeing and Virgin Atlantic carried out a similar test flight that included a biofuel mixture of palm and coconut oil. But that was dismissed as a publicity stunt by environmentalists who said the fuel could not be produced in the quantities needed for commercial aviation. Continental Airlines intends to operate a test flight out of Houston on January 7 using a special blend of half conventional fuel and half biofuel with ingredients derived from algae and jatropha plants. Simon Boxer, of environmental group Greenpeace New Zealand, said it was inevitable that airlines would show greater interest in sustainable biofuels as travelers become more aware of the harm that air travel causes the environment. But he said it wasn't clear whether jatropha was really sustainable. He questioned what the environmental impact would be if jatropha grew popular and more land and resources were needed to produce it on a commercial scale. Ken Morton, a Boeing spokesman, said he expects more airlines will embrace biofuels as countries introduce emission taxes and emission trading schemes that will impact the industry. "It makes a lot of commercial sense to invest in these biofuels," said Morton, who was on hand for the New Zealand flight. "Certainly, it is what the public wants." Jatropha on first glance appears to have many of the attributes demanded from the industry. It grows almost anywhere, so it wouldn't compete with food crops, as corn-based ethanol does, and has a lower freezing point than traditional biofuels like palm oil. India appears to be most bullish on jatropha, with plans to plant 30 million acres (120 million dunams) by 2012. Already, the Indian government says it has successfully run dozens of trucks and buses on jatropha-based biodiesel and 18.5 million acres (74 million dunams) of jatropha saplings are growing along the country's railroad tracks. While Air New Zealand heralded Tuesday's flight as successful, group manager Ed Sims cautioned that it will be at least 2013 before the company can ensure easy access to the large quantities of jatropha it would need to use the biofuel on all its flights. "Clearly we are a long, long way from being able to source commercially quantifiable amounts of the fuel and then be able to move that amount of fuel around the world to be able to power the world's airlines," he told New Zealand's National Radio.