Remember seeing the silhouette of two faces looking at each other and trying to refocus your eyes to see the lamp in the middle? That’s what happened to Fred Below when he started working with tropical maize. As a crop physiologist, he has known for years that corn stores sugar in its stalks. “First it’s in the leaves, then it’s in the stalks, then it’s in the grain where the sugar is converted to starch,” he says. The University of Illinois at Urbana-Champaign researcher was looking at tropical maize plants one day with his graduate students when the obfuscated became obvious.

“It’s a new use for a phenomenon that has been known for a long time,” he explains. Corn, or maize, that has adapted to the photosynthesis periods of tropical regions grows normally there, but when it’s transplanted and growing during longer summer days in Illinois, it behaves differently. In the longer photosynthesis period, the tropical maize delays its flowering cycle and grows taller. Instead of sending its energy into tasseling and cob formation, it stores sugar in the stalk. In other words, it behaves exactly like its sister grassy crops—sugarcane and sweet sorghum.

“We’ve grown some of the material, measured some of its biological potential and squeezed some juice for fermentation studies,” Below says. The stalks yielded about 25 percent simple sugars—mostly sucrose, fructose and glucose. The initial data from fermentation studies indicates that yeast makes good quantities of butanol and ethanol, and there doesn’t appear to be any natural inhibitors, he says.

Midwestern-grown tropical maize easily grows 14 to 15 feet tall, he says, compared with the 7.5-foot typical hybrid corn varieties. Below’s preliminary data indicates that biomass yields will total approximately eight tons per acre. Good biomass yields should be achievable with one-fourth the fertilizer required in conventional corn crops, he says. The heavy nitrogen applications used in corn production are primarily utilized by the corn plants to maximize the yield of grain.

“The nice thing is that it can be planted and managed the exact same way as corn,” he says. “The farmer can use existing equipment, and we think he’ll be able to use silage cutters for harvest.”

More work needs to be done, Below says. As a plant scientist, he will continue to learn how to maximize the plant’s potential. Others working in process engineering will need to examine how it will fit into the ethanol industry. He expects that the simple sugars will be extracted first for fermentation into ethanol in one process, with the remaining pulp, or bagasse, burned for energy or run through a cellulosic ethanol process.

At this point, Below has just enough seed to use for his research in Illinois. However, he is trying to make arrangements to increase seed quantities so that others can plant test plots for research and demonstration. Plus, the original research project using tropical maize will continue. Very little nitrogen is used in the production of corn in the tropics, Below explains, which should result in varieties that are quite efficient in using available nitrogen. Midwestern corn varieties, on the other hand, have been developed in recent years for high responses to added nitrogen. His work with tropical maize began in the search for genes to improve the efficiency of nitrogen utilization in Midwestern corn. It appears that effort will be successful, as well.