sealPurdue News
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June 1998

Purdue research wins battles over sorghum

WEST LAFAYETTE, Ind. -- There's a favorite saying among American farmers that no politician is as important to a farmer as a slow two-inch rain in July.

That saying plays in Africa, too, where a Purdue University research team has had to overcome politicians, as well as horrible droughts and bizarre parasitic plants, in an effort to fight famine.

In the early 1960s, when John Kennedy urged Americans to look to their better selves to solve the world's problems, some researchers at Purdue decided there wasn't anything they could do to stop the wars, political corruption, dictators or rampant poverty of Africa. But they decided they could do something to fight famine, which too often was the end result of these troubles. They set out to improve the genetics of some of the major food crops of the sub-Saharan regions of Africa, particularly sorghum.

Thirty-five years after the launch of the program, the fruits of their labor are literally coming to harvest in countries such as Chad, Ethiopia, Mali, Niger, Rwanda and the Sudan.

The improved crops have been so successful in Africa that some farmers there have smuggled the seeds across hostile borders, and at some sites the seeds have had to be put under armed guard.

People are willing to take such risks for the Purdue seed because sorghum is the primary food source for 300 million people in sub-Saharan Africa. Sorghum is able to withstand droughts and poor soils, and, as a crop indigenous to the region, it is widely available. According to John Axtell, Purdue's Lynn Distinguished Professor of Agronomy, the people in Africa use the grain to make an array of products, including bread; a thick porridge, which is something like oatmeal; a thin porridge or gruel; and what he euphemistically calls in grant applications "thin fermented porridge," otherwise known as beer.

But the story didn't stop with a successful program to help Africans. The sorghum breeding program has benefited American farmers, too, Axtell says, by:

  • Training students in crop genetics. One of the students who graduated from the program led a team that developed Pioneer hybrid 3394, one of the best-selling corn hybrids in U.S. history.

  • Improving sorghum varieties that are grown in this country. Sorghum is an important livestock feed, particularly in the western states.

  • Gaining knowledge of crop genetics. Because of a new field of biology, "genomics," information learned about sorghum genetics can be applied to other cereal crops such as corn. "Sorghum is a much easier crop to work with than corn," Axtell says. "It has one-third of the DNA per cell that corn has, so it is much easier to find important genes for crop improvement. The genes are in the same locations, though, so once we find an important gene in sorghum, we have a good idea where it is in corn."

For their perseverance and years of hard work, the researchers involved with the Purdue sorghum breeding program have been given the Purdue School of Agriculture's 1998 Interdisciplinary Team Award. Members of the team are Axtell; Gebisa Ejeta, professor of agronomy; John Sanders, professor of agricultural economics; Katy Ibrahim, administrative assistant, Purdue International Programs in Agriculture; Bruce Hamaker, associate professor of food science; and, posthumously, Larry Butler, professor of biochemistry.

Among the breakthroughs for the research team:

  • Sorghum varieties that resist witchweed. Witchweed, also known as striga, is a parasitic plant that can cause crop losses of up to 40 percent in parts of sub-Saharan Africa. It is considered the largest biological threat to crops there, a more serious threat than insects, birds or plant diseases. Ejeta and Butler developed eight striga-resistant strains of sorghum, and with the help of the Christian foreign-relief organization World Vision, they were able to ship eight tons of seed to Africa in 1996.

When the government of Ethiopia decided not to allow the seed into that country for political reasons, Ethiopian farmers sneaked into Sudan to get bags of the seed to bring back into their country. The next year the Ethiopian authorities agreed to allow the seed to be distributed in their country.

"If farmers in those countries determine that something offers an advantage, no politician is going to be able to stop them from using the technology," Ejeta says.

  • Drought-resistant varieties of sorghum. Sorghum is a good crop for semiarid regions, which is why it is an important crop in sub-Saharan Africa and in the southwestern United States. Ejeta and other members of the research team are investigating genetic mechanisms that offer even more drought tolerance. "We have developed and released 10 drought tolerance lines that have been used by the seed industry in the United States, India and Africa," Ejeta says.

  • More nutritious varieties of sorghum. In the early 1960s, Purdue researchers developed high-lysine corn. Lysine is one of the essential components that the body uses to build cells, but the human body doesn't produce lysine on its own. Most people get adequate amounts of this essential amino acid by eating meat, but in poorer countries meat isn't a common part of the diet. High-lysine cereal grains can counter this dietary deficiency. When Axtell joined the faculty at Purdue, he began investigating whether he could develop sorghum that also had elevated levels of lysine. In 1973 he was successful in creating this extra-nutritious variety.

  • More digestible varieties of sorghum. One of the major problems with sorghum -- and a reason why it isn't used as a food grain by more people throughout the world -- is that it is the least digestible of all of the world's cereal grains. As with any food, part is digested by the body and part passes through. Previous studies have found that the protein in wheat is 81 percent digestible; the protein in corn is 73 percent digestible; and the protein in sorghum is 46 percent digestible. Cooking lowers the digestibility of sorghum even more.

    Hamaker identified a special variety of sorghum that is 87 percent digestible protein, and is still more than 80 percent digestible after cooking. This has obvious benefits for those people who rely on sorghum for their diets, but it also will make sorghum a better livestock feed, and it could mean that people in many countries will begin adding sorghum to their diets.

  • The establishment of a seed industry in Africa. Ejeta developed the first commercial sorghum hybrid in Africa, a line known as HD1. Now, 500,000 acres of commercial sorghum varieties are grown in Sudan alone. This means that where there previously was no commercial seed industry in Africa, now entrepreneurs in many countries, particularly Sudan and Niger, have launched agribusinesses that increase economic development in those countries.

In addition to Purdue's role an international center of sorghum research, it also is a clearinghouse for the exchange of sorghum varieties by scientists and businessmen around the world. "A large amount of Sudanese raw sorghum germplasm was introduced to the United States for the benefit of public and private sorghum research programs here," Ejeta says. "In the Sudan, approximately 90 percent of the improved sorghum germplasm was introduced from the United States. When you consider that sorghum was first domesticated in Sudan and Ethiopia, this is quite an accomplishment.

"We have effectively catalyzed the movement of sorghum germplasm around the world, both to developing countries and to industry in this country."

Sources: John Axtell, (765) 494-8056; jaxtell@dept.agry.purdue.edu;
Web, http://www.agry.purdue.edu/agronomy/staffbio/jdabio.htm

Gebisa Ejeta, (765) 494-4320; e-mail, gejeta@dept.agry.purdue.edu;
Web, http://www.agry.purdue.edu/agronomy/staffbio/gebio.htm

Bruce Hamaker, (765) 494-5668; e-mail, hamakerb@foodsci.purdue.edu;
Web, http://www.foodsci.purdue.edu/personnel/hamaker.html

Writer: Steve Tally, (765) 494-9809; e-mail, tally@aes.purdue.edu
Web, http://www.agcom.purdue.edu/AgCom/homepages/tally/

Purdue News Service: (765) 494-2096; e-mail, purduenews@purdue.edu


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