YORK, Neb. — Stan Jensen knows everything there is to know about corn.
A South Dakotan by birth, Jensen has spent most of his life in Nebraska, dedicated to his genetic research on corn. He was the first full-time Pioneer Hi-Bred (now Corteva Agriscience) employee in Nebraska during the mid- to late 1950s, and has made many significant contributions to modern day agriculture. Though he has been retired for several years, Jensen has never lost his passion for corn, its history and contribution to society.
“My work really was a spiritual thing for me,” Jensen said. “It really was.”
Jensen began his story by crediting his experiences growing up during a pivotal time in the nation’s history — the Dirty ’30s — near Vermillion, S.D., as instrumental in compelling him to work in the area of drought research.
“The stress on families was serious,” he said. “Many of the farmers lost their farms and their sanity. Ditches were filled with dust and grasshoppers would eat what little green tissue was left.
When people got together, whether it was in town on Saturday night or after church on Sunday, the discussions centered around when or if it was going to rain.”
Jensen attended South Dakota State, where he earned a master’s degree in corn breeding financed by Pioneer. His thesis involved a study of inbred lines in a drought chamber for the purpose of measuring tolerance to heat and drought. From this study, he noted, they were able to conclude genetic differences in response to drought conditions. His work would later earn him the title of the “Father of Drought Tolerant Corn” within the company.
Raymond Baker was the director of corn breeding for Pioneer at the time when Jensen started.
“One of the first things we did was set up a yield test in an irrigated field, with the plan not to water it except save the crop,” Jensen recalled. “I still remember Raymond’s parting words as he left the field that day, ‘I hope you have the guts not to water it.’”
This was the first “managed stress” test for Pioneer. It was 1957 and it was most likely the first “managed stress” test in the country, maybe in the world, Jensen noted.
Eventually, additional Pioneer breeding stations were added in South Dakota, Kansas and western Nebraska. This also meant transportation was needed, as well. Jensen remembered talking to Baker about getting a car for his work traveling to research plots. He smiled as he recalled being approved to get a 1955 Chevy. Jensen said he asked for a radio, but it was made clear that no radios were allowed in company cars at the time.
Jensen noted that compared to the technology available today, those original drought tests were “fairly crude … but they were better than anything that we had available up until that time.”
After retiring from his work with Pioneer, Jensen continued to share the story of corn and remained connected with researchers around the world. About five years ago, Jensen was invited by a fellow researcher from Croatia to travel to Budapest to give a lecture to researchers, college students and others with a presentation entitled: Key Milestones in Corn Improvement that outlined corn development more than 5,000 years ago to today.
“Many people still do not know if it were not for the Native American women, we would not have the corn we know today,” Jensen began. “The Native Americans in Southwest Mexico started using the plant teosinte (a Mexican grass that is one of the parent plants of modern corn) as a food source. The tassel of this plant has seeds in it that they started using for food. There was no cob on the original plant. Then they started farming teosinte and not just growing it in the wild, and in that process, they selected the better-looking plants over the centuries.”
Jensen added that the Native Americans eventually changed the teosinte plant from the seed in the tassel to a plant that develops a cob. They also developed popcorn (made it easier for them to pop and get the starch out), flint corn, sweet corn, flour corn and dent corn.
Due to their ingenuity in farming and plant breeding, Native Americans were instrumental in the spread of corn crops all over both continents, from Argentina, across Central America to the highlands of South America, Jensen said. Over time, that territory expanded to include Arizona, New Mexico, Nebraska, South Dakota, New England, Virginia and the Carolinas.
“By the time the colonials arrived there were a lot of different types of corn, but there were two main types — the New England Flint, a hard-textured corn that is adapted early and grows in cooler climates and had eight-kernel rows and the Southern Dent that has a softer texture and has 22-kernel rows,” Jensen explained. “The cross of these two is what most historians believe was the basis of all the open-pollinated varieties developed over the next 300 years in the Central Corn Belt.
“The native people used corn as food but the colonials preferred wheat as their base for food and fed corn to livestock. It takes far more corn to feed livestock than to use for food and that created a need for a great number of acres of corn and was the basis for the current ag industry.”
Jensen said immigrant farmers also became corn breeders and developed varieties where they lived.
“Ohio adapted to Ohio, Nebraska adapted to Nebraska and so forth,” he said, “and they developed some really good varieties like Reid Yellow Dent, Krug and Lancaster.”
Hybrid vigor corn — a cross between two unrelated strains that results in large increases in vigor in the next generation — was developed in 1892. Around 1928, Pioneer sold its first double-cross hybrid, which crosses two lines to make a single cross, then crosses another single cross, and finally crosses those two together to make a high-yielding female seed parent. Jensen said that resulted in the 30-bushel seed parent moving to a 150-bushel seed parent.
A big change, in more recent years, has also been the number of plants per acre that are planted.
“Increase in plant density is parallel with an increase in yield,” Jensen explained. “Farmers were planting up to 16,000 plants per acre in the 1980s, and then they developed new varieties that would tolerate up to 30,000 plants and up.”
Biotechnology came into the picture with the most recent mapping of the corn genome in 2009.
He said now they estimate 30,000 genes in the corn genome, and with everything mapped, farmers can select genes that increase yield, drought tolerance, disease resistance, and insect resistance.
Jensen has some concerns about the resistance that is increasing with the broad use of products like Roundup herbicide in both corn and soybeans. He said the next chapter — gene editing — is also something humanity needs to make sure they are using for the good.
“It is good to ask ourselves the question, ‘Should we do this?’” Jensen said. “We have the ability now to change our evolution. If you want to change your baby that you have coming, you can go in and edit a gene. Some of this may be good when considering the ability to remove genes that, say, are causing physical defects. But we don’t fully understand the science and the impact yet and we need to moving forward make sure we are making moral decisions on these issues.
“We have learned that the corn genome is much more malleable than we thought just a few years ago. The evolution of the corn plant has been going on for 10,000 years and will continue to develop. The demands of environmental change will force the selection in different directions.
The use of the corn plant for something other than a solar collector for the production of starch is likely.
“The corn plant is a marvelously efficient system that will continue to be utilized indefinitely to meet the changing needs of society. The genetic potential is there and will continue to be there.”
Kerry Hoffschneider can be reached at Kerry.firstname.lastname@example.org.