Supersweet Corn

John Laughnan was a corn geneticist and professor of botany at U of I. In the early 1950s he was studying the shrunken-2 (sh2) gene and discovered this gene led to corn that produced kernels with less starch and four times more sugar than other sweet corn at the time. When Laughnan started marketing his varieties of sweet corn with the sh2 gene, he developed the “Illini Supersweet” hybrid. Today “supersweet” is often used synonymously with sh2.

In the 1980s, U of I professor “Dusty” Rhodes discovered the sugary enhanced (se) trait that also produced sweeter kernels, though not as sweet as supersweet varieties. Sweetness is not the only determining factor when contemplating sweet corn preferences. Although se varieties are not as sweet as supersweet, some prefer their texture and tenderness.

Today there are three main types of sweet corn: supersweet (sh2), se, and su, with hundreds of varieties within those three types to choose from.

Although it didn’t catch on right away, supersweet corn has surged in popularity over the decades. By the early 2000s 90% of all sweet corn grown in Florida - one of the top sweet corn producing states - were supersweet varieties. With a longer shelf life than se or su varieties, supersweet corn is ideal for shipping and stocking in grocery stores. It also has more protein and is lower in calories than conventional varieties.

A historical marker stands next to the old College of Agriculture building, Davenport Hall, in honor of Laughnan’s contribution to the sweet corn industry. The marker reads:

“In 1953, John R. Laughnan discovered that kernels of mutant corn were ‘unusually sweet.’ Within eight years, Laughnan had developed the ‘Illini Supersweet’ hybrid that revolutionized the sweet corn industry. Supersweet, now a dominant variety internationally, is higher in protein and lower in calories than conventional sweet corn.”

The Illini Supersweet historical marker outside of Davenport Hall

For more information you can watch this video on supersweet corn.