EWING, Ill. — Like hot dogs and apple pie, sweet corn epitomizes summer in America.
Rare is the picnicker who doesn’t relish biting into a fresh-picked cob slathered with butter and sprinkled with salt and other seasonings. The burst of flavor from the sweet, tender kernels far exceeds the minor inconvenience of occasionally getting one stuck in your teeth.
Whether boiled, grilled, fried or baked, sweet corn is a treat that is as anticipated in late summer as watermelon and peaches.
So it should come as no surprise that agronomists are constantly pursuing the next best thing, breeding corn for sweetness and tenderness, along with agronomic traits that improve yields and quality. Talon Becker is one of them.
The University of Illinois Extension commercial agriculture educator has a small plot at this research center in Franklin County, deep in southern Illinois. He acknowledges sweet corn has been developed virtually to the limit of its sweetness. But like all plants, it is affected by geography and climate. He’s looking to develop hybrids that fare well in the hot, sticky environs of southern Illinois.
“There is an upper limit to how sweet you can make it,” said Becker, whose background is in plant breeding. “The major problem you have with sweet corn is if you increase sugar content you decrease germination rates. The sugar content in that kernel can leach out and create more microbial feeding, rots, and more starch reserves for that embryo.
“At this point in the breeding process we’re looking for something that grows well in this climate. Sweet corn breeding for commercial production is done largely in Florida and other areas of the Southeast, in Wisconsin and a few other places. Nothing is bred necessarily for this micro climate. With natural selection, we’re allowing it to grow out here with our weather, insects and diseases.”
Much research is done in Florida because it can be done year-round. But like field corn, sweet corn prefers cooler environments with adequate rainfall, though it also grows well in heat.
Breeders toss around terms like sugary-1 or shrunken-2 to define the phenotypes. The former is the basis of the original sweet corn hybrids and the latter refers to supersweet varieties, which has virtually no starch in the kernels.
Breeders must also consider agronomic traits such as germination rate; disease and insect resistance; and nutrient uptake.
“Sugary-1 is the initial pre- Columbian mutation,” Becker said. “That one has better agronomics in general across the germplasm, but a lower sugar content. Shrunken-2 has better sugar content and tends to have better shelf life in that the sugar does not convert to starch as fast after you pick it, because all sweet corn becomes less sweet and tender after you pick it. Shrunken-2 is what allowed for corn grown in southern areas to be shipped up to us. You can pick it and have a week or two.”
As most aficionados would agree, fresh is best. The classic recommendation for backyard gardeners is to get the pot of water boiling before picking the ears.
“Out of the field is obviously the peak sugar time,” Becker said. “You’re losing some after that.”
Becker uses breeding stock from USDA’s Germplasm Resources Information Network. They are public varieties. Some are open pollinated.
“There are no patents on them anymore,” he said. “This is my pet project. If we get something really good out of here we’ll apply for plant variety protection. Royalties would come to the farm to fund research here.”
Correction made Aug. 6: A paragraph was removed that was unclear. It should have read: As with more common field corn, some sweet corn is genetically modified, according to Becker. The majority of that is either Roundup Ready – resistant to glyphosate – or Bt.