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Corn+Soybean Digest

Yield Shields Shine

After watching weakened corn stalks continually shed their ears over the corn head's outside rows during a corn borer-infested harvest, Herald Barton took matters into his own hands. To prevent losing more corn, he designed a ¼-in. piece of sheet metal that attached to the row unit's outside points. Then he watched while his invention worked to deflect wayward ears back toward the combine's gathering chains and safely into the feeder house for shelling.

“It's hard to believe how smoothly the corn shields glide through the field now compared to the ones I first developed,” says Barton, who farms near Silver Lake, MN, with his son Barry. “But even my early prototypes did what they were designed to do,” he adds, “and that's to save the farmer corn.”

Barton's corn shields were featured this summer at the Minnesota Inventors Congress 2007 Expo in Redwood Falls, MN, as part of its 50th annual event. More than a decade since the corn shields were first launched commercially, they continue to attract attention from farmers and farm media alike. However, Barton says he didn't create the corn shields to bring him fame or fortune.

“The only thing I ever wanted was that farmers would be able to get them and save their corn,” he says.

Last year, Barton sold the patent to his corn shields invention to May Wes Mfg., a division of Pride Solutions, Hutchinson, MN. “May Wes has the best ag catalogue on the market,” he says. “They will also make it available to any farmer who wants it.”

Corn shields save the most corn wherever it's susceptible to ear drop, regardless of the corn head's make or model, says Barton.

Conditions that might cause ears to weaken on the stalk include corn borer or other corn insect feeding, hail, drought, wind, hard rains, disease or even fast drydown characteristics. The corn shields, which have been sold to farmers in 15 states and Canada, also allow farmers to harvest corn diagonally, to harvest with any size corn head or to plant corn with any size planter without losing corn, he adds.

Barton's invention has paid off for satisfied buyer Duane Jaskowiak, Silver Lake, MN. “The shields work best if you have to combine odd rows like we do,” says Jaskowiak, who operates a 12-row planter and an 8-row corn head. “If we didn't have the shields on, we'd just watch the ears fly over the sides. We've definitely gotten our money back out of the ones we've bought.”

Without the corn shields, Barton estimates losses in a normal year with conventional equipment to be about 12 ears/acre. However, in bad conditions, losses without the invention might total 10-20 times as much, or about 120-240 ears/acre.

According to the National Corn Growers Association, 1 bu. of shelled corn weighs 56 lbs., which represent 92.4 corn ears at an average 1.625 ears/lb. Using those figures, Barton estimates that in an average year, farmers will likely lose about 1 bu. of corn for every 8 acres — or 125 bu. for every 1,000 acres — without the corn shields.

Corn shields save about $400 for every 1,000 acres, at $4/bu. With heavy lodging, however, the potential savings could be 20 times greater, or $7,500-$10,000 for every 1,000 acres, says Barton.

The corn shields currently cost between $300 and $400, depending on the type of corn head to which it will be attached. At those prices, farmers should consider trying them, advises Dale Hicks, University of Minnesota Extension agronomist emeritus.

“I'd want one,” says Hicks. “It's not an expensive item. And at almost $4/bu. corn it wouldn't take a long time to pay for itself.”

The corn shield first came to Hicks' attention about four years ago when he was advising farmers in southwest Minnesota how to manage large amounts of lodged corn. “The corn in that area had been flattened by high winds and never came back up,” he says. “It was impressive to compare corn losses with and without the corn shields.”

Even when corn isn't lodged, farmers who plant in twin-row patterns would likely benefit from the corn shields, says Hicks. “With twin rows, the header slaps the two stalks together quickly,” he explains. “If the shanks aren't solid, the ears will go flying. On the outside rows, it's the ear on the inside twin row that usually flies out over the corn head, unless there are corn shields in place to stop it.”

Given the yield losses that could occur without one, every corn farmer can benefit from them, adds Barton. Over time, he says, they'll prove themselves.

“You mark my words — the day will come when I will be long gone,” he says, “but there'll be corn shields on every corn head.”

Patent Tips For Farmer Inventors

Patents are not for everyone. “You'll want to carefully weigh the costs and gauge the market before you go down the road of getting a patent,” cautions Jeff Thompson, patent attorney for Thompson & Thompson Law Office, Scandia, KS. “The cost varies somewhat by the type of invention and how complicated it is. Typically, a patentability search and opinion from a patent attorney will cost $750-1,000, and it will cost another $4,000-6,000 to get a patent application prepared and filed in the U.S. Patent and Trademark Office. It might cost another $2,000 or more in expenses to get the patent issued.”

Patent owners must also pay maintenance fees on their patent every four years after the patent is issued, Thompson adds. For small entities, such as individual inventors and small companies, the first maintenance fee will cost about $550; the second will cost about $1,250 and the third will cost about $2,000, he says.

Only a small number of inventors prepare and prosecute patent applications without the assistance of a patent attorney. It's difficult to know the many nuances of the patent system, and the legal language used in the patent application to describe and define the scope of the invention is critical to the value of the patent.

Thompson says there are many things inventors can do to help their patent attorney obtain the best patent protection at the lowest cost. Inventors should: organize their materials; arrange personal or telephone conferences with their patent attorney to describe the invention; provide clear sketches and/or photographs to further explain the invention; provide a concise written description of important aspects of the invention and related background information; and describe any alternatives or variations that could be made to the invention.

The Internet offers many resources to help inventors understand and research the patent process. Among those recommended by Thompson is the U.S. Patent and Trademark Office Web site at

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