DES MOINES, Iowa — Darrel McAlexander has been farming for 43 years and he's never seen his corn crop look so good.

"This is probably the best corn crop I've raised," McAlexander said from his farm in the southwestern Iowa town of Sidney.

It's the same across the country as favorable weather has helped farmers produce what could be a huge harvest, with projections calling for 13 billion bushels. That would be just shy of the 13.04 billion bushels harvested in 2007.

The giant crop is good news for farmers and livestock producers, who should benefit from lower feed costs, but it probably won't make a big difference to the cost of groceries.

Although corn is a key ingredient in countless products, from Coke to corn flakes, most of a product's cost is tied to labor and transportation, not ingredients, said Kent Thiesse, a farm management analyst and vice president of MinnStar Bank in Lake Crystal, Minn.

"Depending on what you're looking at on the store shelf, less than 25 percent of the cost goes back to the base product," Thiesse said.

Ephraim Liebtag, senior economist with the U.S. Department of Agriculture's economics research service, agreed.

"The effect of corn changes on retail prices is pretty mild and at this point we don't see anyone predicting a major swing in corn prices," Liebtag said. "If there isn't a major swing there is no major impact and the effect will be pretty negligible for the consumer."

A drop in corn prices is a rare bit of good news for a pork industry that has been battered by pricey feed, a drop in demand due to the recession and unfounded concerns about their product's safety in the wake of the swine flu outbreak that has led other countries to limit imports.

The expected harvest has helped drive down corn prices from about $4.30 a bushel in early July to $3.17 currently. That's a drop from a peak price of more than $6.80 a bushel in mid-2008 when prices soared because of increases in ethanol production and demands by the livestock industry.