Instead of sour grapes, it's more a case of sour Apples between Washington's top two supermarket chains.

Instead of price wars over peanut butter, Safeway Stores Inc. and Giant Food Inc. -- with Apple Computer Inc. joining the fray -- are tussling these days over their popular promotional programs that allow area schools to trade specially marked cash register tapes for free computers and related equipment.

"Every Grocery Store Has Apples, but Only Safeway Has IBMs Too," read recent full-page newspaper advertisements taken out by the No. 2 grocery retailer here, taking aim at No. 1 Giant.

Last year, Landover-based Giant's "Apples For the Students" program outstripped Safeway's "Computers for Classrooms" giveaway program. Giant gave away 5,500 Apple computers, compared with Safeway's 836 IBMs and 63 special-request Apples.

Eyeing those results, the Oakland, Calif.-based Safeway chain decided this year to focus on Apples, the most popular brand in schools, even though the Giant program is the only one with the exclusive support of Apple Computer in this area. The national "Apples For the Students" program, run by New York-based Service Marketing Group, gets its computers directly from Apple at a discount and includes a wide array of support services.

So Safeway formulated a program of its own and is buying its computers from Frederick Computers, a local retailer.

"It's a free country, and Safeway can buy computers like anyone else," said Jim Roberts, Safeway public relations manager. According to Roberts, computers will be installed by the Apple-authorized dealer, and though instruction and other support might not be as wide-ranging as Giant's Apple program, he thinks it will be adequate.

Giant said it considers what Safeway is doing as akin to poaching, since Safeway turned down the Apple-supported program when it was originally offered. Safeway only got interested, said Giant officials, after Giant made it a success, breaking a gentleman's agreement that most supermarket chains honor in other markets.

"It did bother us, since we respected their Apple-sponsored program in the Richmond and Charlottesville area and gave away IBMs instead," said Giant spokesman Barry Scher. Apple recently sent a letter to area school administrators, giving the Giant program its imprimatur.

"Giant Food," read the letter in part, "is the only supermarket tape saver program which is administered under the auspices of, and supported by Apple Computer Inc. in the Maryland, D.C. and Virginia area."

"We wanted to make sure participants knew the Giant program was part of an exclusive agreement with Apple and that this is the program we're behind and think it best," said Apple spokewoman Mary Fallon.

"Still, I guess all's fair in love, war and business."