From a hillock in the San Joaquin Valley, Berne Evans III recently surveyed a citrus grove that stretches as far as the eye can see. "It's the largest clementine planting in the world," he said, smiling.

The groves make Mr. Evans the king of the Cuties, a brand of seedless, sweet and easy-to-peel mandarin that is storming the nation's fruit aisles and changing eating habits that span generations. The navel orange, after reigning supreme for decades, has a challenger.

The rise of Cuties heralds the arrival of big-money marketing in a tradition-steeped corner of American industry. Techniques once reserved for promoting consumer products have now made their way into the produce section. Just as people have long asked for a "Kleenex" instead of a tissue, they are starting to ask for "Cuties" when they mean mandarins.

"I can't think of any other produce that has done this," says John Ball of San Diego branding firm MiresBall. It's "a name that is the thing."

Cuties reflect a defining reality of the American consumer experience: Convenience sells. It's a simple idea, applied in an unexpected place in the case of Cuties. Few people may have looked at the traditional orange and considered it a candidate for the classic American "new and improved" treatment.