ATLANTA — A battle has commenced over the iconic Vidalia onion.

First came the whispers that reverberated from southeast Georgia farms to kitchens across the nation and to halls of power in Atlanta: Vidalia onions aren’t as sweet as they used to be. And they look odd. And go bad quickly.

Georgia Agriculture Commissioner Gary Black heard the talk and decided to act. Now lines have been drawn in the low-sulfur sand that makes a Vidalia a Vidalia. Growers have lined up against growers. And growers have lined up against Black.

Black said that for several years onions harvested too early have resulted in inferior Vidalias with shorter shelf lives.

So the commissioner has imposed an April date before which no onion may be packed, giving the crop 10 to 15 additional days in ground.

While there is broad agreement in the industry that the Vidalia’s quality has been off, not everyone is convinced Black has found the right solution.

Some farmers argue weather conditions and other factors determine when an onion crop is ready to harvest, and that growers are in the best position to make that decision. One prominent Vidalia farmer has hired former Attorney General Mike Bowers to fight the move in court.

It’s no minor issue. Vidalias are Georgia’s most valuable vegetable crop, with an estimated $150 million annual impact on the state economy.

The Vidalia is a keystone of Georgia’s agricultural background. The famed bulbous vegetable is protected by federal trademark and state law that created a 20-county region outside of which an onion is merely an onion. Inside those southeast Georgia counties, onions can grow up to be Vidalias.

For the past few seasons, Black said, there has been a lot of “noise in the marketplace. The onions are not what they used to be. The quality is not holding up.”

Before the rule change, which will take effect next year, a date was selected each year in early spring when farmers could ship onions to distributors and markets. Before that date, a farmer could have his onions inspected. If they met a top federal grade, the onions were good to go.

Delbert Bland doesn’t need anyone to tell him there’s a problem with Vidalias. He’s grown them in Tattnall County, Ga., for 30 years.

“I am 100 percent in favor of doing anything possible to improve the appearance, as well as the quality of the Vidalia onions,” Bland said. “That’s my livelihood. It’s all I’ve ever done.”

Black’s solution, however, “is totally unacceptable. You can’t dictate or set an arbitrary date a year away when Vidalia onions will be mature and ready to ship.”