The 1989 marketing order also established the Vidalia Onion Committee, which promotes the industry and handles research.
Tina Wheeler, Vidalia Onion Committee secretary, says the variety gets more popular every year.
"There always is a huge demand," Wheeler says.
The Vidalia, known as "the world's sweetest onion" and honored as Georgia's official state vegetable, has a light brown bulb and a white interior. It is rounded on the bottom and flat on the top or stem end.
Farmers plant Vidalias from September through February and harvest them from April to mid-June. There are 179 growers registered to produce Vidalia onions on 15,183 acres, Wheeler says.
One of them is Fletcher Jones, who lives in Vidalia and has been growing the onions since 1975.
Jones says producing Vidalias is a labor-intensive process, because they must be harvested, graded and clipped by hand. The onions bruise easily because they contain 85 percent water, he says.
The mellow Vidalia is easy on the stomach for people who can't eat regular onions without paying the price, Jones says.
"I'm 52, and it's the only onion I can eat," he says.
Vidalias are a good choice for salads and sandwiches in which regular onions would be too hot or overpowering.
A medium-sized Vidalia onion has 60 calories, is a good source of vitamin C and contains no fat, cholesterol or sodium.
The onions soon will appear in area supermarkets. Most growers will begin harvesting Vidalias around the middle of this month, Wheeler says.
According to Vidalia Onion Committee, 70 percent of the crop is distributed through grocery stores, and the rest is sold through roadside stands and mail-order businesses.
Jones produces only jumbo-size Vidalias - those three inches or greater in diameter. His business, Southern Fresh Farms, supplies the onions for club fund-raisers.
For the second year, Conomac Lions Club of Williamsport is offering Vidalia onions. Club secretary Barbara Sterling, a Williamsport resident, says Vidalia onions are a good fund-raiser because they sell themselves.
"Almost everybody just loves them," Sterling says.
Sterling says she and her husband, Lee Sterling Jr., both enjoy cooking with onions.
"We eat them with every meal," she says.
She prefers Vidalias because they store nicely without becoming strong. She removes the skin, quarters the onions and freezes them.
With careful storage the onions can keep for months, but they are best when they're fresh, Jones says.
"Nothing beats Mother Nature as she does it," Jones says.