An unusually cool spring has delayed two of Georgia's sweetest farm crops: Vidalia onions and watermelons.

Officially, the 2005 Vidalia onion marketing season started the first of this month. This is the first year for a regulated opening selling day for the state's official vegetable.

Vidalia onion farmers usually begin selling their crop around April 20. But the growth of this year's crop is about two weeks behind normal, said Reid Torrance, coordinator for the University of Georgia Extension Service office in Tattnall County.

About 75 percent of Georgia's Vidalia onion crop is grown in Tattnall and Toombs counties in east Georgia.

"The fluctuating weather and cold snaps this spring have slowed the maturity of the crop," Torrance said.

The average daily temperature for Vidalia, Ga., has been 61 degrees since April 1, about 4 degrees below the average for the same time last year. The soil temperature 2 inches deep has been 65 degrees, about 4 degrees below last year's average, according to data collected by the Georgia Automated Environmental Monitoring Network.

Despite some extreme weather, the onions out in the fields now look good, Torrance said. Heavy rain since March has made the early onions taste milder. Farmers will probably harvest around 18,000 pounds per acre, "which is a good yield," he said.

Farmers planted 13,000 acres this year. But one farmer in Tattnall County lost about 1,000 acres to hail in March. They planted 16,000 acres last year and harvested 26,000 pounds per acre in a record-setting crop, Torrance said.

Two new diseases were discovered on Vidalia onion plants in the fall of 2003. Iris yellow spot virus has hurt onions in South America and the Pacific Northwest. Tomato spotted wilt virus has hurt other Georgia crops such as tobacco, peanuts and some vegetables.

The onions appear to have more of both viruses this year, he said. And signs of the viruses' effect on plant foliage have continued into March and April, later than last year. The viruses may have caused some plants not to develop well early, making them more susceptible to harsh weather.

"But so far, we're not seeing any dramatic effect on the crop from these two diseases," Torrance said.

Watermelons around Cordele, Ga., where Georgia's annual watermelon festival takes place, "aren't looking too sporty," said Ken Lewis, UGA Extension Service coordinator in Crisp County.

Farmers began planting melons in mid-March, mostly in south-central Georgia. Several severe storms since then have brought 40-plus mile-per-hour winds to the area and left young vines sandblasted and twisted, he said.

The vines should be about 3 feet long by now. But cool spring temperatures have stunted their growth to only one foot in most fields. Crisp County's average daily high temperature since mid-March has been 72 degrees, about 5 degrees below the historic average, according to the GAEMN.

Hail has beaten down vines in some fields. "Overall, the crop is off to a rocky start," Lewis said.

Farmers planted 4,000 acres of watermelons, mostly seedless, in the Crisp County area, he said. No official acreage number has been released for watermelons this year. Georgia farmers usually grow about 35,000 acres each year.

Once the weather consistently warms up, he said, the watermelon vines should recover. But the harvest will probably be pushed back this year. Georgia farmers target the Fourth of July holiday market, with peak harvest usually starting in mid-June.

The cool wet spring has stunted Georgia's corn crop, too. The state's farmers have started planting cotton now and will begin a flurry of peanut planting in the coming weeks.