Undated (AP) _ Alabama's agriculture commissioner held a news conference to slurp watermelon with his wife. Philadelphia greengrocers reported watermelon sales were way down. Signs have been posted in stores around the country to reassure customers the fruit is safe to eat.

As officials track down pesticide-contaminated watermelons from California believed responsible for nearly 300 illnesses in five states, consumers in many other areas are shying away from the traditional summertime fare, no matter where it's grown.

''We're now getting our first good, hot weather, but my sales were off by about half today,'' John Waleski, a Philadelphia produce company manager, said late Tuesday. ''The customers are being very cautious about what they buy.''

The concern follows reports that some California-grown watermelons were contaminated with aldicarb, a pesticide that can cause nausea, diarrhea and tremors. Illnesses related to the tainted fruit have been reported in California, Oregon, Alaska, Washington and Idaho.

California has ordered disposal of about 1 million watermelons worth an estimated $1.5 million that are already in stores or at wholesalers. State officials declined to estimate the cost of inspecting the state's $25 million watermelon crop to certify uncontaminated fields.

While distribution of contaminated watermelons was limited to a few states, produce companies and grocers elsewhere reported slower sales and customer concern.

''I think anytime there is a story like that sales are affected,'' said Sue Anne Ritchko, a vice president with Golub Corp., which operates Price Chopper Food Stores in New York, Massachusetts, Vermont and Pennsylvania.

Gene Anderson, produce manager for a Kansas City Safeway store, said his sales have been hurt.

''Some people bring them back because they're afraid of them,'' he said.

''Watermelon sales have dropped off drastically. We don't sell California melons. We sell Texas melons, but the attitude people are taking is just not to buy them,'' said Ray England, produce buyer for the Cullum Companies Inc., owner of the Tom Thumb chain in Dallas.

Grocers have tried to head off a watermelon scare by telling customers their melons are not from California. Giant Food, a large supermarket chain in the Washington, D.C., area, posted signs ''indicating we only carry East Coast watermelons,'' said company spokeswoman Sue Challis.

Wayne Szabla, owner of the Watermelon Depot, Chicago's largest watermelon distributor, said ads that stress his melons come from Florida and Georgia have helped salvage his business.

''Right now the temperature's 90 degrees. Sales are great,'' he said.

Concern in other melon-producing states has led to extraordinary steps. On Tuesday, Alabama Agriculture Commissioner Albert McDonald called a news conference where he and his wife Shirley ate watermelon before reporters.

''I wanted to show consumers they could have confidence in Alabama-grown watermelons,'' McDonald said.

In Cordele, a south-central Georgia community that bills itself ''Watermelon Capital of the World,'' farmers were shipping 9 million pounds of watermelon a day to points in the East and Midwest. The crop puts an estimated $12 million into the local economy.

But Don Sims, head of the local Chamber of Commerce, said there are fears the California problem could hurt the entire industry.

''We're nervous about people's attitude toward watermelons, that this thing could develop into a general consumer distaste for watermelon,'' he said.

But some consumers, even those in California, remain faithful to their hot weather treat.

''I'm very upset - I just love watermelon,'' said Alene Zweig after she found it missing at her Marina Del Rey grocery store. Ms. Zweig said she was no more worried about buying watermelon than other foods.

''I'm concerned about everything I'm eating,'' she said. ''It seems like they're screwing everything up.''