“People just like a sweet, little melon,” she said.

But in this part of Arkansas, where the soil is sandy and the summer hot enough at just the right time so the watermelons grow particularly sweet and big, that kind of change comes hard. Growing up here meant 40-pound watermelons, and even those were considered on the small side. You ate the first of them on the Fourth of July and spit your last seeds on Labor Day, when you were just about sick of watermelon anyway.

And for fun, you went and looked at the giant watermelons. They’ve been grown in Hope, like a sporting event, since the 1920s. The biggest compete for local honors and are still auctioned off at the annual watermelon festival here, held last weekend. The lesser ones supply the watermelon-eating and seed-spitting contests.

Hope dominates the international stage as well. The world’s biggest watermelon on record, all 268 pounds and 8 ounces of it, was produced here in 2005. The man who grew it is Lloyd Bright, 67. Six world champions have come from his fields.

“When I was growing up, the guys were always talking big melons,” said Mr. Bright, a retired biology teacher and school administrator who got into the big-melon game in 1973.

These giant watermelons, called Carolina Cross, grow so fast that a day or two after one shows up on the vine, it’s the size of a small loaf of bread. They’ll continue to put on three or four pounds a day. Mr. Bright sells a few of his biggest for $75 to $80, and he peddles the seeds online, sometimes getting $20 for a dozen from watermelons that topped 200 pounds.

“That’s just enough to pay for the gas and fertilizer,” he said.

Before he harvests the seeds, he cuts out the hearts and puts them in the refrigerator to eat. He says they’re delicious, though his monsters weren’t ripe when this reporter was standing in his fields late last month, hinting around for a taste. He won’t harvest the biggest ones until later in August and September.