A new world record was set this month for the heaviest pumpkin ever grown. Taking first place at the Stillwater Harvest Fest in Minnesota -- and beating last year's record by 85 pounds -- this Sasquatch of squashes weighed in at just over 1,810 pounds.
To pumpkin enthusiasts like Chris Stevens of Wisconsin, a contractor who grew this record-breaker, the giant pumpkin is both a work of art and the product of an ever-evolving amateur science.
"There's a tremendous amount of tender loving care that goes into this," said Tim Beeman, who coordinated the 2010 Safeway World Championship Pumpkin Weigh-Off in California's Half Moon Bay. "These guys are like mad scientists."
These super-sized pumpkins have also attracted the attention of university scientists, who are helping growers to better understand how their pumpkins get so large and how to make them even larger.
Giant pumpkins on display in festivals across the country trace their ancestry back to Atlantic Giant pumpkin seeds first patented in 1979 by Howard Dill, who set the world record in 1980 with a 459-pounder.
Today, giant pumpkins regularly weigh more than a thousand pounds and are thought to thrive in a "golden zone" that stretches across southern Canada and the northern half of the United States.
Loading one of these monsters into a pickup truck for a trip to the local fair has become a delicate dance of straps, pulleys, and prayers. After the judging, the pumpkins typically find homes on front porches, in casinos or in kitchens that use them to feed underserved populations. Some are even carved into boats.
The increasing size of giant pumpkins over time is partially due to genetic changes brought on by selective culturing. For decades, pumpkin growers have steadily pushed these fruits by swapping seeds and using other traditional breeding techniques that have been around for thousands of years.
"These are just ordinary people doing this who don't understand genetics," said Jules Janick, a horticulturalist at Purdue University in West Lafayette, Ind. "It's the way that a lot of crops like corn were originally developed."
Growers cross the biggest, most desirable pumpkins -- which produce seeds the size of a peach pit that can fetch $850 each, according to Janick -- with each other and let nature improve them over several generations.
This selective breeding is called artificial selection, a term coined by Charles Darwin, and is similar to processes that occur in nature, except in this case the growers are selecting the "fittest" individuals -- the larger pumpkins -- to breed in order to pass on the more desirable genes to help create even larger pumpkins.
"It's very similar to horse racing, where breeders cross the fastest horses. You can see the effect of this breeding if you look at the records," Janick said.
Giant pumpkins grow about a hundred times faster than a typical pumpkin. They can gain an average of 20-40 pounds in a single day, and as much as 60 pounds a day under the right conditions.
For engineer David Hu, an assistant professor at the Georgia Institute of Technology in Atlanta who studies how the shells of plants and animals get their shape and size, these fruits are a biological puzzle. Small pumpkins are roughly spherical. But giant pumpkins tend to be irregular, lopsided, and as much as twice as long as they are tall.