In August last year, while weeding a patch of garden behind their home in New Zealand, Colin and Donna Craig-Brown struck gold, or what seemed like the world’s largest potato.
“I had a big hoe in my hand, and it went, ‘clonk,’” said Mr. Craig-Brown, speaking by phone on Thursday from his farm near Hamilton, where a cow could be heard in the background. “I said to my wife, ‘What the hell’s that?’”
Then, he said: “I got a great big four-pronged garden fork and laid into it, like an over-excited Viking warrior. I thrust my foot deep into the earth, dragged this thing out, kicking and screaming. It was the size of a rubbish bin lid.”
They called it Doug.
Doug, spelled Dug in some news reports, was as bronze and as burly as any Thanksgiving turkey and weighed 17.4 pounds. It came seemingly out of nowhere, and to Mr. and Ms. Craig-Brown, it looked, tasted and felt very much like a big potato. (They cut off and ate a small piece of it — raw.)
The discovery made its way into the news media, and with subsequent weigh-ins, excitement grew. After friends and family suggested the protuberance might be a contender for the Guinness World Records, the couple submitted an application for “the world’s heaviest potato,” sat back and waited.
All over the world, people have grown, proudly displayed and sometimes won prizes for their giant pumpkins, potatoes and tomatoes. In February, a farmer in Israel was confirmed to have grown the world’s heaviest strawberry, according to Guinness: 289 grams (10.19 ounces). For some, it’s a hobby; for others, an obsession with the promise of a world record, fleeting fame and perhaps a few chuckles. For the Craig-Browns, it was an accident.
Mr. Craig-Brown, 62, is the son of a horticultural scientist. He and his wife, Donna, 60, ran a small farm. The couple had not previously grown potatoes, meaning Doug would have had to have been self-seeded. At 17.4 pounds, it was substantially larger than the world’s heaviest known potato, which weighed in at 11 pounds and was unearthed in 2010 by Peter Glazebrook, a seasoned grower of massive vegetables in Britain.
As the couple waited for word from Guinness, doubts began to creep in elsewhere. To some in the trade, the photos of Doug suggested that, while impressive, it wasn’t quite a potato.
Then, an email from Guinness landed in Mr. Craig-Brown’s inbox last week. A slice of the growth had been submitted for DNA testing, and the results confirmed the doubters’ suspicions: Doug was not a potato at all.
“Sadly the specimen is not a potato and is, in fact, the tuber of a type of gourd,” a spokesman for the organization wrote, adding, “For this reason we do unfortunately have to disqualify the application.”
To those without green thumbs, “tuber of a type of gourd” might be frustratingly oblique wording. A tuber can be any kind of swollen underground stem — including a potato. Gourds, which include pumpkins, marrows and cucumbers, are entirely unrelated plants.
So what is Doug really, where did it come from, and why did it show up in the garden near Hamilton, a city in New Zealand’s North Island? No clear answers have emerged.
Chris Claridge, a horticulturist and the chief executive of the industry group Potatoes New Zealand, which assisted in the DNA testing, described the growth as a kind of scar tissue on a wound, similar to the lumps sometimes seen on trees after a branch is removed.
“It could have had an infection, it could have had a disease, it could have just formed and grown as an accident of nature,” he said. “But it’s not even the same family as the potato.”
He added: “Put it this way: We’re good at growing potatoes in New Zealand, but we’re not that good.”
For Mr. Craig-Brown, the result was disappointing. It was also a puzzle that kept him awake at night.
“How could a bloody gourd get in my garden?” he recalled thinking.
And then, a possible breakthrough.
“There was a stage where I was growing these hybridized cucumbers, right where Doug appeared,” he said. “During a hybridization process, who’s to say they didn’t crossbreed it with a gourd plant to give it tremendous disease resistance or prolific flowering?”
In a statement, Adam Millward, managing editor of Guinness World Records, said, “This has been a fascinating journey of discovery, and we’re glad we’ve been able to get to the root — well, technically, tuber — of the matter.”
He also wished the Craig-Browns the best in their future horticultural endeavors.
As for Doug, Mr. Craig-Brown said: “He’s a pretty cool character, aye.”
“He’s pretty happy sitting there in the cryogenic storage facility that we’ve got here on the farm — the deep freezer. He’s not fazed at all.”
