This pumpkin could make a Halloween 'lamp' for an elephant. On Monday, Thad Starr's 686 kg (1,524-pound) Atlantic Giant pumpkin broke all previous Half Moon Bay records at the city's annual World Championship Pumpkin Weigh-Off, bringing him the prize of $9,144.

Surprisingly, the pumpkin grower from Pleasant Hill, Oregon, obtained the 'giant' from the seeds of a 227-pound (102 kg) 'mother' pumpkin, dwarf by the standards of Atlantic Giant pumpkin.

Starr, 40, has been growing giants for only two years, and won over the previous champion Joel Holland of Puyallup, Washington, who followed him with an Atlantic Giant of 623 kg (1,384 pounds), out of 70 competitors. Holland has been the winner of the Half Moon Bay contest for the past three years.

The Half Moon Bay competition brings cultivators from Washington, Oregon and Northern California. Warmer climates with little rain and fertile soil in northwestern US are the ideal conditions for obtaining giant pumpkins. Starr says the has used a souped-up organic compost, adding to it fish fertilizer, seaweed, nitrogen, potassium and phosphate to "pump steroids" into his pumpkin. And, of course, "yards and yards" of chicken manure. Weather, patience and a little bit of luck contributed to it, too.

But he insisted that, in the end, the seed is the main factor. All Atlantic Giant pumpkin seeds, the world's largest variety of pumpkin, descend from the original Atlantic Giant, cultivated by Nova Scotia farmer Howard Dill two decades ago. But Dill's giants did not overweigh 135 kg (300 pounds). But as the hobby spread, the increasing number of cultivators started to cross-pollinate pumpkins, selecting the resulting seeds for increasingly larger future plantings.

The seeds were traded across US and overseas, and the process repeated till the achievement of the new Atlantic Giant, pale yellow, bulbous and colossal. Starr chose his seed because it came from two well-grown pumpkin lines, not because of the size of its progenitor. The record-holder of the largest pumpkin is Joe Jutras of Rhode Island, with a 760 kg (1,689-pound) pumpkin presented at the Topsfield Fair in Massachusetts on September 29.