Geoff Frohloff has grown a 196-kilogram pumpkin to win the Royal Queensland Show's Giant Pumpkin Competition.

Frohloff's almost 200-kilogram giant gourd saw him claim the coveted Champion Heaviest Pumpkin of Show title, according to Queensland Country Life.

"I used a lot of fertilizer and mulch, plus during the hot weather, I watered them every day - some days they received 1,000 liters of water," Frohloff was quoted as saying.

The veteran grower, who still holds the 261.5-kilogram Ekka record set in 2015, was almost beat by an eight-year-old youth entrant from Bowenville with his record-setting 171-kilogram youth entry pumpkin.

The eight-year-old said he only expected his pumpkin to grow to supermarket size. "I watered it, put fertilizer on it and I sang to it," he was reported as saying.

Second and third place in the Open class was given to pumpkins weighing in at 174-kilograms and 171.5-kilograms, respectively.