REPUBLIC, Mo. — Usually on the first Saturday in October, the downtown portion of Main Street in Republic is lined with giant pumpkins and watermelons; dozens of them, with weights for the pumpkins sometimes exceeding 1,000 pounds.

It’s part of the annual “Pumpkin Daze” event, the town’s largest yearly festival – but not this year. The event was Oct. 1 as planned, and the crowds showed up, but due to summer conditions which caused most of southern Missouri’s pumpkin crop to fail, there were few pumpkins on display. Those there were small, and even the “giant” pumpkins did not get over 100 pounds – with one exception.

Richard Bottorf, who was also the grower of Missouri’s largest pumpkin in 2010, came to this year’s weigh-off with one pumpkin weighing 511 pounds and another, 676 pounds. The latter won him the $600 first-place award, much to Bottorf’s surprise, as he expected other growers to bring a few 700- or 800-pounders. Instead, his largest pumpkin turned out six times larger than any other present.

“HOW?” was the question everyone asked. After the weigh-off, about a dozen farmers, gardeners and interested community members went to the nearby Historical Society meeting room to find that out.

Unlike some giant-produce competitors, Bottorf is not secretive about his methods. Some, he says, are new or little-known, such as the use of Styrofoam supports.

“I never seen such a cold May as we had (this year),” he said. “I put out plants the 10th of May.” The wet spring, followed by a long drought and record summer heat, combined to make the worst possible conditions for cucurbit vegetable crops.

Most pumpkin and squash growers had a crop failure. Bottorf said he shaded the plants with tarps during the heat of the day, using a material developed for soldiers’ tents under the Afghan and Iraqi desert sun.

But more than any special tarp material, he credits his success to the use of Styrofoam props: Small rectangles of foam placed under the vines. This allows the adventitious root systems to develop, without creating the additional risk of rot sometimes encountered when growers bury the vine stems underground.

Bottorf uses a drip irrigation system, which helped him get through the summer drought, but would have made rotting more likely if he had buried the vines.

The key to getting a successful crop among pumpkins and squashes, Bottorf said, is largely found in planting time. Too-early or -late plantings both have negative consequences for pollination and fruiting. He said the optimum pollination time is usually of two weeks’ duration or less, and missing this window can seriously undercut harvest potential.

Last year he had a pumpkin growing 30 pounds daily at one point, in wet weather during summer. If the planting had been only a week off, the result would have been far less impressive.

Seed source is also important, since even within a variety (such as Atlantic Giant pumpkins) there can be a great deal of variation. Bottorf obtains his pumpkin seeds from P & P Seed, based in Quebec.

In some cases, maintaining one’s own seed strain of a variety can be better than purchasing from a company, since the grower can select the best examples of each year’s crop and improve the strain. Dan Westfall, the Missouri contest’s melon prize winner this year and a former state pumpkin record-holder, does this and has been maintaining his own strains for years.