CHAMPAIGN, Ill. — As Midwest farmers finish harvesting corn in the worst drought conditions since the 1930s, early indications are the latest drought-resistant seeds helped growers salvage some measure of a decent crop.

“Drought can wreak a lot of havoc on crops, even today, but there’s no question growers did better this year than they did in 1988, and that’s because of advancements in seed development and better technology,” said Emerson Nafziger, a crop science professor at the University of Illinois at Urbana-Champaign.

Based on his early projections, Illinois corn growers likely will lose about one-third of their total corn crop, Nafziger said. In 1988, growers lost nearly half of their corn.

Overall, the USDA is projecting the nation’s corn harvest this year will be down by about 13 percent, despite farmers planting 4 percent more acres of corn. Yields are expected to come in at about 120 bushels per acre; last year the average exceeded 154.

The top three volume seed companies, Monsanto Co., DuPont Co.’s Pioneer and Syngenta AG, each touted new drought-resistant seeds going into this year’s growing season. Officials with each company said recently that each performed reasonably well and gave growers a better shot at greater yields.

One of the most recent independent studies that looked at drought-resistant hybrids, completed in 2010 by researchers at Iowa State University, concluded that seeds bred to be hardier, along with better farming techniques, have added 1 percent to corn yields each year for the past three decades.

And a 1 percent increase each year has had “a huge economic impact,” said David Lightfoot, a genetic researcher at Southern Illinois University Carbondale.

“It’s the crop that’s grown in some of the driest areas of the Midwest, and it’s the one where progress is going to have the biggest payoff,” Lightfoot said. Without advances in seed development, he said, this year’s harvest undoubtedly would have been much worse.

Syngenta has had a drought-tolerant corn called Agrisure Artesian that has been in limited use during the past two years, and the company claims it can increase yields by as much as 15 percent compared to other hybrids, said Wayne Fithian, a Syngenta product manager.

Pioneer’s latest drought-resistant product is called AQUAmax, and this year the seed is expected to produce yields that are 8 percent higher than other hybrids, a company spokesman told The Associated Press.

Monsanto tested this year its first seed that was genetically engineered for drought tolerance, called DroughtGard, and the company said early projections are that it produced about five bushels more per acre than other hybrids.