SAN DIEGO (Reuters) - Biotechnology in agricultural will be key to feeding a growing world population and overcoming climate challenges like crop-killing droughts, according to a group of leading industry players.

"It is critical we keep moving forward," said Thomas West, a director of biotechnology affairs at DuPont, interviewed on the sidelines of a biotechnology conference in San Diego. "We have to yield and produce our way out of this."

DuPont believes it can increase corn and soybean yields by 40 percent over the next decade. Corn seeds that now average about 150 bushels per acre could be at well over 200 bushels an acre, for example, DuPont officials said.

Crop shortages this year have sparked riots in some countries and steep price hikes in markets around the globe, and questions about how to address those issues were the subject of several meetings at the BIO International Convention being held this week.

Despite persistent reluctance in many nations and from some consumer and environmental groups, genetically modified crops, -- and the fortunes of the companies that make them -- have been on the rise. Growing food and biofuel demands have been helping push growth.

By using conventional and biotech genetic modification, crops can be made to yield more in optimum as well as harsh weather conditions, can be made healthier, and can be developed in ways that create more energy for use in ethanol production, according to the biotech proponents.

"You can bring a number to tools to bear with biotechnology to solve problems," said Syngenta seeds executive industry relations head director Jack Bernens. "As food prices increase ... it certainly brings a more practical perspective to the debate."

Syngenta is focusing on drought-resistant corn that it hopes to bring to market as early as 2014, as well as other traits to increase yields and protect plants from insect damage. Disease-resistant biotech wheat is also being developed.

Syngenta and other industry players are also developing biotech crops that need less fertilizer, and corn that more efficiently can be turned into ethanol.

Bayer CropScience, a unit of Germany's Bayer AG, has ongoing field trials with biotech canola that performs well even in drought conditions, said Bayer crop productivity group leader Michael Metzlaff.

Water scarcity is a problem seen doubling in severity over the next three decades even as the world population explodes, and will only be exacerbated by global warming climate change, he said.

With some 9 billion people expected to populate the planet by 2040 and 85 percent of the population seen in lesser developed countries, decreased land for agriculture and multiple demands on water use will come hand in hand with an expected doubling in food demand, said David Dennis CEO of Kingston, Ontario-based Performance Plants.

Performance Plants is working with the Africa Harvest Biotech Foundation International to develop and field test drought-tolerant white maize.

"The biggest problem we have in crops is environmental stresses and the biggest stress is drought," said Dennis.

Biotech crop opponents rebuke the idea that biotechnology is the answer, and say industry leaders continue to focus much of their efforts on plants that tolerate more chemicals even as they push up seed prices and make more farmers reliant on patented seed products that must be repurchased year after year.

"I know they love to talk about drought tolerance but that is not what they are really focusing on," said Bill Freese, science policy analyst at the Washington-based Center for Food Safety.

Freese said conventional breeding had the ability to address climate change and food needs, but funding cuts to public-sector crop breeders had reduced the ability of non-biotech groups to advance crop improvements.

"The facts on the ground clearly show that biotech companies have developed mainly chemical-dependent GM crops that have increased pesticide use, reduced yields and have nothing to do with feeding the world," Freese said. "The world cannot wait for GM crops when so many existing solutions are being neglected."