The chief scientist at PepsiCo, the largest U.S. food company, is challenging American agriculture to “dig in” and take greater steps to help provide nutritious, affordable food to a world population that will surpass 9 billion people by mid-century.

Dr. Mehmood Khan, who oversees PepsiCo’s sustainability program and leads the company’s R&D efforts, issued the challenge Thursday evening at the opening night dinner of USDA’s Agricultural Outlook Forum in Arlington, Va.

Making that basic challenge more complex, said Khan, are a subset of challenges that must be met, including climate change, recruiting new farmers and ag-related scientists to replace the aging populating now filling those roles, and finding a new way to deal with a new wave of consumers, which he described as “ethical eaters.”

“We are to blame” for the skepticism many people show toward biotech developments that have the potential to vastly increase crop yields, Khan said. ‘We lived in our ivory towers and sometimes talked down to people.”

“Trust me,” consumers were told, he said. Meanwhile, the story of technology in food was being told people who were not knowledgeable, who didn’t have the facts and “sometimes had a different agenda.”

Khan, an endocrinologist by training, specifically called on USDA to take a more active role in dealing with some of the most persistent problems facing agriculture, like citrus greening, which he noted had destroyed roughly half of Florida’s orange crop over the past decade. Yet Khan said he’s seen little progress in countering the disease over that 10-year period.

USDA, he said, should use its convening power to bring all parties involved together in a pre-competitive setting – growers, start-ups, academics and others, including PepsiCo, which owns Tropicana, the largest orange juice brand – to try to turn the corner on citrus greening.

“If this was a human epidemic we would convene everybody,” he said, “and yet we haven’t done that.”

Khan cited the Midwest Row Crop Collaborative as an example of what such a “convening” might look like. The initiative has brought together major companies including PepsiCo, Cargill, Monsanto, McDonald’s and Walmart with government representatives from Iowa, Illinois and Nebraska and environmental groups such as the Nature Conservancy and the World Wildlife Fund in an effort to improve soil and water quality in the Upper Mississippi basin.

Khan ended his address by praising USDA for figuring out how to codify and implement the work of Norman Borlaug, the American agronomist known as the Father of the Green Revolution whose work, he said, has saved an estimated billion lives, “more than any human being in the history of mankind.”

“Nobody has done this better than this agency,” he said, referring to USDA.