According to the prize citation, 17 million farmers worldwide grew these 'GMO' crops in 2012, more than 90 percent of them small-scale farmers in developing countries. It says the technology increased yields, reduced harmful pesticide use, and will be a key tool to feed the 9 billion people expected on Earth by 2050.

　　But critics of the technology question the role of genetically modified organisms in fighting world hunger.

　　When Mary Dell Chilton started her scientific career in the 1970s, she believed that a microscopic bacterium and a stalk of corn were much too different to be able to exchange genetic code.

　　“And I was soon to find out that this very deep-seated belief was just wrong," said Chilton.

　　She found that out studying a common plant infection called crown gall. Building on work by Belgian scientist Marc Van Montagu, she discovered that these ugly lumps form when a germ called Agrobacterium inserts a piece of its own DNA into the plant cell’s genes. The plant then makes food for the bacteria.

　　“I was very surprised. I was blown away....Agrobacterium was really being a genetic engineer," she said.

　　Chilton and Van Montagu, and Rob Fraley with the agribusiness company Monsanto, quickly realized that scientists could put these tiny genetic engineers to work making plant breeding more flexible and precise than ever.

　　Every plant’s DNA is like hundreds of books’ worth of information: genes for productivity... flavor... heat tolerance... even harmful or toxic traits.

　　Conventional breeding produces offspring with a random assortment of those books - good and bad.

　　But genetic engineering can insert just a page's worth of information - say, instructions for a protein that kills insect pests but is safe for people.

　　“That means that you don’t have to put insecticides on those corn plants to protect them and enhance the yield that you get. That’s a good thing," said Chilton

　　Nearly all the corn and cotton grown in the U.S. contain this type of gene, reducing insecticide use by at least 50 million kilograms per year.

　　Critics, however, note that another modification - adding genes for herbicide resistance - has increased the use of weed killers.

　　Chilton is now with seed and chemical company Syngenta. Not everyone believes she, Van Montagu and Fraley deserve the World Food Prize.

　　“I was rather shocked, actually," said Hans Herren, 1995 World Food Prize winner.

　　Hans Herren won the prize in 1995 for using natural methods to control a devastating insect pest outbreak in Africa. He says genetically modified organisms are not the best way to fight hunger.

　　“Because I think the cause of the food shortages in some places have nothing to do or can’t be fixed with GMOs," he said.

　　Herren sees GMOs as just the latest version of the water-, fertilizer- and pesticide-intensive form of agriculture that he says is a dead end.

　　“We need to change the paradigm because we are running out of fertilizer. Fertilizer production produces a lot of CO2. Water is limited, and will be even more limited in the future. So, again, we have to find better solutions," he said.

　　And Herren says more research is needed on the health, environmental and social impacts of GMO crops that are rapidly spreading around the world.

　　Opposition to them is also spreading rapidly. In the Philippines, protesters have uprooted test fields of rice modified to produce vitamin A.

　　But, Mary Dell Chilton is confident GMO technology will help feed the world.

　　"We need it. There are too many people in this world and we need to feed them in order to keep them from fighting with each other," she said.

　　Meanwhile, the fight over the technology is sure to continue.