The man who fed the world
In 1970 the American scientist, Norman Borlaug, was awarded the Nobel Peace Prize for his pioneering work developing disease-resistant crops.
His discoveries are credited with saving millions of people from starvation.
But some critics say the new grain varieties were too reliant on chemical fertilisers.
Professor Ronnie Coffman, student and friend of Norman Borlaug, spoke to Witness History.
Witness History: The stories of our times told by the people who were there.