Crop yields increased dramatically in the 20th century. That increase has been powered by changes in the genetic potential of the crop and in the way in which it has been managed. Nevertheless, the challenge to feed a world population that is likely to rise to 8 billion is formidable, particularly since recent analyses suggest that the rate of increase in yields of several crops may have dropped over the last decade. This paper discusses some of the technologies that will be available in the 21st century to meet this challenge.