Weeds do become resistant to herbicides, and it needs to be managed with multiple herbicides.

As people around the world become more affluent, they are demanding diets richer in animal protein, which will require ever more robust feed crop yields to sustain.

We have domesticated crops over a very long period of time, like tens of thousands of years. And crops get - seeds get carried. Sometimes, if they're very small seeds, they get scattered off trucks. Pollen travels.

We need to continue to decrease the growth rate of the global population; the planet can't support many more people.

Even as the population doubled from three to six billion, we managed to race ahead with all kinds of technological and scientific events in agriculture - from using more fertilizers to mechanization to advanced plant breeding.

If everybody switched to organic farming, we couldn't support the earth's current population - maybe half.

New molecular methods that add or modify genes can protect plants from diseases and pests and improve crops in ways that are both more environmentally benign and beyond the capability of older methods.