Thanks for the feedback - I've updated my comment to express uncertainty.

As I understand it, a big part of the green revolution, especially initially, was Borlaug developing a strand of wheat that was resistant to many common diseases and had higher yields. This seems born out by a quick skim of his [wikipedia article](https://en.wikipedia.org/wiki/Norman_Borlaug), although I'm sure nitrogen fertilizer, etc, also played large roles.

I don't have the time to do a deep dive right now, so I've just updated my previous comment to be uncertain.