What was the most used crop?

It's impossible to say definitively which crop is the most used without more context. Do you mean:

* Most used globally? In that case, it's likely rice, as it's the staple food for a huge portion of the world's population.

* Most used in terms of total production? This would likely be corn, as it's used for various purposes like animal feed, ethanol production, and human consumption.

* Most used in a specific region or country? This would depend on the location and its agricultural practices.

To provide a more accurate answer, please specify what criteria you're using to define "most used".