What is St. main crop?

Please provide more context! "St." is too short to determine what you're referring to.

For example:

* Do you mean a specific place? (e.g., "St. Louis", "St. Augustine")

* Do you mean a specific saint? (e.g., "St. Patrick", "St. Michael")

* Are you referring to a specific type of crop? (e.g., "St. John's Wort" is a type of plant)

Once you provide more information, I can help you determine the main crop.