From the Producer (Account) screen, scroll down to the Crops sub-panel and expand the area.  

Next, click on the Create button (not the drop-down arrow).  This opens a data entry form to populate a Crop for a certain fiscal year.  If you hover over the form fields with the mouse, there are descriptions of each attribute.  

The Offer(s) represent the Quantity of crop that the Producer is willing to set at a certain price.  Continue clicking the + button to add multiple offers or the - button to remove the offers.

A separate Crop record must be created for each commodity (corn, soybeans, etc.) for each crop fiscal year.

When the Crop record is saved, there are some attributes that are automatically calculated: Crop Name, Total Production, and Quantity Unpriced.  

Once a set of Crops is created for each year, the Crops can be edited or removed.