1. A method of generating crop biometric information in field conditions, said method comprising: scanning top surfaces of various plant crown structures of a plurality of plants in one or more rows of plants within a field to collect scan data of the crown structures; converting the scan data into a high spatial resolution 3-dimensional field contour map; and extracting, from the high spatial resolution 3-dimensional field contour map, biometric information relating to the plants in each of one or more selected rows of the scanned rows of plants.