This invention comprises a device for measuring root pulling force (RPF) in a plant. The RPF device comprises a plant grasping mechanism, as well as a force measurement sensor. In certain embodiments, the device is automatic, so that the “hand of man” is not required to exert force on the plant while the root pulling force of the plant is being measured. Also disclosed is a root pulling force motion mechanism, which brings the RPF device into proximity of a plant to be measured. Further disclosed is a method for measuring root pulling force of a plant.