A round bale baling apparatus includes an accumulator for rolling crop material into a round bale, a twine dispenser adapted to hold and dispense twine, and a twine tensioner. The twine tensioner is adjustable and includes an energizable actuator and switch for operating the actuator to adjust the twine tension. Specifically, the switch can be manipulated to selectively decrease tension on the twine during initial gripping of the free end of the twine by a rolling loose bale, and to selectively increase tension on the twine once the twine is sufficiently wrapped onto the bale to provide a secure pulling force. The actuator can be electric, such as a reversible DC motor or solenoid, or can be another energizable device actuable from a remote position. Methods related to the above are also defined.