Knot-relieving twine tensioner for baler

A twine tensioner includes upper and lower ribbed rollers biased together so as to engage a length of twine passing between them so as to cause a predetermined tension to be required for advancing the length of twine through the rollers. The upper roller is mounted for movement relative to the lower roller and is guided such that, as it moves away from the lower roller, the twine tension first increases and then does not undergo any appreciable increase or spike as a knot in the length of twine passes through the nip of the rollers. The tensioner is constructed such that the upper roller may be easily manually moved away from the lower roller so as to permit twine to be threaded through the tensioner without requiring any additional tool.