Three methods for conducting purity analysis of Kentucky bluegrass seed were compared. They were: (1) hand method-preliminary separation made with a blower and the final differentiation of questionable florets by hand, (2) standard method-separation with a blower using the same pure seed criteria as for the hand method and (3) climax method-separation with a blower at a level which gives the maximum pure live seed percentage.

Three blowers (the Ottawa, Erickson and Ames) were included in the study. Four laboratories cooperated in the investigation. Variations within laboratories were compared; variations between laboratories were not considered.