The Collaborative International Dictionary of English v.0.48:
Detractive \De*tract"ive\, a. 1. Tending to detractor draw. [R.] [1913 Webster] 2. Tending to lower in estimation; depreciative. [1913 Webster]WordNet (r) 3.0 (2006):
detractive adj 1: causing to decrease in importance or value; "detractive influences on the volume of investment"