Preliminary results are presented on the use of AFIS for rapid fiber quality testing of the effects of premature application of the harvest-aid chemical ethipon (PREP(TM)) . Two cottons, Deltapine-50 and MD-51ne, were treated with PREP(TM) at times significantly earlier than recommended. Fibers harvested from the lower, middle, and top plant zones from both check and treated crops were ginned and tested on conventional laboratory instruments and AFIS. Results with AFIS for fineness, maturity and length agreed well with conventional tests. When PREP(TM) was prematurely applied there was a significant decrease in fiber wall development for the top portion of the plant with a corresponding increase in neps (as measured with the AFIS Neps Module). There was, however, no significant reduction in fiber length or strength in the top zones of the plants tested with premature PREP(TM) application.