Timing of irrigation in cotton is critical to maintain optimal yields. Traditional methods of monitoring crop status for scheduling supplemental irrigation are time consuming and error prone. Remote sensing offers the potential for rapid, accurate determination of crop status over wide areas. We assessed physiological and reflectance changes in cotton with water stress, with an end to developing correlations between physiological indicators of water stress and plant reflectance that can be monitored remotely. The results presented here describe differences in leaf and canopy reflectance and photosynthetic pigment content of leaves for two production systems, conventional and conservation tillage, with and without irrigation. Stress responses typically are reflected in altered carotenoid content, particularly of xanthophylls cycle intermediates. Relationships between pigment content and reflectance data should yield similar patterns.