The experimental plant regulator XE-1019, a product of Chevron Chemical Company, was applied to 'Deltapine 50' cotton at the University of Arizona Marana Agricultural Center in 1985. Plant height was modified by the chemical due to greatly shortened internode length. The 1.0 lb. a.i. XE-1019 per acre rate applied before bloom yielded significantly less than the other treatments at final harvest. Data collected from eight harvests through the season from sub-plots resulted in significant yield differences form the second through the sixth harvest dates.