The objectives of this three-year (2004-2006) project were to document the effects of several plant growth regulators (PGRs) on cotton growth and development, crop maturity, lint yield and fiber quality in the Texas High Plains. The trials were conducted at two locations in 2004 and 2005, Muleshoe, TX and Lubbock, TX. A large plot trial was conducted in 2006 at Muleshoe, TX. The Muleshoe site was conducted in a commercial sprinkler irrigated cotton field in all years and the Lubbock site was located in a commercial subsurface drip irrigated field in 2004 and a LEPA irrigated field in 2005. The experimental design was a randomized complete block with four replications of treatments. The small plot trials had a plot size of 4 rows wide by 50 feet long and the large plot trial had a plot size of 6 rows wide by 1300 feet long. PGR applications were made with a self-propelled sprayer at all sites except the Muleshoe 2004 location at which a CO2 pressured back pack sprayer was utilized. Sprayers were calibrated to deliver 15 gallons total volume per acre. Plant mapping data were collected. The small plots were hand harvested and the large plots were stripper harvested, samples were taken from each plot to obtain percent lint turnout and fiber quality. Samples were ginned at the Texas A&M University Agricultural Research and Extension Center at Lubbock. Lint samples were submitted to the Texas Tech University International Textile Center at Lubbock for high volume instrument (HVI) analyses.