The recently registered cotton plant growth regulator, REIGN, was evaluated in Georgia on 50 acres of large-scale commercial plots under an EUP in 2005. REIGN is a premix of cyclanilide and mepiquat chloride. Comparisons were made with commercial standard treatments that included mepiquat chloride, Mepex Gin-Out and Pentia. Whole-plant evaluations were made of internode lengths at the completion of the application season. This allowed a comparison of both the intensity and longevity of growth inhibition by each treatment. Seven locations with varying soil, weather and fertility conditions are compared. Samples were made from randomly selected groups of plants in uniform portions of each field plot. At two locations yields were taken. The internode shortening impact of REIGN was equal or superior to commercial standard treatments in all cases when used at 3 oz/A applied at the same timings as commercial pgr treatments. When an initial appliication of REIGN was made at 2 oz/A and increased to 3 oz/A for subsequent applications, the REIGN treatments were less effective than the commercial standard Pentia treatment.