Heat stress during the summer production period can severely reduce cotton lint yields in the low desert, evidenced by flower abscission and resulting lowered retention percentages. During 2005 and 2006 a number of growth enhancement chemistries (Chaperone, AuxiGro, HappyGro, BM86, ReTain, Stance, Foligro Aminofol Maximize) were applied to several low desert cotton varieties in commercial fields experiencing heat stress. Data were collected on plant growth aspects (height, retention percentages, chlorophyll content). Application of HappyGro resulted in highest numbers of calculated fruiting structures per plant in both DPL449BR and DPL555BR at approximately 25 days after application in 2005, followed by AuxiGro. Lint yields and quality data were collected for 2005. Data indicate that differences in sensitivity to certain plant growth enhancement chemistries exist between varieties, with DPL555BR responding much differently than DPL449BR to ReTain. Increased retention percentages sometimes resulted in reduced yields when only a single application of plant growth enhancement chemistries were involved, especially when later planted fields were involved. Addition of phosphorus fertilizer to plant growth enhancement chemistries increased lint quality. Highest yields, quality and greatest net increased value per acre were noted when a plant growth enhancement chemistry (BM86) was applied in combination with mepiquat chloride.