Abstract Nitrogen and mepiquat chloride are two key products that farmers utilize in producing high yielding cotton. Previously completed research has shown that nitrogen is the most critical nutrient for successful high yield cotton production. However, providing an abundant nitrogen source can cause potential rank growth problems as well as prolong maturity. Multiple applications of mepiquat chloride may be necessary in order to control this rank growth, therefore requiring a higher input cost. With efficient application timing of mepiquat chloride and nitrogen, cotton can help produce high yields and be profitable for the producer. The objectives were; what is the maximum amount of nitrogen that can be applied to produce high yields and still be profitable with inputs of both nitrogen and plant growth regulators. The field experiment was conducted in 2005 at the Upper Coastal Plain Research Station in Rocky Mount, NC and also, at the Tidewater Agricultural Research and Extension center in Suffolk, VA. These two locations represent a diverse range in soil types ranging from sandy loam to silt loam and represent most areas that produce cotton in North Carolina and Virginia. Cotton variety “Stoneville 5599BG/RR” was planted on 38 inch bedded rows using a John Deere 4 row max-emerge planter at a seed rate of 9.84 seeds per meter row on May 5, 2005. Treatments were arranged in a randomized complete block design and replicated four times. Treatments consisted of three side dressed applications of nitrogen at 49.94, 99.88, and 149.68 kg/ha along with an untreated check 0 kg/ha. Both locations received a nitrogen starter fertilizer application at planting along with an application at first square to achieve desired rates. Mepiquat chloride was applied at 16, and 32 oz/A along with no application of mepiquat chloride per nitrogen rate applied. The data that was collected from this test includes: heights and nodes at first PGR application and then subsequent bi-weekly collection after that. Nodes above white flower (NAWF) were collected on July, 7 and August 15. Percent defoliation and desiccation was collected at 7,14, and 21 days after initial defoliation (AID). Leaf and Petiole samples were collected to acquire data of nitrogen uptake per treatment in the plants were collected at cutout. Percent boll open and nodes above cracked boll were collected were at defoliation to determine regrowth and effects of higher nitrogen rates. Plots were harvested using a John Deere 9910 two row spindle picker and the harvested cotton will be sampled and weighed for yield. Cotton samples were ginned using a saw tooth gin and the lint samples were weighed for percent lint and analyzed with High Volume Instrumentation (HVI) analysis.