In the early 1980's the initial use of mepiquat chloride focused on cotton that exhibited excesseively rank vegetative fields that were prone to boll rot. Mepiquat chloride is an excellent product in that it significantly improves the vegetative to reproductive ratio that facilitates mechanical harvest and earliness. Yield responses have been more erratic in promoting significant lint increases particularly in cotton not prone to rank growth. In recent years several new formulations have been tested that would consistently give adequate height controll, earliness and yield. The objective of this research was to evaluate several of these formulations across the cotton belt as to biological activity. Replicated plots under the supervision of professional crop consultants in Mississippi (3) and University trials in Virginia (1), Arkansas (1) and Texas (2) will be reported. Standard mepiquat chloride (MC) was compared to formulations containing (1)synthetic cytokinin, (2) cyclanilide, (3)pentaborate and (4) Bacillus cereus. Interactions between MC and synthetic cytokinins that promote cell division, MC and cyclanilide which is an auxin transport inhibitor, MC and pentaborate that promotes movements of sugars and MC and Bacillus cereus which reportedly increases the movement of carbohydrates to developing bolls will be investigated.