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US Cotton growers are adopting COTMAN, a COTton MANagement system developed at the University of Arkansas. Currently, research-based recommendations are available for safe termination of insecticides and the application of defoliants based on physiological cutout, or NAWF=5. An area of crop production that may benefit from COTMAN is the decision of when to stop irrigating the cotton crop. The objective of this research was to investigate a crop-based recommendation for timing the final irrigation on cotton. Three furrow-irrigated large-plot irrigation studies were conducted in north Arkansas during the 2000 growing season to investigate the response to late-season irrigation. Irrigation treatments consisted of five different irrigation termination times at each site, with the first termination treatment targeted for approximately NAWF=5. Two of the three studies showed significant differences in cotton yield with later irrigation. In the case where yield differences were not significant, early-season stress may have affected the response. All three studies showed significant earliness effects, with a lower percent first harvest associated with later irrigation. The marginal economic returns from later irrigations were significantly affected in one study, with the latest irrigations not covering the costs of application.