A lateral move sprinkler and a drip irrigation system have been used since 1984 to conduct irrigation termination studies. Lint yields were significantly reduced when irrigations were terminated prior to first open boll. No statistical differences in yield were found among irrigations terminated at first open boll or later. These later termination dates delayed the date when 90% of final harvest weight was open by 5 to 8 days as compared to the last irrigation at first open boll, In the dry year of 1986, no significant losses due to boll rot were found.