Water is the most liming factor in cotton production, and numerous efforts have been made to improve crop drought tolerance. Glycine betaine was applied to field-grown cotton at two rates with and without adjuvants. Some plants received applications at first flower + one and two weeks, while others were treated at first flower + one,two, three, and four weeks. Treated plants had significantly higher midseason boll numbers, stomatal resistance rates, number of effective sympodia, and boll retention in the second fruiting position. No significant differences were observed between treatments in yield measurements at time of harvest. Trends suggested glycine betaine has the potential to increase yield in cotton subjected to mild water-deficit stress, however more research needs to be conducted regarding optimal rate and timing of applications.