Aims: This study was performed in 2015-2016 in order to determine howthe foliar application of sulfur helped reduce the effects of long-termwater stress in Carisma variety cotton plants in different periods ofdevelopment, namely vegetative growth (VG), flowering and bolldevelopment (FB), and boll opening (BO) periods.Methods and Results: The study was set up in randomized complete blockwith three replications. Development periods (OOO, TTT, TOO, OTT, OTO,TOT) were assigned to main plots and sulfur doses (S0: Control, S1: 150 mlda-1, S2: 250 ml da-1, S3: 350 ml da-1) were assigned to sub-plots.Measurements were made on stomatal conductance, as well asevaporatranspiration and yield to evaluate the physiological effects ofwater stress. The average amounts of irrigation water used in each fullirrigation were 127.5 and 138 mm respectively, for the treatment years.As for the evaporatranspiration values, in the first treatment year it wasfound between 304 and 1012 mm and in the second year from 256 to 1070mm. Stomatal conductance values ranged from 269 to 1067 mmol m-2s-1in the first year and from 205 to 407 mmol m-2s-1 in the second year withthe highest stomatal conductance value obtained from full irrigation (TTT)during all growth periods in both years.Conclusions: The effects of sulfur dosage on stomatal conductance andyield varied due to exposure to long-term water stress at differentdevelopmental periods; however, generally speaking, the doses of S1 andS2 cause these values to increase.Significance and Impact of the Study: In the Amik Plain, there was nodetailed study to determine how foliar sulfur applications changed thestomatal conductance of cotton when drip-irrigated and subjected towater stress during the different development stages. This researchrevealed in what dose sulfur should be given to reduce the effects of longterm water stress in Carisma variety cotton plants in Amik plain.