Influence of Irrigation Timing on Lint Yield of Four Commercial Cotton Varieties

This study represents the initial characterization of yield responses to the timing of drip irrigation of lint yields of four commercial cotton varieties.  Four commercial varieties were planted in Lubbock, Tx during the 2014 growing season.  Replicated plots received either 2.5 mm of irrigation per day or 17.5 mm of irrigation once a week.  Plant responses to this limited irrigation were evaluated using a chlorophyll fluorescence stress bioassay previously reported by Burke.  Varietal differences in plant stress were detected for the two irrigation strategies.  Changes in plant size, boll production, and timing of cutout were observed.  Two varieties exhibited no yield differences between the irrigation regimes, while two varieties showed yield decreases (25% and 20%) under the 2.5 mm daily irrigation regime. Cotton Incorporated Project #13-461TX.