Assessing the Utility of Primed Acclimation for Improving Water Use Efficiency in a Sensor-Based Irrigation Scheduling System.

A type of irrigation management strategy called Primed Acclimation aims to limit water availability early in the growing season to promote root development, which potentially helps prepare plants for episodic drought in years with limited water.  Recent advances in continuous and remote soil moisture monitoring will allow for a more definitive assessment of 1) the utility of the primed acclimation strategy and 2) the thresholds needed to achieve the maximum benefit from this strategy. The goal of this project was to quantify the effects of primed acclimation irrigation treatments on cotton physiology such as plant height, total nodes, boll distribution, and yield.  Treatments were implemented at University of Georgia’s Stripling Irrigation Research Park (UGA SIRP) under a variable rate center pivot irrigation system for 2014 and 2015.  The treatments were T1 (-20 cb pre bloom), T2 (-40 cb pre bloom), T3 (-70 cb pre bloom), T4 (-100 cb pre bloom), and T5 (dryland). All irrigated plots were irrigated with -35 cb triggers upon the first week of bloom. In-season physiological data included plant height, and total nodes, while remote sensing data were collected weekly and included Normalized Difference Vegetation Index (NDVI), and aerial RGB photography. End of season data collected included lint yield, fiber quality, and total water applied. Preliminary results indicate that substantial early season water savings are possible without detrimentally affecting lint yield.