Physiological Responses to Primed Acclimation Irrigation Treatments: An Initial Study

The most important first step to a productive yield is good stand establishment.  Second is promoting the plant to develop a healthy rooting system and above ground biomass.  Studies have been performed that have shown irrigation treatments early in the season can help to promote these developments, especially to aid in preparations for years with limited water.  These treatments are called Primed Acclimation.  The theory is to limit the soil moisture supply earlier in the season to promote deeper rooting depth and development.  The increased root development can provide increased resistance to dry periods.  The goal of this project was to quantify the effects of primed acclimation irrigation treatments on cotton biomass and rooting development, and yield.  Treatments were implemented at University of Georgia’s Stripling Irrigation Research Park (UGA SIRP) under a variable rate center pivot irrigation system.  The treatments were full irrigation, semi-primed, full primed, optimally primed, and dryland.  Three Watermark moisture sensors installed in a probe (the UGA Smart Sensor Array (SSA)) were used to monitor soil tension.  The UGA SSA’s were used to trigger irrigation events at predetermined centibar readings, which correlated to the earlier mentioned treatments.  Above ground biomass collections were collected at biweekly intervals beginning four weeks after emergence.  Minirhizotron tubes were installed in each of the plots.  Pictures were taken twice at the end of the season to determine if there were visible differences in the rooting differences between the irrigation treatments.  Yield will be collected at the end of the year.  Initial data indicate large differences in the dryland and irrigated treatments in above biomass collections.