Economics of Remote Sensing Technology Used to Determine Mepiquat Chloride Application on Cotton under Variable Rate Irrigation: Results of a Two-Year Study

Irrigation and plant growth regulators such as mepiquat chloride (MC) affect cotton growth, height, and development. Irrigation increases crop height and delays maturity, while the addition of MC decreases crop height and hastens maturity. Irrigation and MC application both increase cotton management costs. We examined the effects of varied irrigation and MC application based on remote sensing to test the effects of precision MC application on crop yield and net returns to irrigation and MC application. Cotton was grown under a variable rate irrigation center pivot system at the Stripling Irrigation Research Park in Camilla, Georgia during crop years 2007 and 2008. There were four levels of irrigation and four replicates. Subplots within each irrigation plot had four levels of MC application. One level was a standard application, the second and third levels were based on varying degrees of oversight using aerial imagery throughout the season, and the fourth level was a non MC applied regime. Revenues were determined by yield and based on the southeast base price. Costs were based on irrigation application, MC amount and ginning, storage and warehouse expenses. There was no significant difference in total costs in 2007. However in 2008, the plots where remote sensing technology was used, cost significantly less (an average $3.89/acre across all levels of irrigation) than the plots that received the standard application amount. In 2007 the 100%-irrigated plots had significantly higher net returns per acre than the non-irrigated plots by $49.75/acre averaged across all MC treatments. In 2007 the non MC plots returned significantly higher net returns per acre (an average $58.50/acre across all levels of irrigation) than those treated with the standard application of MC. The net returns for the plots where remote sensing technology was utilized fell between those of the standard and non-MC plots in 2007 and 2008, but they were not statistically different from either. Although there was a cost savings in 2008, it did not significantly impact net revenue. There was no significant difference in net revenues in 2008. Future analysis on the impact of quality (premiums and discounts) will be conducted pending the data.