Using Technologies to Improve the Efficiency of Water Use and Disease Management of Peanut Production in Florida

Water-saving technology is being promoted as an important means to improve water use efficiency in peanut production. Attractive cost-sharing incentives for adoption of water­saving technology are being offered to farmers by government agencies such as the Florida Department of Agriculture and Consumer Services and water management districts. Adoption of efficient water use practices will be driven by pressure to improve economic returns on production while minimizing environmental impact. Water efficient production will utilize irrigation scheduling models combined with information from in-field moisture sensors and variable rate irrigation technology to enable optimal water use while reducing leaching of nutrients. This study is the first year of a multi-year project investigating the impact of water efficient irrigation scheduling methods and variable rate irrigation on peanut production. A secondary goal of the study is to investigate the impact of water-use efficient irrigation strategies on management of three important diseases (white mold, Rhizoctonia limb rot, and leaf spot). Soil properties (e.g. texture, organic matter, and moisture content), field topography, and rnicroclimatic conditions within the peanut leaf canopy are key environmental factors influencing the severity of these diseases. Our goal has been to determine the impact of sensor-based irrigation on irrigation frequency, soil moisture, leaf canopy microclimatic conditions, and subsequent disease development. In the 2017 season, the sensor-based and ET-based irrigation schedules resulted in less water applied than the standard irrigation schedule without compromising yield. Relative to a standard scheduling approach, soil moisture sensor-based scheduling resulted in a 66% reduction in water use with a 50% maximum allowable depletion threshold, or 54% reduction in water use with a 30% maximum allowable depletion threshold. ET-based irrigation scheduling resulted in a 40% reduction in water use relative to a standard scheduling approach. Disease severity did not differ among irrigation treatments but did vary across different management zones illustrating the importance of microclimates for disease development. It is important to consider that the above average rainfall experienced in the 2017 season likely masked the impact of irrigation treatments on disease due to the frequent rainfall events in 2017.