Physiological and Quality Responses of Turfgrass and Ornamental Plants to Weather-Based Irrigation Control

At 600 L person⁻¹ d⁻¹, the United States has the highest water use per capita in the world. In urban settings, large portions of municipal water supplies are used for the irrigation of amenity landscapes, which often include turfgrass, as well as other ornamental plant materials. As water resources have become more constrained, irrigation technologies such as weather-based irrigation controllers have been promoted as one component of comprehensive water conservation efforts. While weather-based controllers have been shown to save water over standard, manually programmed irrigation controllers, the effects of their use on plant physiology and quality remain largely unknown. This study investigated the physiological and plant quality responses of a Kentucky bluegrass blend (Poa pratensis L.) and two perennial plant species [Euonymus alatus (Thunb.) Siebold ‘Compactus’ and Paeonia lactiflora Pall.] to the use of three weather-based irrigation controller schedules–depths and one standard, manually programmed irrigation controller schedule–depth. Kentucky bluegrass and P. lactiflora both exhibited physiological stress, as well as negative plant quality responses to the use of some weather-based controllers. Further research is needed to identify weather-based controllers that successfully combine water saving potential with positive plant physiological and quality responses.