Syringing Kentucky Bluegrass: Frequency Impacts Canopy Temperature and Growth.

Kentucky bluegrass (Poa pratensis L.) is the most commonly planted turfgrass species. Unfortunately, it is susceptible to heat and water stress. This species thrives at about 22°C, but summer temperatures often exceed 32°C in a majority of the cool season climate in which this species is grown. When temperatures are excessively high, syringing with water is a known method to cool the canopy. However, there is a lack of precise information regarding the effect on plant health as a function of syringing duration and frequency and the impact on total water use. A growth chamber study was conducted with Kentucky bluegrass with three syringing amounts of 0, 1.6, 2.4, and 3.2 mm compared to a control. Temperatures were reduced by 8.7, 9.9, and 11.6°C for the 1.6, 2.4, and 3.2 mm treatments. However, rebound time was not impacted by the volume of water delivered—all canopy temperatures were fully rebounded within 107-116 m. Further study is underway to evaluate impacts on shoot and root biomass, verdure, NDVI, and water use efficiency.