Cool‐season golf course fairway species irrigation requirements under limited irrigation

Abstract

Improving water conservation efforts for golf course turf is a constant industry goal. While creeping bentgrass (Agrostis stolonifera L.; CBG) is the preferred fairway species throughout most of the cool‐humid regions, water requirements of alternative cool‐season species with better acute drought tolerance at fairway mowing heights (e.g., <0.5 inch) are not well documented. A 2‐yr field study compared two irrigation strategies (80% reference evapotranspiration, ETo, replacement or a green cover threshold, GCT, response‐based approach) for a 60‐d summer period for six cool‐season species grown under a fixed roof rainout structure on a silt‐loam soil. For the GCT approach, plots were imaged three times per week and if a plot fell below the GCT, 55 and 65% green cover in 2017 and 2018, respectively, a predetermined amount of water was added. The 80% ETo replacement plots received a total of 8.63 and 8.26 inches of irrigation in 2017 and 2018, respectively. By contrast, the GCT strategy required substantially less water which varied by species and year. Among species, turf‐type tall fescue [Festuca arundinacea Schreb.; syn. Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.] and a Mid‐Atlantic type Kentucky bluegrass (Poa pratensis L.) required approximately 45 and 52% less irrigation compared to CBG in 2017 and 2018, respectively. Where water conservation is paramount, planting more drought tolerant species and cultivars and employing alternative irrigation strategies like a GCT can result in significant water savings.

Brown patch severity as affected by cool‐season turfgrass species, cultivar, and nitrogen rate

“…Turfgrass was hand trimmed with scissors three times per week at 1.9 cm, with clippings removed. Mowing height and frequency was selected to prevent potential scalping of CBG and CLBG at mowing heights >1.9 cm and demonstrated tolerance of mowing height in a previous field study evaluating irrigation needs among the same species evaluated (Powlen & Bigelow, 2023). Relative canopy growth rate of each grass was determined by dry matter yield (DMY).…”

“…While previous research has focused on differences among cool‐season turfgrass species (supplemental irrigation needs, N fertilization requirements, subsequent canopy growth rates, and insect tolerance), relative resistance levels to R. solani among these species remains limited (Crutchfield & Potter, 1995; Powlen & Bigelow, 2023; Walker et al., 2007). Additionally, conflicting results regarding N rate and brown patch severity are potentially due to differential responses like growth rate or leaf canopy architecture (e.g., upright vs. prostrate) among the cool‐season species when fertilized with different N rates.…”