Performance in the Transition Zone of Two Hybrid Bluegrasses Compared with Kentucky Bluegrass and Tall Fescue

Abstract

Hybrid bluegrasses (HBG) are crosses between Kentucky bluegrass (Poa pratensis L.) (KBG) and Texas bluegrass (Poa arachnifera Torr.), which may exhibit better heat tolerance and drought resistance than other cool-season turfgrasses. Two HBG cultivars (‘Thermal Blue’ [HBG1] and ‘Dura Blue’ [HBG2]), one KBG (‘Apollo’), and one tall fescue (Festuca arundinacea Schreb.; ‘Dynasty’ [TF]) were evaluated for two years in northeastern Kansas for establishment rates after seeding, visual quality and growth characteristics, and drought resistance. Irrigation treatments included 60% and 100% evapotranspiration (ET) replacement and a control receiving only natural precipitation. Tall fescue reached full cover 37, 52, and >73 days faster than HBG1, KBG, and HBG2, respectively. In both years, average quality over the growing season ranked: TF > KBG > HBG1 > HBG2; an infestation of bluegrass billbugs (Sphenophorus parvulus Gyllenhal) in 2003 reduced quality among bluegrasses but not TF. Canopy density was lower in HBG2 and higher in TF among treatments. Clipping biomass of TF was 42 to 73% higher than that of the bluegrasses. Vertical growth rates were highest in HBG1 and TF and lowest in KBG. Drought generally reduced quality among bluegrasses, but effects on TF were negligible. Results indicate that TF is better adapted than HBG where soils are deep in the transition zone. Further research is needed using new cultivars of HBG and in areas with different soils.