Response of Tall Fescue and Kentucky Bluegrass Mixtures to Wear

Tall fescue (TF) [Schedonorus arundinaceus (Schreb.) Dumort.] and Kentucky bluegrass (KBG) Poa pratensis L.) are often seeded as mixtures in temperate and transition climates. This study assessed the performance and species composition of TF and KBG mixtures containing newer cultivars that were subjected to wear. Individual plots of TF cultivars were established in 2010 on a loam along with 16 mixtures of TF and KBG (TF 90/KBG 10; w/w). Wear was applied during autumn 2011, 2012, and 2013. Plots were evaluated for turfgrass quality, brown patch disease (caused by Rhizoctonia solani), and species composition. Data were analyzed using a 5 × 4 × 2 factorial of KBG (none, ‘Midnight II’, ‘Blue Note’, A05–361, A05–361), TF (‘Falcon V’, ‘Mustang 4’, ‘Justice’, ‘Greenkeeper’), and wear (no wear and wear) arranged in a strip plot design with three replications. Wear reduced quality but had no effect on species composition. Mixing KBG with Falcon V or Mustang 4 TF had no effect on quality after wear compared with either TF alone; however, the quality of Greenkeeper TF was better when mixed with Midnight II or Blue Note KBG, whereas mixing with A05–361 and A05–344 KBG had no effect on quality. Kentucky bluegrass selection had a much greater influence on species composition compared with TF selection. Tall fescue composition was influenced by KBG cultivar and ranged from 37 to 79%. Brown patch severity was decreased in TF mixtures with KBG and was more strongly influenced by KBG cultivar than TF cultivar. Our data indicate that KBG cultivars can dramatically affect TF composition of mixes and brown patch severity, whereas autumn wear does not.