Impact of Hybrid Bluegrass and Tall Fescue Seeding Combinations on Brown Patch Severity and Weed Encroachment

Abstract

Tall fescue (Festuca arundinacea) and hybrid bluegrass (Poa pratensis L. × Poa arachnifera) can both be successfully grown in the transition zone of the United States. However, each grass has limitations. Tall fescue is susceptible to the fungal pathogen Rhizoctonia solani, whereas slow establishment and susceptibility to weed infestations limit hybrid bluegrass. Previous studies have shown the benefits of combining kentucky bluegrass with tall fescue in seeding mixtures. Research was conducted to evaluate the impact of two seeding combinations of hybrid bluegrass and tall fescue (one combination seeded at a 1.9:1 seed count ratio favoring tall fescue, the other combination seeded at a 1:1.8 seed count ratio favoring hybrid bluegrass) as well as monocultures of the species on turfgrass cover, weed species infestation, brown patch disease severity caused by R. solani, sod strength and species ecology. The seeding combinations had lower weed density during establishment and greater turf cover than the monoculture of hybrid bluegrass. The monoculture of tall fescue was subjected to more brown patch disease than the seeding combinations during and after the first year of establishment. Brown patch infestations likely reduced tall fescue cover and led to a species shift favoring hybrid bluegrass in the seeding combinations based on tiller count and weight data. Seeding combinations of tall fescue and hybrid bluegrass are beneficial from an epidemiological perspective because they reduce disease and weed infestations compared with monocultures of either species. From an agronomic perspective, the seeding combination favoring tall fescue provided the densest turf, whereas the seeding combination favoring hybrid had the greatest sod strength. Chemical name used: clopyralid (3,6 dichloropyridine-2 carboxylic acid)