Competitive Ability of Tall Fescue against Alfalfa as a Function of Summer Dormancy, Endophyte Infection, and Soil Moisture Availability
Academic Article
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
ABSTRACTManagement practices of summerdormant coolseason grasses, including compatible legume species, are not well understood. In a greenhouse experiment, competitive ability of two summerdormant (Flecha and TX06V) and a summeractive (PDF) tall fescue [Schedonorus arundinaceus (Schreb.) Dumort = Lolium arundinaceum (Schreb.) Darbysh.] was evaluated in associations with alfalfa (Medicago sativa L.) cv. Bulldog 505. Fescue cultivars were either infected with Neotyphodium coenophialum (MorganJones & Gams.) Glenn, Bacon, & Hanlin comb. nov. fungal endophyte or noninfected. Monocultures and binary mixtures were exposed to a gradually imposed soil moisture deficit stress (30% soil water capacity [SWC]) from June through August or maintained at 90% SWC (control). Indices of competitive interactions (relative yield [RY], relative yield total [RYT], and aggressivity [AGR]) were calculated. The RY of summerdormant tall fescue was less, whereas RY of summeractive tall fescue was similar to that of alfalfa. The RYT values for alfalfatall fescue mixtures were not different from 1 under nonlimited soil moisture, but alfalfaFlecha mixture had RYT <1 under soil moisture deficit. The AGR of summerdormant tall fescue was lower, but AGR of summeractive tall fescue was similar to that of alfalfa. Results suggest that summeractive tall fescue effectively competes with alfalfa, but summerdormant tall fescue cultivars have lower competitive ability than alfalfa. In addition, endophyte infection increased competitive ability of TX06V and PDF but not of Flecha.
