Tall Fescue Response to Clipping and Competition with No‐Till Seeded Alfalfa as Affected by Fungal Endophyte

Abstract

AbstractTall fescue (Festuca arundinacea Schreb.) is generally less productive, persistent, and competitive under stress after removal of its fungal endophyte, Neotyphodium coenophialum (Morgan‐Jones & W. Gams) Glenn, Bacon & Hanlin (syn. Acremonium coenophialum Morgan‐ Jones & W. Gams). Our objectives were to compare endophyteinfected (E + ) and endophyte‐free (E −) tall fescue for (i) forage yield and tiller response at different cutting frequencies and heights and (ii) competition with no‐till seeded alfalfa (Medicago sativa L.). Factorialized combinations of 3‐wk and hay‐stage harvest intervals with clipping heights of 3.8 cm (low) and 7.6 cm (high) were used with E + and E − tall fescue in a 4‐yr study. ‘Alfagraze’ alfalfa was no‐till seeded into E + and E − ‘Kentucky 31’ tall fescue, E − ‘AU Triumph’ tall fescue, orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinacea L.), and Kentucky bluegrass (Poa pratensis L.) in each of 3 yr. Forage yield of E + and E − Kentucky 31 was similar (P > 0.05) within a cutting treatment. When cut at 3‐wk intervals, a low as compared with a high clipping height had no effect (P > 0.05) on total forage yield of E + Kentucky 31 tall fescue, but forage yield of E − Kentucky 31 and E − AU Triumph were reduced by 23 and 28%, respectively, in the fourth year. Both E + and E − tall fescue cut every 3 wk during a dry, hot summer at a low clipping height had autumn forage yields only 20 to 25% of that at a high clipping height. Tiller populations declined more on AU Triumph than E − Kentucky 31 in response to cutting. Cutting height had a minor effect on yield with hay‐stage harvest. Endophyte infection had no effect on stands or forage yield of no‐till seeded alfalfa. Alfalfa forage yields were lower with tall fescue than with the other grass species. AU Triumph, a winter‐productive tall fescue, was the grass most competitive with alfalfa.