Timing of Glyphosate for Conversion of Bermudagrass Turf to Tall Fescue1

Renovation of bermudagrass [Cynodon dactylon (L.) Pers.] turf to tall rescue [Festuca arundinacea Schreb. ‘Kentucky 31’] is a major problem since soil fumigation is usually necessary to completely kill the existing turf. This study was conducted to determine if bermudagrass could be controlled with a fall application of glyphosate [N‐(phosphonomethyl) glycine] and the turf successfully reestablished by over‐seeding with tall rescue without disturbing the soil surface. Herbicidal treatments were applied 0, 1, 5, or 10 days before overseeding, and 1, 5, or 7 days after overseeding. Bermudagrass ground cover was reduced most after 1 year where glyphosate was applied any time before overseeding in fall 1973 (1 to 4% ground cover), and l0 days before overseeding in fall 1974 (6% ground cover). After the second growing season, bermudagrass ground cover ranged from 9 to 18% cover. Glyphosate treatments did not injure tall rescue either year when applied 1, 5, or 10 days before overseeding. Glyphosate applied as a single treatment significantly reduced bermudagrass ground cover, but did not give complete control.