CULTURAL-FACTORS FOR MINIMIZING BERMUDAGRASS INVASION INTO TALL FESCUE TURF

Tall fescue (Festuca arundinacea Schreb.) is becoming increasingly popular for turf in areas where bermudagrass [Cynodon dactylon L. (Pers.)] has traditionally been grown. Volunteer bermudagrass can be a serious weed problem in tall fescue lawns, and presently there are no reliable herbicides to eradicate bermudagrass without injury to the fescue. The purpose of this study was to examine multiple cultural factors to see if a combination of treatments might be used to prevent bermudagrass invasion into fescue turf. Cutting height (19 and 57 mm), fescue cultivar ('Kentucky-31' and 'Mustang'), fescue seeding rate 12 100, 12 900, and 34 400 pure-live seeds (PLS) m-2], fertilization rate (49 and 244 kg N ha-1yr-1), and source of bermudagrass introduction [seed, rhizomes, or stolons (clippings)] were examined in this 2-yr field study performed on Kirkland silt loam soil (fine, mixed, thermic, Udertic Paleustolls) in central Oklahoma. No bermudagrass invaded plots that were seeded to the two higher fescue seeding rates and mowed at the higher cutting height. The greatest number of bermudagrass originations (6 crowns m-2) and amount of stolon coverage (42%) occurred in plots of Mustang seeded to the lowest seeding rate, mowed at the lower cutting height, and fertilized at the heavier rate, with seed as the source of bermudagrass introduction. In conclusion, if tall fescue is managed like bermudagrass turf (closer mowing, higher fertilization), then the stand may eventually give way to invading bermudagrass.