The effect of mowing regime on lateral spread and rhizome growth of dallisgrass and bahiagrass was determined in field studies conducted in 2003 and 2004 in North Carolina over 5 mo. Treatments were selected to simulate mowing regimes common to intensively managed common bermudagrass turfgrass and include 1.3-, 5.2-, and 7.6-cm heights at frequencies of three, two, and two times per week, respectively. A nonmowed check was included for comparison. Lateral spread of dallisgrass was reduced 38 to 47% regardless of mowing regime when compared with the nonmowed check. Rhizome fresh weight of dallisgrass was reduced 49% in 2003 and 30% in 2004 when mowed at the 7.6-cm regime after 5 mo, whereas the 5.2-cm mowing regime caused a reduction of 31%. Rhizome fresh weight of dallisgrass was most negatively affected by the 1.3-cm regime, which caused reductions of 57% in 2003 and 37% in 2004. Lateral spread of bahiagrass was more strongly affected by mowing height and frequency than dallisgrass, with reductions of 21 to 27%, 40%, and 44 to 62% when mowed at 7.6, 5.2, and 1.3-cm regimes, respectively. Rhizome fresh weight of bahiagrass was reduced 24 to 33%, 55%, and 70 to 73% when mowed at 7.6, 5.2, and 1.3 cm, respectively. Based upon these results, areas mowed at a golf course rough height (≥ 5.2 cm) may be more conducive to bahiagrass spread, whereas dallisgrass may tolerate areas mowed at a fairway height (1.3 cm). Mowing at the shorter heights examined in this study clearly reduced the potential of Paspalum spp. vegetative spread and may help to explain observed distributions of Paspalum spp. infestations in bermudagrass turfgrass.

Nomenclature: Bahiagrass, Paspalum notatum Flueggé PASNO; bermudagrass, Cynodon dactylon (L.) Pers; dallisgrass, Paspalum dilatatum Poir. PASDI