Crabgrass (Digitaria spp.) is a common weed of warm- and cool-season turfgrasses. A survey of the southern United States conducted by Webster (2000) ranked crabgrass as the most common turfgrass weed in 10 of 12 southern states. Compared with desirable turfgrass species such as bermudagrass (Cynodon spp.) or tall fescue (Lolium arundinaceum Schreb.), the light green color and coarse texture of crabgrass foliage can reduce overall turf quality (Hall et al., 1994). PRE herbicides such as dithiopyr, indaziflam, oxadiazon, prodiamine, and pendimethalin are labeled for selective control of smooth crabgrass (Digitaria ischaemum Schreb.) and large crabgrass [Digitaria sanguinalis (L.) Scop.] in turf (Anonymous, 2012a, 2012b, 2012c, 2007, 2009).
Previous research has reported reductions in crabgrass cover by increasing turf mowing height. Specifically, Dernoeden et al. (1993) reported ≈3% smooth crabgrass cover in non-treated tall fescue mowed at 8.8 cm compared with 40% and 80% smooth crabgrass cover in plots mowed at 5.5 and 3.2 cm, respectively, at the conclusion of a 3-year study. Reductions in smooth crabgrass cover with increased mowing height have been observed in other cool-season turfgrass species, including kentucky bluegrass (Poa pratensis L.), tall fescue, perennial ryegrass (Lolium perenne L.), and several fine fescue species (Festuca spp.) (Debels et al., 2012; Dernoeden et al., 1998; Dunn et al., 1981; Jagschitz and Ebdon, 1985; Voigt et al., 2001). To date, minimal information has been published regarding effects of mowing height on crabgrass cover in warm-season turfgrass species such as common bermudagrass (Cynodon dactylon L.) (Callahan, 1978; Hoyle et al., 2014).
Integrated pest management has been defined as the thoughtful combination of multiple approaches such as synthetic chemical applications and cultural practices to control pests (Busey, 2003). Although the efficacy of PRE herbicides for crabgrass control and effects of mowing height on crabgrass incidence have been studied, research exploring the integration of these two practices is limited. Dernoeden et al. (1993) monitored smooth crabgrass cover after applications of dithiopyr and pendimethalin to tall fescue turf maintained at 8.8, 5.5, and 3.2 cm. Herbicide rates were reduced by 50% at the end of the 3-year study and plots mowed at 5.5 and 8.8 cm did not require a herbicide in the final year of the experiment. Smooth crabgrass cover in dithiopyr- or pendimethalin-treated plots was similar (3% or less) during the first 2 years of the study, regardless of mowing height. However, in the third year, smooth crabgrass cover was greater in tall fescue turf mowed at 3.2 and 5.5 cm than 8.8 cm after pendimethalin or dithiopyr application. The researchers concluded that annual dithiopyr or pendimethalin applications at labeled rates would be required when mowing tall fescue at 3.2 and 5.5 cm. However, reduced rates and less frequent applications of these herbicides could provide acceptable turf quality when mowing height was increased to 8.8 cm.
Changes in common bermudagrass mowing height may affect the efficacy of PRE herbicides labeled for crabgrass control. However, minimal data have been published regarding integrated programs for managing crabgrass infestations using PRE herbicides in combination with mowing height adjustment. Therefore, the objective of this research was to determine the effect of mowing height on the efficacy of several PRE herbicides labeled for crabgrass control in common bermudagrass turf.
Anonymous, 2007 Ronstar Flo herbicide label. Bayer Environmental Sciences, Research Triangle Park, NC. p. 1–12
Anonymous, 2009 Pendulum AquaCap herbicide label. BASF Corporation, Research Triangle Park, NC. p. 1–19
Anonymous, 2012a Dimension 2EW herbicide label. Dow AgroSciences, Indianapolis, IN. p. 1–17
Anonymous, 2012b Specticle Flo herbicide label. Bayer Environmental Sciences, Research Triangle Park, NC. p. 1–15
Anonymous, 2012c Barricade 4 FL herbicide label. Syngenta Professional Products, Greensboro, NC. p. 1–32
Debels, B.T., Griffith, S.E., Kreuser, W.C., Melby, E.S. & Soldat, D.J. 2012 Evaluation of mowing height and fertilizer application rate on quality and weed abundance of five home lawn grasses Weed Technol. 26 826 831
Dernoeden, P.H., Carroll, M.J. & Krouse, J.M. 1993 Weed management and tall fescue quality as influenced by mowing, nitrogen, and herbicides Crop Sci. 33 1055 1061
Dernoeden, P.H., Fidanza, M.A. & Krouse, J.M. 1998 Low maintenance performance of five Festuca species in monostands and mixtures Crop Sci. 38 1645 1649
Dunn, J.H., Nelson, C.J. & Winfrey, R.D. 1981 Effects of mowing and fertilization on quality of ten Kentucky bluegrass cultivars, p. 293–301. In: Sheard, R.W. (ed.). Proc. 4th Intl. Turfgrass Res. Conf., Guelph, Ontario, Canada, 19–23 July 1981. Ontario Agric. College, Univ. of Guelph, and Int. Turfgrass Soc., Guelph, Ontario, Canada
Hall, D.W., McCarty, L.B. & Murphy, T.R. 1994 Weed taxonomy, p. 1–8. In: Turgeon, A.J. (ed.). Turf weeds and their control. Amer. Soc. of Agron., Madison, WI
Hoyle, J.A., Gannon, T.W. & Yelverton, F.H. 2014 Effect of common bermudagrass mowing height on large crabgrass incidence Applied Turf Sci. 11 1 2
Jagschitz, J.A. & Ebdon, J.S. 1985 Influence of mowing, fertilizer, and herbicide on crabgrass infestation in tall fescue turf, p. 699–704. In: Lemaire, F. (ed.). Proc. 5th Intl. Turfgrass Res. Conf., Avignon, France, 1–5 July 1985. Institute National de la Recherche Agronomique, Paris, France
Johnson, B.J. 1981 Effect of herbicide and fertilizer treatments on weeds and quality of Kentucky bluegrass turf, p. 19–23. In: Sheard, R.W. (ed.). Proc. 4th Intl. Turfgrass Res. Conf., Guelph, Ontario, Canada, 19–23 July 1981. Ontario Agric. College, Univ. Guelph and Intl. Turfgrass Soc., Guelph, Ontario, Canada
King, C.A. & Oliver, L.R. 1994 A model for predicting large crabgrass (Digitaria sanguinalis) emergence as influenced by temperature and water potential Weed Sci. 42 561 567
Masin, R., Zuin, M.C., Archer, D.W., Forcella, F. & Zanin, G. 2005 WeedTurf: A predictive model to aid control of annual summer weeds of turf Weed Sci. 53 193 201
National Climatic Data Center 2013 4 Dec. 2013. <http://ggweather.com/normals/TN.html#K>
Proctor, C.A., Sousek, M.D., Patton, A.J., Weisenberger, D.V. & Reicher, Z.J. 2012 Combining preemergence herbicides in tank mixtures or as sequential applications provides season-long crabgrass control in the upper midwest HortScience 47 1159 1162
Senseman, S.A. 2007 Herbicide handbook. 9th ed. Weed Science Society of Amer., Lawrence, KS. p. 283–290
Shaner, D.L. 2014 Herbicide handbook. 10th ed. Weed Science Society of Amer., Lawrence, KS. p. 283–290
U.S. Environmental Protection Agency 1996 Environmental chemistry methods: Pendimethalin. Washington, DC. 19 Dec. 2013. <http://www.epa.gov/pesticides/methods/ecmmethods/445276-01-SW.pdf>
Voigt, T.B., Fermanian, T.W. & Haley, J.E. 2001 Influence of mowing and nitrogen fertility on tall fescue turf Intl. Turfgrass Soc. Res. J. 9 953 956