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Cogongrass in the United States: History, Ecology, Impacts, and Management

  • Hallie Dozier (a1), James F. Gaffney (a2), Sandra K. McDonald (a3), Eric R.R.L. Johnson (a4) and Donn G. Shilling (a4)...


Cogongrass is a weed throughout the tropics and subtropics. Introductions early this century have spread into forests, rangelands, reclaimed mined areas, roadsides, and natural ecosystems in the southeastern United States. Vegetative reproduction is the primary mechanism for survival and local spread, and sexually produced seeds of this obligate outcrossing species provide natural long-distance dispersal. Highly germinable (≥ 90%) seeds have no dormancy, though spikelet fill may be low (≤ 40%) in natural populations. Early seedling establishment, prior to rhizome development, is low (< 20%), occurring in areas with little competition; ≥ 75% bahiagrass sod cover is required to prevent cogongrass seedling establishment. Imazapyr and glyphosate are the most effective herbicides for cogongrass control. Younger cogongrass shoots are very susceptible to these herbicides; however, longer term control of adult plants requires translocation and thereby control of the rhizomes. Autumn applications of glyphosate and imazapyr provided greatest suppression of rhizome regrowth. Effective cogongrass management options exist and depend on integrating several control strategies. Mechanical control alone provides short-term control, whereas multiple discings plus herbicide application provide longer term control. Some combinations of herbicide, discing, and revegetation with desirable plant species provide excellent control. Because of the large geographic area infested with cogongrass and the often economically and environmentally unacceptable management techniques, biological control organisms also should be researched.



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Akobundu, I. O. 1993. Chemical control of cogongrass (Imperata cylindrica (L.) Raeuschel) in arable fields. Weed Sci. Soc. Am. Abstr. 33:6.
Allen, C. M. 1974. Nineteen species of grasses (Poaceae) new to Louisiana. Proc. L. Acad. Sci. 37:1820.
Allen, C. M., Thomas, R. D., and Lelong, M. G. 1991. Bracharia plantaginea, Imperata cylindrica, and Panicum maximum: three grasses (Poaceae) new to Louisiana and a range extension for Rottboellia cochinchinensis . SIDA Contrib. Bot. 14:613615.
Ayeni, A. O. 1985. Observations on the vegetative growth pattern of spear-grass [Imperata cylindrica (L.) Beauv.] Agric. Ecol. Environ. 13:301307.
Boerboom, C. M. and Wyse, D. L. 1988. Influence of glyphosate concentration on glyphosate absorption and translocation in Canadian thistle. Weed Sci. 36:291295.
Boonitee, A. and Ritdhit, P. 1984. Allelopathic effects of some weeds on mungbean plants (Vigna raiata), Proc. Trop. Weed Sci. Soc. 2:401406.
Bryson, C. T. and Carter, R. 1993. Cogongrass, Imperata cylindrica, in the United States. Weed Technol. 7:10051009.
Cheatham, S., Johnston, M. C., and Marshall, L. 1995. The Useful Wild Plants of Texas, the Southeastern and Southwestern United Slates, the Southern Plains, and Northern Mexico. Austin, TX: Useful Wild Plants, Inc. 568 p.
Coile, N. C. and Shilling, D. G. 1993. Cogongrass, Imperata cylindrica (L.) Beauv.: A Good Grass Gone Bad! Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Botany Circular, Vol. 28. 3 p.
Dean, C. E., Shilling, D. G., and Willard, T. R. 1988. Management of Noxious-Exotic Grasses on Highway Rights-of-Way. 99700-7352. Tallahassee, FL: Florida Department of Transportation. 117 p.
Dickens, R. 1974. Cogongrass in Alabama after sixty years. Weed Sci. 22:177179.
Dickens, R. 1976. Weed watch—cogongrass. Weeds Today 7:5.
Dickens, R. and Buchanan, G. A. 1971. Old weed in a new home—that's cogongrass. High. Agric. Res. 18:2.
Dickens, R. and Buchanan, G. A. 1975. Control of cogongrass with herbicides. Weed Sci. 23:194197.
Elmore, C. D. 1986. Weed survey—southern states. Res. Rep. South. Weed Sci. Soc. 39:136158.
Eussen, J.H.H. 1980. Biological and ecological aspects of alang-alang (Imperata cylindrica (L.) Beauv.). Biotrop. Spec. Bull. 5:1522.
Eussen, J.H.H. and Soerjani, M. 1975. Problems and control of alang-alang (Imperata cylindrica (L.) Beauv.) in Indonesia. Asian-Pac. Weed Sci. Soc. Fifth Conf., Bogor, Indonesia, pp. 5865.
Eussen, J.H.H. and Wirjahardja, S. 1973. Studies of an alang-alang (Imperata cylindrica (L.) Beauv.) vegetation. Biotrop. Bull. 6:124.
Falvey, J. L. 1981. Imperata cylindrica and animal production in southeast Asia: a review. Trop. Grassl. 15:5256.
Falvey, J. L., Hengmichai, P., and Pongpiachan, P. 1981. The productivity and nutritive value of Imperata cylindrica (L) Beauv. in the Thai highlands. J. Range Manage. 34:280282.
Gabel, M. L. 1982. A Biosystematic Study of the Genus Imperata (Gramineae: Andropogoneae). . Iowa State University, Ames. IA. 94 p.
Gaffney, J. F. 1996. Ecophysiological and Technological Factors Influencing the Management of Cogongrass (Imperata cylindrica). , University of Florida, Gainesville, FL. 128 p.
Greenlee, J. 1992. The Encyclopedia of Ornamental Grasses: How to Grow and Use Over 250 Beautiful and Versatile Plants. Emmausn, PA: Rodale Press. 186 p.
Hall, D. W. 1983. Weed watch—cogongrass. Fla. Weed Sci. Soc. Newsl. 5:12.
Hall, D. W. 1998. Is cogongrass really an exotic? Wildland Weeds 1:14.
Holm, L. G., Plucknett, D. L., Pancho, J. V., and Herberger, J. P. 1977. The World's Worst Weeds: Distribution and Biology. Honolulu: University Press of Hawaii. 609 p.
Hubbard, C. E., Brown, D., Gray, A. P., and Whyte, R. O. 1944. Imperata cylindrica: Taxonomy, Distribution, Economic Significance and Control. Imperial Agricultural Bureau Joint Publication 7:163.
Jagoe, B. B. 1938. The effect of lalang grass (Imperata cylindrica) on the growth of coconut palms. Malay. Agric. J. 26:369376.
Johnson, E.R.R.L., Gaffney, J. F., and Shilling, D. G. 1997. Revegetation as part of an integrated management approach for the control of cogongrass. Proc. South. Weed Sci. Soc. 50:141.
Lang, S., Dunmire, J. R., Edinger, P., Williamson, J. F., Walheim, L., and Overbeck Bix, C. 1997. Sunset National Garden Book. In Brenzel, K. N. ed. Sunset Books. Menlo Park, CA: Sunset Books, Inc. 656 p.
Lee, S. A. 1985. Bud development in the rhizomes of Imperata cylindrica (L.) Beauv. after glyphosate treatment. MARDI Res. J. 14:3945.
Lee, S. A. 1986. Effects of dalapon and glyphosate on Imperata cylindrica (L.) Beauv. at different growth stages. MARDI Res. J. 14:3945.
Lelong, M. G. 1977. Annotated list of vascular plants in Mobile, Alabama. SIDA. Contrib. Bot. 7:118146.
McDonald, S. K., Shilling, D. G., Bewick, T. A., Gordon, D., Hall, D., and Smith, R. 1996a. Factors influencing cogongrass, Imperata cylindrica (L.) Beauv., dispersion, establishment and persistence. Weed Sci. Soc. Am. Absts. 36:46.
McDonald, S. K., Shilling, D. G., Okoli, C.A.N., Bewick, T. A., Gordon, D., Hall, D., and Smith, R. 1996b. Population dynamics of cogongrass, Imperata cylindrica . Proc. South. Weed Sci. Soc. 49:156.
Patterson, D. T., Flint, E. P., and Dickens, R. 1980. Effects of temperature, photoperiod, and population source on the growth of cogongrass (Imperata cylindrica). Weed Sci. 28:505509.
Patterson, D. T. and McWhorter, C. G. 1980. Distribution and control of cogongrass Imperata cylindrica in Mississippi. Proc. South. Weed Sci. Soc. 33:251.
Patterson, D. T., Terrell, E. E., and Dickens, R. 1983. Cogongrass in Mississippi. Miss. Agric. For. Res. Exp. Sta. 46:13.
Peng, S. Y. 1984. The Biology and Control of Weeds in Sugarcane. New York; Elsevier Science. 336 p.
Sajise, P. E. 1972. Evaluation of Cogon (Imperata cylindrica (L.) Beauv.) as a Seral Stage in Philippine Vegetational Succession: I. The Cogonal Seral Stage and Plant Succession. II. Autecological Studies on Cogon. . Cornell University, Ithaca, NY.
Sajise, P. E. 1980. Alang-alang (Imperata cylindrica (L.) Beauv.) and upland agriculture. Biotrop. Spec. Bull. 5:3546.
Santiago, A. 1980. Genecological aspects of Imperata weed and its practical implications. Proc. BIOTROP Workshop on Alang-alang. Bogor, pp. 2334.
Shatter, D. L. 1988. Absorption and translocation of imazapyr in Imperata cylindrica (L.) Raeuschel and effects on growth and water usage. Trop. Pest Manage. 34:388392.
Shilling, D. G., Bewick, T. A., Gaffney, J. F., McDonald, S. K., Chase, C. A., and Johnson, E.R.R.L. 1997. Ecology, Physiology, and Management of Cogongrass (Imperata cylindrica). Final Report. Florida Institute of Phosphate Research. 128 p.
Shilling, D. G. and Gaffney, J. F. 1995. Cogongrass control requires integrated approach. Rest. Manage. Notes 13:227.
Shilling, D. G., Gaffney, J. F., and Waldrop, P. 1995. Cogongrass: problem and solutions. Alabama's Treasured Forests 3:89.
Shilling, D. G. and Haller, W. T. 1989. Interactive effects of diluent pH and calcium content on glyphosate activity on Panicum repens L. (torpedograss). Weed Res. 29:441448.
Sriyani, N. 1992. Glyphosate absorption, translocation, and rhizome bud kill in cogongrass (Imperata cylindirca). Proc. North Cent. Weed Sci. Soc. 47:108.
Tabor, P. 1949. Cogongrass, Imperata cylindrica (L) Beauv., in the southeastern United States. Agron. J. 41:270.
Tabor, P. 1952. Comments on cogon and torpedo grasses: a challenge to weed workers. Weeds 1:374375.
Tanner, G. W., Wood, J. M., and Jones, S. A. 1992. Cogongrass (Imperata cylindrica) control with glyphosate. Fla. Sci. 55:112115.
Townson, J. K. and Butler, R. 1990. Uptake, translocation and phytotoxicity of imazapyr and glyphosate in Imperata cylindrica (L.) Raeuschel: effect of herbicide concentration, position of deposit and two methods of direct contact application. Weed Res. 30:235343.
Townson, J. K. and Price, C. E. 1987. Tropical weed control: an approach to optimising herbicide performance with very low volume application. Aspects Appl. Biol. 14:305306.
Watson, L. and Dallwitz, M. J. 1992. Grass genera of the world: descriptions, illustrations, identification, and information retrieval; including synonyms, morphology, anatomy, physiology, phytochemistry, cytology, classification, pathogens, world and local distributions, and references. URL, World Wide Web:
Wilcut, J. W., Dute, R. D., Truelove, B., and Davis, D. E. 1988a. Factors limiting the distribution of cogongrass, Imperata cylindrica, and torpedograss, Panicum repens . Weed Sci. 36:577582.
Wilcut, J. W., Truelove, B., Davis, D. E., and Williams, J. C. 1988b. Temperature factors limiting the spread of cogongrass (Imperata cylindrica) and torpedograss (Panicum repens). Weed Sci. 36:4955.
Willard, T. R. 1988. Biology, Ecology and Management of Cogongrass (Imperata cylindrica (L.) Beauv.). . University of Florida, Gainesville, FL. 127 p.
Willard, T. R., Gaffney, J. F., and Shilling, D. G. 1997. Influence of herbicide combinations and application technology on cogongrass (Imperata cylindrica) control. Weed Technol. 11:7680.
Willard, T. R., Hall, D. W., Shilling, D. G., Lewis, J. A., and Currey, W. L., 1990. Cogongrass (Imperata cylindrica) distribution on Florida highway rights-of-way. Weed Technol. 4:658660.
Willard, T. R. and Shilling, D. G. 1990. The influence of growth stage and mowing on competition between Paspalum notatum and Imperata cylindrica . Trop. Grassl. 24:8186.
Willard, T. R., Shilling, D. G., Gaffney, J. F., and Currey, W. L. 1996. Mechanical and chemical control of cogongrass (Imperata cylindrica). Weed Technol. 10:722726.


Cogongrass in the United States: History, Ecology, Impacts, and Management

  • Hallie Dozier (a1), James F. Gaffney (a2), Sandra K. McDonald (a3), Eric R.R.L. Johnson (a4) and Donn G. Shilling (a4)...


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