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Evaluation of Fungal Pathogens as Biological Control Agents for Cogongrass (Imperata cylindrica)

Published online by Cambridge University Press:  20 January 2017

Camilla B. Yandoc*
Affiliation:
U.S. Horticultural Research Laboratory, U.S. Department of Agriculture–Agricultural Research Service, 2001 South Rock Road, Fort Pierce, FL 34945
Raghavan Charudattan
Affiliation:
Plant Pathology Department, University of Florida, Gainesville, FL 32611
Donn G. Shilling
Affiliation:
Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602
*
Corresponding author's E-mail: [email protected]

Abstract

Based on field surveys and evaluations in the greenhouse, two fungal pathogens, Bipolaris sacchari and Drechslera gigantea, were identified as promising biological control agents for cogongrass. In greenhouse trials, the application of spore suspensions of these fungi containing 105 spores/ ml in a 1% aqueous gelatin solution to cogongrass plants and their incubation in a dew chamber for 24 h resulted in disease symptoms that ranged from discrete lesions to complete blighting of leaves. Disease severity (DS), based on a rating scale for southern corn leaf blight with 50% as the maximum DS rating, ranged from 42 to 49%. In greenhouse experiments, the application of spores formulated in an oil emulsion composed of 4% horticultural oil, 10% light mineral oil, and 86% water resulted in higher levels of foliar blight with no dew exposure or shorter periods of dew exposure (4, 8, or 12 h) as compared with the application of spores formulated in 1% gelatin. Field trials demonstrated that under natural conditions, the application of a spore and an oil emulsion mixture containing 105 spores/ml of either fungus could cause foliar injury from disease and phytotoxic damage from the oil emulsion. Depending on the application rate (100 or 200 ml/plot), the level of foliar injury ranged from 40 to 86% (based on a field assessment scale of 0 to 100% foliar injury) with B. sacchari as the test fungus. However, with D. gigantea as the test fungus, foliar injury ranged from 9 to 70% depending on the application volume and the oil concentration used. Although B. sacchari and D. gigantea were capable of causing foliar blight on cogongrass, the regenerative ability of the rhizomes allowed cogongrass to recover from the damage caused by these fungi. However, the level of injury caused by these fungi is sufficient to support their use as components for integrated management of cogongrass.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Abbas, H. K. and Egley, G. H. 1996. Influence of unrefined corn oil and surface-active agents on the germination and infectivity of Alternaria helianthi . Biocontrol Sci. Technol 6:531538.Google Scholar
Auld, B. A. 1993. Vegetable oil suspension emulsions reduce dew dependence of a mycoherbicide. Crop Prot 12:477479.CrossRefGoogle Scholar
Barratt, R. W. and Horsfall, J. G. 1945. An improved grading system for measuring plant disease. Phytopathology 35:655.Google Scholar
Boyette, C. D. 1994. Unrefined corn oil improved the mycoherbicidal activity of Colletotrichum truncatum for hemp sesbania (Sesbania exaltata) control. Weed Technol. 8:526529.Google Scholar
Boyette, C. D., Quimby, P. C. Jr., Caesar, A. J., Birdsall, J. L., Connick, W. J. Jr., Daigle, D. J., Jackson, M. A., Egley, G. H., and Abbas, H. K. 1996. Adjuvants, formulations, and spraying systems for improvement of mycoherbicides. Weed Technol. 10:637644.Google Scholar
Bryson, C. T. 1985. A new food plant record for Atalopedes campestris (Boisduval) (Hesperiidae). J. Lepid. Soc 39:335.Google Scholar
Bryson, C. T. 1987. Native butterflies accepted cogongrass (Imperata cylindria [L.] Beauv.) as host plant. Proc. J. Miss. Acad. Soc 3:1.Google Scholar
Bryson, C. T. and Carter, R. 1993. Cogongrass, Imperata cylindrica, in the United States. Weed Technol. 7:10051009.Google Scholar
Byrd, J. D. Jr. and Bryson, C. T. 1999. Biology, Ecology, and Control of Cogongrass (Imperata cylindrica [L.] Beauv). Fact Sheet 1999-01. Mississippi State, MS: Mississippi Department of Agriculture and Commerce, Bureau of Plant Industry. 2 p.Google Scholar
Caunter, I. G. 1996. Colletotrichum caudatum, a potential bioherbicide for control of Imperata cylindrica . in Moran, V. C. and Hoffman, J. H., eds. Proceedings of the IX International Symposium on Biological Control of Weeds. Stellenbosch, South Africa: University of Cape Town. Pp. 525527.Google Scholar
Chandramohan, S. and Charudattan, R. 2001. Control of seven grasses with a mixture of three fungal pathogens with restricted host ranges. Biol. Control 22:246255.CrossRefGoogle Scholar
Chase, C. A., Shilling, D. G., Bewick, T. A., and Charudattan, R. 1996. Fungal isolates with potential for the biological control of cogongrass (Imperata cylindrica [L.] Beauv). Weed Sci. Soc. Am. Abstr 160:49.Google Scholar
Coile, N. C. and Shilling, D. G. 1993. Cogongrass, (Imperata cylindrica (L.) Beauv.): A Good Grass Gone Bad! Botany Circular 28. Gainesville, FL: Florida Department of Agriculture and Consumer Services, Division of Plant Industry. 3 p.Google Scholar
Dickens, R. 1974. Cogongrass in Alabama after sixty years. Weed Sci. 22:177179.Google Scholar
Dozier, H., Gaffney, J. F., McDonald, S. K., Johnson, E. R. R. L., and Shilling, D. G. 1998. Cogongrass in the United States: history, ecology, impacts and management. Weed Technol. 12:737743.Google Scholar
Falvey, J. L. 1981. Imperata cylindrica and animal production in Southeast Asia: a review. Trop. Grassl 15:5256.Google Scholar
Greaves, M. P., Holloway, P. J., and Auld, B. A. 1998. Formulation of microbial herbicides. in Burges, H. D., ed. Formulation of Microbial Biopesticides. Dordrecht, The Netherlands: Kluwer. Pp. 203233.CrossRefGoogle Scholar
Holm, L. G., Plucknett, D. L., Pancho, J. V., and Herberger, J. P. 1977. The World's Worst Weeds: Distribution and Biology. Honolulu, HI: University Press of Hawaii. Pp. 6271.Google Scholar
Imaizumi, S., Nishino, T., Miyabe, K., Fujimori, T., and Yamada, M. 1997. Biological control of annual bluegrass (Poa annua L.) with a Japanese isolate of Xanthomonas campestris pv. poae (JT-P482). Biol. Control 8:714.CrossRefGoogle Scholar
James, C. 1971. A Manual of Assessment Keys for Plant Diseases. Ottawa, Canada: Canada Department of Agriculture; St. Paul, MN: American Phytopathological Society. 78 p.Google Scholar
Klein, T. A. and Auld, B. A. 1995. Influence of spore dose and water volume on a mycoherbicide's efficacy in field trials. Biol. Control 5:173178.Google Scholar
Masuzawa, T., Suwa, H., and Nakasuji, F. 1983. Differences of oviposition preference and survival rate of two skipper butterflies Parnara guttata and Pelopidas mathias (Lepidoptera: Hesperiidae) on rice plant and cogongrass. New Entomol 32:110.Google Scholar
Mortensen, K. and Makowski, R. M. D. 1989. Field efficacy at different doses of Colletotrichum gloeosporiodes f.sp. malvae as a bioherbicide for round-leaved mallow (Malva pusilla). in Delfosse, E. S., ed. Proceedings of the VII International Symposium on Biological Control of Weeds. Rome, Italy: Instituto Sperimentale perla Patologia Vegetale, Ministro dell' Agricultura e delle Foreste (MAF). Pp. 523530.Google Scholar
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.CrossRefGoogle Scholar
Potyka, I. 1995. Emulsion-Formulation of Microbial Herbicides. Ph.D. thesis. University of Bristol, Bristol, UK. 255 p.Google Scholar
Shilling, D. G., Gaffney, J. F., and Waldrop, P. 1995. Cogongrass: problem and solutions. Ala. Treas. For 3:89.Google Scholar
Shrum, R. D. 1982. Creating epiphytotics. in Charudattan, R. and Walker, H. L., eds. Biological Control of Weeds with Plant Pathogens. New York: J. Wiley. Pp. 113116.Google Scholar
Van Loan, A. N., Meeker, J. R., and Minno, M. C. 2002. Cogongrass. in Van Driesche, R., Blossey, B., Hoddle, M., Lyon, S., and Reardon, R., eds. Biological Control of Invasive Plants in the Eastern United States. Morgantown, WV: Forest Health Technology Enterprise Team, Technology Transfer-Biological Control, FHTET-2002-4, U.S. Department of Agriculture, Forest Service. Pp. 353364.Google Scholar
Yandoc, C. B. 2001. Biological Control of Cogongrass (Imperata cylindrica [L.] Beauv). Ph.D. dissertation. University of Florida, Gainesville, FL. Pp. 2393.Google Scholar