Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-17T16:14:02.931Z Has data issue: false hasContentIssue false

The Pathogenicity, Virulence, and Biocontrol Potential of Two Bipolaris Species on Johnsongrass (Sorghum halepense)

Published online by Cambridge University Press:  12 June 2017

Richard S. Winder
Affiliation:
Dep. Bot., North Carolina State Univ., Raleigh, NC, U.S.A. 27695-7612
C. Gerald Van Dyke
Affiliation:
Dep. Bot., North Carolina State Univ., Raleigh, NC, U.S.A. 27695-7612

Abstract

Bipolaris sorghicola (isolate BS1) and an unidentified Bipolaris species (isolate BX1) were isolated from johnsongrass in North Carolina. Inoculum of BX1 was mass produced in solid and liquid cultures, whereas inoculum of BS1 could only be produced in solid cultures. When six formulations of inoculum of BX1 were compared, vegetable oil was the best adjuvant. Isolate BX1 displayed some host specificity in pathogenicity tests. In the greenhouse, isolate BS1 was more virulent on johnsongrass than isolate BX1. In growth chambers, increasing conidium concentration and younger plant ages interacted to increase virulence of BX1, as did interactions between inoculation, johnsongrass density, and low soil fertility. In Raleigh, NC, isolate BX1 caused very little damage in the field, with or without pretreatment with metolachlor. In Greenville, MS, isolate BX1 caused significant (52%) mortality to annual johnsongrass with very little damage to corn or grain sorghum. The biocontrol potential of the two organisms is uncertain.

Type
Special Topics
Copyright
Copyright © 1990 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Bannon, J. S. and Walker, H. L. 1987. The influence of non-ionic surfactants and non-phytotoxic crop oils on control of sicklepod by Alternaria cassiae . Proc. South Weed Sci. Soc. 40:27.Google Scholar
2. Beckman, P. M. and Payne, G. A. 1983. Cultural techniques and conditions influencing growth and sporulation of Cercospora zeae-maydis and lesion development in corn. Phytopathology 73:286289.CrossRefGoogle Scholar
3. Blaney, C. 1987. Fungal pathogens for biocontrol of yellow nutsedge (Cyperus esculentus L.). M.S. Thesis, North Carolina State Univ. 44 pp.Google Scholar
4. Borges, O. L. 1983. Pathogenicity of Drechslera sorghicola isolates on sorghum in Venezuela. Plant Dis. 67:996997.Google Scholar
5. Chiang, M., Van Dyke, C. G., and Leonard, K. J. 1989. Evaluation of endemic foliar fungi for potential biological control of johnsongrass (Sorghum halepense): Screening and host range tests. Plant Dis. 73: 459464.CrossRefGoogle Scholar
6. Delmacio, S. C. 1986. Target leaf spot. Pages 1617 in Frederiksen, R. A., ed. Compendium of Sorghum Diseases. Am. Phytopathol. Soc., St. Paul, MN.Google Scholar
7. Elazequi, F. A. and Exonde, O. R. 1973. Host-parasite relationship in Helminthosporium leaf spot of sorghum. Philip. Agric. 57:210218.Google Scholar
8. Farr, M. L. 1987. A consistent method for producing gram quantities of typical Bipolaris zeicola and B. maydis conidia. Mycologia 79:97116.Google Scholar
9. Lefebvre, C. L. and Sherwin, H. S. 1948. An undescribed species of Helminthosporium on Sudan grass and sorghum. Mycologia 40: 708716.Google Scholar
10. McWhorter, C. G. 1971. Introduction and spread of johnsongrass in the United States. Weed Sci. 19:496500.CrossRefGoogle Scholar
11. Nelson, R. R. and Kline, D. M. 1961. The pathogenicity of certain species of Helminthosporium to species of the Graminae. Plant Dis. Rep. 45:644648.Google Scholar
12. Phatak, S. C., Sumner, R., Wells, H. D., Bell, D. K., and Glaze, N. C. 1983. Biological control of yellow nutsedge with the indigenous rust fungus Puccinia canaliculata . Science 219:144147.Google Scholar
13. Ravenell, D. 1985. Evaluation of Bipolaris setariae as a potential biocontrol agent for Brachiaria platyphylla: efficacy and host range studies. M.S. Thesis, North Carolina State Univ. 60 pp.Google Scholar
14. Southern Weed Science Society. 1986. Weed science and risk management. Res. Rep. South. Weed Sci. Soc. 39:1205.Google Scholar
15. Stevens, R. B., ed. 1981. Mycology Guidebook. Univ. of Washington Press, Seattle. Page 665.Google Scholar
16. TeBeest, D. O. and Templeton, G. E. 1985. Mycoherbicides: Progress in the biological control of weeds. Plant Dis. 69:610.Google Scholar
17. Walker, H. L. and Riley, J. A. 1982. Evaluation of Alternaria cassiae for biocontrol of sicklepod. Weed Sci. 30:651654.Google Scholar
18. Wilson, S. and Hall, R. L. 1987. Potential of Pyrenophora avenae for biological control of wild oats, Avena fatua . Aust. Weeds Conf. 8: 105108.Google Scholar
19. Winder, R. S. and Van Dyke, C. G. 1987. A rapid screening and culture technique for detecting potential fungal pathogens of weeds. J. Elisha Mitchell Sci. Soc. 102:16.Google Scholar