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An Evaluation of Hydrophilic Polymers for Formulating the Bioherbicide Agents Alternaria cassiae and A. eichhorniae

Published online by Cambridge University Press:  12 June 2017

Yasser M. Shabana
Affiliation:
Plant Pathology Department, Faculty of Agriculture, Mansoura University, El-Mansoura, Egypt
R. Charudattan
Affiliation:
Plant Pathology Department, University of Florida, Gainesville, FL 32611
James T. Devalerio
Affiliation:
Plant Pathology Department, University of Florida, Gainesville, FL 32611
Mohamed A. Elwakil
Affiliation:
Plant Pathology Department, Faculty of Agriculture, Mansoura University, El-Mansoura, Egypt

Abstract

Eight polymers capable of forming aqueous gels were compared for their capacity to retain hydration over time, to promote spore germination, and to prolong the viability of germinated spores (= germlings) of Alternaria cassiae, a bioherbicide agent for sicklepod. When compared at a standard 0.1% w/w (gel/water) concentration, the eight gels retained hydration for 6 d with no significant differences among them in the rate of dehydration. The best concentration of each gel that yielded 95 to 100% spore germination within 6 h after hydration was then chosen, and the gels were compared at these concentrations to determine the duration of effectiveness of the gels. The effectiveness was rated on the basis of the proportions of alive germlings versus germinated spores and alive germlings versus total spores, determined with the aid of a fluorescent vital stain. Based on these two parameters, the most effective gel was Kelzan® xanthan gum. However, all gels supported > 50% alive germlings over a period of 1 wk, suggesting that the addition of any of these polymers to the inoculum suspension should enable the fungal propagules to remain moist for a prolonged period, benefit from the high ambient moisture to improve germination, and promote disease development. Accordingly, seven of these gels were tested for their ability to enhance pathogenicity of a mycelial inoculum of A. eichhorniae, a bioherbicide agent for waterhyacinth. Gellan gum and Kelgin®-HV were most effective in promoting disease, followed by Evergreen® 500 polyacrylamide, and Kelgin®-LV, Metamucil®, Kelzan® xanthan gum, and N-Gel™ were no better than the control inoculum without any gel. Thus, the gels may have differential effects on different fungi and inoculum types. Nonetheless, the results confirm the utility and feasibility of hydrophilic gels as formulating materials for bioherbicides.

Type
Research
Copyright
Copyright © 1997 by the Weed Science Society of America 

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References

Literature Cited

Amsellem, Z., Sharon, A., Gressel, J., and Quimby, P. C. Jr. 1990. Complete abolition of high inoculum threshold of two mycoherbicides (Alternaria cassiae and A. crassa) when applied in invert emulsion. Phytopathol. 80:925929.Google Scholar
Boyette, C. D., Quimby, P. C. Jr., Connick, W. J. Jr., Daigle, D. J., and Fulgham, F. E. 1992. Progress in the production, formulation, and application of mycoherbicides. In TeBeest, D. O., ed. Microbial Control of Weeds. London: Chapman and Hall. pp. 209225.Google Scholar
Charudattan, R., Walker, H. L., Boyette, C. D., Ridings, W. H., TeBeest, D. O., Van Dyke, C. G., and Worsham, A. D. 1986. Evaluation of Alternaria cassiae as a mycoherbicide for sicklepod (Cassia obtusifolia) in regional field tests. Southern Cooperative Series Bulletin 317. Alabama Agricultural Experiment Station, Auburn University. 19 p.Google Scholar
Freeman, T. E. and Charudattan, R. 1984. Cercospora rodmanii Conway, a Biocontrol Agent of Waterhyacinth. Florida Agricultural Experiment Station Bulletin 842. Gainesville, FL: University of Florida. 18 p.Google Scholar
Gottlieb, D. 1978. The Germination of Fungus Spores. Durham, England: Meadowfield Press. 166 p.Google Scholar
Heiny, D. K. and Templeton, G. E. 1991. Effects of spore concentration, temperature, and dew period on disease of field bindweed caused by Phoma proboscis . Phytopathol. 81:905909.Google Scholar
Huber, L. 1992. Modeling leaf wetness in relation to plant disease epidemiology. Annu. Rev. Phytopathol. 30:553577.Google Scholar
Ingold, C. T. 1978. Water and spore liberation. In Kozlowski, T. T., ed. Water Deficits and Plant Growth: Water and Plant Disease. London: Academic Press. pp. 119140.Google Scholar
Lacey, J. 1986. Water availability and fungal reproduction: Patterns of spore production, liberation, and dispersal. In Ayres, P. G. and Boddy, L., eds. Water, Fungi, and Plants. Cambridge, UK: Cambridge University Press. pp. 6586.Google Scholar
Nag Raj, T. R. and Ponnappa, K. M. 1970. Blight of waterhyacinth caused by Alternaria eichhorniae sp. nov. Trans. Br. Mycol. Soc. 55:123130.CrossRefGoogle Scholar
Quimby, P. C. Jr., Fulgham, F. E., Boyette, C. D., and Connick, W. J. Jr. 1989. An invert emulsion replaces dew in biocontrol of sicklepod—a preliminary study. In Hovde, D. A. and Beestman, G. B., eds. Pesticide Formulations and Application Systems. Volume 8. ASTM STP 980. Philadelphia, PA: American Society for Testing and Materials. pp. 264270.Google Scholar
SAS Institute. 1985. SAS/STAT User's Guide. Release 6.0. Cary, NC: SAS Institute. 378 p.Google Scholar
Shabana, Y. M. 1992. Biological control of waterhyacinth by using plant pathogens. . Mansoura University, Egypt. 240 p.Google Scholar
Steel, R.G.D. and Torrie, J. H. 1980. Principles and Procedures of Statistics: A Biomedical Approach. 2nd ed. New York: McGraw-Hill. 633 p.Google Scholar
TeBeest, D. O., Yang, X. B., and Cisar, C. R. 1992. The status of biological control of weeds with fungal pathogens. Annu. Rev. Phytopathol. 30:637657.Google Scholar
Templeton, G. E. and Heiny, D. K. 1989. Improvement of fungi to enhance mycoherbicide potential. In Whipps, J. M. and Lumsden, R. D., eds. Biotechnology of Fungi for Improving Plant Growth. Cambridge, UK: Cambridge University Press. pp. 127152.Google Scholar
Templeton, G. E., TeBeest, D. O., and Smith, R. J. Jr. 1979. Biological weed control with mycoherbicides. Annu. Rev. Phytopathol. 17:301310.Google Scholar
Walker, H. L. and Boyette, C. D. 1985. Biological control of sicklepod (Cassia obtusifolia) in soybeans (Glycine max) with Alternaria cassiae . Weed Sci. 33:212215.Google Scholar