The Effect of Trifluralin on Rhizoctonia solani (isolate AG۴), Causal Agent of Soybean Damping off

Damping off caused by Rhizoctonia solani (isolate AG۴) constrains growing soybean in the north Iranian province of Golestan. The pathogen was grown on malt agar containing ۰, ۵۰, ۱۰۰ or ۲۰۰ ppm trifluralin then its vegetative growth and virulence were evaluated. The response of soybean cv. Williams seedlings grown in soil containing ۰, ۰.۵, ۱ and ۲ ?g ai g-۱ trifluralin was investigated. On malt agar containing trifluralin, the radial growth of the fungal colonies was slower than that on untreated medium. There was no significant difference between these two types of colony in their abaility to cause disease symptoms on soybean seedlings. The incidence of soybean damping off in autoclaved soil treated with trifluralin was significantly higher than that in untreated soil. The results indicate that trifluralin enhanced the susceptibility of soybean radicles to the pathogen.   REFERENCES  Altman, J. and Rovira, A. D. (۱۹۸۹) Herbicide-pathogen interactions in soilborne root disease. Cand. J. Botani, ۶۶, ۱۵۴۷-۱۵۵۵. Bauske, E. M and Kirby, H. W. (۱۹۹۲) Effects of dinitroanaline herbicides, carboxinpentachloronitrobenzene seed treatment, and Rhizoctonia disease on soybean. Plant Disease, ۷۶, ۲۳۶-۲۳۹.  Chandler, J. and Santelman, P. W. (۱۹۶۷) Interaction of four herbicides with Rhizoctonia solani in seedling cotton. Weed Sci., ۱۶, ۴۵۳.  Doupnik, B. Jr. (۱۹۹۳) Soybean production and disease loss estimates for the north central United State from ۱۹۸۹-۱۹۹۱. Plant Disease, ۷۷, ۱۱۷۰- ۱۱۷۱. Hamdollah-zadeh, A. and Rahimian, H. (۱۹۸۹) Anastomosis group ۴ is the major cause of Rhizoctonia solani of cotton and soybean in Gorgan. In Proceeding of the ۹th Plant Protection Congress of Iran, ۹-۱۴ Sept. ۱۹۸۹, Ferdowsi University, Mashhad, Iran, p. ۱۱۰. Harikrishman, R. and Yang, X. B. (۲۰۰۲) Effects of herbicides on root rot and damping- off caused by Rhizoctonia solani in Glyphosate- tolerant soybean. Plant Disease, ۸۶, ۱۳۶۹- ۱۳۷۳. Levesque, C. A., Rahe, J. E. and Eaves, D. M. (۱۹۸۷) Effect of glyphosate on Fusarium spp.: its influence on root rot colonization of weeds, propagule density in the soil, and crop emergence. Cand. J. Mic., ۳۳, ۳۵۴- ۳۶۰. Morejohn, L. C., Bureau, T. E., Mole- Bajer, J., Bajer, A. S. and Fosker, D. E. (۱۹۸۷) Oryzalin, a dinitroanaline herbicides bins to plant tubulin and inhibits microtubule polymerization in vitro. Planta, ۱۷۲, ۲۵۲- ۲۶۴.  Ross, M. A. and Lembi, C. A. (۱۹۹۹) Applied Weed Science, ۲nd Edition. Prentice Hall Inc., New Jersey. ۴۵۲ p. Sanogo, S., Yang, X. B. and Scherm, H. (۲۰۰۰) Effects of herbicides on Fusarium solani f. sp. glycines and development of sudden death syndrome in glyphosate tolerant soybean. Phytopathology, ۹۰, ۵۷- ۶۶.  Sharon, A., Amsellem, Z. and Gressel, J. (۱۹۹۲) Glyphosate suppression of induced defense responses: increase susceptibility of Cassia obtusifolia to a mycoherbicide. Plant Physiol., ۹۸, ۶۵۴- ۶۵۹. Sinclair, J. B. Backman, P. A. (۱۹۸۹) Compendium of Soybean Diseases, ۳rd ed. American Phytopathological Society Press,  St. Paul, MN. Vencil, W. K. (۲۰۰۲) Herbicide Handbook, ۸th Edition. Weed Science Society of America, USA. ۴۹۳ p. Wiley, G. L. and Ross, M. A. (۱۹۷۴) Effect of herbicides on Rhizoctonia root rot of soybean. In the Proceedings of North Central Weed Control Conference, ۲۹, ۳۳-۳۴

کلیدواژه ها:

Damping off ، Rhizoctonia solani ، Soybean ، Trifluralin