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The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens
  • Matthew G. Bakker, United States Department of Agriculture
  • Jyotsna Acharya, Iowa State University
  • Thomas B. Moorman, United States Department of Agriculture
  • Alison E. Robertson, Iowa State University
  • Thomas C. Kaspar, United States Department of Agriculture
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Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.


This article is published as Bakker, Matthew G., Jyotsna Acharya, Thomas B. Moorman, Alison E. Robertson, and Thomas C. Kaspar. "The potential for cereal rye cover crops to host corn seedling pathogens." Phytopathology 106, no. 6 (2016): 591-601. doi: 10.1094/PHYTO-09-15-0214-R.

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
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Matthew G. Bakker, Jyotsna Acharya, Thomas B. Moorman, Alison E. Robertson, et al.. "The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens" Phytopathology Vol. 106 Iss. 6 (2016) p. 591 - 601
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