Location: Agroecosystems Management ResearchTitle: Effect of date of termination of a winter cereal rye cover crop (Secale cereale) on corn seedling disease
|ACHARYA, J - Iowa State University|
|LENSSEN, A - Iowa State University|
|ROBERTSON, A - Iowa State University|
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2015
Publication Date: 1/1/2016
Citation: Acharya, J., Bakker, M.G., Kaspar, T.C., Moorman, T.B., Lenssen, A., Robertson, A. 2016. Effect of date of termination of a winter cereal rye cover crop (Secale cereale) on corn seedling disease. American Phytopathological Society Annual Meeting. 106:S1.1.
Technical Abstract: Cover cropping is an expanding conservation practice that offers substantial benefits to soil protection, soil health, water quality, and potentially crop yields. Presently, winter cereals are the most widely used cover crops in the upper Midwest. However, winter cereal cover crops preceding corn, may dampen beneficial soil health and rotation effects by putting two grass species in succession. We quantified densities of Fusarium graminearum, Fusarium oxysporum, Pythium sylvaticum and Pythium torulosum in roots of glyphosate terminated cereal rye cover crops from several field experiments with qPCR. In general, we found that corn seedling pathogens can increase in density on recently killed roots of cereal rye. F. oxysporum was detected in 96% of cereal rye root samples, with a maximum density of 201 pg DNA mg-1 dry root tissue. Corresponding values for P. sylvaticum were 78% and 620 pg mg-1; for P. torulosum, 42% and 1.5 pg mg-1; for F. graminearum, 25% and 0.8 pg mg-1. We also tracked fungal and oomycete community succession in roots of cereal rye over time after determination and detected other potential shared pathogens between cereal rye and corn using a non-targeted DNA sequencing approach. This work suggests the potential for elevated disease pressure on corn seedlings following cereal rye cover crops, although this risk will be heavily influenced by environmental conditions.