Location: Agroecosystems Management ResearchTitle: Winter rye cover crops as a host for corn seedling pathogens Author
Submitted to: American Phytopathological Society
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2015
Publication Date: 1/1/2016
Citation: Bakker, M.G., Moorman, T.B., Kaspar, T.C., Manter, D.K. 2016. Winter rye cover crops as a host for corn seedling pathogens. American Phytopathological Society. 106:S1.2. doi: 10.1094/PHYTO-106-1-s1.1
Technical Abstract: Cover cropping is a prevalent conservation practice that offers substantial benefits to soil protection, soil health and water quality. However, emerging implementations of cover cropping, such as winter cereals preceding corn, may dampen beneficial rotation effects by putting similar crop species in succession. Here, we show that cereal rye cover crops can host pathogens capable of causing corn seedling disease. We quantified densities of Fusarium graminearum, Fusarium oxysporum, Pythium sylvaticum and Pythium torulosum in roots of cereal rye from several field experiments with qPCR, demonstrating 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 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 in corn planting following cereal rye, although this risk will be heavily influenced by environmental conditions.