Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 2/12/2004
Publication Date: 2/12/2004
Citation: Harbur, M.M., Evans, E.E., Nickel, L.M., Sheaffer, C.C., Wyse, D.L., Allan, D.L., Nickel, P., Forcella, F. 2004. Organic weed management research in southwestern Minnesota [abstract]. Weed Science Society of America. p. 29-30. Interpretive Summary:
Technical Abstract: The University of Minnesota received funding in 2002 from the CSREES Organic Conversion Program (OCP) to investigate several weed management strategies for application to organic cropping systems. The first objective is to compare the effects of two organic management systems on annual weed populations (predominantly Setaria spp.) and crop productivity. Experiments are being conducted on corn-soybean and corn-soybean-oat-alfalfa rotations. The two organic management systems differ in the form of organic amendments (heap manure or compost), schedule of rotary hoeing and use of fall cover crops. The effectiveness of systems will be determined from crop yield, weed biomass eight weeks after planting and weed seed production. The second objective is to evaluate the effects of species composition and planting date effects on the establishment, biomass production and weed suppression potential of fall cover crops. The two species compositions included in the experiment are hairy vetch/winter rye and red clover/ annual rye grass. Cover crops are broadcast following the last row cultivation in early summer, in early August, or following crop harvest in fall. Cover crops performance is evaluated in both corn and soybean. Treatments will be compared based on cover crop stand, biomass production and weed seedling recruitment and growth in the following crop. The third objective is to compare three-year organic Canada thistle (Cirsium arvense (L.) Scop.) management systems. Management phases within systems include repeated tillage, row crops, smother crops and fall cover crops. Repeated tillage will be initiated either in mid-May or in mid-June in order to evaluate the effect of tilling Canada thistle that is in the bud stage. Smother crops include green pea, buckwheat, cowpea, pearl millet, winter wheat and alfalfa. Cover crops are winter rye and oilseed radish. The sequences of management phases within the system are varied between treatments in order to identify the best strategy for Canada thistle management. Treatment effectiveness will be evaluated based on crop yield (where applicable), Canada thistle biomass, Canada thistle population density and Canada thistle patch size.