Hoerning, Cody2019-06-122019-06-122019-02https://hdl.handle.net/11299/203570University of Minnesota M.S. thesis. February 2019. Major: Applied Plant Sciences. Advisor: Donald Wyse. 1 computer file (PDF); vii, 55 pages.Midwest crop production is dominated by two summer annual crops grown in rotation, corn (Zea mays L.) and soybean [Glycine max (L.) Merr.]. The rotation leaves a productivity gap during the spring and autumn. Winter oilseed crops, such as pennycress (Thlaspi arvense L.), and winter camelina [Camelina sativa (L.) Crantz], can fill this gap and provide ecosystem and economic benefits. The objectives of this study were to: i) examine the tradeoffs between soybean and winter oilseed yields in the relay-cropping system, ii) determine legacy impacts on corn one year after oilseed-soybean relay-cropping, iii) evaluate the weed suppression abilities of the winter oilseeds. iv) evaluate the host susceptibility of the winter oilseeds to SCN in the greenhouse, and v) evaluate pennycress germplasm collection for major resistance genes to SCN. Three sites were used across Minnesota to evaluate winter oilseeds and commodity crop yields in a relay-cropping production system. Total seed production of the system (winter oilseed crop + soybean) was increased by 20% at one site, while at the other two sites, there was no significant difference in total yield when compared to mono-cropped soybean. Soybean yield was reduced at two-of-three sites by the inclusion of winter oilseeds by 20% and 47%. Soybean yield was unaffected by inclusion of winter oilseeds at the third site. Corn yield, in the subsequent year, was unaffected by the winter oilseed treatments. Weeds were suppressed by the winter oilseeds crops. The pennycress treatment reduced weed biomass by 97% to 100%. Likewise, the camelina treatment reduced weed biomass by 85% to 87%. The inclusion of winter oilseeds in the corn-soybean cropping system can increase overall seed production and suppress early-season weeds. Through greenhouse evaluation it was determined that pennycress is an alternate host for soybean cyst nematode; while camelina is a poor or non-host. Including pennycress as a winter annual cover crop in rotations with soybean has the potential to increase SCN pest pressure. Genetic screens for SCN resistance found variation in the population. Lines tested ranged in Female Index values from 27-143. Indicating diversity in the germplasm that may be able to be exploited for resistance development. The inclusion of winter oilseeds in the corn-soybean cropping system can increase productivity and decrease weed populations, but also may increase pest pressure of SCN in the cropping system.enThesis or Dissertation