2012 Annual Report
We increased seed, under carefully controlled field conditions, of accessions of Palmer amaranth collected from throughout the southern U.S. for use in common garden competition experiments. Special care was taken to avoid introducing a seedbank for these species. We also monitored and measured the demography and growth of the energy crops Miscanthus giganteus and Miscanthus sinensis in old field and forest environments in central Illinois, again with special procedures to minimize invasion risk. Finally, we continued our work on the management and environmental risk factors associated with the evolution and spread of glyphosate resistant waterhemp in Illinois grain crops, beginning database construction and statistical analysis.
Several experiments concerning weed management in sweet corn were conducted. Organic weed management systems in Illinois and Washington were examined, whereby combinations of competitive crop cultivars and mechanical weed management tactics were tested. In other work, integrated weed management alternatives to atrazine– the most widely used herbicide in corn production – were tested in Illinois and Minnesota. Finally, we quantified the extent to which climate region (Midwest versus Pacific Northwest), cytochrome P450 genotype in sweet corn, and herbicide tankmix influenced crop tolerance to HPPD-inhibiting herbicides. Processing pumpkin productivity and weed community characteristics also are being quantified in different production systems, including a bioenergy-vegetable double-cropping system. Biomass feedstock (rye+vetch) was fall-planted and spring-seeded; processing pumpkin is grown in different tillage and residue treatments. We have been successful in cultivating processing pumpkin, which has required some new field equipment and an aggressive fungicide application schedule. At the request of vegetable industry stakeholders, new agronomic and weed management research in vegetable soybean (edamame) is underway. One set of experiments is being used to quantify the shortcomings of current weed management systems built around the small number of herbicides being considered for use in the crop. Another set of experiments has been deployed to characterize important agronomic traits, including disease susceptibility, herbicide sensitivity, and weed suppressive traits, among new and old commercial and public cultivars.
1)new hybrids have largely shifted away from sugary (su1 endosperm) to supersweet (sh2 endosperm) types;.
2)the basis for sweet corn resistance to the rust Puccinia sorghi has come to be largely based on a single class of genes (Rp gene = resistance to Puccinia); and.
3)there is considerable potential for improving sweet corn tolerance to herbicides, given that 20% or more of the hybrids evaluated since 2002 are able to detoxify many herbicidal compounds metabolically (using the cytochrome P450 pathway). This research has become the primary source for the sweet corn industry (growers, processors, seed companies, crop protection companies) to determine hybrid tolerance to herbicides and resistance to prevalent diseases.
Pataky, J.K., Williams, M., Headrick, M.M., Nankam, C., Du Toit, L., Michener, P.M. 2011. Observations from a quarter century of evaluating reactions of sweet corn hybrids in disease nurseries. Plant Disease. 95:1492-1506.
Williams, M.M. II, Pataky, J.K. 2011. Interactions between maize dwarf mosaic and weed interference on sweet corn. Field Crops Research. 128:48-54.
Williams, M.M. II. 2011. Agronomics and economics of plant population density on processing sweet corn. Field Crops Research. 128:55-61.
Davidson, A.N., Ho, C., Chee Sanford, J.C., Lai, H.Y., Klenzendorf, J.B., Kirisits, M.J. 2011. Characterization of bromate-reducing bacterial isolates and their potential for drinking water treatment. Water Research. 45(18):6051-6062.
Williams, M., Boydston, R.A., Peachey, R.E., Robinson, D. 2011. Significance of atrazine as a tank-mix partner with tembotrione. Weed Technology. 25(3):299-302.
Bicksler, A., Masiunas, J., Davis, A.S. 2012. Canada thistle (Cirsium arvense) suppession by sudangrass interference and defoliation. Weed Science. 60:260-266.
Davis, A.S., Ainsworth, E.A. 2012. Weed interference with field-grown soybean (Glycine max) decreases under elevated [CO2] in a FACE experiment. Weed Research. 52(3):277-285.
Matlaga, D.P., Schutte, B., Davis, A.S. 2012. Age-dependent population dynamics of the bioenergy crop Miscanthus x giganteus in Illinois. Journal of Invasive Plant Science and Management. 5:238-248.
Davis, A.S., Daedlow, D., Schutte, B.J., Westerman, P. 2011. Temporal scaling of episodic point estimates of weed seed predation to long-term predation rates. Methods in Ecology and Evolution. 2:382-692.
Davis, A.S., Landis, D.A. 2011. Invasive species in agriculture. In: M. Rejmanek and D. Simberloff, editors. Encyclopedia of Introduced Invasive Species. Berkeley, CA: University of California Press. p. 7-11.
Sims, G.K., Kanissery, R. 2012. Transformation of herbicides under transient anoxia. In: Casteneda, S.F., Emerson, M.L., editors. Xenobiotics: New Research. Hauppauge, New York: Nova Science Publishers. p. 67-84.
Matlaga, D.P., Quinn, L.D., Davis, A.S., Stewart, R. 2012. Light response of native and introduced Miscanthus sinensis seedlings. Biological Invasions. 5:363-374.
Evans, J.A., Davis, A.S., Raghu, S., Raghavendran, A., Landis, D., Schemske, D. 2012. The importance of space, time and stochasticity to the demography and management of Alliaria petiolata. Ecological Applications. 22:1497-1511.