Research Interests

The goal of my research is optimization of integrated weed management systems by applying safe technologies within the framework of fundamental ecological principles. Study systems are defined by major vegetable and rotation crops, and the predominant weed species that invade these systems. In order to develop robust, inference-based weed management systems, knowledge on crop and weed dynamics is seminal. Due to limited basic information on weeds in vegetables, the initial approach is to quantify several aspects of crop/weed interactions. Results of field-based, multi-site interference studies are being used to parameterize deterministic models of crop/weed competition. These aid weed management decision making by identifying conditions when the crop is susceptible to losses in yield and quality, as well as implications to weed fitness. Furthermore, emerging biological, cultural, and chemical technologies are being examined for their potential role, individually and in a combined approach, in vegetable/rotation cropping systems.

Refereed Publications

Williams, M.M. II , T.L. Rabaey, and Boerboom, C.M. Residual weeds of sweet corn in the north central region. Weed Technology (in press).

Pataky, J.K., Meyer, M.D., Bollman, J.D., Boerboom, C.M., and Williams, M.M. II.  2008. Genetic basis for varied levels of injury to sweet corn hybrids from three cytochrome P-450 metabolized herbicides. Journal of the American Society for Horticultural Science 133(3): 438-447.

Metzger, C., Boydston, R., Ferguson, H., Williams, M.M., Zack, R., and Walsh, D. 2008. Interactions between population density of the Colorado potato beetle, Leptinotarsa decemlineata , and herbicide rate for suppression of solanaceous weeds. 10pp. Journal of Insect Science. 8: 40, available online: insectscience.org/8.38.

Williams, M.M. II and Pataky, J.K. 2008. Genetic basis of sensitivity in sweet corn to tembotrione. Weed Science 56: 364-370.

Nordby, J.N., Williams, M.M. II , Pataky, J.K., Riechers, D.E. 2008. A common genetic basis in sweet corn inbred Cr1 for cross-sensitivity to multiple cytochrome P450-metabolized herbicides. Weed Science 56:376-382.

Williams, M.M. II , Boydston, R.A., and Davis, A.S. 2008. Differential tolerance in sweet corn to wild-proso millet (Panicum miliaceum) interference. Weed Science 56:91-96.

Williams, M.M. II , Boydston, R.A., and Davis, A.S. 2008. Crop competitive ability contributes to herbicide performance in sweet corn. Weed Research 48:58-67.

Williams, M. M. II., R. A. Boydston and A. S. Davis . 2007. Wild proso millet ( Panicum miliaceum ) suppressive ability among three sweet corn hybrids. Weed Science 55: 245-251.

Williams, M.M. II and J.L. Lindquist. 2007. Influence of planting date and weed interference on sweet corn growth and development. Agronomy Journal 99: 1066-1072 .

Davis, A.S. and Williams, M.M. II . 2007. Variation in wild proso millet fecundity in sweet corn has residual effects in snap bean. Weed Science 55: 502-507.

Williams, M.M. II, Ransom, C.V., and Thompson, W.M. Volunteer potato density influences critical time of weed removal in bulb onion. Weed Technology. 21:136-140. 2007.

Chee-Sanford, J.C., Williams, M.M. II, Davis, A., and Sims, G. Do microorganisms influence seed bank dynamics? Weed Science 54:575-587. 2006.

Ortiz-Ribbing, L. and Williams, M.M. II. Conidial germination and germ tube growth of Phomopsis amaranthicola and Microsphaeropsis amaranthi on leaf surfaces of seven Amaranthus species. Biological Control 38:356-362. 2006.

Williams, M.M. II. Planting date influences critical period of weed control in sweet corn. Weed Science 54:928-933. 2006.

Williams, M.M. II and Masiunas, J.B. Functional relationships between giant ragweed interference and sweet corn yield and ear traits. Weed Science. 54:948-953. 2006.

Williams, M.M. II, Boydston, R.A., and Davis, A.S. Canopy variation among three sweet corn hybrids and implications for light competition. HortScience 41:1449-1454. 2006.

Pataky, J.K., Nordby, J.N., Williams, M.M. II, and Riechers, D.E. Inheritance of cross-sensitivity in sweet corn to herbicides applied postemergence. Journal of the American Society for Horticultural Science 131(6):744-751. 2006.

Williams, M.M.II and R.A. Boydston. 2006. Volunteer potato interference in carrot. Weed Sci. 54:94-99. 2006.

Williams, M.M. II, Pataky, J.K., Nordby, J.N., Riechers, D.N., Sprague, C.L., and Masiunas, J.B. Cross-sensitivity in sweet corn to nicosulfuron and mesotrione applied postemergence. HortScience 40(6):1801-1805. 2005.

Williams, M.M. II and Boydston, R.A. Alternative to handweeding volunteer potato in carrots. Weed Technology 19: 1050-1055. 2005.

Williams, MM II, C.V. Ransom, W.M. Thompson. Duration of volunteer potato interference in bulb onion. Weed Science 53:62-68. 2005.

Boydston, R.A. and M.M. Williams II. Managing volunteer potato in field corn with mesotrione and arthropod herbivory. Weed Technology 19:443-450. 2005.

Davis, Adam S., J. Cardina, F. Forcella, G.A. Johnson, G. Kegode, J.L. Lindquist, E.C. Luschei, K.A. Renner,C.L. Sprague, M.M. Williams II. Environmental factors affecting seed persistence of annual weeds across the U.S. corn belt. Weed Sci. 53:860-868. 2005.

Ortiz-Ribbing, L. and Williams, W.M. II. Potential of Phomopsis amaranthicola and Microsphaeropsis amaranthi, as bioherbicides for several weedy Amaranthus species. Crop Protection 25:39-46. 2005.

Williams, M.M. II, D.B. Walsh, and R.A. Boydston. Integrating arthropod herbivory and reduced herbicide use for weed management. Weed Science 52:1018-1025. 2004.

Williams, M.M. II, C.V. Ransom, and W.M. Thompson. Effect of volunteer potato density on dry bulb onion yield and quality. Weed Science 52:754-758. 2004.

Boydston, R.A. and Williams, M.M. II. Combined effects of Aceria malherbae and herbicides on field bindweed growth. Weed Science 52:297-301. 2004.

Dille, J.A., Milner, M., Groeteke, J., Mortensen, D.A. and Williams, M.M. II. How good is your weed map? A comparison of spatial interpolators. Weed Science 51:44-55. 2003.

Boydston, R.A. and Williams, M.M. II. Effect of soil fumigation on volunteer potato (Solanum tuberosum) tuber viability. Weed Technology 17:352-357. 2003.

Williams, M.M. II and Boydston, R.A. Effect of shoot removal during tuberization on volunteer potato (Solanum tuberosum) tuber production. Weed Technology 16:617-619. 2002.

Williams, M.M. II, Mortensen, D.A., Waltman, W.J. and Martin, A.R. Spatial inference of herbicide bioavailability using a geographic information system. Weed Technology 16:603-611. 2002.

Gerhards, R., Sökefeld, M., Timmermann, C., Kübauch, W. and Williams, M.M. II. Site-specific weed control in maize, sugar beet, winter wheat and winter barley. Precision Agriculture 3:25-35. 2002.

Williams, M.M. II, Mortensen, D.A., Martin, A.R. and Marx, D.B. Within-field soil heterogeneity effects on herbicide-mediated crop injury and weed biomass. Weed Science 49:798-805. 2001.

Williams, M.M. II and Mortensen, D.A. Crop/weed outcomes rom site-specific and uniform soil-applied herbicide applications. Precision Agriculture 2:377-388. 2001.

Williams, M.M. II, Gerhards, R. and Mortensen, D.A. Two-year weed seedling population responses to a postemergent method of site-specific weed management. Precision Agriculture 2:247-263. 2001.

Williams, M.M. II, Gerhards, R. and Mortensen, D.A. Spatiotemporal outcomes of site-specific weed management in maize. Pages 897-906. in J.V. Stafford, ed. Precision Agriculture ’99. Sheffield, United Kingdom: Sheffield Academic Press. 1999.

Gerhards, R., Sökefeld, M., Timmermann, C., Reichart, S., Kühbauch, W. and Williams, M.M. II. Results of a 4-year study on site-specific herbicide application. Pages 689-697. in J.V. Stafford, ed. Precision Agriculture ’99. Sheffield, United Kingdom: Sheffield Academic Press. 1999.

Williams, M.M. II, Mortensen, D.A. and Doran, J.W. No-tillage soybean performance in cover crops for weed management in the western cornbelt. Journal of Soil and Water Conservation 55:79-84. 2000.

Williams, M.M. II, Mortensen, D.A. and Doran, J.W. Assessment of weed and crop fitness in cover crop residues for integrated weed management. Weed Science 46:595-603. 1998.

Williams, M.M. II, Jordan, J. and Yerkes, C. The fitness cost of triazine resistance in Jimsonweed (Datura stramonium L.). American Midland Naturalist 133:131-137. 1995.

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