Brief Summary of Minutes of Annual Meeting

Short-term outcomes: The immediate benefits of the NC1191 weed phenology project will be to improve our ability to predict the timing of weed seedling emergence and seed production. This will aid farmers in developing cost-effective management plans for timing weed control efforts on their farm. Outputs: We will generate regional-scale data on the phenology of summer and winter annual weeds of the north central region. These data will be used to update and improve models of weed seedling emergence. Activities: Our team has cooperators in IL, KS, MO, MT, ND, NE, OH, OR, and SD, all working on the same weed phenology field study. We have collected one year of data on the timing of seedling emergence, flowering and seed maturation for common lambsquarters, velvetleaf, field pennycress and marestail. We intend to collect two more years of data on these species, after which this information will be used to test the current parameterization of Hopkins Bioclimatic Law (HBL). By improving HBL, we will be able to develop more accurate predictions of weed phenology in support of weed management. Activity 1.2 - spring: collect/bury winter annual weed seeds (cohort II), monitor winter annual weed flowering and seed development (cohort I) and summer annual seedling emergence (cohort I); fall: collect/bury summer annual seeds (cohort II), monitor winter annual weed seedling emergence (cohort II) and summer annual flowering and seed development (cohort I). Activity 1.2 Milestones: statistical modeling activities to improve HBL and create HBL.2 finished by end of Year 2. Preparation of related manuscript for peer-reviewed journal.

Wortman, S. E., A. S. Davis, B. J. Schutte, J. L. Lindquist, J. Cardina, J. Felix, C. L. Sprague, J. A. Dille, A.H.M. Ramirez, G. Reicks, and S. A. Clay. 2012. Local conditions, not regional gradients, drive demographic variation of Ambrosia trifida and Helianthus annuus across northern U.S. maize belt. Weed Science 60:440-450. Ramirez, A. H. M., J. A. Dille, S. A. Clay, A. S. Davis, J. Felix, F. D. Menalled, R. G. Smith, C. L. Sprague, E. Hill. In review. Plant-soil feedback response of giant ragweed (Ambrosia trifida) and common sunflower (Helianthus annuus). Weed Science. Davis, A. S., S. Clay, J. Cardina, A. Dille, F. Forcella, C. Sprague. In review. Overwinter burial environment explains departures from regional hydrothermal model of giant ragweed seedling emergence in U.S. Midwest. Weed Science.