Brief Summary of Minutes of Annual Meeting

Accomplishments and Impacts  NC202 ( Objective 1: Understand the basis and relative importance of spatial, temporal, and biological variability in weed-crop competition. Accomplishments: Field studies have been completed for Objective 1 at many locations across the North Central region. Data have been presented at North Central Weed Science Society annual meetings each year by individual state representatives, some presenting state-specific data, other presenting a regional summary of data. Manuscripts are currently being prepared to bring regional data and results together. Objective 1D was summarized at annual meeting. Results indicated that modeling over-predicts potential crop yield loss, particularly at the second cohort (VE in soybean, V2 in corn). Consensus is that WeedSoft is a good tool to make herbicide recommendations, but it has several problems in its competitive component. B) Objective 2: Understand spatial, temporal and biological variability of weed seed in the soil seedbank and impact on weed-crop competition. Accomplishments: This second objective has fostered close collaboration with other states and researchers regarding the three primary weed species of the north central states. Researchers have determined robust estimates of seed persistence for velvetleaf, common lambsquarters, and giant foxtail. When the seed persistence data are pooled over sites within burial periods, persistence rates for each burial period are the same across years for each of the species (Velvet Leaf: Oct-Mar, 75%, Mar-Oct, 59%; Common Lambsquarters: Oct-Mar, 70%, Mar-Oct, 67%; Giant Foxtail: Oct-Mar, 73%, Mar-Oct, 32%). This has led to considerably heightened understanding and insights into how these species survive in soil seedbanks. As a consequence, our ability to forecast the population dynamics of these species under differing soil management scenarios has increased significantly. C) Objective 3: Develop DSS modules to incorporate risk into weed management recommendations. Accomplishments: There is an overlap of participants in both the multi-state research project with the regional development of the decision support system, WeedSOFT. Knowledge generated from research projects is directly input into annual updates of WeedSOFT for each state. Members of NC202 have met with the WeedSOFT group on numerous occasions to discuss opportunities and plans for integrating information.

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