Project Number: 5012-12220-009-000-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2015
End Date: Sep 30, 2020
Objective 1: Determine how crop management practices (such as cultivar selection) and abiotic factors affect weed ecology in the upper Midwest, especially in vegetable and bioenergy crops. Sub-objective 1a: Identify cover crop residues that favor edamame over the weed. Sub-objective 1b: Quantify the impact of Miscanthus invasion and removal on plant community composition. Sub-objective 1c: Quantify the role of soil environmental parameters (e.g., C, C:N and NO3-:NO2- ratios, pH, diurnal temperature variations, soil moisture) in controlling nitrification along with N-loss (denitrification) vs. N-retention (DNRA), and evaluate the link between measured N-cycle processes to weed seed germination and seedling development. Objective 2: Improve the feasibility of using multi-tactic integrated weed management approaches for regaining control of weeds with resistances to multiple herbicides, and for preventing or slowing the evolution of herbicide resistance in susceptible weed populations. Sub-objective 2a: Evaluate the impact of harvest weed seed control (HWSC) on population dynamics and management of multiple-herbicide-resistant weed genotypes in field crops. Sub-objective 2b: Develop and compare weed management systems in edamame, utilizing cover crops, herbicides, and physical weeding.
Multi-tactic integrated weed management (IWM) offers one potential approach to address the problem of multiple herbicide resistant (MHR) weeds. In IWM systems, suites of multiple complementary tactics are deployed throughout weed life cycles to increase efficacy of weed suppression, prevent survival of weeds that escape earlier management, and reduce weed populations over the long-term. In this project, we evaluate the utility of chemical, cultural, biological, and physical tactics in IWM systems for weed suppression and crop yield protection in fields with MHR weed populations. Edamame (vegetable soybean) cultivars tolerant to cover crop residues will be combined with cover crops, recently registered herbicides, and physical weeding to examine the potential of IWM in legume vegetable production systems. The contribution of improved knowledge of soil N cycling to aid better prediction of weed seedling emergence and community composition also will be evaluated in this production system. In field crops, interactions among weed seed destruction at crop harvest, cover crops, and tank mixtures of herbicides will be quantified for their impact on MHR weeds in corn and soybean. Finally, in a continuation of previous research, the impact of escaped invasive bioenergy crops on weeds of arable areas will be measured.