Research Project: Understanding and Responding to Multiple-Herbicide Resistance in Weeds

Location: Global Change and Photosynthesis Research

2019 Annual Report

Objectives
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.

Approach
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.

Progress Report
Previous years’ field experiments indicated the presence of the genetic potential for dissimilatory nitrate reduction to ammonium (DNRA) as a significant process of nitrogen retention in agricultural soils, but existing molecular probes developed by us in 2014 were not optimized for tracking the genes associated with the process and their expression in soil environments. New molecular probes were developed and optimized for use in conventional polymerase chain reaction applications and new multiplex polymerase chain reaction array systems and were recently applied to track DNRA in a controlled flooding/drainage experiment. Data analysis is in progress. Year 4 field studies determined that nitrous oxide reduction genetic potential was high in two Illinois agricultural soils, and specific nitrous oxide-reducing microbial populations were responding differentially to soil temperature and temporal flooding. To improve understanding of which microbial populations were responding to field conditions and to identify specific environmental drivers of nitrous oxide reduction that account for loss of nitrogen from soil, a series of probes were developed and are currently being tested in field and laboratory microcosm experiments. Collectively, the new molecular probes are intended to provide much needed improvements to molecular research tools to assess the relationship between plants (crops and weeds) and soil microbial communities involved with nitrogen-cycling processes in upcoming experiments. Microcosm-seed germination studies have not yet been conducted. Evaluation of the link between microbial N-cycle processes and weed seed germination and seedling development has proven unworkable. Limitations in microbial detection and protocol development continue to impede measurable progress. Progress continues to be made on how crop management and abiotic factors affect weed ecology in the upper Midwest, especially in snap bean, lima bean, edamame, and sweet corn. This work includes research on improving the feasibility of using multi-tactic integrated weed management approaches for regaining control of weeds with resistances to multiple herbicides in agronomic and vegetable crops. For large-seeded vegetable crops, basic production knowledge of crop competitiveness and the extent of the weed problem is limited, yet essential to addressing project objectives. In addition to experiments outlined in project plan, additional field experiments are being planned or conducted, including aspects of crop population density, stress-resistant cultivars, competitive root traits, crop planting dates, crop tolerance to herbicides, weed surveys of production fields, and post-harvest weed control. Data analysis has been completed on several datasets, including aspects of crop population density, crop tolerance to herbicides, and integrated weed management systems. Six manuscripts are in preparation. Four journal articles have been completed and published, and an additional two manuscripts are in review.

Accomplishments
1. New tools for managing weeds in edamame. Vegetable processors remain interested in growing edamame domestically, and while ARS scientists in Urbana, Illinois, have facilitated the registration of several herbicides on edamame in recent years, the need for non-chemical weed management tactics has grown with the rise of multiple herbicide resistance in weeds. In the last year, ARS scientists in Urbana, Illinois, have published several experiments that have identified new effective tactics, including: 1) direct seeding into an early-killed rye cover crop, which reduces weed density and growth without harming the crop, 2) manipulating crop seed size, as plants grown from large seed tolerate weed interference better than small seed, 3) shallow planting depth, as edamame is more successful at shallow compared to deep planting depth, and 4) cultivar choice because certain cultivars are more weed suppressive than others. Collectively, this knowledge offers vegetable processors and edamame growers several additional tools to manage weeds in their toolkit, for both organic and conventional producers. Having such non-chemical tactics to weed management are critical as multiple herbicide resistance is becoming the norm thought many U.S. cropping systems.

Review Publications
Zalamea, P.C., Dalling, J.W., Sarmiento, C., Arnold, A.E., Delevich, C., Berhow, M.A., Ndobegang, A., Gripenberg, S., Davis, A.S. 2018. Dormancy-defense syndromes and tradeoffs between physical and chemical defenses in seeds of pioneer species. Ecology. 99(9):1988-1998. https://doi.org/10.1002/ecy.2419.
Eslami, S.V., Davis, A.S. 2018. Weed interference with no-till soyabeans influenced by fine-scale covariation between soil properties and cover crop performance. Weed Research. 58:463-474. https://doi.org/10.1111/wre.12334.
Gonzalez-Andujar, J.L., Aguilera, M.J., Davis, A.S., Navarrete, L. 2018. Disentangling weed diversity and weather impacts on the long-term crop production in a wheat-legume rotation. Field Crops Research. 232:24-29. https://doi.org/10.1016/j.fcr.2018.12.005.
Park, A.G., McDonald, A.J., Devkota, M., Davis, A.S. 2018. Increasing yield stability and input efficiencies with cost-effective mechanization in Nepal. Field Crops Research. 228:93-101. https://doi.org/10.1016/j.fcr.2018.08.012.
O'Brien, S.R., Davis, A.S., Riechers, D.E. 2018. Quantifying resistance to isoxaflutole and mesotrione and investigating their interaction with metribuzin POST in waterhemp (Amaranthus tuberculatus). Weed Science. 66(5):586-594. https://doi.org/10.1017/wsc.2018.36.
Evans, J.A., Williams, A., Hager, A.G., Mirsky, S.B., Tranel, P.J., Davis, A.S. 2018. Confronting herbicide resistance with cooperative management. Pest Management Science. 74:2424-2431. https://doi.org/10.1002/ps.5105.
Krichels, A.H., DeLucia, E.H., Sanford, R.A., Chee Sanford, J.C., Yang, W.H. 2019. Historical soil drainage mediates the response of soil greenhouse gas emissions to intense precipitation events. Soil Biology and Biochemistry. 142(3):425-442. https://doi.org/10.1007/s10533-019-00544-x.
Crawford, L., Williams, M.M. II. 2018. Role of edamame (Glycine max) seed size in early-season crop-weed interactions. Weed Science. 66:746-751. https://doi.org/10.1017/wsc.2018.46.
Reddy, K.N., Cizdziel, J.V., Williams, M., Maul, J.E., Rimando, A.M., Duke, S.O. 2018. Glyphosate resistance technology has minimal or no effect on maize mineral content and yield. Journal of Agricultural and Food Chemistry. 66:10139-10146. https://doi.org/10.1021/acs/jafc.8b01655.
Muthukrishnan, R., Jordan, N.R., Davis, A.S., Forester, J.D. 2019. Use of simulation-based statistical models to complement bioclimatic models in predicting continental scale invasion risks. Diversity and Distributions. 21(3):847-859. https://doi.org/10.1007/s10530-018-1864-3.
Williams, M.M. II, Moody, J.L., Hausman, N.E. 2019. Vegetable soybean tolerance to flumioxazin-based treatments for waterhemp control is similar to grain-type soybean. Weed Technology. 33:530-534. https://doi.org/10.1017/wet.2019.15.
Crawford, L.E., Williams, M.M. II. 2019. Planting depth and seed size affect edamame emergence individually. HortScience. 54(1):92-94. https://doi.org/10.21273/HORTSCI13631-18.
Cannon, J.C., Sanford, R.A., Connor, L.M., Yang, W.H., Chee Sanford, J.C. 2019. Optimization of PCR primers to detect phylogenetically diverse nrfA genes associated with nitrite ammonification. Applied and Environmental Microbiology. 160:49-59. https://doi.org/10.1016/j.mimet.2019.03.020.
Houlihan, A.J., Conlin, P., Chee-Sanford, J.C. 2019. Water-soluble exudates from seeds of Kochia scoparia exhibit antifungal activity against Colletotrichum graminicola. PLoS One. 14(6):e0218104. https://doi.org/10.1371/journal.pone.0218104.