Location: Global Change and Photosynthesis Research
2022 Annual Report
Objectives
Objective 1: Develop control measures for weeds in vegetables, fruits, and specialty crops. [NP304, C2, PS 2A]
Objective 2: Determine herbicide residues in harvested product. [NP 304, C2, PS 2A]
Approach
Candidate herbicides for use in minor crops will be identified. Herbicides alone or in combination with other tactics will be evaluated under field conditions and crop and/or weed responses will be determined.
Progress Report
Significant progress has been made on developing control measures for weeds in vegetable crops (Objective 1). The SNap Bean Association Panel (SNAP), a genotyped diversity panel with nearly 400 entries, was used to determine tolerance to several herbicides including sulfentrazone, pyroxasulfone, metribuzin, and flumioxazin under field conditions. Data from sulfentrazone trials has been analyzed, including the use of Genome-Wide Association (GWAS) modeling. These results have identified genomic regions associated with sulfentrazone tolerance. A manuscript has been prepared and published in Frontiers in Agronomy. Data from pyroxasulfone trials also has been analyzed including with GWAS. A manuscript is in preparation. Field trials with metribuzin and flumioxazin are being repeated in the 2022 field season to confirm results. Additional field trials with a subset of the SNAP were conducted with lines tolerant or sensitive to protoporphyrinogen (PPO)-inhibiting herbicides. Herbicides evaluated included PPO-inhibitors sulfentrazone, flumioxazin, fomesafen, lactofen, and saflufenacil; very long chain fatty acid inhibitor dimethenamid-P; and photosystem II-inhibitor metribuzin. This field trial is being repeated in the 2022 field season to confirm results. The SNAP is also being used to understand crop competitiveness with weeds; specifically, the role of biological nitrogen fixation in crop-weed interactions. Field trials in Urbana prove difficult to elucidate these interactions because of excessively high nitrogen levels even in fields deprived of added nitrogen for five years. However, controlled environment studies underway show promise and are ongoing. Research determining the extent to which sweet corn injury from dicamba can be managed with herbicide tolerance alleles and an herbicide safener has been completed and published.
Herbicide residues in vegetable crops was not conducted (Objective 2), because that information was inappropriate for experiments developed for Objective 1, which were centered on crop tolerance to herbicides and crop competitiveness with weeds.
Accomplishments
1. Identified manageable risk of sweet corn injury from dicamba. Use of dicamba herbicide has increased exponentially in recent years with the adoption of dicamba-tolerant (DT) soybean. Volatility of the product driven by later-season applications to DT soybean results in off-target dicamba movement which can injure sensitive crops. This research determined the extent to which sweet corn injury from dicamba can be managed. ARS researchers in Urbana, Illinois, with university partners, showed how crop cultivar, herbicide formulation, and timing of dicamba exposure reduces risk of sweet corn injury from dicamba. This new knowledge offers tangible approaches that growers, sweet corn seed companies, and herbicide manufacturers are adopting to protect domestic production of one of the United States' most favorite vegetables.
Review Publications
Landau, C.A., Bernards, M.L., Hager, A.G., Williams II, M.M. 2022. Significance of application timing, formulation, and cytochrome P450 genotypic class on sweet corn response to dicamba. Weed Science. 70(2):167-173. https://doi.org/10.1017/wsc.2022.5.
Saballos, A., Soler-Garzon, A., Brooks, M.D., Hart, J., Lipka, A., Miklas, P.N., Peachey, R.E., Tranel, P., Williams, M. 2022. Multiple genomic regions govern tolerance to sulfentrazone in snap bean (Phaseolus vulgaris L.). Frontiers in Agronomy. 4. Article 869770. https://doi.org/10.3389/fagro.2022.869770.
