Maxwell Smith, OSU Department of Entomology and Plant Pathology

Peanut weed management trials were established at the Oklahoma State University Caddo Research Station near Fort Cobb. Peanuts were planted on May 12, 2025, in 36-inch rows. Preemergence (PRE) treatments were applied following planting. All trials received Prowl H2O (1 quart per acre, qt/A) PRE-treatment. All trials received a postemergence (POST) treatment of Butyrac 200 (1 pt/A) + Dyne-Amic (6 oz/A) and Select (1 pt/A) + Dyne-Amic (6 oz/A). Trials were irrigated throughout the growing season, and other pests were managed. Trials were evaluated for visual peanut response, visual weed control and yield. Peanuts were dug on Oct. 14 and field-dried and harvested on Oct. 22.

The first trial established was to evaluate weed control and peanut response with preemergence herbicides applied at-plant and at-crack. Peanut response was minimal for most treatments except for Zidua plus Valor EZ applied at-crack and Dual Magnum plus Zidua and Valor EZ applied at-crack, which resulted in 29% and 50% response four weeks after planting (Table 1). Palmer amaranth control ranged from 69% to 95% control eight weeks after planting (Table 2). Texas Panicum control was greater than or equal to 85% for all treatments except Outlook plus Valor EZ applied at-plant and eight weeks after planting (Table 3). Ivy-leaf morning-glory control was greater than or equal to 85% for all treatments eight weeks after planting (Table 4). Peanut yield ranged from 3,949 to 5,641 pounds per acre, but no statistical difference among treatments was observed (Table 1).

The second trial was established to evaluate in-season control of volunteer cotton and peanut response. XtendFlex and Enlist cotton volunteer plants were evaluated. Peanut injury was greatest two weeks after application, ranging from 0% to 15%, but the peanuts recovered from the injury by three weeks after application (Table 5). XtendFlex volunteer cotton control was greater than or equal to 60% six weeks after application with 2,4-DB, Aim, and Aim plus Anthem Flex (Table 6). Enlist volunteer cotton control was 66% with Aim plus Anthem Flex and less than or equal to 48% with all other treatments six weeks after application (Table 6).

Acknowledgements

We would like to thank the Oklahoma Peanut Commission and the National Peanut Board for their support of this research. We would also like to thank the staff at the Oklahoma State University Caddo Research Station: Michael Pettijohn, Brennan Leighton and Harley Houston. This research is possible thanks to these individuals and groups.

All treatments applied immediately after planting unless otherwise noted.

Entire trial area was treated with Prowl H2O (1 qt/A) immediately after planting, Gramoxone 3.0 (8 fl oz/A) at-crack, and Select (1 pt/A) and Butyrac 200 (1 pt/A) postemergence.