Weed control and response of yellow and white popcorn hybrids to herbicides

Popcorn (Zea mays L. var. everta) is an important crop to Midwestern US producers. While there is considerable research on field corn and sweet corn sensitivity to herbicides, there is a lack of information on popcorn sensitivity to herbicides. Field experiments were conducted in 2017 and 2018 to evaluate herbicides labeled for yellow popcorn in commercially available popcorn hybrids for weed control and crop response in Nebraska. The experiments were arranged in a split-plot design. The main plot treatments consisted of two white and six yellow popcorn hybrids. Ten sub-plot treatments consisted of nontreated control, weed-free control, and four pre-emergence (PRE) followed by postemergence herbicide treatments applied at labeled rates (1X) and double the labeled rates (2X). Across hybrids, PRE herbicide treatments resulted in 4–8% injury. Across all PRE herbicide treatments, a yellow hybrid, R265, displayed the greatest average plant injury (11%). At labeled rates, broadleaf weed control in both years, and foxtail control in 2017, ranged from 95–99% with all treatments; however, foxtail control was limited (72–86%) for most treatments in 2018. Weed biomass reduction in all herbicide treatments ranged from 90–98% and 68–97% control in 2017 and 2018, respectively. Yield losses ranged from 0–7% in herbicide treatments, with a 42% yield loss in the untreated control. Although slight hybrid differences in herbicide sensitivity were detected, the differences were not linked to popcorn color. Information reported in this research are the first that determined popcorn sensitivity to herbicides.