2026/01/01 by Donnie K. Miller, Koffi Badou-Jeremie Kouame, Justin L. Chlapecka +4
paper · doi:10.1017/wsc.2026.10125
Abstract Trifludimoxazin + saflufenacil is a premix protoporphyrinogen oxidase (PPO)-inhibiting herbicide with preemergence and postemergence activity pending USEPA registration for burndown application ahead of planting corn ( Zea mays L.), soybean [ Glycine max (L.) Merr.], grain sorghum [ Sorghum bicolor (L.) Moench], and wheat ( Triticum aestivum L.). With early-season soybean growth often occurring simultaneously with preplant burndown of fields in later-planted soybean and grain sorghum, odds of negative impacts associated with off-target herbicide movement to the crop increase. Field studies were conducted in 2024 to evaluate effect of reduced rates of trifludimoxazin + saflufenacil (12.5% to 0.4% of the lowest proposed labeled application rate of 38.3 g ai ha −1 ) applied to 1- to 2-leaf soybean. Reduced rates of 1/8×, 1/16×, 1/32×, and 1/64× resulted in 53%, 43%, 32%, and 21% visual phytotoxicity at 1 wk after treatment (WAT), while at 4 WAT response was 31%, 23%, 17%, and 12%. Trifludimoxazin + saflufenacil at these rates reduced soybean height 30% to 7% and 18% to 4% at 1 and 4 WAT, respectively. Soybean yield was negatively impacted 8%, 5%, 2%, and 0% at these respective rates. Off-target movement of trifludimoxazin + saflufenacil to soybean in early vegetative growth will result in severe visual injury and height reduction, especially with exposure at the three highest rates evaluated. Soybean should not be expected to fully recover and significant negative impact on yield (5% or greater) will be observed at the two highest rates evaluated in this research.