Velvetleaf is an economically important weed in popcorn production fields in Nebraska. Many PRE herbicides in popcorn have limited residual activity or provide partial velvetleaf control. There are a limited number of herbicides applied POST in popcorn compared with field corn, necessitating the evaluation of POST herbicides for control of velvetleaf. The objectives of this study were to (1) evaluate the efficacy and crop safety of labeled POST herbicides for controlling velvetleaf that survived S-metolachlor/atrazine applied PRE and (2) determine the effect of velvetleaf height on POST herbicide efficacy, popcorn injury, and yield. Field experiments were conducted in 2018 and 2019 near Clay Center, Nebraska. The experiments were arranged in a split-plot design with four replications. The main plot treatments were velvetleaf height (≤15 cm and ≤30 cm) and subplot treatments included a no-POST herbicide control, and 11 POST herbicide programs. Fluthiacet-methyl, fluthiacet-methyl/mesotrione, carfentrazone-ethyl, dicamba, and dicamba/diflufenzopyr provided greater than 96% velvetleaf control 28 d after treatment (DAT), reduced velvetleaf density to fewer than 7 plants m−2, achieved 99% to 100% biomass reduction, and had no effect on popcorn yield. Herbicide programs tested in this study provided greater than 98% control of velvetleaf 28 DAT in 2019. Most POST herbicide programs in this study provided greater than 90% control of up to 15 cm and up to 30 cm velvetleaf and no differences between velvetleaf heights in density, biomass reduction, or popcorn yield were observed, except with topramezone and nicosulfuron/mesotrione 28 DAT in 2018. On the basis of contrast analysis, herbicide programs with fluthiacet-methyl or dicamba provided better control than herbicide programs without them at 28 DAT in 2018. It is concluded that POST herbicides are available for control of velvetleaf up to 30-cm tall in popcorn production fields.

中文翻译：

---

在内布拉斯加州爆米花中使用 POST 除草剂在两个高度控制绒叶 (Abutilon theophrasti)

Velvetleaf 是内布拉斯加州爆米花生产领域的重要经济杂草。爆米花中的许多 PRE 除草剂具有有限的残留活性或提供部分绒叶控制。与大田玉米相比，在爆米花中施用 POST 的除草剂数量有限，因此有必要评估 POST 除草剂以控制鹿茸。本研究的目的是 (1) 评估标记的 POST 除草剂用于控制存活的鹿茸的功效和作物安全性小号- 异丙甲草胺/阿特拉津在 PRE 和 (2) 应用后确定绒叶高度对 POST 除草剂功效、爆米花损伤和产量的影响。实地实验于 2018 年和 2019 年在内布拉斯加州克莱中心附近进行。实验以裂区设计排列，重复四次。主要小区处理为绒叶高度（≤15 cm 和≤30 cm），次小区处理包括无 POST 除草剂控制和 11 个 POST 除草剂程序。Fluthiacet-methyl、fluthiacet-methyl/mesotrione、carfentrazone-ethyl、麦草畏和麦草畏/diflufenzopyr 在处理后 28 天 (DAT) 提供大于 96% 的绒叶控制，将绒叶密度降低到少于 7 株 m-2，实现了 99% 到 100% 的生物量减少，并且对爆米花产量没有影响。本研究中测试的除草剂计划在 2019 年对 28 DAT 的天鹅绒叶进行了超过 98% 的控制。本研究中的大多数 POST 除草剂程序对长达 15 厘米和 30 厘米的天鹅绒叶进行了超过 90% 的控制，并且在观察到密度、生物量减少或爆米花产量，除了 2018 年 28 DAT 使用 Topramezone 和烟嘧磺隆/甲基磺草酮。在对比分析的基础上，在 28 DAT 的 28 DAT 时，使用氟噻草酮或麦草畏的除草剂方案比没有它们的除草剂方案提供了更好的控制。 2018. 得出的结论是 POST 除草剂可用于控制爆米花生产田中高达 30 厘米高的绒叶。