Goosegrass control options in bermudagrass are limited. Topramezone is one option that offers excellent control of mature goosegrass, but application to bermudagrass results in unacceptable symptoms of bleaching and necrosis typical of hydroxyphenylpyruvate dioxygenase inhibitors. Previous research has shown that adding chelated iron reduced the phytotoxicity of topramezone without reducing the efficacy of the herbicide, resulting in safening when applied to bermudagrass. Our objective was to examine additional iron sources to determine whether similar safening effects occur with other sources. Field trials were conducted in the summers of 2016 to 2018 (Auburn University). Mixtures of topramezone and methylated seed oil were combined with six different commercial iron sources, including sodium ferric ethylenediamine di-o-hydroxyphenyl-acetate (FeEDDHA), ferrous diethylenetriamine pentaacetic acid (FeDTPA), iron citrate, FeSO4, and a combination of iron oxide/sucrate/sulfate, some of which contained nitrogen. Bermudagrass necrosis and bleaching symptoms were visually rated on a 0% to 100% scale. Reflectance (normalized difference vegetation index) and clipping yield measurements were also collected. Application of FeDTPA and FeSO4 reduced symptoms of bleaching and necrosis when applied with topramezone. Other treatments that contained nitrogen did not reduce injury but did reduce bermudagrass recovery time following the appearance of necrosis. Inclusion of small amounts of nitrogen often negated the safening effects of FeSO4. The iron oxide/sucrate/sulfate product had no effect on bleaching or necrosis. Data suggest that the iron source had a differential effect on bleaching and necrosis reduction when applied in combination with topramezone to bermudagrass. Overall, FeSO4 and FeDTPA safened topramezone the most on bermudagrass.

中文翻译：

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铁制剂对百慕大草的topramezone损伤的影响

狗牙根中的鹅草控制选项是有限的。Topramezone 是一种可以很好地控制成熟鹅草的选择，但应用于狗牙根会导致不可接受的漂白和坏死症状，典型的羟苯基丙酮酸双加氧酶抑制剂。先前的研究表明，添加螯合铁可降低托普美宗的植物毒性，而不会降低除草剂的功效，从而在应用于百慕大草时具有安全性。我们的目标是检查其他铁源，以确定其他铁源是否会产生类似的安全效应。现场试验于 2016 年至 2018 年夏季（奥本大学）进行。Topramezone 和甲基化种子油的混合物与六种不同的商业铁源相结合，包括乙二胺铁钠○-乙酸羟苯酯 (FeEDDHA)、二乙烯三胺五乙酸亚铁 (FeDTPA)、柠檬酸铁、FeSO4，以及氧化铁/硫酸盐/硫酸盐的组合，其中一些含有氮。狗牙根坏死和白化症状以 0% 至 100% 的等级目视评定。还收集了反射率（归一化差异植被指数）和修剪产量测量值。FeDTPA和FeSO的应用4与topramezone一起使用时可减轻漂白和坏死的症状。其他含氮处理并未减少损伤，但确实减少了坏死出现后狗牙根的恢复时间。包含少量氮通常会抵消 FeSO 的安全作用4. 氧化铁/硫酸盐/硫酸盐产品对漂白或坏死没有影响。数据表明，铁源与托普美松联合应用于狗牙根时，对漂白和减少坏死有不同的影响。总体而言，FeSO4和 FeDTPA 在狗牙根上对 topramezone 的保护作用最大。