Medusahead [Taeniatherum caput-medusae (L.) Nevski] is an invasive annual grass spreading into rangelands throughout the western United States. We tested cattle (Bos taurus L.) utilization of T. caput-medusae following treatment with glyphosate in two forms of its salt (potassium salt and isopropylamine salt) at three different rates of application; low (236 g ae ha−1), medium (394 g ae ha−1), and high rates (788 g ae ha−1) in eastern Washington. The herbicide was applied on April 26, 2016. A second location, northern Utah, was treated with glyphosate in the form of its isopropylamine salt at the high rate. The herbicide was applied on June 5, 2019. Cattle were allowed to start grazing T. caput-medusae 15 d after glyphosate treatment and had unlimited access to the glyphosate-treated plots for more than 85 d. The greatest utilization of T. caput-medusae occurred at the highest glyphosate application rate (P < 0.05), in Washington, with no difference between forms of glyphosate salt. Cattle also consumed T. caput-medusae at the Utah site (P < 0.05). Glyphosate treatment preserved the water-soluble carbohydrate content of T. caput-medusae at levels greater than the nontreated controls (P < 0.05) at both locations. The glyphosate treatment assisted in the increased utilization of T. caput-medusae by cattle and is a viable option for the reduction of T. caput-medusae while increasing the forage value of the weed.

中文翻译：

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使用除草剂作为增加牲畜食用美杜莎（Taeniatherum caput-medusae）的工具

美杜莎[水母带绦虫(L.) Nevski] 是一种侵入性的一年生草，蔓延到整个美国西部的牧场。我们测试了牛（金牛座L.) 利用T. caput-medusae在以三种不同的施用率用两种形式的盐（钾盐和异丙胺盐）处理草甘膦后；低（236 g ae ha-1), 中 (394 g ae ha-1) 和高比率 (788 g ae ha-1) 在华盛顿东部。该除草剂于 2016 年 4 月 26 日施用。犹他州北部的第二个地点以异丙胺盐形式的草甘膦高速处理。除草剂于 2019 年 6 月 5 日施用。允许牛开始放牧T. caput-medusae草甘膦处理后 15 d 并且在超过 85 d 的时间内可以无限制地进入草甘膦处理的地块。最大的利用T. caput-medusae在华盛顿州，草甘膦施用率最高（P < 0.05），草甘膦盐的形式之间没有差异。牛也吃掉了T. caput-medusae在犹他州 (P < 0.05)。草甘膦处理保留了水溶性碳水化合物的含量T. caput-medusae在两个位置均高于未处理对照 (P < 0.05)。草甘膦处理有助于提高植物的利用率T. caput-medusae由牛和是一个可行的选择，以减少T. caput-medusae同时增加杂草的饲料价值。