Giant miscanthus has the potential to move beyond cultivated fields and invade noncrop areas, but this can be overshadowed by aesthetic appeal and monetary value as a biofuel crop. Most research on giant miscanthus has focused on herbicide tolerance for establishment and production rather than terminating an existing stand. This study was conducted to evaluate herbicide options for control or terminating a stand of giant miscanthus. In 2013 and 2014, field experiments were conducted on established stands of the giant miscanthus cultivars ‘Nagara’ and ‘Freedom.’ Herbicides evaluated in both years included glyphosate, hexazinone, imazapic, imazapyr, clethodim, fluazifop, and glyphosate plus fluazifop. All treatments were applied in summer (June or July) and September. For both years, biomass reduction ranged from 85% to 100% when glyphosate was applied in June or July at 4.5 or 7.3 kg ae ha−1. No other treatment applied at this timing provided more than 50% giant miscanthus biomass reduction 1 yr after application. September applications of glyphosate were not consistent: treatments in 2013 reduced biomass by 40% or less, whereas in 2014, at all rates provided at least 78% biomass reduction. Glyphosate applied in June or July was the only treatment that provided effective and consistent control of giant miscanthus 1 yr after treatment.

中文翻译：

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巨型芒草（Miscanthus x giganteus）生物量减少的除草剂功效和施用时机评估

巨型芒草有可能超越耕地并侵入非农作物地区，但这可能被美学吸引力和作为生物燃料作物的货币价值所掩盖。大多数关于巨型芒草的研究都集中在对除草剂的建立和生产的耐受性上，而不是终止现有的林分。进行这项研究是为了评估用于控制或终止巨型芒草林的除草剂选择。2013 年和 2014 年，在巨型芒草品种“Nagara”和“Freedom”的既定林分上进行了田间试验。这两年评估的除草剂包括草甘膦、六嗪酮、灭草定、灭草烟、烯草酮、氟草啶和草甘膦加氟草啶。所有处理均在夏季（六月或七月）和九月进行。这两年，-1. 此时应用的其他处理在应用 1 年后没有提供超过 50% 的巨型芒草生物量减少。9 月草甘膦的应用并不一致：2013 年的处理使生物量减少了 40% 或更少，而在 2014 年，无论如何处理都提供了至少 78% 的生物量减少。在 6 月或 7 月施用的草甘膦是唯一能在治疗 1 年后对巨型芒草提供有效和持续控制的治疗方法。