Wild oat (Avena fatua L.) is one of the most problematic weed species in western Canada due to widespread populations, herbicide resistance, and seed dormancy. In wheat (Triticum aestivum L.), and especially in shorter crops such as lentil (Lens culinaris Medik.), A. fatua seed panicles elongate above the crop canopy, which can facilitate physical cutting of the panicles (clipping) to reduce viable seed return to the seedbank. However, the viability of A. fatua seed at the time of panicle elongation is not known. The objective of this study was to determine the viability of A. fatua seed at successive time intervals after elongation above a wheat or lentil crop canopy. A 2-yr panicle clipping and removal study in wheat and lentil was conducted in Lacombe, AB, and Saskatoon, SK, in 2015 and 2016 to determine the onset of viability in A. fatua seeds at successive clipping intervals. Manual panicle clipping of A. fatua panicles above each crop canopy began when the majority of panicles were visible above respective crop canopies and continued weekly until seed shed began. At the initiation of panicle clipping, A. fatua seed viability was between 0% and 10%. By the last clipping treatment (approximately 6 to 7 wk after elongation), 95% of the A. fatua seeds were viable. Seed moisture and awn angle were not good predictors of A. fatua viability, and therefore were unlikely to provide effective tools to estimate appropriate timing for implementation of A. fatua clipping as a management technique. Based on A. fatua seed viability, earlier clipping of A. fatua is likely to be more effective in terms of population management and easier to implement in shorter crops such as lentil. Investigations into long-term effects of clipping on A. fatua populations are needed to evaluate the efficacy of this management strategy on A. fatua.

中文翻译：

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野燕麦 (Avena fatua) 穗修剪时间影响种子活力

野燕麦（燕麦L.) 是加拿大西部最成问题的杂草物种之一，原因是种群广泛、抗除草剂和种子休眠。在小麦（小麦L.)，尤其是在小扁豆等较短的作物中（烹饪透镜梅迪克），A. fatua种子圆锥花序在作物冠层上方伸长，这可以促进圆锥花序的物理切割（修剪），以减少有活力的种子返回种子库。然而，生存能力A. fatua不知道穗伸长时的种子。本研究的目的是确定A. fatua在小麦或扁豆作物树冠上方伸长后连续时间间隔播种。2015 年和 2016 年，在拉科姆，AB 和萨斯卡通，SK 对小麦和小扁豆进行了为期 2 年的穗修剪和去除研究，以确定小麦和小扁豆的活力开始。A. fatua在连续修剪间隔的种子。手动剪穗A. fatua每个作物冠层上方的圆锥花序在各个作物冠层上方可见大部分圆锥花序时开始，并且每周持续直到种子棚开始。在开始剪穗时，A. fatua种子活力在 0% 和 10% 之间。到最后一次剪断处理（大约在伸长后 6 到 7 周），95% 的A. fatua种子是可行的。种子水分和芒角不是很好的预测因子A. fatua可行性，因此不太可能提供有效的工具来估计实施A. fatua剪裁作为一种管理技术。基于A. fatua种子活力，较早修剪A. fatua在种群管理方面可能更有效，并且更容易在小扁豆等较短的作物中实施。对削波的长期影响的调查A. fatua需要人群来评估这种管理策略的有效性A. fatua.