Harvest weed seed control (HWSC) is an increasingly popular integrated weed management tactic to catch, destroy or remove weed seeds at crop harvest. However, most weed species shed some seed prior to crop harvest, and we have little data on the value of HWSC for those species with high or variable rates of seed shedding. In the current study, Bromus diandrus and Hordeum spp. were identified as problematic weeds with variable rates of seed shedding. Field data on B. diandrus and Hordeum spp. density, seed production and resulting crop yield were used to validate the output of a decision support tool: the Weed Seed Wizard. The tool was then used to generate a six-year crop rotation scenario for each weed species. The level of annual HWSC in the scenario was set at 1%, 20%, 40%, 60%, 80% and 100% seed removal. The results indicated that B. diandrus in particular was difficult to control with herbicide alone and a conventional harvest (1% weed seed removed as a contaminant of the grain). By comparison, the total weed seed bank in the soil at the end of six years could be reduced by 46% using HWSC to annually destroy 20% of seed at crop harvest. Hordeum spp. were easier to control with herbicide, but HWSC still changed final seed density in the soil seed bank. Therefore, HWSC may be an effective management tactic for those weed species with early seed shedding, but this needs to be confirmed with field based research.

中文翻译：

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模拟收获杂草种子控制对 Bromus diandrus 和 Hordeum spp 等物种的长期影响。在收获前脱落一部分种子

收获杂草种子控制 (HWSC) 是一种越来越流行的综合杂草管理策略，用于在作物收获时捕获、破坏或去除杂草种子。然而，大多数杂草物种在作物收获前会脱落一些种子，我们几乎没有关于种子脱落率高或可变的物种的 HWSC 值的数据。在当前的研究中，Bromus diandrus和Hordeum spp。被确定为具有可变种子脱落率的有问题的杂草。B上的现场数据。 diandrus和大麦属 密度、种子产量和由此产生的作物产量被用来验证决策支持工具的输出：杂草种子向导。然后使用该工具为每个杂草物种生成六年轮作方案。该情景中的年度 HWSC 水平设置为 1%、20%、40%、60%、80% 和 100% 的种子去除率。结果表明，B . 单用除草剂和常规收获（去除作为谷物污染物的 1% 杂草种子）尤其难以控制雄花雄螟。相比之下，使用 HWSC 每年可在作物收获时破坏 20% 的种子，六年后土壤中的总杂草种子库可减少 46%。大麦属 用除草剂更容易控制，但 HWSC 仍然改变了土壤种子库中的最终种子密度。因此，HWSC 可能是对那些种子脱落较早的杂草种类的有效管理策略，但这需要通过实地研究来证实。