With the increasing pressure on crop production from the evolution of herbicide resistance, farmers are increasingly adopting Integrated Weed Management (IWM) strategies to augment their weed control. These include measures to increase the competitiveness of the crop canopy such as increased sowing rate and the use of more competitive cultivars. While there are data on the relative impact of these non-chemical weed control methods assessed in isolation, there is uncertainty about their combined contribution, which may be hindering their adoption. In this article, the INTERCOM simulation model of crop/weed competition was used to examine the combined impact of crop density, sowing date and cultivar choice on the outcomes of competition between wheat (Triticum aestivum) and Alopecurus myosuroides. Alopecurus myosuroides is a problematic weed of cereal crops in North-Western Europe and the primary target for IWM in the UK because it has evolved resistance to a range of herbicides. The model was parameterised for two cultivars with contrasting competitive ability, and simulations run across 10 years at different crop densities and two sowing dates. The results suggest that sowing date, sowing density and cultivar choice largely work in a complementary fashion, allowing enhanced competitive ability against weeds when used in combination. However, the relative benefit of choosing a more competitive cultivar decreases at later sowing dates and higher crop densities. Modeling approaches could be further employed to examine the effectiveness of IWM, reducing the need for more expensive and cumbersome long-term in situ experimentation.

中文翻译：

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使用模拟模型研究播种率、播种日期和品种选择对杂草竞争的累积影响

随着除草剂抗性演变对作物生产造成的压力越来越大，农民越来越多地采用综合杂草管理 (IWM) 策略来加强杂草控制。这些措施包括提高作物冠层竞争力的措施，例如提高播种率和使用更具竞争力的品种。虽然有单独评估这些非化学杂草控制方法的相对影响的数据，但它们的综合贡献存在不确定性，这可能会阻碍它们的采用。在本文中，INTERCOM 作物/杂草竞争模拟模型用于检验作物密度、播种日期和品种选择对小麦（Triticum aestivum）和 Alopecurus myosuroides 之间竞争结果的综合影响。Alopecurus myosuroides 是西北欧谷物作物的一种有问题的杂草，也是英国 IWM 的主要目标，因为它已经进化出对一系列除草剂的抗性。该模型针对具有对比竞争能力的两个品种进行了参数化，并在不同的作物密度和两个播种日期下进行了 10 年的模拟。结果表明，播种日期、播种密度和品种选择在很大程度上以互补的方式起作用，组合使用时可以增强对杂草的竞争能力。然而，选择更具竞争力的品种的相对收益会随着播种日期的推迟和作物密度的增加而降低。建模方法可以进一步用于检查 IWM 的有效性，减少对更昂贵和繁琐的长期原位实验的需要。