Weed management in carrot is challenging, given slow and inconsistent crop emergence and early-season growth and the lack of practical season-long management tools such as herbicides. We investigated holistic carrot production systems with a focus on minimizing inputs while optimizing resource use. In an overall sense, results of this work were consistent between years, and stark. The choice of carrot variety had a moderate influence on carrot foliar canopy development and, subsequently, weed density. For example, ‘Cupar’ carrot formed a complete crop canopy sooner than the other dicer-type ‘Canada’ variety. Likely as a result, density of weed species such as spotted ladysthumb and common lambsquarters was less where ‘Cupar’ was grown compared with where ‘Canada’ was grown. Gibberellic acid as a foliar application was not successful in these studies and, in a few cases, may have even increased weed-seed germination and establishment. Adding two carrot rows to the current regional industry-standard three-row bed system not only enhanced competitiveness with weeds but also improved carrot yield without additional fertilizer, water, or pest management inputs. By far, though, the most successful strategy to reduce weed density while maintaining or improving carrot yield was to delay seeding by 17 to 19 d. We anticipate more holistic production system research that integrates low-input alternatives in other crops as herbicide-resistant weeds proliferate while few new herbicides are developed. As was demonstrated in this research, such novel approaches can be successful without adding significant economic burden to the farmer or increasing risk of crop failure.

中文翻译：

---

用于整季杂草管理的整体胡萝卜生产系统

鉴于作物出苗缓慢且不一致，早季生长以及缺乏实用的长季管理工具（如除草剂），胡萝卜中的杂草管理具有挑战性。我们调查了整体胡萝卜生产系统，重点是在优化资源使用的同时最大限度地减少投入。总体而言，这项工作的结果在不同年份之间是一致的，而且很明显。胡萝卜品种的选择对胡萝卜叶冠发育以及随后的杂草密度有中等影响。例如，“Cupar”胡萝卜比其他切丁型“Canada”品种更早形成完整的作物冠层。可能因此，与种植“加拿大”的地方相比，种植“Cupar”的地方杂草种类（如斑点瓢虫和普通羊羔）的密度较低。赤霉酸作为叶面施用在这些研究中并不成功，在少数情况下，甚至可能增加杂草种子的发芽和建立。在当前区域行业标准的三行床系统中增加两行胡萝卜，不仅增强了与杂草的竞争力，而且在不增加肥料、水或害虫管理投入的情况下提高了胡萝卜产量。然而，到目前为止，在保持或提高胡萝卜产量的同时降低杂草密度的最成功策略是将播种延迟 17 至 19 天。我们预计将进行更全面的生产系统研究，将低投入替代品整合到其他作物中，因为抗除草剂杂草会激增，而新的除草剂很少开发。如本研究所示，