Chia (Salvia hispanica L.) is a promising crop valued as a sustainable source of omega-3. However, chia yield and quality are reduced because of weed competition and the lack of registered herbicides. This study evaluated how chia spatial arrangement suppresses weed growth and provided management options for this crop. The performance of chia plants was assessed over three growing seasons in field experiments using a factorial design that considered spatial arrangement (narrow and wide), weed management (control without weeds, soil bank brassica (Brassica rapa L.), and sown brassica), and cover crop (with or without a rye (Secale cereale L.) cover crop during chia fallow). Chia and brassica are not complementary, leading to resource competition (relative yield total around 1) and negative effects on each other. A significant decrease in chia grain yield of 0.9% per unit increase in the percentage of weeds in total biomass was observed. As chia had a competitive advantage over brassica, the grain yield reduction was ameliorated with a narrow spatial arrangement. Narrow spatial arrangement promotes faster canopy closure during the early growth stages, decreasing light penetration and suppressing weed growth. The high extinction coefficient of chia (0.91) and the low critical LAI (3.3) contributed to this light interception behavior. Accordingly, to maximize chia productivity and profitability, a narrow spatial arrangement is an effective management strategy to suppress weeds. This study contributes valuable insights into chia-weed interactions and emphasizes the importance of sustainable crop management practices.

中文翻译：

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奇亚籽对芸苔属杂草的竞争力通过狭窄的空间布局提高


奇亚籽 （Salvia hispanica L.） 是一种很有前途的作物，被视为 omega-3 的可持续来源。然而，由于杂草竞争和缺乏注册除草剂，奇亚的产量和质量有所下降。本研究评估了奇亚籽的空间排列如何抑制杂草生长，并为这种作物提供了管理选择。在田间试验中，使用因子设计评估了奇亚籽植物在三个生长季节的表现，该设计考虑了空间布局（窄和宽）、杂草管理（无杂草控制、土壤银行芸苔属 （Brassica rapa L.） 和播种的芸苔属植物）和覆盖作物（在奇亚休耕期间有或没有黑麦 （Secale cereale L.） 覆盖作物）。奇亚籽和芸苔属植物不互补，导致资源竞争（相对产量总量约为 1）和相互不利影响。观察到奇亚籽粒产量显著下降，杂草占总生物量的百分比每增加一单位，下降 0.9%。由于奇亚籽比芸苔属植物具有竞争优势，因此通过狭窄的空间布局缓解了谷物产量的下降。狭窄的空间布置在生长早期促进了树冠的快速关闭，减少了光线的穿透并抑制了杂草的生长。奇亚籽的高消光系数 （0.91） 和低临界 LAI （3.3） 促成了这种光拦截行为。因此，为了最大限度地提高奇亚籽的生产力和盈利能力，狭窄的空间安排是抑制杂草的有效管理策略。本研究为奇亚籽与杂草的相互作用提供了有价值的见解，并强调了可持续作物管理实践的重要性。