Annual sowthistle (Sonchus oleraceus L.) is a broadleaf weed that is increasing in prevalence in the northern cropping regions of Australia. Being a member of Asteraceae family, this weed possesses many biological attributes needed to thrive in varying environments and weed management pressure. Interference of this weed was examined in a wheat (Triticum aestivum L.) crop through field studies in 2016 and 2017. Different densities of S. oleraceus were evaluated for their potential to cause yield loss in wheat: 0.0 (weed free), low (9 to 15 plants m−2), medium (29 to 38 plants m−2), and high (62 to 63 plants m−2). Based on the exponential decay model, 43 and 52 plants m−2 caused a yield reduction of 50% in 2016 and 2017, respectively. Yield components such as panicles m−2 and grains per panicles were affected by weed density. At the high weed infestation level, S. oleraceus produced a maximum of 182,940 and 192,657 seeds m−2 in 2016 and 2017, respectively. Sonchus oleraceus exhibited poor seed retention at harvest as more than 95% of seeds were blown away by wind. Adverse effects on crop, high seed production and wind-blown dispersal may lead to an increased prevalence of this weed in the absence of an integrated weed management strategy utilizing both herbicides and non-chemical options.

中文翻译：

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一年生槐（Sonchus oleraceus）对小麦的干扰

一年生水飞蓟 (苦参L.) 是一种阔叶杂草，在澳大利亚北部种植区的流行率正在增加。作为菊科的一员，这种杂草具有在不同环境和杂草管理压力下茁壮成长所需的许多生物学特性。在小麦中检测了这种杂草的干扰（小麦L.) 2016 年和 2017 年的田间研究作物。苦苣菜评估了它们导致小麦产量损失的潜力：0.0（无杂草），低（9 到 15 株 m-2), 中等 (29 到 38 株 m-2) 和高 (62 至 63 株 m-2）。基于指数衰减模型，43 和 52 株 m-2导致 2016 年和 2017 年的产量分别下降 50%。产量成分，如圆锥花序 m-2每穗粒数受杂草密度的影响。在杂草侵染程度高时，苦苣菜最多生产 182,940 和 192,657 粒种子 m-2分别在 2016 年和 2017 年。苦参由于超过 95% 的种子被风吹走，因此在收获时表现出较差的种子保留率。在缺乏使用除草剂和非化学方法的综合杂草管理策略的情况下，对作物、高种子产量和风吹散布的不利影响可能导致这种杂草的流行率增加。