A stakeholder survey was conducted from April through June of 2018 to understand stakeholders’ perceptions and challenges about cropping systems and weed management in Brazil. The dominant crops managed by survey respondents were soybean (73%) and corn (66%). Approximately 75% of survey respondents have grown or managed annual cropping systems with two to three crops per year cultivated in succession. Eighteen percent of respondents manage only irrigated cropping systems, and over 60% of respondents adopt no-till as a standard practice. According to respondents, the top five troublesome weed species in Brazilian cropping systems are horseweed (asthmaweed, Canadian horseweed, and tall fleabane), sourgrass, morningglory, goosegrass, and dayflower (Asiatic dayflower and Benghal dayflower). Among the nine species documented to have evolved resistance to glyphosate in Brazil, horseweed and sourgrass were reported as the most concerning weeds. Other than glyphosate, 31% and 78% of respondents, respectively, manage weeds resistant to acetyl-CoA carboxylase (ACCase) inhibitors and/or acetolactate synthase (ALS) inhibitors. Besides herbicides, 45% of respondents use mechanical, and 75% use cultural (e.g., no-till, crop rotation/succession) weed control strategies. Sixty-one percent of survey respondents adopt cover crops to some extent to suppress weeds and improve soil chemical and physical properties. Nearly 60% of survey respondents intend to adopt the crops that are resistant to dicamba or 2,4-D when available. Results may help practitioners, academics, industry, and policy makers to better understand the bad and the good of current cropping systems and weed management practices adopted in Brazil, and to adjust research, education, technologies priorities, and needs moving forward.

中文翻译：

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在巴西引进抗生长素作物之前评估作物和杂草管理策略

2018 年 4 月至 6 月进行了利益相关者调查，以了解利益相关者对巴西种植系统和杂草管理的看法和挑战。受访者管理的主要作物是大豆（73%）和玉米（66%）。大约 75% 的受访者已经种植或管理一年生种植系统，每年连续种植两到三种作物。18% 的受访者只管理灌溉种植系统，超过 60% 的受访者采用免耕作为标准做法。根据受访者的说法，巴西种植系统中最麻烦的五种杂草是马草（哮喘草、加拿大马草和高蓬）、酸草、牵牛花、鹅草和白昼花（亚洲白昼花和孟加拉白昼花）。在巴西有记录的九种已进化出对草甘膦的抗性的物种中，据报道，马草和酸草是最令人担忧的杂草。除草甘膦外，分别有 31% 和 78% 的受访者处理对乙酰辅酶 A 羧化酶 (ACCase) 抑制剂和/或乙酰乳酸合酶 (ALS) 抑制剂具有抗性的杂草。除除草剂外，45% 的受访者使用机械除草策略，75% 使用文化（例如免耕、轮作/连续）杂草控制策略。61% 的受访者在一定程度上采用覆盖作物来抑制杂草并改善土壤化学和物理特性。近 60% 的受访者打算采用对麦草畏或 2,4-D 有抗性的作物（如果有）。结果可能有助于从业者、学者、行业、