The causal agent of Phytophthora stem and root rot (PRR), Phytophthora sojae Gerdemann and Kaufman, is a major pathogen of soybean (Glycine max (L.) Merr.). Integrated pest management strategies for PRR consists of planting varieties with effective single-dominant resistance genes (Rps genes), partial resistance (field tolerance) and seed treatments containing oomicides such as ethaboxam and mefenoxam. To investigate the interaction of PRR partial resistance and seed treatment on soybean stand, vigor and yield, soybean plots were inoculated in-furrow with P. sojae isolates able to overcome the Rps genes present in the planted soybean varieties in Michigan in 2018 as well as Michigan, Indiana, and Minnesota in 2019. Nine commercial soybean varieties with contrasting Phytophthora resistance profiles received three different seed treatments: 1) non-treated, 2) base (ipconazole and clothianidin), and 3) Intego Suite (base + ethaboxam and mefenoxam) in Michigan, with four of the same varieties and seed treatments being planted in Indiana and Minnesota. Soybean stand was significantly protected with Intego Suite in the nine varieties tested in Michigan 2018, eight of nine in Michigan 2019, and two of four in Indiana 2019. Significant differences in yield between seed treatments were observed in three varieties of nine in Michigan 2018. The effect of partial resistance on plant health and final yields was not apparent given the supplied company partial resistance scores across locations and years. In conclusion, this study finds that oomicide seed treatments are useful in protecting soybean stand under PRR disease pressure in multiple locations in the Midwest United States.

疫霉茎和根腐病（PRR）的病原体，大豆疫霉Gerdemann和Kaufman，是大豆的主要病原体（Glycine max (L.) Merr.）。PRR 病虫害综合治理策略包括种植具有有效单显性抗性基因（Rps基因）、部分抗性（田间耐受性）的品种和含有杀虫剂（如噻唑菌胺和甲灭氧菌灵）的种子处理剂。为了研究 PRR 部分抗性和种子处理对大豆林分、活力和产量的相互作用，在大豆地块上接种了能够克服Rps的大豆假单胞菌分离株。2018 年密歇根州以及 2019 年密歇根州、印第安纳州和明尼苏达州种植的大豆品种中存在基因。 9 个商业大豆品种与疫霉属对比抗性概况接受了三种不同的种子处理：1) 未处理，2) 碱（ipconazole 和噻虫胺），和 3) Intego Suite（碱 + 噻唑菌胺和甲灭酸），在密歇根州种植了四个相同品种和种子处理印第安纳州和明尼苏达州。在 2018 年密歇根州测试的九个品种中，Intego Suite 显着保护了大豆林分，2019 年密歇根州测试了九个品种中的八个，2019 年印第安纳州测试了四个品种中的两个。在 2018 年密歇根州的三个九个品种中观察到种子处理之间的产量存在显着差异。鉴于提供的公司在不同地点和年份的部分抗性得分，部分抗性对植物健康和最终产量的影响并不明显。综上所述，