Abstract Farmers face many choices when selecting seed for soybean (Glycine max (L.) Merr.) production, including highly desired herbicide tolerance traits. Despite the convenience of herbicide tolerance, resistant weeds and technology fees may reduce utility and profitability of these varieties, especially when commodity prices are low. Sporadic outbreaks of soybean aphid (Aphis glycines Matsumura, Hemiptera: Aphididae) that require insecticide use for optimal yield can be a further complication for farmers in Iowa. Soybean aphid-resistant varieties are commercially available, but in limited genetic backgrounds without herbicide tolerance. We hypothesized yield and value of resistance traits will vary based on the environment. We established plots at two locations with different risks of soybean aphid outbreaks and used two planting dates at each location to mimic different yield environments. In 2016 and 2017, we planted four varieties that varied in their susceptibility to soybean aphids and glyphosate, and applied insecticides if aphid populations reached an economic threshold. Regardless of genetic background, aphid-resistant varieties prevented populations from reaching the economic threshold at all environments. We observed no significant difference in yield between resistant and susceptible varieties, revealing this trait is as effective at protecting yield as an insecticide application on susceptible varieties at the high-risk location. We also explored the value of each variety in different environments. Resistant varieties produced greater potential net revenue than susceptible varieties at the high-risk location, while the opposite occurred at the low-risk location. Resistant varieties with herbicide tolerance, if made available, would be the most valuable across all environments.

中文翻译：

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评估不同环境中大豆抗蚜虫品种以估计财务结果

摘要 农民在为大豆 (Glycine max (L.) Merr.) 生产选择种子时面临许多选择，包括非常需要的除草剂耐受性状。尽管耐除草剂很方便，但抗性杂草和技术费用可能会降低这些品种的效用和盈利能力，尤其是在商品价格较低的情况下。需要使用杀虫剂才能获得最佳产量的大豆蚜虫（Aphis gamines Matsumura，半翅目：蚜科）的零星爆发可能是爱荷华州农民的进一步复杂化。大豆蚜虫抗性品种在商业上可获得，但在有限的遗传背景中没有除草剂耐受性。我们假设抗性特性的产量和价值会因环境而异。我们在大豆蚜虫爆发风险不同的两个地点建立了地块，并在每个地点使用两个种植日期来模拟不同的产量环境。2016 年和 2017 年，我们种植了四个对大豆蚜虫和草甘膦易感性不同的品种，如果蚜虫种群达到经济门槛，则使用杀虫剂。不管遗传背景如何，抗蚜虫品种在所有环境中都阻止了种群达到经济阈值。我们观察到抗性和易感品种在产量上没有显着差异，表明该性状在保护产量方面与在高风险地区对易感品种施用杀虫剂一样有效。我们还探索了每个品种在不同环境中的价值。在高风险地区，抗性品种比易感品种产生更大的潜在净收入，而在低风险地区则相反。具有除草剂耐受性的抗性品种，如果可用，将是所有环境中最有价值的品种。