Growers across theU.S. Southeast use a diversity of soybean [Glycine max (L.) Merr.] planting dates, maturity groups, and seeding rates for soybean production depending on their rotational complexity. Studies were conducted across seven North Carolina environments in 2019 and 2020 to determine the effect of planting date (mid-March through mid-July), maturity group (MG 2–8), and seeding rate (185,329–432,434 seeds ha^–1) on soybean emergence, stand, and yield. Across environments, soybean typically emerged more quickly with later planting dates; however, there were location-specific variations in soybean emergence due to weather conditions around the time of planting. The longest and shortest emergence periods were 26 d for soybean planted in mid-March and 4 d for soybean planted in June and July, respectively. In the higher yielding environments, yield was maximized with MG 3–4 cultivars planted at early April planting dates and yield declined as planting was delayed. In the low yield environments, yield was maximized with late April to mid-May planting dates, typically with MG 5–7 cultivars. There was a penalty in both yield environments to planting past mid-May and in the low yield environments for planting before mid-April. Across environments, yields tended to be more similar among cultivars higher than MG 3 at planting dates in June and July. The effect of seeding rate on soybean yield was variable across planting dates, maturity groups, and yield environments. Future research is needed in North Carolina to validate the planting date and maturity group interactions on yield observed in this experiment to capture more variation in weather conditions.

中文翻译：

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通过了解北卡罗来纳州的种植日期、成熟组和播种率相互作用，最大限度地提高大豆产量

美国各地的种植者 东南部使用多种大豆 [ Glycine max  (L.) Merr.] 种植日期、成熟组和大豆生产的播种率，这取决于它们的轮作复杂性。2019 年和 2020 年在北卡罗来纳州的七个环境中进行了研究，以确定种植日期（3 月中旬至 7 月中旬）、成熟组（MG 2-8）和播种率（185,329-432,434 颗种子公顷^–1) 对大豆出苗、站立和产量的影响。在不同的环境中，大豆通常随着种植日期的推迟而出现得更快；然而，由于种植期间的天气条件，大豆出苗的位置存在差异。3 月中旬播种的大豆出苗期最长和最短，分别为 26 d 和 6 月和 7 月播种的大豆 4 d。在高产环境中，在 4 月初种植日期种植的 MG 3-4 品种产量最高，但随着种植推迟，产量下降。在低产量环境中，产量在 4 月下旬至 5 月中旬种植日期最大化，通常是 MG 5-7 品种。在 5 月中旬以后种植的产量环境和在 4 月中旬之前种植的低产量环境中都有损失。跨环境，在 6 月和 7 月的种植日期，高于 MG 3 的品种之间的产量往往更相似。播种率对大豆产量的影响因种植日期、成熟组和产量环境而异。北卡罗来纳州需要进一步研究以验证种植日期和成熟组对本实验中观察到的产量的相互作用，以捕捉天气条件的更多变化。