The following descriptions of soybean growth stages are taken from the Iowa State University publication "Soybean Growth and Development " (PM 1945). You may use the information from this web page for educational use. Please credit the source with our name and URL: Soybean Extension and Research Program, Department of Agronomy, Iowa State University (http://extension.agron.iastate.edu/soybean/).
You can also obtain a print copy of this 29-page, full color publication by visiting the website of the Iowa State University Extension Distribution Center, or by calling them at (515) 294-5247.
Using soybean growth stages to maximize yield
Management strategies for improving soybean yield are most effective when you are able to identify the growth stage in which potential yield is affected. For example, the effects of fertilization, frost or hail, moisture stress, plant diseases, and pesticide application on yield will be determined by the growth stage in which these events occur.
How to identify growth stages
The system of soybean growth stages divides plant development into vegetative (V) and reproductive (R) stages. The vegetative stages are numbered according to how many fully-developed trifoliate leaves are present. The reproductive (R) stages begin at flowering and include pod development, seed development, and plant maturation.
The stages can overlap. When determining the growth stage of your crop, consider that a growth stage begins when 50% or more of the plants are in or beyond that stage.
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SU Extension publication Soybean Growth and Development (PM 1945)
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