It’s important to always know or have a close idea of where your soybeans are in their growth stage. This information is important not only when making fungicide applications, but also to evaluate the potential risk of threats that could be associated with the current and rest of a growing season. In 2019 several bean fields are slow to advance into the R7-R8 stages, which means there’s a large percentage of yield that is yet to be made and retained.
Chart 1 shows the eight growth stages of a soybean plant. The reproductive stages of the soybean plant are focused on producing high pod counts and, more importantly, preserving as many as possible. During this time a soybean plant is trying to balance its hormones and determine what number of pods and seeds it can successfully feed and finish. Stress (disease, nutritional, insect, water and heat) during this time can cause the plant to eliminate pods and seeds.
Evaluating Pod Counts – What to Look For:
Remove all the pods from the plant
Separate the pods based off 4, 3, 2, 1, 0 beans per pod
Count how many pods were aborted
Record information to compare field to field and season to season
After taking a look at the plant’s pod counts, one can determine the quality of life an individual bean plant has had. This information can provide insight into potential yield, which varieties can withstand stress and how well one’s management practices are working. Yes, it’s always important to see a yield bump from trying a new practice, but it’s even more important to understand how and why, so it can be replicated for years to come.
Steinacher is an ISA CCA Soy Envoy alum and currently supports ISA on agronomic content as well as serving as an Illinois CCA board member. He was recently awarded the 2020 IL CCA of the Year & the 2021 International CCA of the Year. He has over 15 years agronomic experience, currently working with AgriGold and GROWMARK previously. Steinacher has an associate degree from Lincoln Land Community College, a B.S. in agronomy and business from Western Illinois University and a master’s degree in crop science from the University of Illinois at Urbana-Champaign.