Dr. Shawn Conley’s virtual Soybean Summit session held on Wednesday, February 10, discussed how changes in soybean physiology have influenced soybean yield potential. Conley also walked through the growing season and discussed the interaction of inputs with soybean growth stage and calculated the role that soybean phenology plays in overall yield response. Below are questions from audience members and his responses to their inquiries.

Q: If we can go down to 80K plants/acre and still have 98% yield, should we only be planting at 100K plants/acre initially? Save on seed cost? – Neil Stoller, Akron Services, Inc.

A: I am not ready to make a wide spread recommendation to do this, but I think in early planted, good fertility, highly productive ground situations where farmers have a solid weed management plan this can work. I would ease into this practice especially though with commodity prices being where they are today.

Q: What is your opinion on using a roller on V1 or V2 soybeans to increase branching and yield? Can we get the same effect from just lowering seeding rates without rolling? – Don Kyle, Corteva Agriscience

A: I have not seen any data to support a consistent yield increase using this technique. Anectotally farmers tell me this practice increases soybean harvestabilty by pushing corn root balls down. This benefit is difficult to put hard numbers too!

Q: Do you feel any of the biologicals currently on the market provide added yield potential in soybeans? If so, can you comment on the soil applied biologics versus these that take up residence in the plant tissue? – Michael Gill, Illinois Soybean Association

A: I have tested a few of these products and have a difficult time seeing a stable and predictable yield response. These products come into the market place so fast and switch formulations it is a challenge to get a good handle on whether these products are effective or not.

Q: Has there been any work done planting determinate soybean varieties in the Midwest and what effect does it have on physiology/yield potential? – Jessica Herdes, Bayer CropScience

A: We have tried a few experiments with determinates. The challenge especially in WI is the photoperiod and GDU’s needed to get them to maturity is is dififficult. If we can get them to maturity the yield isn’t there either.

Q: Can you review more about the effect of early planting on plant development and flowering? – Brian Hall, Hall Consulting

A: This publication gets into the detail: Soybean Flowering Fallacy

Q: When is the best time to apply K to the soybean plant? – Josh Griffin, Winfield United

A: From what I can surmise it really doesn’t matter as long as the K is available to that crop in that year.

Q: Won’t prophylactic fungicides cause the same resistance problem we saw with glyphosate? – Drew Harmon, CNH Industrial

A: I totally agree. We do not recommend a prophylactic application of fungicides. The experiment I spoke too is just a proof of concept that we are testing. Can our farmer driven data and subsequent data analytics develop a sweet of recommendations that farmers can adopt in a region.

You can view the recorded Soybean Summit sessions including Dr. Conley’s keynote by logging in to your registration here and toggling between the event dates.

There are two more opportunities to attend and engage with soybean experts during the virtual Soybean Summit live broadcasts. Visit ILSoyAdvisor to learn more or click here to register today!

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About the Author: Shawn P. Conley