Why Treating your Soybeans Pays

Soybean treatment has increased from 8% in 2009 to 70% in 2013. The need for a good seed treatment is due to earlier planting dates and reduced planting populations. Utilizing a simple fungicide and insecticide seed treatment has shown to increase seed survival rate to V2 by 8% +. That may seem like a small number, but it can allow you to decrease your planting population by 20,234 seeds per acre. It will also give plants better health to handle stressful environments that we can face. You can increase your return on investment by simply combining earlier planting dates, reducing planting population, and a good insecticide + fungicide seed treatment.

I receive a lot of questions around seed treatment and how it affects your bottom line. In this session of our Agronomy Update, I want to help you understand the benefits of seed treatment on your soybeans and how you can maximize your return on investment.

I am sure that there are many of you that still remember when seed treatment was a fairly new concept. According to an article written by G.P. Munkvold in 2009, only 8% of soybeans were treated in 1996. Those numbers slowly increased to 30% in 2009 and again in 2013 to 70%. As more data comes out surrounding soybean production more and more growers find it important to treat their soybeans with a good treatment package. There are three main packages of soybean seed treatment, fungicide only, fungicide and insecticide, and fungicide, insecticide, and nematicide. There are several additional components that can be added, inoculants, biologicals, micro-nutrients, seed finishers, etc., but they will not be addressed in this article. Our main goal by treating the seed is to improve seedling/plant health by minimizing the many diseases and insects in the seed’s environment.

One trend that we have been consistently seeing in soybean production is earlier planting dates resulting in higher yields. According to Beck’s PFR 20-year planting date study, the highest yields are achieved by planting from April 15 through April 30. When planting early there is a higher likelihood that field conditions are going to be cooler and wetter.  This increases the risk of disease impeding the germination of a soybean seed. A second trend that we have been seeing is a decrease in soybean planting population. Dr. Mark Licht from Iowa State University Extension notes that prior to 2006 the recommended seeding rate for soybeans was 150,000 SPA (Seeds per Acre) for 30” rows and 175,000 SPA for 15” rows at 90% germination. He now recommends 125,000 to 140,000 SPA for both row widths depending on other farm practices, such as tillage, fertilizer, IPM (Integrated Pest Management), etc. With better technology there is a call to growers to change traditional way of thinking from “soybeans are just a way to improve my corn yield” to “soybeans should be treated equally as important as corn” along with the mentality that “every seed counts.”

As already mentioned, earlier planting dates result in a higher probability that the seed bed conditions will be optimal for decreased seedling vigor and germination. This is where soybean seed treatment pays the most. There are two general thoughts around farming. The first is how can I cut cost, and the second is how can I maximize ROI (Return on Investment)? Seed treatment allows growers the opportunity to find a solution to both thoughts. Treating your soybeans with a good treatment allows producers to lower their seeding rates and ultimately their cost of seed per acre if they choose. This is confirmed by Gaspar et al. (2014) and Cox and Cherney (2011) through their research resulting in a recommended decrease of the soybean seeding rate when using a fungicide/insecticide seed treatment of 20,234 SPA. This allows growers to maximize their partial profit. In a 2-year (2011 & 2012) study completed by the University of Wisconsin they determined that FIN (Fungicide + Insecticide + Nematicide) seed treatments produced the highest plant stands across 10 different environments. These trials utilized 15-inch rows at a planting population of 139,943 SPA. The plant stand for each treatment was recorded at the V2 growth stage, approximately 25-30 days after planting. Below is a table that shows the plant stand, survival rate of the seed to the V2 growth stage, and the yield. 

This study shows the untreated check and the fungicide only treatment were statistically insignificant in terms of survival rate. Additionally, it shows that all yields were within a bushel from the average yield of 69.47 Bu/A (Bushels per Acre). These yields do not fall under the category of statistically insignificant, but it is not enough to say that seed treatment will pay for itself in terms of yield. We can determine that seed treatment significantly impacts the number of seeds that make it through emergence to V2. There are many more studies that have resulted in supporting the conclusion, that seed treatment increases the survival rate. Several entities have studied the impact of seed treatment directly correlating to yield, but it has not led to a clear answer. University of Wisconsin Extension conducted a similar study, Response of Broad Spectrum and Target Specific Seed Treatments and Seeding Rate on Soybean Seed Yield, Profitability and Economic Risk, where they concluded “At current seed and seed treatment costs, CB (Commercial Base seed treatment) and ILeVO at 140,000 SPA reduced economic risk by at least 70% and increased average profit ($4-19/A) across environments and grain sale prices.

Reviewing these studies and others we can determine that yield increase is not the reason why treating soybeans pays. Research consistently shows that treating your soybeans with a fungicide + insecticide combination shows that growers can significantly increase seed survival rate and decrease economic risk. When this practice is paired with utilizing each field’s optimized seeding rate producers will decrease wasteful costs and increase their ROI. It is our recommendation that growers strongly consider utilizing a fungicide + insecticide soybean seed treatment program in conjunction with an optimized seeding rate for your fields. As always, we are here to help you through these decision-making processes and provide insight. We look forward to making your seed count!

References

P Gaspar, Adam & Marburger, David & Mourtzinis, Spyridon & Conley, Shawn. (2014). Soybean Seed Yield Response to Multiple Seed Treatment Components across Diverse Environments. Agronomy Journal. 106. 1955-1962. 10.2134/agronj14.0277.

Gaspar, A. P., Mueller, D. S., Wise, K. A., Chilvers, M. I., Tenuta, A. U., & Conley, S. P. (2017). Response of Broad-Spectrum and Target-Specific Seed Treatments and Seeding Rate on Soybean Seed Yield, Profitability, and Economic Risk. Crop Science,57(4), 2251. doi:10.2135/cropsci2016.11.0967

Licht, M. (n.d.). Soybean Plant Population. Retrieved from https://crops.extension.iastate.edu/soybean-plant-population

2017 Indiana Soybean Planting Date Study. (n.d.). Retrieved from https://www.beckshybrids.com/pfresearch/Detail/ArtMID/1316/ArticleID/1289/2017-Indiana-Soybean-Planting-Date-Study

Naeve, S. L. (n.d.). Soybean growth stages. Retrieved from https://extension.umn.edu/growing-soybean/soybean-growth-stages#days-between-stages-539862

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