Seed treatments have gained in popularity over the last few years, but are they a smart investment for soybean farmers? And if so, what kind of treatments are your best options?
You are faced with many choices of products that can be placed on the seed. With millions of dollars are spent on seed treatments each year, it’s important to understand what you’re investing in before making those decisions. Our options for seed treatments include fungicides, insecticides, nematicides, and biologicals.
Fungicide treatments help combat soil-borne diseases that affect seedlings like Phytophthora and Pythium. The problem is it’s hard to know if seed/seedling diseases will be a big problem from one year to the next. If you know you have a history of seedling diseases, a fungicide treatment is an option to consider.
Many of the major seed treatments use an insecticide from the neonicotinoid family. These insecticides will work well on early season bugs or seed-attacking insects. But, seed treatments only help control insects very early on and don’t provide long-term control. We also have very few (if any) early season bugs that cause a yield loss. The use of insecticidal seed treatments on soybean is not recommended in North Carolina since they have never been shown to improve yield in NCSU Extension replicated trials.
Biologicals have become more popular over the last few years, and that’s probably companies are investing millions of dollars into research in this field. Biologicals include a variety of options, including inoculants, nutrient supplements, fungicides, and nematicides. In high-yield environments, a biological that includes a nutrient supplement may be a smart option.
Theoretically, a nematicide seed treatment should help protect the early seedlings from root damage from nematodes. However, most of the research to test the efficacy of these products thus far has shown inconsistent results. If you have very high nematode populations, a nematicide seed treatment may be worth trying, but don’t expect any miracles.
If we look at historical data, across the US, we see it is difficult to prove the worth of a seed treatment and that is in part because it’s difficult to quantify the level of disease and other pests in a field. A group of private agronomists evaluated a number of different seed treatments on soybeans across North Carolina in 2014. Results from this trial are below and show little differences in the yield of plots with seed treatments compared to the untreated control plots. But that could be because there was little stress on the seedlings in those fields.
While seed treatments have proven useful in some situations, they only work if the problem they solve exists. If you are planting into cool, wet soil or if you are planting into cover crops that may harbor insects, seed treatments may be a smart option. If on the other hand, you are planting into an adequately warm environment, they will likely be of little use to you. Seed treatments are essentially an insurance policy. The amount of insurance you get depends on the premium paid. The only way to answer the question is to put the pencil to the paper and determine what your risks are and how much “insurance” you’re willing to buy to try to avoid those risks.
To begin to answer the question for your operation, you need to consider your specific needs on a farm by farm basis. Things to think about include:
- When are you planting?
- What kind of conditions are you planting into?
- Do you have a history of soil-borne diseases in your fields?
Answering these questions will help determine your risks, and thus decide if you need an “insurance policy” for your seeds/seedlings this year.
Hefty, D. 2013. Soybean Seed Treatments. http://www.agphd.com/ag-phd-newsletter/2013/05/27/soybean-seed-treatments-2/.
Kee, D. 2016. Tools of the Trade: Seed Treatment Economics. https://mnsoybean.org/blogs/david-kee/tools-trade-seed-treatment-economics/.
Porter, S. 2016. Does it Pay to Use a Soybean Seed Treatment? http://www.ilsoyadvisor.com/agronomy/2016/january/does-it-pay-to-use-a-soybean-seed-treatment/.