By Darren Hefty

One of the best things occurring in the soybean industry over the last 5 years has been a major improvement in soybean seed treatments.  Coinciding with that has been a widespread acceptance among farmers that seed treatments are providing a positive return.  The questions now are which ones work best and what combinations of treatments can be used together?

First of all, there are five categories of seed treatment products:

  1. Inoculant
  2. Fungicide
  3. Insecticide
  4. Biological
  5. Fertility

Inoculant – I would classify inoculant as “live rhizobia bacteria” products designed to increase nodulation on soybean roots.  There are so many false claims in this category of treatments with every company claiming to have the highest bacteria counts and the longest life on the seed.  There are two things you need to know about inoculants.

  1. All rhizobia bacteria inoculants contain live bacteria that begin to perish the instant you put them on unplanted seed.  The sooner you get the seed in the ground, the more bacteria survive and eventually colonize on your roots.  From what we’ve seen, after 30 days, about 90% of rhizobia bacteria die on unplanted seed even with the best extenders on the market.
  2. Bacteria counts are nice, but can be deceiving.  Companies have gone to using concentrated product and/or frozen product that you must mix with water before applying.  By doing so, they can have a higher concentration of bacteria per gram in the container, but when you dilute them with water for application the counts are often lower than the “ready to use” formulations like ROOTastic.  We have found ROOTastic inoculant to have the highest effective bacteria counts and the best performance.

Fungicide – There are quite a few fungicide seed treatments out there, and most of them are pretty good.  The key is to find the ones that work best on the diseases you have in your area.  Pythium protection is still best accomplished with metalaxyl, and most fungicide combo products have it.

Insecticide – All of the main insecticidal seed treatment products use one of the neonicotinoid family of insecticides: Poncho, Cruiser, and Gaucho.  These are the three brand names associated with this family of chemistry, but there are several variations off of each one.  Most commonly, you find insecticides in pre-packed solutions with two or more fungicides plus one of the insecticides for around $10/unit.  My best suggestion is to look for a product with the best re-spray program in case you need to treat for insects later.  At Hefty’s, we offer up to 2 free resprays if you purchase a qualifying product like Inovate or Acceleron Fungicide/Insecticide pre-treated at one of our stores.

Biological – There are quite a few biological seed treatments out there.  We’re experimenting with a couple of them again this year.  We’ve had consistently good response using QuickRoots.  The challenge to measuring the performance of any of these products has been the settings on the yield map.  Quite commonly, we see 4 to 5 bushel per acre breaks on the yield map.  Either set your yield map to measure 1 bushel per acre differences or just weigh each round as you’re going through comparisons in your fields this fall.  Just a half bushel to a bushel gain will give you a great payback on many of these types of products.

Fertility – We’re getting a number of questions about seed treatment fertilizer products again this spring.  You have to watch out, because it’s difficult to put enough fertility on the seed to help the plant without putting too much on and causing some damage.   We’ll keep watching for good products in this category and let you know when we’ve found some.

Finally, consider combining products.  Inoculants are a must.  They are very inexpensive and have been shown to give a good return on investment.  Follow the label for guidance when mixing with fungicide and insecticide products.  All three can be safely used together, but you may not be able to have them mixed together long before planting.  The biologicals vary in their ability to be used in conjunction with fungicide/insecticide combo products.  QuickRoots allows for mixing with most of them.  We work with a large number of farmers who use QuickRoots plus inoculant plus a fungicide/insecticide product like Acceleron.  Such three-way mixes are fine, but you must watch for putting on more liquid than can be reasonably absorbed by the seed.