Seeds can’t hold an infinite amount of coatings so choose smartly based on need.
If you’ve ever built a shed, you’ve likely spent countless hours figuring out how to make best use of the space. You want to be efficient and get the most bang for your buck with the available square footage. The same process applies to selecting seed treatments.
Often overlooked in seed coatings is what I like to refer as the “seed real estate.” If you’re like most growers you plant treated seed, but do you know what is in those treatments? Are you optimizing what products are used, or are you simply ordering what the seed dealer or seed company offers? Seed treatments and other add-ons can significantly impact stand establishment and returns.
Most seed companies now offer a free replant policy for growers using the “standard” seed treatment offered. The standard treatment often contains two, three or four fungicides as well as an insecticide. These treatments offer broad-spectrum protection against the main seed-borne diseases such as Phytophthora, Pythium, Fusarium and Rhizoctonia. The insecticide portion is a highly systemic insecticide that can offer two to four weeks of seedling protection as well. This is a great foundation for a seed treatment, but there are more seed treatment choices to offer fungal protection, increase seedling vigor and promote nodulation, as well as offer nematode protection.
Soybeans offer only about 8 ounces per 100 pounds of “real estate” to apply seed treatments—and that isn’t much. The standard seed treatments take up 3 to 4 ounces of this real estate. A dealer can shave about 1 ounce off that if an insecticide isn’t necessary or recommended. Once basic fungicide and insecticide needs are met growers should evaluate their main yield-robbing pests and determine if another seed applied treatment can offer control or suppression.
Soybean cyst nematodes (SCN) are the number one soybean pest, responsible for about $1.5 billion in crop loss per year in the United States. An SCN test can show if cyst levels in the soil are above threshold and potentially causing yield loss. Many growers plant an SCN-resistant variety without knowing whether it offers sufficient resistance to the race of SCN in their fields. At a rate of 1.5-2 ounces per 100 pounds, another treatment can be applied to either keep cysts from colonizing or to kill the nematodes. These treatments range from $6 to $10 per acre.
A more recent yield-robbing disease is Sudden Death Syndrome (SDS). With SDS, the infection occurs early in the seedling or plant, but the disease is not expressed until later reproductive phases. Yield loss occurs when the plant leaves become necrotic and drop off, pod abortion occurs and seed size is reduced. In fields with a history of SDS or when planting early, where SDS infections are increased, a seed-applied fungicide can offer excellent protection against infection. The rate is just under 2 ounces per 100 pounds of seed and costs $8 to $14 per acre.
Inoculants introduce the rhizobia bacteria that promote root nodules that fix atmospheric nitrogen. There is no real test to know how much rhizobia is in the soil, but if fields have been in multiple years of corn there is a likelihood that rhizobia levels have decreased. Years ago, inoculants were delivered via planter box peat-based products. We now have a multitude of seed-applied products that deliver rhizobia accurately.
Planter box treatments are still not a bad way to go to insure nodulation, especially if seed “real estate” isn’t available. Most inoculants are applied at 2 ounces per 100 pounds. At a cost of less than $5 per acre, inoculants provide great returns, especially in high-yield environments or after multi-year corn rotations. Downfalls to seed-applied inoculants are storage limitations and timing of treatment. Once applied, the seed needs to be stored above 40 degrees and planted within 120 days.
Another growing segment of seed treatments includes growth hormones, micro nutrients, and fulvic and humic acids. These treatments tend to be prescriptive and typically have more variability in results and return on investment. Some seed companies also apply polymers or finishing products to increase flowability through planters.
There is no doubt that seed treatment options can be numerous and confusing, but may also offer great potential for protection and profit returns. I encourage growers to do their homework, ask questions and evaluate their options. Understanding the soybean “seed real estate” and product options available could open the door to maximizing yield potential on your farm.
Kris Ehler was the first Illinois Soybean Association CCA Master Adviser award winner in 2017.