Why Use a Soybean Seed Treatment?

• The color of a soybean seed treatment doesn’t mean much. Instead it is important to know the active ingredients and that it was applied properly.
• It can be compelling to cut seed treatment investments to help with overall spending, even though value may have been seen in previous years. It is critical to consider the needs of the field for insect, disease and nematode control.

Many farmers have witnessed the value and return on investment of a seed treatment on soybeans, especially when protecting seed when planting earlier to try and optimize yield. Research has shown that seed treatment can help reduce seeding rates and reduce seed costs. The problem today is that the color of the seed doesn’t mean it’s fully protected. With tight operating margins, farmers have to understand what they’re purchasing and if it was applied properly. This requires knowing what active ingredients, additives and rates were used. Otherwise farmers may just be purchasing a flashy color.

Insecticide
Many seed treatment packages consist of insecticides that are labeled to protect against insects such as aphids, bean leaf beetles, seedcorn maggot, and other early season pests. It’s important to understand the rate used as there can be significant differences in performance. Value of a seed-applied insecticide can change from year to year depending on the level of insect pressure. However, as planting dates move earlier to help maximize yield, potential for insects increases. First-planted soybean fields often have more yield potential but are also most likely to encounter bean leaf beetles. Planning ahead with a robust offering like Golden Harvest® Preferred Seed Treatment can help take advantage of early planting. But even in the absence of insect pressure, seed-applied insecticides have shown a positive vigor effect, increase in speed to canopy and potential yield increase.

Fungicide
Multiple fungicide components are needed in a seed treatment in order to protect against soil pathogens Pythium sp., Phytophthora, Rhizoctonia and Fusarium sp. Golden Harvest Preferred Seed Treatment offers a combination of active ingredients to provide broad-spectrum protection across the most common soilborne pathogens. Some of these active ingredients also give flexibility to manage seedborne disease, such as Phomopsis sp, that might not even be present in the field but could be introduced from the prior year’s seed production fields. Golden Harvest Agronomy in Action research continues to look at potential new fungicide active ingredients for continued improvement.

Nematicide
Soybean cyst nematode (SCN) pressure can be unevenly distributed throughout a field, with no obvious injury visible. Heavy reliance on a single source of plant genetic resistance, PI 88788, has reduced its overall effectiveness for managing SCN. Due to this, SCN populations can grow, increasing the need to consider using seed-applied nematicides for early season SCN management. Reduced feeding can also indirectly reduce the number of pathways of soilborne pathogens to enter roots, reducing the risk of diseases such as Fusarium virguliforme, commonly known as sudden death syndrome (SDS). Saltro® seed treatment is a newly registered fungicide that also provides protection against nematodes. Saltro provides direct activity on fusarium and SCN, which also helps indirectly lessen fusarium infection by reducing SCN root injury. Many biological nematicides are now available. However many do not have direct activity on SCN, but instead create protective zones around roots. Performance can vary greatly among biological nematicides.

Biologicals and Inoculants
Biologicals are often produced from natural microbes (bacteria or fungi). They can have a variety of claims to improve insect, disease and SCN control or for enhancing nutrient uptake to promote growth and yield. Some biologicals promote minor to significant yield increases. Consistency of many of these products can sometimes be challenging to understand the return on investment.

Inoculants are another form of a natural solution that has evolved over many years. Most inoculants contain soil bacteria called Rhizobia which is needed as part of a symbiotic relationship with soybeans to help roots fix nitrogen. In some instances, research has shown 1 to 2 bushel-per-acre yield responses when new inoculants are used within a corn – soybean rotation. On-farm research, such as replicated, side-by-side strip trials over multiple years, is suggested prior to adding inoculants into a farming operation.

Premix Formulations vs. Custom Blends
In efforts to provide a low-cost treatment, downstream treaters sometimes use custom blends of individual seed treatment products to provide broad-spectrum control. Custom blends are separately registered products that are mixed together just in time for delivery and use. Since custom blends are not precisely formulated to be intermixed in all combinations, the overall use rate can often be higher than a similar premix product that was carefully designed and formulated together to deliver at lower use rates. Seed treatment recipes exceeding 7 fl. oz. per 100 lb. of seed can be more difficult to dry and will sometimes result in poor seed flow and plantability issues. Depending on the recipe and number of products, it may be challenging to add products, such as inoculants, to the overall treatment recipe.

Return on Investment
With tight margins, it can be compelling to cut seed treatment investments to help with overall spending even though value may have been seen in previous years. Multi-year analysis at the University of Wisconsin has shown that in 40-80 bushel yield environments, fungicide and insecticide seed treatments offered return on investments 88-98% of the time based on field trials.

Summary


Remember that all seed treatments are not created equal. Just because soybeans are colored and shiny doesn’t mean they have a high-quality seed treatment. Some seed treatments may only contain a single fungicide or a reduced rate of multiple active ingredients. If you’re not sure what’s on the beans, consult the seed supplier.  When planting early or late, foregoing a seed treatment increases risk. Whether it be for insect protection or fungal protection, high-quality seed treatments are a must – especially with reduced seeding rates.

Ultimately, the goal for using high-quality treated seed includes:

• Improved emergence
• Increased vigor
• Earlier canopy closure
• Broad-spectrum insect protection
• More yield potential