Features Agronomy Soybeans
Value of seed treatments spreads to more crops

The use of seed treatment in all cereals is nearly 100 percent.

Seed treatments have played an important role in the production of healthy, profitable corn and cereal crops for many years. And as insects, diseases and variable soil conditions continue to affect crops, seed treatments are gaining prominence as an important agronomic tool to improving productivity in corn, cereals, and now in soybeans. Crop protection chemistry and seed treatment application methods also continue to evolve, helping growers to keep pace with nature’s challenges to ensure valuable seed gets the best start possible. 

Corn and cereals already benefiting
Today, most corn seed arrives at the farm with a commercially applied seed treatment to protect hybrids from insect pests and diseases. Growers rely on this treatment for a yield increase of as much as 5 bu/ac, according to Luc Bourgeois, research and development manager with Bayer CropScience in Eastern Canada. “Cereal seed treatments offer a yield increase by creating a better stand with an average increase in plant emergence of 10 percent,” says Bourgeois. He estimates that 95 percent of all cereals are treated: 100 percent of winter wheat and 90 percent of spring cereals. Wheat is most commonly treated with a fungicide, and in some cases, an insecticide too. “There are many seed-borne diseases that decrease cereal yield and quality, and a lot can happen between planting and seed emergence, making it critical to plant treated seed.”

“Seed treatments are a must,” says Peter Johnson, cereals specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). This is especially true when growing winter wheat in the Ontario snowbelt with the presence of soil-borne diseases like dwarf bunt. Bunt (dwarf and common) has the greatest economic impact with the potential to cause complete yield loss. Smut, another soil-borne disease, can reduce yield by as much as 10 percent, and can be controlled with seed treatments. Insecticide seed treatments also provide protection against soil insects such as wireworm, European chafer and white grubs.

A growing body of research points to the benefits of treating soybean seed. Photos courtesy of Bayer CropScience.

Growing trend in soybeans
Treating soybean seed is an emerging trend to protect against soil-borne diseases, and unfavourable soil conditions and to protect the seed and seedlings from insect pests. “Soybean growers are beginning to recognize the benefits of seed treatments,” says Horst Bohner, soybean specialist with OMAFRA. “In 2007, only three percent of certified soybean seed used in Ontario was treated with an insecticide and fungicide, and in 2009 that number jumped to 30 percent.” Soybean seed treatment is most beneficial in stressful seeding conditions such as heavy clay or sandy soils, in fields with a history of root rot or insect pests, in no-till fields and for early-season planting. However, there are other considerations when making the decision about using a soybean seed treatment. Bohner has been investigating how seed treatment affects seeding rates and the role that seed treatments play in early soybean planting, along with possible yield increases with earlier planting dates.

Early protection and an economic advantage
“Seed treatments have proven effective and offer more protection for the early planting of soybeans,” says Bohner, who has seen yield increases of 4 bu/ac when planting soybeans in early May, rather than late May. Early planting can be tougher on the seed because soil conditions are often cooler and wetter, creating the perfect environment for disease.  In these conditions seeds can benefit from a protective seed treatment.

Soybean seed treatments also offer economical advantages by reducing seeding rates. “Seeding rates can be reduced by at least five percent by using a combination treatment of insecticide and fungicide,” says Bohner, who is involved in research that may indicate seeding rates could be reduced by up to 10 percent. Typically, soybeans have 75 percent emergence and seed treatment can boost emergence and produce a more consistent stand, often resulting in 10,000 more plants per acre. Lowering seeding rates while protecting plant health with seed treatment can have a positive economic result. Growers can benefit from reduced input costs while maintaining or increasing yield.

Seed treatments are most effective at protecting the seed and early plant stages. Growers should refer to seed tag or product labels to determine how long a particular treatment will last. Many fungicides protect for a number of weeks, whereas some insecticide seed treatments are systemic and continue to work within the plant, fighting pest infestation.  In-season applications of fungicides or insecticides may be necessary, depending on disease and insect pressure in a particular field.

Improving treater technology
Corn seed treatment is applied, and there is a growing trend towards purchasing commercially treated certified soybean and cereal seed. Seed protection is limited, to some extent, by the quality of seed treatment application. Uniform, precise application is important to ensure correct rates are applied to each seed. “When establishing a crop, it’s important to do everything we can to reduce insect and disease pressure,” says Marty Vermey, product manager for Hyland Seeds. “And applying the proper amounts of treatment to the seed will provide the best control.”

Convenience, environmental stewardship and yield gains are important considerations that have led many farmers to purchase commercially treated seed. Commercial application does more to ensure that the seed is treated with the appropriate amount of product to prevent unnecessary leaching into soil. Excess application can also harm the seed, reducing quality and yield while unnecessarily increasing treatment costs.

To improve the accuracy of all its commercially applied seed treatments, Hyland Seeds recently invested in a new Gustafson continuous flow commercial seed treater that accurately applies treatments on a variety of crops, with the flexibility of applying up to nine products in a continuous, closed-loop system.

Vermey expects a continuous increase in the use of seed treatments, especially in soybeans, and this new investment will ultimately offer growers more options and flexibility for new advancements in seed treatments. “In the past, seed treatments were applied based on bulk weight, which could lead to over- or under-applying, as seeds vary in size,” says Vermey. “Today, seed treatments are often applied by seed count, a much more accurate application method.”