Food security

Protecting seeds: The what, why, and how of seed treatments

For millennia, people have understood the need to protect seeds. They are precious packets of life that bring us food. As early as 2000 BC, there are records of people soaking seeds in cypress sap or onion extracts to protect them from damage by disease, insects, or rodents.

Since those days, scientists have made many innovations to protect our seed supply. Seed treatments provide tailored products that are safe for seeds, safe for people and safe for the environment. These innovations help maximize protection of the seed and developing seedling during planting and in the first few weeks of emergence and seedling growth, the most vulnerable time for a plant.

What are seed treatments, anyway?

Seed treatment “recipes” can include many individual products. Each ingredient has a specific role in protecting the seed from a certain vulnerability or direct attack. Others maximize the health and vigor of the seedling as it is developing.

Treated seeds come in many colors: bright pink, brilliant green or blue, or even vibrant purple. These are all purposefully unnatural colors to help buyers know that treatments are on the seeds. The colorant is required by law in most jurisdictions globally to specifically distinguish that this seed has been treated with pesticides, to help ensure that treated seed is not used in grain (food or feed) distribution channels. The colorant is used to show that the seed has been treated, and therefore the seed buyer needs to investigate further, using the seed bag tag or seed package label.

Watermelon seeds with orange fungicide treatment coating.
These watermelon seed are orange because they are coated with a fungicide seed treatment. The coating helps the watermelon seeds and seedlings fight diseases as the crop begins to grow. Credit: Cristine Bradish

Seed treatments are tailored for a specific seed type, and in some cases, tailored for a specific genetic makeup. This is just one of many safeguards in place to ensure seed treatment products and treated seeds are used safely.

Beyond protection, why do we use seed treatments?

Farmers use treated seeds for a multitude of interrelated reasons. In the end, it is about maximizing and protecting the yield potential of the seed. To achieve that, farmers, and therefore technology providers, consider a complex matrix of genetic, environment, and management factors and decisions:

•             Soil type

•             Soil moisture, drainage, and irrigation

•             Planting date, density/seeding rate

•             Manure application on-field or nearby

•             Prior cropping and cover crop history

•             Tillage type

•             Weed pressure

•             Neighboring crops/plants

•             Genetics of hybrid/variety

•             Pest/disease history

For example, decades of research determined that the early spring planting of corn increases yields. However, early planting increases the risk of damage from early season insect pests. In addition, there is increased risk of diseases that come with the challenging cool, and wet soil conditions of early spring.

Seed treatments are critical tools that help to reduce those early season risks. By coating seeds with insecticides that protect against wireworm or seed corn maggots, for example, farmers can reduce the risk of crop loss from these pests. Fungicidal and biological seed treatments can protect crops from diseases such as Pythium or Rhizoctonia. When coupled with the right combination of hybrid or varietal characteristics, agronomic decisions, and core farm management, seed treatments are a key part of an integrated crop management strategy.

Soybeans coated in green
These soybeans, loaded into a planter on a farm, are treated with fungicide and insecticide. They are also coated with inoculant, a thin powder that encourages soybeans to develop beneficial root nodules. Credit: Rachel Schutte

Another often overlooked benefit of seed treatment that they can prevent the transmission of seed-borne or vector-borne diseases. Bean leaf beetles could get onto soybean seeds, and if untreated, these beetles could contaminate the seeds with bean pod mottle virus in soybeans.

In addition to protection from known or established pests and diseases, seed treatments can also help reduce the impacts of emerging pests. Take the case of fall armyworm. These pests have ruined thousands of hectares of farmland in parts of Africa and Asia. Fall armyworm feeds on at least 80 different crops. These include staples like rice, sorghum, millet, and maize, which form a crucial part of the daily diets of rural households on these continents. Treated seeds offer farmers a critical method of protection, especially from pests that attack early in the season.

Getting the crop established with a solid beginning is crucial for later stage crop growth and development. This leads to a strong harvest yield. That’s exactly what seed treatments are designed to do.

In fact, most conventional seed treatment products break down or dilute over time – usually in the first six-to-eight weeks after the seed has been planted. In most cases, seed treatments are no longer detectable within the plant at the end of the season when the crop is harvested. Other methods of plant protection may be used as needed during the later stages of the plant’s life cycle.

cupped hands with black gloves holding red and purple corn seeds.
This corn seed is not treated with fungicide or insecticide. The seed is colored to show it is only intended for planting – not for food or feed use. The purple corn seeds mixed in with the red corn seeds are called “refuge” seeds. These seeds do not have the Bt (Bacillis Thuringiensis) insecticide trait, which helps ensure insects won’t develop resistance to the trait. Credit: Rachel Schutte

How are seed suppliers working to innovate and steward treated seeds?

Like all tools, seed treatments must be used properly. The seed industry is fully committed to the safe use and disposal of seed. It is essential that everyone who treats, handles, transports, and plants treated seeds manages them properly and in accordance with label instructions. Accordingly, seed suppliers have worked together through the American Seed Trade Association to enhance stewardship best practices across the seed industry:

  • development of stewardship and quality management programs for seed suppliers,
  • education and outreach initiatives for ASTA members and farmers,
  • delivery of core stewardship messages to thousands of farmers using social media and radio campaigns during planting and harvest seasons regarding the handling and planting of treated seeds.

There is no question that today’s food production system faces very real threats. From climate change and environmental threats, to rapidly evolving pests and disease, all threaten our food supply. Continued innovation in agriculture is crucial to ensure sustainable food production and long-term global food security. Seed treatments are one of the many valuable and innovative tools that enable America’s farmers to meet these new and emerging challenges, while realizing healthy yields – all while protecting our land and natural resources for the future.

Keri Carstens, Corteva Agriscience, and Seed Treatment and Environment Committee, American Seed Trade Association

For more information about seed treatments, including videos and downloadable communications resources, visit: seed-treatment-guide.com.

Please visit our Please visit our Please visit our Seed Week webpage for more information.

Read the other blogs in our seed series!

How can you prevent weed seeds from germinating in your garden?

How are seeds labeled for a farmer’s purchase?

How does the USDA help make global seed trade safer?

The Incredible, Edible Seed

Why are seeds of different sizes and shapes?

What are seeds made of – and how can they grow into fruitful plants?!

About us: This blog is sponsored and written by members of the American Society of Agronomy and Crop Science Society of America. Our members are researchers and trained, certified, professionals in the areas of growing our world’s food supply while protecting our environment. We work at universities, government research facilities, and private businesses across the United States and the world.

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