Why are Soybean Seeds Pink?

Jul 27, 2022

By Willard Jack

The farm’s new seed treater prepped and ready for soybean seeds. Photo Credit: Willard Jack

When spring planting comes around each year, it never fails that a visitor at our farm will ask, “Why are your soybean seeds hot pink?” I can tell that some ask out of pure curiosity, and others are bothered by it because a hot pink soybean seed seems unnatural. We recently purchased a seed treater, with plans to treat our soybean and cotton seeds in-house for 2022. Originally, my intent for this article was to talk about our new seed treater; however, as I started writing, I decided to write about the basics of seed treating—the why, what and how.

Why do we treat our seeds?

We treat our cotton and soybean seeds in-house. Our corn and rice seeds come to the farm already treated by the supplier. The reason we treat seeds is to mitigate early season risk of disease and insects and to maximize yields. The practice of treating seeds is nothing new. According to a 2009 article that I read in Cotton Grower magazine, seed treatment dates back over 350 years. In 1670, a ship carrying wheat sank off the coast of Bristol, England. Since it sank close to the coastline, farmers tried to salvage the wheat. The farmers then decided to plant some of the wheat they salvaged because the quality was too poor to make flour. As the crop grew, they noticed that the fields planted with wheat from the sunken ship had much less incidence of smut, a wheat disease. Going forward, it became a common practice for the farmers in that area to treat grain seed with freshwater and salt, lye or even urine.

Since then, seed treating technology has come a long way from salt water and urine. For us and others in the mid-South, seed treatment has become a standard practice because our mild winters and long growing seasons lead to considerably more pest pressure. Each year, as we choose our crop mix, we also decide what products are needed to protect our seeds from disease and insects and allow them to grow to their full potential.







Untreated soybean seed (left) and treated soybean seed (right) Photo Credit: Willard Jack

What does it mean to treat seeds?

Seed treatments are made up of a combination of ingredients to protect the seeds. Common ingredients include fungicides, insecticides and additives. Each ingredient has the purpose of either protecting the seed or maximizing the potential of the seed. For example, fungicides protect seeds from fungal diseases, and insecticides defend against below-ground insects and provide seedlings with early protection from above-ground insects. Additives help to give the seed a head start in the early crop season. For example, we treat our soybeans with Vitalis, an inoculant additive that adds bacteria to the seed to increase the uptake of nitrogen from the air. Our soybeans are also treated with one insecticide and three fungicides, in addition to the inoculant. Treating our seeds with the right “recipe” of ingredients will grow a healthy, higher-yielding crop that uses soil nutrients efficiently.

How do we treat seeds in-house?

In our warehouse, we store our seed and crop protection products. Our warehouse also stores our seed treater. Prior to planting, we feed the untreated seeds through our seed treater, which applies the specific recipe of fungicides, insecticides and additives that we have chosen for that particular seed variety. The seed treatment ingredients are sprayed onto the outer layer of the seed. When complete, the seed will be coated in the treatment. The treatment will be visible to the eye by the colorant in the treatment.

Why are treated seeds pink?

The colorant is required by law so that it is obvious if a seed has been treated or is untreated. The bright color reminds our employees that they are handling treated seed and should use proper personal protective equipment, or PPE, such as gloves and a long-sleeve shirt. Also, the colorant makes other end users aware that the seed has been treated to be planted in the ground and cannot be used as feed.

In conclusion, seed treatments are just our first line of defense to threats to our seeds’ growth potential. They set the foundation for our plants to grow. Six to eight weeks post-plant, conventional seed treatments break down and dilute. By the time the plant reaches maturity and is ready for harvest, the seed treatments are in most cases no longer detectable within the plant.

Willard Jack (center) is a farmer from Belzoni, Mississippi, and actively served on the American Soybean Association Board of Directors from 2015 to early 2022. Jack is a first-generation farmer who moved from Canada to the United States in 1979. He and his family grow soybeans, cotton, rice, corn and wheat. He runs Willard Jack Trucking and is chairman of the board for Silent Shade Planting Co., a 12,000-acre irrigated operation.