Seed Trait Ratings: What’s in a Number?

Seed Trait Ratings: What’s in a Number?

Each rating is backed by thousands of research hours and on-farm trials.

Seed trait ratings sound so simple, you might think they’re at best a guess and at worst an outright lie. You might ask yourself, what’s really the difference between a 5 and 8 stress emergence score, and can I trust it?

Each time you see seed trait ratings – whether it’s a Pioneer® brand product or another seed brand – you’re looking at a highly precise and lengthy process that involves potentially hundreds of people and thousands of hours. Let’s dive in to see how the process works.

At Pioneer, all new germplasm is evaluated with specific protocols against all the key diseases and wind-related lodging events that can affect products across the country. Once evaluations are complete and data analyzed, trait scores are given for agronomic, disease and grain quality trait characteristics. Scores range from 1 to 9, with one being the worst and nine being the best.


A word about trait ratings – there’s no independent industry body that provides seed trait ratings. As a result, Pioneer and other seed brands have developed their own testing and rating methods. Pioneer scores go from 1 (worst) to 9 (best) while others may be from 9 (worst) to 1 (best) or use another scoring method. It’s important to understand what the rating means and how it’s reached.


Gary Henke
Gary Henke, Corteva
Senior Research Scientist

“You’ll see in the product catalog that most scores start in the four range and end in the seven-to-eight range,” Gary Henke, Senior Research Scientist with Corteva Agriscience, says. “This is because all the poor germplasm in a breeding program would score a one or two, or even a three for disease, gets discarded in the early stages of development. Similarly, on the higher end of the scale, you likely won’t see many nine for stalk or root lodging since those generally will not be competitive for yield. It’s always a balance of bringing yield stability along with agronomics. It’s just like a farmer trying to balance his risk and reward levels on his farm for different inputs like seed, fertilizer and chemicals.”


"That’s what these scores are meant to do — give farmers a tool to manage the risk in their operations,” Henke says.

Product managers, research scientists, disease scientists and silage scientists make up the team that scores these traits. Each scientist with the appropriate level of experience and expertise is the key individual to assign the scores for a given hybrid or variety.

The initial scoring is then followed by a review with commercial and product lifecycle leaders. Products that fall on the bubble between two scores will generate a discussion between research and commercial leaders to determine the most conservative score for the product. It is a highly deliberate and careful process.

“Our sales force trusts and relies on these scores to help position our products on our customers’ fields,” Henke says. “So even if a farmer is not using these scores directly, it is likely that those scores were used to develop the product positioning information to help the sales rep and grower make the right placement decision for a specific field.” 

Reality of Ratings

Disease ratings come from the results of disease characterization trials that strongly challenge the plants’ disease tolerance.

Scott Heuchelin
Scott Heuchelin
Corteva Senior Scientist
& Leader, North American
Pathology Group

“We locate these trials in areas that have the greatest natural disease pressure. Then, we enhance the environment with irrigation and we inoculate the plants with the pathogen itself,” Scott Heuchelin, Senior Scientist and Leader of the North American Pathology Group for Corteva, says. “We heavily inoculate the plants with that pathogen in an ideal environment for disease development. So, we’re putting the maximum disease pressure on them, something the genetics would rarely ever experience in the field. As a result, our disease ratings are conservative. When we assign a rating, a four for example, on a corn product, we are telling customers that if the disease develops along with the perfect environmental conditions, that product is not going to perform any worse than a four.”

This approach has practical implications. A farmer may be able to run with a four very well and not have to apply fungicide if they’re in a relatively arid area compared to eastern regions where that same four may yield well, but need some management, such as fungicide to help it reach maximum yield. Or, farmers in wetter areas may lean toward products with a disease rating of six or seven.

“On our one to nine rating scale, a one would be the worst possible scenario with the plant prematurely dying and a nine would be pretty much immune to disease. There are few if any products immune to disease, so you’ll see most of our products rated three to eight,” Heuchelin says. “Products with a nine rating sometimes may exist, but they tend to have so much disease resistance and have little yield to go with them, so they don’t make it to a commercial product.

“The ratings we put out for products we sell are the same ratings we have for research and development. As products come up through our pipeline, they get at least three to four years of disease testing. Along the way, we see products that are too susceptible and these ones, twos or even some threes will be weeded out of the product line.”

As a result, farmers will see mostly fours, fives, sixes and sevens for Pioneer brand products. Occasionally there will be some threes and eights.

“The message here is that Corteva gives farmers true disease numbers they can trust,” Heuchelin adds. “The numbers are conservative and they’re what farmers can expect from the product in the worst-case scenario or the perfect storm of disease.”


Continuous Updating

It takes a lot of potential products and research to keep delivering new products that meet ongoing yield and disease challenges.

Darren Barker
Darren Barker
Leader, Corteva
North America
Corn Portfolio

“We start with thousands of combinations and work things down from there,” Darren Barker, North America Corn Portfolio Leader, says. “After multiple years of testing, we advance about 45 to 50 products every year. At the same time, we bring new products into the lineup we phase out older products so we can maintain an overall healthy product portfolio for our customers.”

He says replacing products depends on decreasing demand for existing ones, as well as sales representatives’ and customers’ input. The team also considers what new traits may be coming and what potential they may have.

“We look years ahead, so we have to be thinking about how the transition will take place as we begin to phase out a product from the lineup while adding a new one,” Barker says. “As we look across North America, there are different disease and agronomic trait needs depending on geography. Trait ratings can be used as a guide to help us determine where the best fit is for a product and if a product has the right agronomic or disease tolerance for a specific geography.”

Feedback from the field and sales team is critical as well. Product agronomists evaluate products during the last stages before advancement and help to provide feedback on initial ratings. Once a product is advanced, field agronomists, sales reps and others evaluate products during on-farm testing trials. They provide valuable feedback as to how well initial ratings hold up. Their observations are shared with the scoring team who then re-reviews the product.

“We have a lot of confidence in our ratings and we want to make sure we’re testing these products well in each geography,” Barker says. “It’s important to make sure our confidence is backed up so farmers can be assured that our data and field observations support the trait scores we provide. This also ensures there are no surprises for us or our customers.

“These ratings are an important tool for farmers as they can be used as a guide for both product positioning and product management,” he adds. “They can help growers position the right product for the right acre, help prioritize in-season disease scouting and help with harvest management considerations.”

Barker highlights that trait scores are supported by highly experienced sales representatives who have solid experiences with the ratings, as well as the products. Their role is to offer management suggestions and products to help farmers grow healthy crops and make the most profit possible.

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What Pioneer® Brand Trait Ratings Mean

Backed by years of research, product testing and scoring, the numerical ratings for Pioneer seed products are straightforward and serve as a sound management tool farmers can use to manage risks and expectations of crop performance. Pioneer score guidelines provide consistent management recommendations across geographies. Local conditions, including increased disease and pest pressure, as well as weather, may influence crop performance and yield.

Look for certain descriptor words as stand ins when scores aren’t listed. Certain brands may always use the same descriptors for ratings. With Pioneer products, an “excellent” hybrid scores an 8 or 9 for that rating, whereas a 7 rating would be described as “very good”. Ask your Pioneer Sales Representative for more information.