Happy accident: Researchers discover promising new seed treatment

How it works is still a mystery, but new compound boosts germination, root development, and resistance

Lab trials of a manure-derived seed treatment have usually shown increased root growth (as seen on the right) as well as better resistance to environmental stressors.
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Good things generally don’t happen by accident in science — they’re the result of countless hours of trial and error, replication and peer review.

However, University of Saskatchewan researchers may be looking at the closest thing to a scientific miracle: A natural seed treatment that increases germination in just about any crop you can name, at least under controlled laboratory conditions.

It was discovered entirely by accident and that’s perhaps not surprising given the source: Manure.

Plant scientist Karen Tanino describes the discovery of the compound as “serendipitous.” Several years ago Andrew Olkowski and Bernard Laarveld (colleagues from the department of animal and poultry science) developed a compound to break down animal manure for field application. As a precautionary measure, they applied the treatment to barley seed to rule out any toxic side-effects.

Karen Tanino. photo: Supplied

“Instead of being toxic, it in fact enhanced barley seed germination,” said Tanino.

The unnamed compound has been tested on 30 crops and cultivars and has usually produced better, earlier germination and enhanced lateral root growth, as well as resistance to a wide range of crop ailments.

“I would say over 90 per cent (of the crops and varieties tested) responded with enhanced germination under all temperature conditions, including cooler spring temperatures,” said Tanino, project lead on the research.

There’s still a lot of work to be done before it’s ready for prime time, but it’s been so promising the U of S has filed for a patent on the treatment.

“We have enough significant observation and data to allow us to say there’s something going on with this seed treatment that is not just significant to one crop,” she said. “We’ve looked at lentils, peas, chickpeas, soybeans, wheat, malting barley, flax, canola, some horticulture crops and are starting to look at forages.”

The trick now is to replicate the lab success in a field-scale trial. Optimization (figuring out how much to apply and how best to apply it for different crops) will also be a crucial step in commercialization.

The compound itself is the result of a catalytic reaction between food-grade chemicals including transition metals such as iron or copper.

“One useful aspect about this material is that we use food-grade products which are inexpensive, giving it potential for the organic food industry as well as the conventional,” Tanino said.

“We are not introducing anything that the plant doesn’t already have. We think we’re just triggering reactions within the seed but we really don’t know the mechanism.”

Yield gain uncertain

Still, the compound has been an unqualified success in the lab, with most treated crops consistently displaying greater germination and root growth compared to controls treated only with water.

However, there’s a very significant ‘but.’

Most of the test crops weren’t taken to the yield stage, and wheat and canola in plot trials had only slightly higher yields.

“We saw some consistencies between the lab and the field — including increased lateral roots and tillering in the wheat — but we didn’t see a significant difference in yield compared to the water control,” said Tanino. “I’m not sure if it’s because there was no environmental stress in those years. Maybe if it was a really stressful year perhaps the water control would have suffered.”

Part of the problem may be the treatments haven’t been fully optimized. A related challenge is the fact that for unknown reasons, there are response differences between cultivars within a crop.

“Once we understand why there is a difference we can then provide a better seed treatment optimized for the cultivars. Let’s say one cultivar has a slightly thicker seed coat than another. If we know that in advance we can say that cultivar would need to have a higher treatment concentration applied than another cultivar.”

Determining the best application method will also be key.

Much like other seed treatments, application methods include dipping or soaking the seed or spraying the seed. Most of the lab applications involved soaking, which takes a lot of time. Many farmers prefer spraying their treatments onto seed using a device such as a Storm Seed Treater, said Tanino.

“We need to do more research in that area. We haven’t had enough time to look at cultivar-dependent spraying and spraying is what will work best on the field.”

She added that she has been working with a skeletal research team throughout the project’s five years to date, contributing to its slow progression. However, they are taking their first steps into spray application.

“In the lab we don’t have equipment like the Storm Seed Treater so we’re mimicking that process through a vortex. But we may be damaging the seed coats a little bit. Working with seed treatment companies would really be beneficial since they have the right equipment to test the application methods.”

Crop stress resistance

How the treatment will perform on farm is still anyone’s guess, but there is room for optimism. Although it’s been subject to a field trial on 80 acres of farmer-owned land, the research team was unable to take data from the trial before it was aborted due to bad weather. However, Tanino was still able to observe enhanced root growth in plants grown with the treated seed in the field.

In the lab, the treatment seemed to drive a unique reaction in legumes.

“We have seen increased nodulation without inoculation. I haven’t tested the specific activity of the nodules but they do look pink so they seem to be active.”

But one of its biggest draws may be its potential for disease and environmental resistance. The catalytic reaction creates a common chemical compound known to increase resistance to a wide range of environmental stresses, said Tanino.

Although the specific mechanism which creates the treatment is still a mystery, this X factor may be the driver behind its enhanced resistance to environmental factors such as low temperatures, heat stress and salt stress. It may also account for increased nodulation, she said.

The compound may even hold a key to better drought resistance.

“It is remarkable that a single treatment applied to the seed can have such long-lasting effects on the whole plant.”

There’s a caveat here, too. Just as it takes money to make money, the plant already has to have resistance to a given environmental stress in order for the treatment to help.

“The plant already has to have that genetic machinery in order to respond, but if it has that potential I think the seed treatment may be able to increase multiple stress resistance responses.”

To date, Tanino hasn’t had the time or opportunity to thoroughly investigate several key traits. And that’s the rub. The treatment could be commercialized in a few years if there is enough research support from the industry, she said.

“Realistically it depends on how many people work on it. If the industry comes on board and a seed treatment company comes on board and we put their people on it beyond COVID-19 and test it in the field, then perhaps we will have a commercial product in five years.”

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