As growers explore the potential of not treating farm-saved seed, CPM weighs up the pros and cons for those sat on the fence over whether to treat, or not to treat.

Seed is the building block for everything else in the season.

By Charlotte Cunningham and Lucy De La Pasture

Getting the best from farm-saved seed is as much about cleaning and preparing it effectively, as it is about growing the right stuff in the first place.

But with more growers testing the water when it comes to not treating their seed, it poses the question – do we really need to?

According to Tim Eaton, seed treatment account manager at Certis, treating seed can help to give growers an advantage in terms of performance, before it’s even in the ground. “Seed is the building block for everything else in the season. Cleaning and treating it effectively and thoroughly can make all the difference in growing a successful crop – or not.”

While cost-saving measures could be a reason that some growers choose to skip the treatment stage, Tim says that single purpose seed dressings are actually a very cost-effective option. “Single purpose dressings have been standard practice for a while now and they’re very good at what they do. Diseases like bunt are very rarely seen as this type of treatment is used 99% of the time.

“On top of this, they’re very cheap as well, compared with a lot of other seed costs – with a spend of roughly £40-£50 per tonne of seed.

“In the grand scheme of things, this is a small investment to make on such a critical part of the crop production process.”

Despite their proven success, seed treatments aren’t for everyone, but there are some pitfalls to be aware of if growers do choose to go down the untreated route, adds Tim. “Obviously, the biggest issue when growers don’t treat is seed and soil-borne disease burdens. My advice for best practice is to accurately sample the seed and send it off for analysis to find out exactly what is or isn’t present.”

Independent mobile seed cleaner Jenny Eaves, of Premier Seed Services, says she’s seen a small increase in reclean only, but believes the decision should come down to grower preference and each individual situation. “As a business we’ve always been about giving farmers control and choice, enabling them to produce high quality farm-saved seed.”

“On the one hand, if the application of a seed treatment doesn’t also save a spray the way Redigo Deter (prothioconazole+ clothianidin) did, you can’t always immediately see the direct cost benefit. But in the same breath, the comparatively low-cost investment in a seed treatment is like getting a vaccine – they protect the quality of your seed and reduce the risk of the return of forgotten seed diseases, such as bunt, in future harvests.”

Though the level of control offered by single purpose seed treatments is satisfactory, Jenny believes there has been a lack of manufacturing investment in new seed treatment development resulting in missed opportunities for UK growers.

“It’s a shame there’s not the wider choice of new conventional seed treatments available for growers in the UK, as there are for growers in other countries across the world.

“The possibilities for the future use of seed treatment as a delivery method for innovative plant protection products – including nutrition at the point of drilling or bio-pesticides – could be really exciting.”

While it’s important that growers consider carefully whether or not they treat their farm-saved seed, one area Jenny strongly advises not scrimping on is proper cleaning. “Growers get good value for money using farm-saved seed. Proper cleaning, including gravity separation, is an investment into the quality of your next harvest.

“Taking seed ‘off the heap’ should be a last resort, it risks drilling a multitude of problems which will cost more to address further down the line. It also does nothing to protect the quality reputation and right to farm save in the UK which provides growers an equally high quality, but lower cost alternative to bought-in seed.”

So the theory is there, but how does the debate stack up in the field?

Herts farmer, Jamie Melrose, takes a mixed approach when it comes to dressing his farm-saved seed. “As a rule, I’ve traditionally treated the autumn crop seed but not the spring crops. We grow a lot of spring oats and it’s a fairly low-risk crop so I don’t see any obvious necessity to apply it.

“As well as this, the person we sell the oats to prefers less chemical to be used as it’s better for traceability reasons, so that’s something we keep in mind too.”

When it comes to autumn seed, like many growers, Jamie had historically used Deter (clothianidin). But with this now no longer an option, he’s considering whether or not treatment will be part of the strategy going forward. “About 80% of what we sowed this autumn had a dressing of Beret Gold (fludioxonil), but 20% had no kind of treatment.

“The blocks of crops are side-by-side and in all honesty, there’s no visible difference between the treated and untreated blocks.”

Jamie echoes the views that the options for growers are limited and says that there’s not a solution for some of his biggest concerns on farm. “There’s the option to go down the Beret Gold route as I’ve done this year, but for me, the biggest concern is BYDV and it doesn’t protect against that.”

Going forward, Jamie says he could see a bigger shift towards using untreated seed. “While there would be some marginal cost-saving benefits, the biggest benefit would be the reduced man-power involved with treating farm-saved seed. At the moment we’re doing about 200-300t a year which requires a lot of effort.

“Skipping treatment also helps from a flexibility perspective. For example, at the moment I’ve got 30t of treated seed sitting in a bag in a shed. Not only is this an issue if it gets contaminated but can also be a problem if you decide you no longer want to grow a certain crop or variety the following year.

“Time will tell, but at the moment, I’m certainly inclined to grow a lot less treated seed going forward.”

Advice on dealing with left over treated seed

Though the thought of having left over dressed seed is a reason some growers choose not to treat, storing it safely and efficiently is quite straight forward, according to Tim. “Hopefully, any growers with autumn 2019 seed will have already stored it carefully, but the main things to ensure is that any remaining seed is dry, out of direct sunlight and free from vermin.

“I would also say it’s important to get a germination test on the seed before it’s drilled. It may or may not have dropped, but either way, it’s important to know so seed rate can be adapted accordingly.

“If everything is done correctly, there’s no reason treated seed won’t last all year.”