Chemistry bans – we need Batman AND Robin!

A few decades ago, with only a handful of products designed to eradicate diseases rather than protect, it might have been a pretty simple job to decide on a programme.

We then went through a period where the role of agronomist became more complicated as, for a while at least, it seemed almost impossible to keep up with the burgeoning number of new products and formulations coming onto the market.

Nowadays, however, it’s more likely to be keeping abreast of what’s been taken off the market, what new restrictions have been placed on their use or, perhaps most worrying of all, how effective any particular product is likely to be given the build up of resistant disease strains and races.

One old-timer, however, has been out there helping us with our fungicide programmes for many years now. And, no, before you ask, I’m not speaking about our own agronomist on this occasion – but with that faithful companion in tank mixes, the fungicide chlorothalonil,which was originally sold variously as Bravo, Echo and other trade names before it became more generic.

While it might have been kicking around for close to 30 years, there’s still no major sign of resistance building up to chlorothalonil – simply because of its multi-site mode of action, which doesn’t seem to apply a selection pressure on the diseases. So, it’s currently a cornerstone of spray programmes which allow us to control the key diseases of septoria in wheat and both rhynchosporium and ramularia in barley.

For, as the more targeted – and originally more effective – systemic fungicides, such as azoles and SDHIs have seen resistance build up year on year when one particular mode of action is relied upon too heavily, this old workhorse has seen a new lease of life playing a crucial partnering role which helps extend the lifespan of other actives by offering a diverse mode of action in tank mixes.

While it might originally have been viewed as playing Robin to the newer chemistry’s Batman, at the moment we’re not only relying more on it for control but more critically as a resistance management tool which helps nurse the more targeted chemicals along by slowing the rate at which resistant disease strains build up.

So, that’s why it’s such bad news that the European Commission has been talking about tabling a motion which will seek to remove its licence for use on crops – and while it’s only really the UK and Ireland which suffer from damp climate disease scenarios which it helps control, there probably won’t be too many voices speaking in its defence.

While the convoluted corridors of power in Brussels have been passing the issue around for some time now, there is a very real threat that the plug could shortly be pulled on this product which lies at the heart of our disease control and resistance management strategies.

But while our government is making a pig’s ear of pulling the chain on our membership of the EU, it’s pretty unlikely that if chlorothalonil was banned in the Europe that we’d be allowed to continue using it in the UK after we’d left – deal or no deal.

This does raise the question of just how far the UK will be able to make its own choices on such issues after Brexit. If, as everyone hopes, there is some sort of deal which would provide frictionless trade then we’re bound to be pretty much aligned on this front if we wanted to sell our grain to EU member states.

If we get no deal, then there might be more lee-way – but this would have to be viewed against the background of a government which seems keener than most to listen to every qualm and fad expressed by the urban majority when it concerns the food which we eat.

On the wider front, though, it was interesting to hear both Defra secretary, Michael Gove and farm minster, George Eustice, suggesting that we might be able to adopt new breeding techniques such as gene editing to help improve performance, including disease resistance, in our cropping sector.

A world apart from the older genetic modification techniques – which often saw the introduction of genes from different species altogether – the editing procedures manipulate what is already present in the plant.

Researchers tell me that this pretty much means that you can only get the same results as you would eventually get with traditional breeding techniques – only a hell of a lot faster.

So, such techniques seemed to offer a glimmer of hope that we would be able to breed plants less susceptible to the major diseases within a far shorter timescale while also allowing us to rely less heavily on the spray can – a situation which sounded like a win-win situation all round.

However, much to the scientific community's surprise, last year the European courts ruled that the same restrictions would be applied to plants manipulated by gene editing as are applied to transgenic modifications, quashing hopes of growing such crops commercially at a stroke.

But both Gove and Eustice stated recently that following Brexit a 'discussion' needs to take place on what approach the UK should take. They indicated that they would be in favour of removing some of the restrictions, thus allowing our scientists to help feed the growing number of mouths on the planet while possibly reducing our reliance on chemical pesticides and fertiliser inputs.

So far so good – but you might ask what would the view of the Scottish Government, which has been pretty hard-core in its anti-GM stance, be on this one? So did I – and I put it to them last week, only to get the following response from a Scottish Government spokesman:

“While we very much value the views of our scientific community, the government has a responsibility to consider other social, environmental and economic factors too.

“Food safety standards are currently regulated at EU level, it is essential that our high standards of food production and animal welfare continue post-Brexit in order to protect the clean, green status of Scotland’s £14.3bn food and drink sector.

“An example of this is where three quarters of Scottish seed potato exports – worth some £60m per year – require specific confirmation that they are GM-free. Allowing GM crops to be grown in Scotland could, therefore, have a hugely damaging economic impact on this important sector.”

Adding by way of background that the Scottish Government’s policy for GMOs was precautionary and while recognising that cutting-edge GM science is undertaken in research laboratories across Scotland, it remained focused on preventing the cultivation of GM crops in the open air. (Let’s just hope that no one lets on to them that tatties are actually clones, or they’ll maybe ban them too!)

So it’s no real surprise that, just like everything else in the Brexit mix, there’s no clear steer on which direction we’re likely to start heading in eight weeks time …