BGTF Podcast: How to continue using glyphosate for black-grass control

Read the transcript of the podcast below.

Podcast 9

Dr. BlackGrass:

Welcome to the June edition of Dr Blackgrass On Air. Like many of you, earlier this month I was at the Cereals Event, and discussion amongst many farmers was that it's been quite a bad year for black-grass. I spoke to Peter Brumpton of AICC for his thoughts on this.

I'm here with Peter Brumpton, AICC. Peter, certainly driving round the country and going into a few fields, there seems to be quite a lot of black-grass this year. Is that just my opinion or is that the actual case in the fields?

Peter:

I think quite a bit's probably an understatement, to be fair. It's certainly a lot different to last year. Last year we had quite good control. This year is totally the opposite. It's one step forward, two steps back I'm afraid.

Dr. BlackGrass:

What do you put the difference down to?

Peter:

I think the weather primarily, to be fair, but the attention to detail probably gone a little bit. We need to up our game again, like we did last year, and get back on track really.

Dr. BlackGrass: This year, your clients, were they putting on a similar sort of pre-emergent stack?

Peter:

Very similar, yeah. Probably even a bit stronger, to be fair, but obviously the weather affected that and it didn't do what it wanted to do really. Not good.

Dr. BlackGrass:

What changes will people make for this year? You said more attention to detail, up people's game. Is there anything else people can do?

Peter:

I think just the same messages really. Later drilling has obviously had a good effect on some farms. Try and do that, and where it's not having a good effect we probably go to spring cropping on a wider scale really.

Dr. BlackGrass:

At the moment, maybe it's done as an occasional thing in the rotation. Are you thinking it might be even 50% of rotations in years to come?

Peter:

Quite potentially, yeah. I mean, certainly on the worst black-grass land most definitely. The other thing is bringing the plough in a bit more, but then, on some of these stronger farms, it's trying to plough to a quality and we really want to be match ploughing so we bury everything and really do a proper job.

Dr. BlackGrass:

Now, the other big concern people have at the moment is their glyphosate potentially not being available, or available for much less uses. What are your thoughts on that?

Peter:

It's not good news, obviously, but hopefully we've got it. Obviously, we're going to have to use it smarter, and that's going to be the message. Use it at the right time and the right occasions.

Dr. BlackGrass:

Are there any uses for it that you think maybe people should be shying away from? Maybe pre-harvest desiccation or anything like that?

Peter:

I think, potentially, we'll lose pre-harvest desiccation. It's unfortunate, but from a black-grass point of view, it's not the end of the world, because probably at that stage we are too late anyway.

Dr. BlackGrass:

Just moving away from black-grass, are there any other weeds, broad leaves or grass weeds, that are causing people a bit of a nuisance at the moment?

Peter:

Yeah, poppies are really resistant, poppies are coming on big style.

Dr. BlackGrass:

That's ALS resistant poppies?

Peter:

Absolutely. Certainly, again, it's trying to protect that sulfonylurea with another active that's not resistant, and that's what I've been trying to do in a lot of situations this time.

Dr. BlackGrass:

As I discussed with Peter, a restriction on the use of glyphosate is a big concern for all farmers, not least those dealing with difficult black-grass populations. I spoke to Dr Paul Gosling of AHDB for his take on the situation.

This was recorded in the run up to the vote on glyphosate usage which took place at the end of June. On the 28th of June the EU commissioner announced that the decision had been made to extend the approval of glyphosate as an active substance in Europe for another 18 months. Some of the discussion you’re about to hear is speculative as it took place before the vote. But the majority of it is still highly relevant for people using glyphosate as part of their weed control program I'm here with Dr Paul Gosling from AHDB. He is part of the Crop Protection Division with a particular focus in weeds. At the moment there's a lot of concern about glyphosate from two angles really. The first one is the re-registration in Europe, and the second one is the potential for glyphosate resistance in European weeds, which you've already seen in weeds in the USA and other parts of the Americas. Let's start with the re-registration. What's the situation at the moment, Paul?

Paul:

We're still waiting for the EU to make its decision. The vote has been delayed several times already, which is rather disappointing. Glyphosate is an important active for UK farms and across the whole of Europe. Farmers are really waiting on the vote to go through, and we're hoping it will be by the end of the month when the registration ends, but we really don't know what the situation is in Europe. We didn't think it would go this far. Anything could happen, I think, at this stage.

Dr. BlackGrass:

OK. Reading the media reports so far, there's the possibility that it's re-registered for the full duration, which is 15 years, a shortened amount of time, say 6 or 7 years, or an even shorter amount of time, 18 months. Which one of those is likely to happen, and what would the impacts be on farmers?

Paul:

Well, we've seen various compromises proposed, and every compromise seems to be a shorter and shorter period, and, as you say, we're down to 18 months now. I think that's the most likely scenario. Obviously, that's going to mean uncertainty for farmers again, which is not ideal at all, but we have to deal with what Europe throws at us I'm afraid.

Dr. BlackGrass:

So, if we do have an 18 month re-registration, we're really in re-registration period immediately after that decision's made, aren't we?

Paul:

Yes, I mean that 18 month period is to cover another report that will come out of Europe on the potential cancer causing properties of glyphosate. That's why they're talking about an 18 month registration to see what the result of that is, and then I would imagine if that's a positive result, i.e. there's no evidence of cancer causing activity glyphosate, they would then go for a longer registration. As we've seen with this registration, anything can really happen in Europe. It's a political game as much as a scientific game, I'm afraid, now.

Dr. BlackGrass:

Are there likely to be any recommendations for changes of use, or restrictions on pre-harvest desiccation, or that kind of thing, or restriction on the number of applications in a season?

Paul:

Well, we have seen those sort of proposals put forwards, and I think Greenpeace are compromising, or appearing that they might accept some sort of compromise in terms of restricting use pre-harvest or perhaps the number of applications per crop. As I say, we really don't know what's going to happen at the moment.

Dr. BlackGrass:

Okay, and worst case scenario, glyphosate is banned or its use severely restricted. How will people go about weed control then? What are the options?

Paul:

I think if we see a complete ban then we're into a very difficult situation. You'd see a lot more cultivation. A lot more use of the plough, which obviously has its own environmental implications. More fuel use. I think some farms, because of the extra cost and time involved, you could look at it pushing at businesses that are already under stress in terms of economics, being pushed perhaps a little bit too far. We might see some areas of very severe black-grass might have to go into fallow, because we just haven't really got adequate tools to control black-grass and very severe infestations of black-grass without glyphosate.

Dr. BlackGrass:

Has any research been done on the potential economic impacts of a ban, like how much it would cost each farmer, or each maybe wheat farmer, in the UK?

Paul:

There has been some research done and it's making some businesses look very marginal. It's not good news at all. I think it's not just in the UK. Across Europe there are farmers in certain systems that would struggle without glyphosate. Dr. BlackGrass: OK, and then, as I mentioned before, resistance to glyphosate in weeds is also a concern. What's the current situation in the UK?

Paul:

Currently in the UK we have no confirmed cases of resistance to glyphosate. Obviously in the US they've got a big problem, and other parts of the world, driven by GM crops. Herbicide tolerant GM crops. We have glyphosate resistant rye grass in Europe, and obviously with so much black-grass around and so much glyphosate being applied in this country, there's a concern. We've seen in glasshouse studies, you can push black-grass into resistance if you do really silly things with it and you use too much glyphosate. We've got a project at the moment which is looking at how you can sensibly use glyphosate to get good control of black-grass, but not push the resistance too hard. That's a five year project. It's coming to the end of its first year now. That will obviously give us some better answers as how to manage glyphosate and give us some improved guidelines for growers to preserve the active, because, as we've already said, without it people with serious black-grass problems would really struggle.

Dr. BlackGrass:

What is the basic advice for farmers in the field at the moment, for protecting glyphosate's activity?

Paul:

What we're really saying at the moment is, yes you can use glyphosate on stubbles to control your black-grass, but you really need to ensure that any survivors from that black-grass, any individuals that might be, if not resistant have a higher tolerance, they need to be destroyed by some sort of cultivation. The real high risk situations are where you apply glyphosate and then there's no follow up cultivations or other means, or other actives, going on that would kill those potential survivors. Particularly high risk situations are no-till or strip-till, where you're going in and those cultivations aren't being followed up and there's not an adequate follow up herbicide regime to kill any potential survivors.

Dr. BlackGrass:

From the research you've done, is resistance to glyphosate, is that a target-site mutation or is that a enhanced metabolism type of resistance?

Paul:

Well, globally, if you look at the glyphosate resistance in different species around the world, there's several different mechanisms involved. Some are target-site, but a lot is enhanced metabolism. We're seeing in the UK black-grass populations an increasing tolerance to glyphosate, which is enhanced metabolism, so I think that's probably what we would see. There's probably a number of minor genes involved, which are each giving a small increase in tolerance, and when you start to add those up you get towards a resistance situation.

Dr. BlackGrass:

Finally, you've said that they need to use other actives. Obviously there is resistance to other actives as well. What if glyphosate is really the last weapon that farmers feel confident of using? How can they go about protecting it then? Is it just more cultivation, as you mentioned?

Paul:

Well, I think a robust pre-em program is really the backbone of black-grass control, certainly, because the post-emergence herbicides are under a lot of pressure. If you're relying on those, (a) you may not get good activity certainly on some populations, but even on the populations that are still susceptible to those post-emergence herbicides, you don't really want to be relying on those, because that's just going to push more resistance to appear.

Dr. BlackGrass:

Thank you very much, Paul.

Paul:

Thank you.

Dr. BlackGrass:

Paul reminded us that farming without glyphosate, or with many glyphosate resistant weeds, would be a real challenge. One farmer who's trying to stay ahead of the curve is Richard Hinchliffe. Richard is a Nuffield Scholar with a project looking specifically at weed resistance in the UK, but taking learnings from all around the world. Richard and I both visited Bayer's research facilities in Germany last month and Richard gave me an outline of what he's dealing with on his farm, and what he's hoping to find out with his research.

Richard:

We're a family farm based in Eastern South Yorkshire. 1,400 acres growing combinable crops. We've got about a third of that area where we've got problem black-grass, so it's an important weed to us.

Dr. BlackGrass:

How have you been controlling black-grass so far? What's your strategy been?

Richard:

We're moving towards a more cultural method of control. As time goes on, chemistry isn't working quite as well, so it's all about integrating weed management these days.

Dr. BlackGrass:

OK, and you're obviously quite interested in the weed control topic, because you've become a Nuffield Scholar looking at weed resistance around the world. Is that right?

Richard:

That's right. I'm a 2016 Nuffield Scholar for United Kingdom. My project title is, it's quite a mouthful, "Herbicide Resistant Weeds: Investigating a Sustainable Future for Arable Farming." I'm looking at a whole wide range of things. I'm particularly interested in glyphosate resistance, because I think it's a real danger for UK arable sector, because it's a real good active ingredient. It's a once in a hundred year discovery. It's not going to come along again. Cultural control, such as direct drilling, or cover cropping, or mixing rotations. Anything new, interesting. Seed destructors in Australia. You name it, I'm looking to find it.

Dr. BlackGrass:

We're here in Germany at the Weed Competence Centre. We've both actually visited the glasshouses and so on. What have you learned during this trip?

Richard:

It's a global problem, which we already know. It's good to see so much resource and looking at trying to solve the problem, some of the mysteries and actually how resistance works. Actually the level of the testing of weeds from around the world, it just reinforces some of the things that you've read on textbooks and online.

Dr. BlackGrass:

What about on-farm decisions? Will you change anything?

Richard:

It's reinforced what we're trying to do. One of the main things that I like to think about is, if you doing something and if it's working, then you need to change it straightaway, because you need to do something different while it's still working, to prevent it from breaking.

Dr. BlackGrass: Exactly. Where next on your Nuffield travels?

Richard:

In three weeks’ time I'm heading off to the United States. I'm getting in a car in Chicago and driving right down to North Carolina over a month period.

Dr. BlackGrass:

What are you going to be looking at there?

Richard:

I'm going to be meeting with manufacturers, chemical manufacturers, university professors, farmers, most importantly, because they're for guys and for ground, agronomists. That kind of thing.

Dr. BlackGrass:

Do you have any idea what sort of weed problems they're coping with over there?

Richard:

It's mostly broad leaf weeds, which is totally different to our problems within the UK, but some of the principles are the same.

Dr. BlackGrass:

Would you be able to come back once you've been to the States and give us an update of what you've found out? Richard: Yeah, I'd love to.

Dr. BlackGrass:

OK. Thank you very much.

Richard: Cheers.

Dr. BlackGrass:

Thanks a lot, Richard. As discussed, Richard will hopefully be coming back onto the show later in the summer to give us an update about what he's learnt. That's all we have time for this month. By the time of our next podcast in July, the first combines will probably have been through a couple of early maturing crops, and thoughts will already be turning to post-harvest control and cultivations. We'll give you a full update of all the options available to you then, but until that time, goodbye.

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