BGTF Podcast: Get the best black-grass control this spring

Read the transcript of the podcast below.

Podcast 7

Dr. Black-Grass: Welcome to Dr. Black-Grass on air, for the first podcast of 2016. Later on in today's program, we're going to be thinking about spring applications of Atlantis. But first of all, we're going to hear from David Foyers, an arable farmer based near Worksop. I spoke to David last week, and he gave me a rundown of how well his weed control program has gone so far.

David Foyers: Well, that's the way we've had heavy rates of Liberator. We've also had heavy rates of Crystal. We've had all the concoctions, depending on how strong the black-grass is. We've had an autumn application of Atlantis in most places, and having walked over the land only on Friday up to now, we're very pleased with the black-grass control.

However, where we did have a bit of a problem ... Obviously, where we have any serious problems, not that we've got that many, we plan to run with spring barley. However, where it was borderline between second wheat, on good second wheat land , and we had where we know we can get a good crop, if we can get away with the black-grass, we went down the route of ploughing it. We had a slight chit with the top down, got the black-grass, sprayed it on, ploughed it, drilled it from around the 15th to the 20th of October, because obviously the conditions were good. We even managed to roll it in some cases. Obviously got the pre-emergence on, quite textbook, really. Black-grass control up to now is all looking very good. And again, where we've needed to Atlantis it, looking back, it would've actually been around the 29th of November. But appreciate, where those second wheats have not being drilled until the 15th or the 20th of October. It needs enough time to get something like a target to better spray onto. Up to now, we'd have liked it with the black-grass control.

Dr. Black-Grass: Okay, so there's not a great deal there?

David Foyers: No, not at all, really, this time. Don't get me wrong, I'm not saying we're not going to get any spring germination, but in fields where, back in 2012, where we weren't able to get pre-emergence on, it's in a wet year. There were some areas in this particular field that were basicbasically, you had to spray the lot off. We’ve walked directly to those areas this time, and to be fair, it's very clean. Not saying that we're not going to have to do a bit of rogueing, but by no means are we going to have to go in and think about bringing any large areas off with the sprayer.  

Dr. Black-Grass: So David managed to get Atlantis on pre-Christmas on much of his farm. I asked him about any land which hasn't had a post-em yet.

David Foyer: We've got about a 60-acre block, out of about 750 acres of wheat, where we've not got Atlantis where we'd have liked to have done. To be fair, there isn't any black-grass on that land, it's predominantly rye grass if anything. You know, it's a 60 acre field, and if you like, probably 50-55 acres of it is as clean as a whistle, and always has been. It borders onto a motorway, on the side of the M1. I don't know whether it's ... for what we think it is. We seem to get seed in off the grass banks of the motorway, we’ve got rye grass issues. It always seems to be where the field adjoins the motorway, within a 24 metre headland, if you like. However, as you get further across the field, away from the motorway banks, where it's away from seeding areas, then the field’s a lot cleaner, to be honest with you. When we were Atlantis-ing, we prioritized what we thought was, that we didn't really see, as desperate to get it on as some other blocks. Last year, the same block that was first wheat but this year is the second wheat, we actually used Pacifica ... probably around the beginning of March last year. To be fair, other than a couple of isolated areas, we sort of took the bull by the horns and desiccated off, the control on 55 acres of a 60 acre plot was very good last year. As a second wheat this year, we ploughed it. Again, the weather being kind through mid-October, rather than get itchy feet and wanting to drill it at the beginning of October, for fear of not getting it in, the ploughing sort of baked, we ploughed it early. The ploughing baked out, when we did get a bit of rain, beginning in October, the 20ml or so that we had, it just softened it nicely and it allowed it to grow in good conditions around the 15th. Obviously, one thing - it was ploughed. And two - it didn't go in too early. And again, it managed to get rolled, you know, pre-emergence went in good timing. Good conditions. I think that's been good in many ways, whereas just last year, when we did have to desiccate a few areas, obviously that was our shout, to have done that. But to be fair, it was drilled quite early, probably around the 20th of September. That's probably why we did get the rye grass come that did, and obviously it was mid-tilled after rape.

Dr. Black-Grass: Thanks, David. I'm sure some listeners are slightly envious of David having done so much of his herbicide program already. But for those of you who will be making an Atlantis, or perhaps a Pacifica application in spring, here's Ben Giles of Bayer with an overview of what to look out for. Ben, what should people applying Atlantis in the spring be looking for?

Ben Giles: Well, the first thing to consider is when to go. That is revolved revolves around when active growth starts in the spring. You might say, "What do you mean by 'active growth?'" Clearly, the black-grass has to be growing to take in the Atlantis chemical. The easiest way to determine that is either walk the fields, obviously, but you can do something as simple as look out the kitchen window on your lawn in the garden. That will generally start growing about the same time as black-grass would in the field - depends when that could be. In a very mild spring, it could be as early as late January, February. You may have to wait a bit if we come out of a particularly cold winter, to allow the soils to warm up and the black-grass to really get going.

Dr. Black-Grass: So what growth stage do you want to be applying Atlantis in the spring?

Ben Giles: The answer is really as soon as is possible ... As small as is possible, let's say, obviously. That will be greatly determined by a number of factors. Some determined from the autumn, so, when was the crop drilled? Earlier-drilled crops will obviously potentially have more growth in the autumn, be bigger black-grass in the spring. "How cold was the winter?" will certainly be a determining factor. If it's a particularly cold one, obviously, the crop, the black-grass won't be able to grow as fast. It will be smaller coming into the spring timing. The other thing is now, more and more residual chemistry is being used in the autumn, and bigger stacks are being used. They might well be holding the black-grass back, if they're not outright killing it, making it feel sick. It won't be growing as much through the winter. And it will possibly be a few growth stages smaller, coming into the spring timing.

Dr. Black-Grass: Is there any situation in spring where you might consider delaying an application of Atlantis?

Ben Giles: I think in almost every situation, the answer is, "Go as soon as possible." Black-grass-wise, you must not let it get too big before trying to control it. You can also add in residual partners, still into the spring, 0.3 of Liberator being a very good example, which will allow you to top up some residual chemistry in the soil to allow control of some spring germinators. But, in answer to your question about, "Is there a situation?" Yes, I would say there is probably one, and that is where you’ve got spring germinating bromes, so rye, meadow bromes, for example, where they might germinate a bit later within the spring. If you go too early, you might miss them. The thing to do there would be, firstly, to step up to the 0.5 kilo dose of Pacifica, and then you would probably have to slightly delay from your ideal black-grass timing to make sure those bromes are actually there before you hit them.

Dr. Black-Grass: Final question - sometimes if people think their residual stacks did a very good job, they might be reluctant to spray any post-em product at all in the spring. What are your thoughts on this?

Ben Giles: I think that they're a very rare occasion that you won't need to apply anything post-emergence in the spring. What a big residual stack might do is lower the potential for a large amount of stuff to come up. Now, that might mean that you've got less broad leaves to deal with, which is a good thing. It might mean you've got, obviously, less grass weeds as well, but I think there is still a very good case for a post-emergence follow-up of Atlantis, even when there's only a few black-grass left. They can easily produce a large number of tillers, and it's all about seed return. Don't let too much seed go back in. Hit it at every possible opportunity.

Dr. Black-Grass: Thank you, Ben. So, by now, you know you need to get out there and spray, but chances are conditions aren't a perfect sunny day with a gentle breeze. I spoke with David Felce, an experienced sprayer-operator at Midloe Grange Farm, for his thoughts on spraying in tricky conditions. In winter and early spring, obviously conditions are actually quite difficult to spray. Yet, the black-grass is at a small growth stage, so a lot of people know that it's a good time to spray. How do you actually make the decision to get out there and do anything?

David Felce: It's always tricky, the mentality has to be to take those opportunities, because they're few and far-between, or can be few and far-between, depending upon the season. You may get a couple of hours in the middle of the day, it may be between 11 o'clock, maybe a little bit after 2 o'clock, something like that, to allow time for the spray to dry on. The mind-set has to be to take those opportunities, and it might just be one load, but it's about making the use of that chance, and making sure that any chance that’s taken does make the best use of the product that you're applying.

Dr. Black-Grass: Thinking specifically about the weather conditions, what should it be like outside?

David Felce: Drying, I think, is the thing to work with. Obviously, this time of year, it's unlikely to be perfect. I think if you wait for the perfect day, you probably aren't going to spray any Atlantis. I think there are compromises to be made, but you just have to pick the right ones. So, it's about looking at the conditions to be as good as they're likely to be, and then taking that chance.

Dr. Black-Grass: How do you deal with the changeability? Because obviously the conditions can change quite often at this time of year, and when you decide to fill up the sprayer, it's good. By the time you've driven to the field, it's bad. What's your advice for facing that?

David Felce: It's one of those sad realities of spraying life, I'm afraid. You have to just keep an eye on the weather. I know that sounds an obvious thing to say, but keep an eye on the weather and ... I think, to some degree, you do have to push it a little bit, because otherwise you won't get those applications made when the black-grass is small, and you'll start running in the spring, the black-grass will be bigger. And you'll start to get compromises with other tank mixes that you might be wishing to make. I think you do, to a certain extent, have to push it a bit, and take opportunities, but you need to be selective about how you do that.

Dr. Black-Grass: So David, you've loaded up the sprayer. You've made it to the field. Hasn't started blowing a gale. You're going to be spraying, but what sort of things do you need to do with the equipment, the application technique, to make sure that you've made the most of it?

David Felce: So, having got to the field and made that decision to go, which is some of the hardest things, actually, is to make the decision to go, hopefully the choices that will have been made will mean that the application is good. So, the choice of nozzle, hopefully you've selected a flat fan nozzle. That will mean that we get a finer, medium finer quality spray, which will give the Atlantis the best chance of hitting the target and being retained by it. Having selected that, it may be more prone to drift, so that's why it's really important to keep the boom height down, make sure half a metre is the level that you're running the boom at when spraying the crop. That minimizes drift to a huge extent.

The other things would be to ensure that the speed is not excessive. Depends, to a degree, on the stability of your boom and how level your fields are, but keeping that speed down will reduce the potential for drift, and also will reduce the turbulence that is created as you spray, which can also capture those small droplets, and mean that they may not hit the target in the best way.

And, final thing to think about is pressure. If you start to go faster with modern sprayers, they usually have the ability to keep the application rate the same but they alter the pressure or increase the pressure as you speed up, which will mean that the smaller droplets get even smaller and are maybe therefore more prone to being drifted away from the target.

Dr. Black-Grass: Thanks a lot, David. There's lots of good information there for anyone going out and spraying over the next couple of months. If you want more information about applying Atlantis, then there are plenty of resources on the Bayer website. That's all for the first podcast of 2016. We'll be back later in the year to review how people have got on. In the meantime, you can stay in touch by tweeting us at @DrBlackgrass. Until next time, goodbye.

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