Combine Cleaning: A Simple Step to Reduce Weed Seed Dispersal
Rodrigo Werle, Extension Weed Scientist and Daniel H. Smith, Nutrient and Pest Management Program Manager, demonstrate where weed seeds hide in a combine and how to clean a combine for weed seed management.
Transcript
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Hi, I’m Daniel Smith, the program manager for the Nutrient Pest Management
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Program, the University of Wisconsin Madison Division of Extension.
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Hello, everybody, Rodrigo Werle,
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extension weed scientists at the University of Wisconsin Madison.
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Rodrigo, we’re out in front of our 21st Combine today.
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Talking about combine cleaning.
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We’re on a beautiful November day.
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The combine has just finished harvesting corn, and we have lots of weed seeds to look at.
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Yeah, absolutely right, Dan.
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So I think this is the time of the year that we reflect on,
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you know, all the weed control, uh, successes
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and potentially failures, uh, that we have had.
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You and I work extensively with growers and their
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decision influencers around the state, on weed management issues.
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And I think the one issue that keeps popping up is waterhemp, right?
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It’s becoming a lot more expensive,
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to control, and even with some of the expensive chemical
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treatments that we have, out there, oftentimes we’re not achieving
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the very high or excellent levels of control that we want to
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see, and one of the main reasons for that is resistance.
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Uh, wate hemp is, uh, it’s
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amazing to me how fast waterhemp has been, evolving resistance uh, to the multiple herbicides.
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And with all that said, one of the common questions that we get
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from our growers is Rodrigo, Dan, what
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else can we be doing in our operations in order
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to help fight waterhemp and also other tough weeds back, right?
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And I think this is why we’re here today.
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So, what do you think here, Dan?
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How can we control?
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How can we relate weed control to harvest now?
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Yeah, absolutely.
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So combine cleaning is part of an integrated approach for weed management.
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And 99% of the weed seeds on a water hemp plant
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are retained until they’re mechanically separated.
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And this machine behind us is excellent at mechanically separating those weed seeds.
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So essentially as that waterhemp plant is pulled into the combine head.
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Some of the weed seeds are dropped off on the head.
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We have lamb’s quarter today to illustrate that.
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A lot of lamb’s quarter seeds on the head.
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Those seeds in are pulled into the combine, and
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a lot of them go right out the back with the rest of the residues.
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A really troublesome weed.
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Yeah, that’s really good, Dan.
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So with that in mind now, knowing that, you know, the
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combines here are one of the most efficient.
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We’d see dispersal agents out there, as
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a farmer, what can you do?
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Yeah, so we can take about 30 minutes to clean a combine.
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And when we first started doing this, we had some pretty broad recommendations.
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30 minutes also got us laughed at a few times.
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It’s very realistic, though, for weed seeds only.
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If we’re doing a non-GMO cleanout, if we’re doing an identity
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preserved grain type cleanout, then it’d take us a little bit longer, probably
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a day or 2 to really clean all that grain out of the combine to switch to another crop.
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For weed seed, though, we’ve learned that there’s some target areas.
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In 2020, Nick Arnison led a study in Wisconsin, showing
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where some of those areas are, and thankful for all the farmers and agronomists that send in samples, so we’d have that data.
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Essentially, the weed seeds are on the head in the feeder house and in the rock trap.
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About 1% of weed seeds actually make it into the rotor.
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Once they’re in the rotor, they’re probably going to stick around for quite a while because
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they get settled out into one of those many corners the rotors have.
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The feeder house is a little tricky if we’re not taking off the head.
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The weed seeds are typically right there in the very front corner where
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those pieces of metal are welded together in square corners.
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So that’s very good, then, because when, you know, when we started going
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around, and I, you know, I remember this vividly, you go around, and we
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would explain all these things to farmers, consultants, our industry.
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They understood.
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The problem, right?
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They understood the situation and what you’re trying to recommend.
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But when fall comes, they want to be done harvesting, right?
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So they got to go through and then when we say, hey, you got to stop and clean.
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You know, in my mind, I’ll say, hey, if I got to stop and
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clean, it’s going to take a full day, but you just shared some exciting news.
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We don’t need a full day.
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Right?
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We don’t necessarily need a full day and there’s, there are strategic spots
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here in this combine, and I mean, you and I just got here walking through.
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We already saw where they are.
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So a little bit of effort here.
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Uh, for a little bit of time can pay dividends long term, right?
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And is that what you’re telling us?
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Right.
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So we think about the number of seeds that a water implant can produce, and it’s 1000s of seeds.
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And we’re harvesting those, so 99% of those are making it to the combine.
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And then we’re using the combine to spread those seeds.
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Now, that’s okay if the whole field is full of water hemp.
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Really, nothing we can do, nothing to worry about with the combine.
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There’s other things we need to be focusing.
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Our energy on for weed control.
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But if we’re thinking about this is maybe the
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next field we’re going to is weed free, or there’s only a single patch
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of weeds in this field, then shutting down the combine, cleaning it off after
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we’ve essentially put all those weed seeds on the combine,
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really pays off because then we prevent those from moving further into the field or onto the next field.
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That’s really, really good.
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Then, so the one question here that I
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have for you, you mentioned, this is the 21st time that
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we are doing this, so 21 machines that we have had the
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chance to look at, how many of them have you found weed seeds in?
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19?
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19?
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Okay, so 19 out of 21.
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That’s a pretty high number.
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What happened to the other 2 combines?
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There, I bet our audience.
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is very curious, you know what?
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What do those farmers do so you couldn’t find seeds in them?
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They bought a new combine.
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All right, some brand new combine.
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Okay.
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Those are the only 2 machines we never see on weed seeds in.
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We’ve gone to some very, very clean machines to do these clinics throughout the wintertime.
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And we’ve still found some weed seeds hanging out in those machines.
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We’ve actually found weed seeds growing on the machine.
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So I’ve seen Palmer amaranth growing on the cornhead.
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We’ve seen amaranthus species growing in the feeder house now on 2 different occasions.
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We’ve seen wheat growing near the rotor.
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So, um, the examples of where some of these hideout
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and really take off is everywhere on the combine.
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That’s really good.
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And again, we just got to this combine.
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This combine just came out of a cornfield.
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You and I were just taking a look here and without a lot of effort.
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I mean, this is a highly concentrated amount of common
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hem scored seed here that you’re going to be showing a little more detail.
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So again, just looking at this combine here, the exterior parts here.
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You can see a lot of weed seeds.
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So blowing this around would probably pay off.
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But the question that we get from our growers, the
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end when we’re talking about cleaning that combine, as they either
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hit a weedy patch or they travel from field to field or
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if they want to do it, at the end of the day, every time, you know, uh,
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before they start the next day, where should they be doing that, right?
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Because you’re also got to be strategic about that piece.
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So what is your answer to them?
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They gravel a lot in front of the shop works really well if it’s the end of the day.
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There’s usually some light there.
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There’s access to tools like an air compressor, works out pretty well and we can control that environment.
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If it’s one patch out in the middle of the field, I’d clean the combine right
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there in the middle of the field, to prevent that patch from growing.
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If we’re moving on to another field, or we’re coming from another
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field, and we know there’s weed seeds, right there in the field where the weed seeds were is the best place to do this.
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That way, we’re not further spreading our problems of having these weeds out of control.
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Very good, and perhaps a good thing to do if you’re not doing
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it in a gravel lot if you’re actually doing out on the field is kind of,
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Take note where to happen, right?
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And pay attention to those fields next year.
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Because those are the areas you’re going to have very high concentration of weeds coming through.
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You don’t need to deploy multiple post-passes.
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You control all that, perhaps be strategic and do some spots spraying.
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If you got a gator on the farm there.
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It can come and just clean those areas right in so you prevent
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the problem from continuing to spread.
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So I think that’s very good.
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Very, very good.
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All right, Dan.
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So with that, why don’t we, you know, why don’t you start walking us through the process here, starting from safety?
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And then other spots here that you want to
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show us that we should be thinking about if we want to do a quick cleanup
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of our combine, thinking about reducing the spread and dispersal of weed seeds.
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Sounds great.
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Let’s do it.
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Thanks, Rodrigo.
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Thank you Dan.
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Okay, so before we clean the combine, we really want to take a little bit of time to think about safety of doing this.
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The combine that we’ve been in front of has been turned off, the
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keys have been removed from it, and the head was locked up, so there was no
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danger of that head falling down on us, and the parking brake was set.
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Always read, follow, and understand all the instructions that come with the
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combine and all the cleaning equipment that we’re going to be using today and that you’d be using at home.
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The 1st step is is eye protection.
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We’re gonna be kicking up a lot of dust.
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We want to wear some safety goggles when we clean the combine.
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We also really want to think about respiratory health.
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So we’re in a full-faced respirator or a vented mask with an N95 or P100.
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Rating is going to be really important to keep the dust out of our lungs.
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And then finally, we need to be thinking about your protection.
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So we have a couple different options.
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We have earplugs, and then, of course, we have ear muffs, and the ratings
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for noise reduction vary on those, so pick out a good pair.
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What I have gone to, though, after our 1st combine cleaning clinic,
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one of the farm staff recommended a full face respirator.
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And if you’re doing a lot of this, you can actually get your glasses
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built into a full face respirator, and it has the same cartridges on it.
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So this is kind of nice because this is integrating your goggles and your respiratory protection all in one.
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Moving on, then from that, if we’re doing this at night, we want to be really careful as well.
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So a good flashlight is going to be critical.
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And then finally, when we 1st did the video back in 2017, a gas powered leaf blower was used in that video.
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Gas is kind of hard to deal with in the combine cab, but most
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of our cordless tool brands now have a cordless leaf blower.
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We can keep in the cab of the combine, interchange that with any other tools we
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might have, and it works really well at cleaning a combine.
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All right, Dan, thank you so much for the safety tips there.
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I’m looking at this combine here as a weed scientist.
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I’m already getting a little anxious, right?
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And I’m thinking about problems for next year.
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I’m looking right here in front of me, and then you start, you know, fasten your hand there.
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What are you seeing there?
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Yeah, there’s 1000s of lambs quarter all over this combine.
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It’s incredible.
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And if we would have combined a field with a lot of water hemp, that would be the same as well.
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We’d have 1000s of seeds on the head and the feeder house and rock traps.
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So we made it to that 30 minute cleaning.
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We’ve got a relatively simple machine to clean here today.
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This is very similar for a soybean platform as well.
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We just blow out the corners, blow out the sickle bar, and we remove the majority of those weed seeds that are hanging out there.
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Very, very good.
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So really, really helpful tips here.
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Uh, folks that are really worried about, uh, their weed management.
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We discuss, you know, the costs are going high and high and
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high as far as chemical goes, invest in some time here, right
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in, in the fall, can pay dividends in the year to come.
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So with all that said, then, thank you so much, and why don’t you kind of show us here what you do next?
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Yeah, absolutely.
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Rodrigo, how long did that take us?
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Well, then that took us about a good 30 minutes here, I would say,
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to do a good job cleaning it, but I think it’s absolutely worth it.
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Just watching the amount of weed seed that we were able to remove, right?
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And so it kind of pays off, right?
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And it’s not perfect either, right?
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The viewers at home can still see there’s some residue hanging on in the combine.
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You’re not gonna get it all off in 30 minutes, but it helps.
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It helps remove a lot of those weed seeds and majority of them.
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It also helps with fire prevention, which is really important with combining too.
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Yes, and again, thinking long term here.
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Weed management is only getting more complicated.
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Uh, more expensive, right?
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So this is one of the steps here, that we can take, we like that we can take.
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We like to say that controlling weeds, the integrated approach is that multiple
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little hammers strategy rather than using a single hammer.
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And this is one of the little hammers, you know, trying to clean your
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combine as often as possible, you should reduce the dispersal of weed seeds.
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And again, we didn’t talk much about that, but being strategic about harvest order as well.
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So all together, adds more complexity to our
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systems, to our decision, but we control is becoming very, very complicated, and the more complexity we have.
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The more successful, I think, we’re likely to be right then.
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Absolutely.
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So thank you all for watching.
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Thanks, Dan.
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Thank you.
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