Open Integrated Pest Management Education Resource

Initial Results using Saturated Steam Equipment for Weed Management 12/06/2018




[00:00:00]

Chris: We are really lucky today to have Dr. Cheryl Wilen from UC IPM. She's based in San Diego, but she's come all the way here to talk about some of the work she's been doing on steam weeding. This is something that has come up. There's renewed interest in steam weeding and other forms of physical-mechanical control for weeds, especially in light of the Roundup restrictions and so forth that we've been seeing the past couple years. I think I said it in the email the technology has been around a long time, but there are some new gizmos out there and we want to know how well they work, so that's why we have Cheryl here to tell us.


[00:01:00]

Dr. Cheryl Wilen: Here's how it's going to work. Let me just get this all keyed up here. A lot of people don't like this, but I like it, so since I'm giving the presentation, it's going to be the way I do it, is that if you have a question, just ask it in the middle of the presentation and I'll be happy to answer it then. Then we'll go from there. I have a presentation I want to start. Hopefully that'll work. There we go. Technology. Please just, if you have a question, just go ahead and ask it and we'll go from there. Apparently, I have a lot of time, and since I'm from Cooperative Extension, I can talk forever, so you might have to hold me back. [00:02:00]


I was asked to give a little presentation about what's going on with this steam weeding work that I've been doing or steam weeder. The background for this was that the Department of Pesticide Regulation wanted me to essentially do some demonstrations for school sites. Because of the Healthy Schools Act, the schools don't want to use pesticides if they don't have to around school sites, and a lot of times herbicides are used in many different ways, whether they're keeping weeds out of cracks or in the playing fields or just around different places. They said, "Look, here's a tool that perhaps it can work, but you really need somebody to really sort of get out there and look at it before a school starts spending a lot of money and then deciding that it's really not going to be worth their time."


This is the one. There's two companies, really, that have what I consider viable machines. [00:03:00] One is this company called Weedtechnics, and they make this type of steamer, although this is the smallest one. This is the baby steamer, and they've got bigger ones that you can mount on a truck and they have water tanks and everything, but because of the limitations that I have and where I'm going to store things and whether or not I can put things on a truck or not, I couldn't permanently mount it. I got this one. It's called the SW, which I assume stands for steam weeder, 700, which means they probably had 699 other versions before they got to this one. [LAUGHTER] I think I've seen about 400 of those that didn't work, but this one actually works okay now. It's really now more of a commercialized machine that they're selling, and I think people are picking up on it.


[00:03:44]

Male: Can you share this presentation with us when you're done?


[00:03:47]

Dr. Cheryl Wilen: The tip pot is right here. Yeah. [LAUGHTER] It's fine. Actually, Chris has a copy, if you want to just send it out after.


[00:03:54]

Chris: I was going to post it on the website and we also have the video.


[00:03:59]

Dr. Cheryl Wilen: Great, yeah.


[00:04:00]

Female: How much does that weigh?


[00:04:01]

Dr. Cheryl Wilen: It weighs 500 pounds.


[00:04:04]

Female: Oh, my gosh!


[00:04:04]

Dr. Cheryl Wilen: What I have to do for this one… that's a good question. Do you mind if I kind of go off on it? I mean I can really just talk about some of the things that we found, and this is a good picture just to kind of show that just to begin with. Like I said, there's some that you can mount on a truck. This comes out of Australia, so all the technology comes out of Australia, but there's a company in Fresno that actually puts everything together that they don't need from Australia.


For example, let's try this. I feel like the hand of God doing that. This comes from Australia. This comes from Australia. This comes from Australia. The motor and the pump to everything, that's just a Briggs & Stratton motor, so they can just get that anywhere. The pressure, this is the boiler for the hot water. I think they might have to get that from Australia, but anyway, so it kind of saves some money by not having a lot of things that have to be imported. Like I said, so this place in Fresno puts it together. [00:05:00] Really, really good customer service. If I have any problem, I call them up and they're right there and they're like, "Hey, you know what? We can drive there tomorrow if you need something. We can get it going." On that end, quite good.


They'll sell it to you, whatever you want. If you want a big tank for water, they can put a big tank on the truck. If you want something like this, they can do that. Now the thing about this is that we found that's problematic and I thought it would work out really well is this whole thing is 500 pounds, right? I bought a trailer so I could just pull it up on the trailer and I pull that, and that seems to work okay. The problem is once you take it off the trailer, these wheels don't turn. I don't know why they made it like that. You can do really well on a straight line, but if you've got to turn, it's like… [LAUGHTER] Check out the biceps. Yeah, so that's kind of the problem with that. [00:06:00] Just a consideration. I don't know.


[00:06:04]

Female: So who does that work for?


[00:06:05]

Dr. Cheryl Wilen: Who does it work for? It works for me, [LAUGHTER] because I have small areas that I do. What is your site, again?


[00:06:11]

Female: The water department, which could not be steeper.


[00:06:14]

Dr. Cheryl Wilen: Right. But the other thing is that there is and you'll see it in some of the pictures is there actually is and they can make longer hoses, too, but you get approximately… so you can just have that sit there. This one is direct connect to a water source, so I've got a hose, like a regular garden hose and I can have the hose as long as I want. It can be 400 feet. Then there's another hose that goes from the tank to the wand. That can be 100 feet. If you really wanted to, you could have 400 feet worth of play in that.


[00:06:47]

Male: There's no water tank, then?


[00:06:48]

Dr. Cheryl Wilen: Not on this one because it's meant to be mobile.


[00:06:50]

Male: Is there anything proprietary to that in that I have a pressure washer that has a diesel thing that heats up the water and boils that.


[00:07:00]

Dr. Cheryl Wilen: Right. The key to this, there's three things, actually, proprietary. One is that the head, they're actually made pretty fine-tuned. They emit five liters per minute of water. They hold the heat in there, and there are special ways to connect it and so forth for safety issues so they don't blow off. There's that. The other thing that's different from a pressure washer is that the pressure washer… like the company that makes these in Fresno is actually a steam-cleaning company. They'll make that. But the key about this is it's not just water heated to 212 to boil it. It's actually heated to 250 and it's higher pressure. That's the key to this one that makes it a little bit more effective than just high pressure.


In fact, this water, when it comes out, it's not really that high a pressure. If you had that, it's more of a mechanical thing. If you want weeds out of a crack, that high-pressure thing could just go like that [00:08:00] way out of there, which is fine, actually, in my opinion. [LAUGHTER] But this, really, is just the super-hot water coming out, so that's the difference. People have asked me. It's like, "Hey, I can get one of these things that steams your clothes. How come I can't just retrofit something like that?" It's, again, it's the pressure, even though it's not a lot of pressure, plus the higher temperature. Those two things together really makes this a little bit different.


This little machine probably costs about $11,000. Yeah, $11,000 for the little one. I can see this is going to go for two hours. [LAUGHTER] We had somebody from a school district. You're all aware of the contact herbicides like Avenger and Suppress, right? You've probably used those as sort of your alternative herbicides. Yes, no? Yeah, okay. I had a school district when we were watching a demo of this. [00:09:00] We had the company come in — this is $11,000 — and he was saying that he just spent $8,000 just on the chemicals. That's a one-time thing. If you're going to amortize this over four or five years, it actually comes out cheaper in the long run.


But again, this is the little one. The bigger one costs about $25,000, but you could have two people working at the same time with that. Again, this is something that you're going to have to decide where it's most appropriate to use, where it might be workable, where it's not going to be workable, and so forth. Any other questions about this? Yeah.


[00:09:40]

Female: Those are two different heads they could use?


[00:09:43]

Dr. Cheryl Wilden: Three heads, actually. Yeah, so this is the smaller one. This is 12 inch and then there's a bigger one, 24 inches. They can also make different sizes. I mean, again, they could fabricate what you need. The key is this connection here and what's inside here. [00:10:00] So the outside is sort of just what they can make to hold in the steam and the heat. Then the other one is the showerhead they call it. There's three there.


[00:10:13]

Salvador: We have a large unit which is mounted in a trailer. We tried to use it on the trucks for a little bit, but that needs to be special bolt on the truck. [INAUDIBLE 00:10:23 – 00:10:34].


[00:10:35]

Dr. Cheryl Wilden: Yeah, the big one. You have it with two hoses?


[00:10:37]

Salvador: We've got two hoses, six [INAUDIBLE 00:10:39].


[00:10:42]

Dr. Cheryl Wilden: But you need a dedicated truck or dedicated trailer, right, so that's an extra expense on top of that. All right.


One of the reasons, obviously, you're going to go to an alternative to glyphosate. Some places get scared of glyphosate, [00:11:00] again, because of public perception. Then, also, because of these bozos like this, this is at a park where we were actually doing our trials. It looks like and you can see tire tracks. Can you see that there? This happened about the same time we started the trial, and so the park manager calls me up, "Cheryl, what did you guys do?" I'm like, "It wasn't us. That would take a lot of work to do that." It looked like what happened is this landscape company, which, by the way, lost the contract for this, had a tank of glyphosate, probably had a wand and somehow the wand was leaking. Probably went over the tires or their boom went over the tires, and so as the truck went along, that glyphosate just kind of dripped along and took it.


This stayed like this for probably about six weeks, [00:12:00] which kind of shows you how long glyphosate lasts. This is on kikuyu grass here, so you can kind of see that type of control, but this is the kind of thing that people see and it is a little bit scary because that landscape company was completely ignorant of the problems that could happen when you don't use a chemical responsibly. Again, they were going to lose the contract, anyway, I have to admit, but I think this just kind of hurried it along. Maybe they wanted to lose the contract. I don't know. All right.


Here's the situation in action. What we did, we started out. You can see this hose here. This is insulated. This is insulate hose on the outside. It's kind of like a fire hose. Inside of that is a… are you familiar with PEX? It's about a half-inch tube. It's like that same kind of diameter, but it's a different material. It's a high-temperature hose because what's coming through there, like I said, is 250 degrees Fahrenheit. [00:13:00] It's kind of high temperature. That's inside that other hose. You can hold that hose. You can hold it with your hand. It'll just feel warm, but if you go and touch the place, so let me get up here. Between right here and where the nozzle trigger is, that can get pretty hot. We recommend that people wear gloves when they use it. You don't need fancy gloves. Gardening gloves is usually enough there. That's all like that. He's got a trigger. He holds that. The hot steam comes out of here, and then he's able to just go place to place with that. He can go pretty fast, actually.


[00:13:52]

Male: Once again, what's the pressure and how many gallons a minute are you using?


[00:13:56]

Dr. Cheryl Wilen: The pressure is 900 psi. [00:14:00] It's weird because, and again, I don't know physics that well, but it's like the lower the pressure the higher the temperature we can get. If I try to get it 1,000, the temperature goes down 212, but it is tricky. That's another thing about this, which I'll talk about, I think. Lower it's about 900 psi and I can get it up to 250. If I want to get a higher temperature, what happens is the pump kind of starts fading out. It's a little bit touchy about this machine, as well. I don't know. What's your name?


[00:14:34]

Salvador: Salvador.


[00:14:35]

Dr. Cheryl Wilen: I'm sorry?


[00:14:36]

Salvador: Salvador.


[00:14:38]

Dr. Cheryl Wilen: Salvador, did you find you've got to mess around with it a little bit?


[00:14:40]

Salvador: Yeah, where we attached the adapter of the nozzle, sometimes it gets very hot. We got a hold of [INAUDIBLE 00:14:48]. We had [INAUDIBLE 00:14:49].


[00:14:50]

Dr. Cheryl Wilen: But for the pressure, did you have to adjust it all the time?


[00:14:53]

Salvador: Yeah, you have to adjust it sometimes.


[00:14:57]

Dr. Cheryl Wilen: For me, this is the guy that works for me. His name is actually Guy, [00:15:00] so it's kind of hard to talk about him. Guy is here, and so he does a lot of the work. I have to stand at the machine and kind of just adjust it. It's really almost like a two-person job even though I'm doing the easy part because I need to watch it.


[00:15:18]

Male: It's a low volume?


[00:15:19]

Dr. Cheryl Wilen: I'm sorry. Yes, you asked that, too. It's five liters per minute, so a gallon and a quarter per minute, but to do this whole park the first time took about three hours, even though not everything was done. Here, this is kind of interesting here. You see we did it around this light pole. You see all that water? That's muddy water, so it does put out a considerable amount of water the longer you hold it. But since it was our first time through, we probably held it a little bit too long in that part, but we were just kind of working through it. After about the third time of doing this, I got a little water meter [00:16:00] and it used 50 gallons in about a half an hour, I think, is about the time.


[00:16:09]

Female: Let's say his is 900 psi. If it's lower than that, what happens?


[00:16:14]

Dr. Cheryl Wilen: Lower than that, the engine starts cutting out, for some reason. The pump starts cutting out.


[00:16:19]

Female: Oh, it's not a delivery need.


[00:16:22]

Dr. Cheryl Wilen: Yeah, and when we see the other one I'm going to show you called Foamstream, I'm going to talk about the comparison between these, sort of the touchiness of them. But the reason I put this picture in here is very telling because here he is. He's doing that and it's noisy. Don't get me wrong. It's like a pretty big lawnmower engine that's running that's pumping this stuff. No muffler. It's pretty loud, but if you have it 200 feet away, that little machine 200 feet away is not quite so bad. But he's able to do that while kids are playing in a playground, [00:17:00] which you can't do even with the organic herbicides.


In that case, you don't really have to worry about the timing of it. You can't say, "Oh, I got to do this before 6AM before people start playing or anything like that because I don't want exposure." It's like you can do this any time of the day. It's not an issue, although I have to say when we started it up the first time, people jumped. [LAUGHTER]


[00:17:24]

Male: What's the difference between this one and Waipuna?


[00:17:27]

Dr. Cheryl Wilen: I'll talk about that in a minute. Waipuna is out of business, but Foamstream, the other one, picked up their patents and that one uses the foam. I'll talk about that, but this one is just strictly water.


[00:17:41]

Male: It's just straight steam?


[00:17:42]

Dr. Cheryl Wilen: Straight steam. Right on. Hose, tank, nozzle.


[00:17:45]

Male: No foam.


[00:17:46]

Dr. Cheryl Wilen: No foam. None at all. In fact, they don't want people to add anything to the tank because some people say, "Can I add a little bit of herbicide in there or can I add some…?" [LAUGHTER] They're like, "No." [LAUGHTER] In fact, people started asking us in this park [00:18:00] because they'd never seen anything like this and they're like, "What are you doing? Are you putting herbicide on there?" No, it's just water. We actually had to make a little sign because we were running out time. People kept asking us, so we just put a sign that said, "We're killing weeds with steam." Yeah, that helped a lot, actually. Yeah, Chris.


[00:18:15]

Chris: Maybe you're getting to this, but about how long does it have to be on a weed?


[00:18:20]

Dr. Cheryl Wilen: Right, okay, so we thought it had to be a long time. Hold it, move it, hold it, move it, but it's really just kind of a very quick… about that speed, actually. Not too long. It's a lot longer than having a backpack sprayer. I'll give you that because, like I said, the first time we went through, it took about three hours for this park. We came back to the car and we were all beat up because we'd been carrying the hose and it got noisy and everything, and I kind of looked around to see what we sprayed, or excuse me, what we treated. I said, "You know what?" Get this on tape, I guess. "If we were doing this with a herbicide, it would have taken us 15 minutes." So just kind of give you an idea. But after that initial time, I'll get you in a second. [00:19:00] After that initial time, the amount of time we spent went down significantly from three hours to a half an hour.


[00:19:08]

Male: So compared to by hand…


[00:19:09]

Dr. Cheryl Wilen: Yeah, compared by hand, right. Yeah, it's a lot better. You're not bending over.


[00:19:12]

Male: Are you guys killing seeds?


[00:19:14]

Dr. Cheryl Wilen: I'm sorry?


[00:19:15]

Male: Is it killing seeds?


[00:19:15]

Dr. Cheryl Wilen: I'll get to that in a second. Let me get this guy here.


[00:19:19]

Male: Does the nozzle have a tendency to lift up because I'd be afraid of it blasting out some [INAUDIBLE 00:19:24]?


[00:19:25]

Dr. Cheryl Wilen: Yeah, no. It's kind of weird, and again, I'm not really familiar or know the physics, but I mean it's coming out at 900 psi, but it's not blasting out. It's not like a what do you call that thing? A cleaner. Yeah, it's not like a high-pressure washer. Even the showerhead, it's not at super-high pressure or anything like that. No rocks or anything went out anywhere. We could even put it over mulch stuff and doesn't blow the stuff around. To your question about the weed seeds. [00:20:00] It's my impression that if weed seeds are on the surface it's likely to kill them. But most of the weed seeds that are problematic, that become part of the seed bank that really can emerge, they're the first inch. What happens after the top? What I've got Guy doing. He's collecting weed seeds right now, and we're going to test that out later on in 2019. We're going to put the stuff in little bags and pose the treatment and then germinate them out and see what happens. Somebody else?


[00:20:35]

Male: The machine itself, do you feel like it's pretty safe in terms of working around it? Have you ever seen it malfunction, like a little steam leak or anything?


[00:20:41]

Dr. Cheryl Wilen: No, nothing like that. We did have a problem in the demo one is that, because they use it a lot, there was a hose problem where the hose did break. In that case, it wasn't like they had a lot of hot water or anything come out, but it is a concern that you really have to watch that.


[00:21:00]

Male: That could be pretty dangerous if there was steam to the face.


[00:21:02]

Dr. Cheryl Wilen: Sure, yeah. But even that wasn't like if you were spraying and you get a hose break like that. I mean that happened to me once. A hose broke and I just got a bunch of stuff on the side of my face, but it's nothing like that at all.


[00:21:18]

Female: Is there any exhaust that you have to keep people away from?


[00:21:20]

Dr. Cheryl Wilen: No, there isn't.


[00:21:25]

Male: How long is the hose?


[00:21:27]

Dr. Cheryl Wilen: The hose is as long as you want it to be, actually. The garden hose for this, it can be long because essentially that's just delivering water to the boiler. As long as that boiler gets constant water, then it's okay. This other one. This is 100 feet, the insulated one, but the company can make them longer. You don't want it super, super long, though, because even though it's insulated…


[00:21:50]

Male: It's temperature wise, the temperature of the hose is [INAUDIBLE 00:21:52].


[00:21:52]

Dr. Cheryl Wilen: Right, so I'd go the other way. Get the garden hose as long as you can. But the fact of the matter is most people [00:22:00] in this room would probably use the truck-mounted one where it has a tank, so you would just drive the truck to where you're going and just move that around. All right?


[00:22:10]

Male: Gas boiler?


[00:22:10]

Dr. Cheryl Wilen: Yeah, it's diesel. So you've got to have two things. You need regular gasoline to run the pump. Then boiler is run on diesel, so it has two tanks there.


[00:22:21]

Male: Last question. Does it really just do top kill or is…?


[00:22:25]

Dr. Cheryl Wilen: Yeah, they have another piece. It's like a spike that you can insert into the ground, and they say it does a good job on perennials like nutsedge or Dallas grass and so forth. We asked them to bring one out because that's another piece and it costs over $100 for that, and I wasn't ready to spring for that. We borrowed one and demoed it. It goes in the ground. It has a spike. It's got holes on the side, so we tried it on Dallas grass. It did a little bit of kill at the first time, but it still came back, so I'm not really sold on that, [00:23:00] to be honest. Even if it worked, I mean you'd be doing that all the time.


Do you have smutgrass, Sporobolus indicus here? No. It's a tough grass. We get it a lot in playing fields and stuff like that. I think that might work in that case because there's very distinct tufts that you could use that.


[00:23:21]

Male: Wouldn't that be a factor of soil texture, too? Like sand, you'd get more penetration?


[00:23:25]

Dr. Cheryl Wilen: Yeah. I mean absolutely, but there's some soils that will work better than others. But I think really the way that it is, because it's so localized, it's really not that big a deal because really the temperature is being moved by the moisture as opposed to the soil. If the soil is more dense, it would probably hold the temperature longer. But again, it's so localized that I think that difference would be miniscule. Whatever that word is. [LAUGHTER]


[00:23:51]

Male: If the taproot on a dandelion or something is longer than five inches, is this not that effective or does it work good on a tap of three inches?


[00:24:00]

Dr. Cheryl Wilen: It wouldn't get the taproot. You'd need that spike, and even that, like I said, I'm not really sure. That spike, if you're interested in the spike, they can make that as long as you wanted, as well. But yeah, it's really top growth. Here are some places where we've used it. We started out in July, end of July. Here's Guy just going along the line here, which worked out really well if you wanted a nice clean edge along there. You can see what happens. I think this was the week after. That's the kind of effect you get and that holds up for about two weeks. If that's what you're going for, it's pretty nice on fence lines and so forth. That's at the top. Then here's another place that's around a baseball field. We have that.


You can see the length is the head. He's got the head turned perpendicular to the wall, for the most part. Here he's got it parallel to the wall. But that's how wide you can get it. [00:25:00] You can get it six inches to the width of that head, or you can go as far as 12 inches. I think we've got a 12-inch head or 24 inches, depending on what you're looking for in that situation.


[00:25:13]

Male: Does it take the same amount of time with 24? How long did it take to do…?


[00:25:19]

Dr. Cheryl Wilen: For that? Like I said, when we first did it, because we really weren't sure about how to do it, that probably took about five minutes to do that. It's about 50 feet. But once we actually saw the demo, now I have to say when you buy this machine, you don't get a choice. You have to buy the training with it. The training is kind of worth it. I think it's a little overpriced, but the training is with it. When that happens, it's really one-on-one and the guy will show you. "This is how fast you have to go," and so forth.


But after we kind of got that, that was faster. Then, again, after the first time, we moved to a showerhead and that's really fast. [00:26:00] You can go pretty fast after that. The first time took about five minutes. After that, probably one minute, I guess, to kind of go through, because keep in mind, if you do the timing right every two or three weeks, now that's a pretty short time between applications, but you're going to not have 100% weed cover all the time. You're probably going to be down to like… we put a trigger in. If it's 70% control or less, that's when we would do another treatment. We had a threshold when we were treating. If you do something like this, I would also suggest that you set some kind of threshold to know when you're going to be treating.


[00:26:39]

Male: Is it pretty easy to see where you've already sprayed?


[00:26:40]

Dr. Cheryl Wilen: Yeah.


[00:26:42]

Male: When you do the big areas?


[00:26:44]

Dr. Cheryl Wilen: Yeah, because the vegetation turns a bright green first, and then you can see that. It's not super-fast like if you just spray a lot of the contact herbicides and you come back a couple hours later and you see they're all wilted and everything, [00:27:00] but it is pretty fast. You will see them wilted. Again, so this is the playground. What we did initially, so we did a first treatment at the end of July and we came back one week later to treat it again. This is what it looked like. It's this edging right here. This is what I want you to look at, so right along there. We did the edging along the playground perimeter. That's what it looks like. Again, that's mostly kikuyu grass. That's what it looked like one week later.


Then we treated it again that day, and then this is what it looks like one week after the second time. It's still pretty good, but we did it two times because we wanted to make sure that we really knocked it back a lot rather than treating it once and then waiting a month and then treating it again, because I think we'd have too much regrowth after that. That was our initial treatments. [00:28:00]


After that, we found that we could actually wait a little bit longer. Again, this is around a picnic table that was on a cement pad. This is what it looked like at the beginning. This is just starting, and so what Guy is doing right here is he's got the head, as you can see, perpendicular to the pad. Then here it is 7-31. We did 8-31. This is three weeks after the second treatment. We did the end of July, did it a week later, so that'd be 8-4. Then a month later is what it looks like.


Really super good edging, right, if that's what you're looking for. Very distinct, although, when this happened, I told the manufacturer, the guy that invented this, I said, "Look how good this is. I'm actually surprised," because I wasn't a big fan of it, to be honest. I said, "Yeah, look how good it is, how nice that edging is." He goes, "Well, you know what? At this type of site, you probably could have just gone with string trimmers. [00:29:00] You really didn't need to use it." He's like, "Use this where you really need it." I thought, "Yeah, but it looks really good."


I mean it's wherever you would be using some kind of herbicide, use this instead. Wherever you use string trimmers, stick with the string trimmers. That way you could probably save a little bit of time that way. But anyway, it looks really good, but after a month, we are seeing some regrowth, but it was less than 70%. I mean so we still had at least 70% control. We probably had 85%, 80% to 85% control around that. That didn't trigger our threshold, so we didn't treat.


[00:29:40]

Male: Were you getting broad weeds?


[00:29:42]

Dr. Cheryl Wilen: Broadleaf weeds?


[00:29:43]

Male: Instead of the grass?


[00:29:44]

Dr. Cheryl Wilen: You can see there's a little bit of clover. It's a little hard because you're at a distance. There's a little bit of clover right there, there. This is the kikuyu right along there. Whatever is mixed in there will come up. Kikuyu grass is kind of interesting, though. [00:30:00] I think and this is what I've observed and there's a little bit of data about this is that when kikuyu grass is decomposing it actually is a little bit allelopathic, so it suppresses a lot of the weeds in there anyway. That may not be the best test to see what's coming up once the competition is released.


[00:30:20]

Male: On the previous example with kind of the edging on the curve there…


[00:30:25]

Dr. Cheryl Wilen: You mean around the playground? Let me go back up there.


[00:30:30]

Male: So prior to this technology, one would use an edger presumably. I'm just trying to…


[00:30:37]

Dr. Cheryl Wilen: Right, if you didn't want any herbicide. I mean typically you'd probably just be edging with a herbicide.


[00:30:42]

Male: I guess my question is how much time? With an edger, you kind of go along. So in terms of the speed, what is the difference between these?


[00:30:51]

Dr. Cheryl Wilen: You mean like an edger with a metal blade as opposed to a string trimmer?


[00:30:53]

Male: Yeah, right.


[00:30:55]

Dr. Cheryl Wilen: I'd say it's about the same amount of time, plus you don't get all that [00:31:00] stuff kicked up. That was the other thing.


[00:31:02]

Male: Your blade is not hitting on the pavement.


[00:31:06]

Dr. Cheryl Wilen: I'd say that. Anyway, so just to show you that you can get good edging with that, but just like any other contact herbicide or this, it's only getting the top growth. The kikuyu grass obviously has stolons and rhizomes, so it's re-growing from there. Whatever is in the seed bank, if the seed bank can be released, that's going to grow up as well.


This is another site. This was kind of interesting. I'm not sure what's going on, but this was Bermuda grass or is it Bermuda grass. Typically, perennials, they will regrow. But for some reason, this is a really nice patch of Bermuda grass over a mulched area, which is kind of growing in there. We have not had to re-treat that. Maybe once. [00:32:00] Again, I'm not really sure what's going on. I'm not sure if I can actually attribute it to the steam, but for some reason, we got very little regrowth of the Bermuda grass at this site. It might be that because it's in the mulch, maybe the rhizomes and stolons are more shallow. Maybe that's doing something as opposed to going into the ground.


[00:32:22]

Male: Maybe Bermuda goes dormant or something.


[00:32:24]

Dr. Cheryl Wilen: That's a really good point because right now we're kind of, at least where I am, doing that transition from summer to winter. We have to be really careful that we attribute management to the actual control as opposed to just natural dormancy or dieback of the plant. But this was in the summer. That is something you just need to consider. Again, just natural life history of these weeds. Don't say, "Oh, yeah, the crabgrass is dying." It's going to die anyway around this time of year. That's where it's at.


This one was actually kind of funny here. [00:33:00] This is, again, that park. We did a lot of this trimming. This is a soda machine and just kind of went around the edge. When we started that day, there was a tree. By the time we finished that day, the tree was gone. I just did it kind of as a joke to say, "Yeah, we can take down a tree with that." [LAUGHTER] But it just so happened that they were removing trees in the park that day. That was kind of cool.


This is where this type of equipment might shine is in controlling weeds in cracks like this. This is it with the showerhead. This applicator here. You have to hold it about this high. What I've seen people do when they are using this, they actually have a tendency to hold it higher. You really have to be careful if you do get this to train your applicators. They really need to hold it about this high off the ground. [00:34:00] Because the higher up it is, the more heat you're going to lose as it goes down. You want to maximize that heat, but you don't want it right on. You don't want it this far because then you would lose a lot of your efficiency because your spray swath, if you want to call it, it's only going to be this big. This is the sweet spot, this length.


You can see how he's holding it. He's able to just walk at pretty much a normal pace along there, and with that showerhead, you get more targeted control. This is actually the inventor here, Jeremy Winer, but what he actually says, in a situation like this, that's best is you get a string trimmer out there and you trim out all this other stuff and blow it away beforehand. Then you hit it with the sprayer to pick up the rest of it, because he says it's not about and I'm not sure I agree with him, but he goes, "It's not about control. It's about presentation." What he's saying is that as long as it looks good, [00:35:00] don't worry if you don't get 100% control because you're just looking at essentially that threshold where people will accept. By doing the trimming, that reduces a lot of what it looks as bad, and then following it up with the spraying helps just the appearance.


[00:35:18]

Male: Cheryl, what do you think the weed is? Is it a [INAUDIBLE 00:35:20]?


[00:35:22]

Dr. Cheryl Wilen: Shoot. It might be purslane.


[00:35:25]

Male: Purslane?


[00:35:26]

Dr. Cheryl Wilen: I'm kind of thinking that's what it is. Yeah, pretty sure. We did a trial in a parking lot as well. Here's Guy. First, he's trimming the weeds and then we're going to come back and hit it with the steamer. This is what we had. This was, I think, two weeks after we did it. Here's just the steaming. You can see up here we have some good cracks in there. You can see a little bit of regrowth at the top left-hand side of this one. [00:36:00] Trimming alone didn't really do it because it was a test, so we're just doing a comparison. We just trimmed. You can see this was Bermuda grass coming back in there. That really didn't do it. This is trimming plus steam in this replication. You can see we've got pretty much 100% control. You can kind of see what I call "weed carcasses" in there.


Actually, that's something that you might consider or worry about a little bit. I don't know if worry is the right word, but you're still going to have the dead weed parts there. It's not going to be beautiful. You're still going to have dead plants. Again, that might be a reason why you might want to trim first because otherwise you still just get a mound of dead leaves and so forth on there. Trimming plus steam. That seems to work okay, but if you don't want to do that extra effort, I think if we started running statistics on this, that steam would probably be just about the same.


[00:36:57]

Male: How many weeks later is that?


[00:37:00]

Dr. Cheryl Wilen: This was, I think, probably four weeks. Yeah, this grew a little slower because it didn't get any irrigation. It's in the summer. It was just whatever was in the parking lot. Tree wells, that's another place where glyphosate is used a lot because you just want to have that nice circle around there so you don't get the mower or the trimmer bumping up against the trunk and hurting that. This is the kind of thing that we get. This was about two weeks after a treatment in a tree well.


Now the thing about tree wells, they kind of go down. They're kind of like a little concave site. Because of that, we get a lot of the water collecting from this. We got pretty good control. What's dead here is goosegrass. Do you get that up here, goosegrass, anybody? It's kind of related to crabgrass. So goosegrass, good control. We get some not weed, not so well controlled. [00:38:00] It killed, and again, it's a little hard to see, but from here out, that part was damaged, but as long as some part of the plant is alive, you still get regrowth here. Here it is re-growing up there. That was kind of an issue.


This, obviously, would have to be retreated sooner than what we expected, but the other problem is, because of all that water that's kind of accumulating in there, that's as if you just irrigated that site. Again, if there's any seeds in the seed bank that are ready to germinate, you're going to get another flush. That might not be too bad of a problem because you're like, "Yeah, now I'm going to get all these weeds now." But if you come back and treat it at the right time, you can actually deplete the seed bank. That might be helpful. We're kind of looking at that as well.


This is, again, another site where we did it. It's not so great. You can see we do have some control around here. [00:39:00] But where the plants are able to regrow, like here, here, here, it still comes up. Again, this would be a threshold for us to treat or re-treat. This is something just to show you if you're going to be using this. This is the first time. This is one week after the first time we treated it, and we're still kind of learning. Guy did a great job. He put the head right up against the edge and was able to really get that nice clean edge that I showed you. I had another guy do it, and he really couldn't quite get it. You can see that he couldn't really know where he was putting the head, and so it's not quite as nice, right? You get this edging here, but there's a lot of still plants growing quite well over there. That's another thing. This isn't set-it-and-forget-it. You've got to really train the applicators to know how they're going to be working in there. [00:40:00] Here, if I came back with this and saw this, that wouldn't be acceptable to me because that would be almost like I didn't do it because that's only about 40% control looking at it.


[00:40:14]

Male: Can you tell what they were doing differently in their style?


[00:40:19]

Dr. Cheryl Wilen: Yeah, what happened is that what Guy did, he put the head right up against the edge, right up here. Whereas the other guy, Fritz, he kind of put half the head on the pad thinking that he would get better coverage, but essentially it made it kind of lift up a little bit, so he didn't get as good contact. But we were trying. I couldn't say one was going to work or not the first time. I thought maybe the other one would have worked better, but that's sort of what we saw.


Here's that tree well. This is what I'm talking about as far as sort of the weed release. [00:41:00] This is purslane mostly in here. This is the summer. Purslane is a warm season annual, summer annual. What happened is with this release and then all this water that came into this tree well, and keep in mind that, which I guess a little information I didn't tell you is that this park really tries to manage its irrigation. By managing its irrigation means that they don't irrigate that much. [LAUGHTER] What happened is all of a sudden this tree well gets a lot of water, and there's all these seeds in the seed bank, and they're going, "Woo hoo!" They came up. Right now, that was a release of the purslane. If you didn't do anything after that, you would have just a big mass of purslane growing there.


What you really have to do is, after this flush of weeds, is come back as soon as you start seeing them germinate and treat it again. This system, by sort of encouraging [00:42:00] germination and then treating and then encouraging germination and then treating again, that's a well-known use in agricultural weed management when you're producing, let's say, lettuce. It's called a stale seed bank technique. Essentially before you plant, you irrigate. You let all the weeds come up, and then you hit it or cultivate to kind of get that first flush of weeds out. You can do it twice, and that really depletes… as long as you don't cultivate. I mean you cultivate shallowly to get rid of them if you don't want herbicides for something, but by doing that, you're reducing the amount of seeds. Remember I said the first inch is where most of the problematic weeds are residing? If you can deplete most of them and don't bring up any ones from lower down, then you can actually reduce the amount of weeds that become problematic.


Essentially, that's what's happening, but you have to remember to come back and re-treat. Again, that's why monitoring is very important with this type of system, [00:43:00] because if you wait too long, just like with any kind of weed management technique you're going to be using, the bigger the plant is, the bigger the weed is, the harder it's going to be to manage.


[00:43:12]

Male: Cheryl, it seems like it might make sense, that might be a good time to use a burndown.


[00:43:15]

Dr. Cheryl Wilen: Yeah, absolutely you could do a burndown with that. Yeah, it'd be absolutely faster in that. Whatever you're going to use. We haven't done it. That takes so much time, but the best thing, any IPM system is a combination of techniques. If you can really kind of tune it in, so okay, the first time we're going to go through with the weed steamer. That takes some time, but you get pretty good weed control. Next time, you get this flush. You can save a lot of time with that contact herbicide, if it's an appropriate site. Sometimes it's not an appropriate site. But yeah, that'll save you a lot of time to come back with that. But again, monitoring is really key, because again, if you're going to be using a contact herbicide, they don't work that well in bigger plants. [00:44:00] You got to make sure you're going to get it in the seedling or not much past the seedling stage. Andrew?


[00:44:09]

Andrew: In the tree well situation, do you think you can damage certain roots?


[00:44:15]

Dr. Cheryl Wilen: We haven't seen that. We've come right up against… even ficus, which has pretty shallow roots. We've come up with that and we haven't really noticed it. Again, I think the temperature is really well buffered by the soil. By the time it gets down to even with the soil, the roots are high up. They're not really damaged.


We did a treatment. Let's see, so in October. We didn't do another treatment here until this is right before we did our next one. This one we had a four-week interval. You can see. Remember how nice that looked, that other picture? You had that nice edging and so forth. It's all grown back. [00:45:00] It's our experience, even as we get into the cooler temperatures, that a four-week interval is too long. Really if you're going to be using this system, you're going to be looking at two- or three-week time. You have to really figure that out for your labor and scheduling. That's kind of a drawback with something like this. Again, where did that guy go? Henry, I think you said hand weeding or somebody.


[00:45:25]

Male: Do you think that it kills just the foliage and then all the root?


[00:45:32]

Dr. Cheryl Wilen: Yeah, absolutely. Just like a contact herbicide. Just killing the top. If we're really lucky, it's kind of damaging a little bit of things that might be growing on the top. Let's say the stolons, so it's not really moving in there. But nevertheless, there's no residual. Even if things might be growing in, again, this is kikuyu grass that grows pretty well. I mean you can see there's still a little bit of control around here, along here. [00:46:00] But for the most part, you would say that this is zero control. There's no difference.


Again, if you're considering doing something like this, you've really got to factor in how many times you're going to have to do it and decide whether you're going to be doing it timewise. Same with the tree wells. This is, again, four weeks after treatment. We get the kikuyu grass coming in again. We're getting some broadleaves coming in. This looks like it hasn't even been treated at all. Four weeks is too long.


Now this is something. Now any questions about that? I can kind of move in a little bit. This is another situation. This is Bermuda grass that kind of got out of hand. This is a parking median strip area. I'm sorry Bermuda grass. This is Rhaphiolepis, Indian Hawthorn or India Hawthorn. That ended up growing into the plant, the Bermuda. [00:47:00] If we did steam over the top, it would likely injure that shrub, but we went as close as we could to kind of kill as much Bermuda grass as we could. We could get in there pretty close, and you can see it does a pretty good job on this Bermuda grass in this case.


But this gets back to that point I was making about the presentation. It's like, "Yeah, okay, I killed it." It still looks trashy, right? So you've still got to remove it. It's just something to consider when you're doing something like this is where is it appropriate to use and where it's not appropriate. Here, it didn't really matter. This is a maintenance yard. They just had plants there to kind of break up the concrete, I guess. But nevertheless, we could get pretty close to the plant in there. In some situations, you can use it.


Other considerations about using this machine is we had two people actually with the hose because the hose is long, [00:48:00] and we've got a lot of obstacles, so one person would be at the end of the wand. One person would help move the hose, and then I was at the end kind of making the adjustments. You could do it with two people. You could do it with one person. I would say if you get that little machine, even though it's the smallest machine, you still need three people if you're going some distance with it. Probably okay with two. Guy and I often just do it by ourselves, so we can do that, but I have to run from the machine. I help him move the hose, and then run back to the machine to make sure everything is dialed in.


We also found, because the park is in use, we have cones around just for safety, just to have people make sure, if they're so dense they can't figure out that there's a hose across the sidewalk, we've got all kinds of things like that. No judgment there, right? [LAUGHTER]


[00:48:57]

Male: How about riding a bike over it?


[00:48:58]

Dr. Cheryl Wilen: You can ride a bike over it. You can drive over it. It's no big deal. [00:49:00] Any questions?


[00:49:04]

Male: I mean maybe a little outside this climate. Can it be used on a root to get moss off? How about an icy path kind of situation?


[00:49:15]

Dr. Cheryl Wilen: Yeah, what's ice? [LAUGHTER] The other thing about this machine, the weed steamer that I just showed you. It comes with two or three other nozzles that you can attach that are more like high-pressure steaming for cleaning moss or gum or graffiti and things like that, too. You can use it on other things as well. In fact, I didn't even know it was there. I just saw a red, green, and blue thing attached. I thought it was just buttons I wasn't supposed to touch. Then when the guy came out to do the demo, he's like, "You know you can use these," and he pulled them out. I'm like, "Oh, okay." [LAUGHTER] Bonus! [00:50:00] How am I doing on time? Good.


The other machine, so this was the Weedtechnics one. There's another one called Foamstream. This is the Foamstream. This one is in size and usage is probably equivalent to the one that Salvador has. It's a bigger machine. It's used for bigger areas. It's on a trailer like this. It's got a long hose. Here's the wand. You see it's got a different kind of head here because foam comes out of there as opposed to high-pressure steam. They do have a smaller one.


[00:50:45]

Salvador: The difference is he has computerized controls.


[00:50:48]

Dr. Cheryl Wilen: Right. I'll get to that in a second, but they do have a smaller one that you can put on the back of a Gator or something like that that's a lot easier to use. [00:51:00] Like Salvador said, this one, okay, so the one that I'm using. I think that's like somebody said, "Hey, let's put all these parts together in the garage and see what happens." That's the kind of feeling I have about it. This one is like Alexis. [LAUGHTER] You turn it on. You press a button, and then when it turns green, did you see it in action? Yeah, do you have one?


[00:51:25]

Salvador: No, we went to borrow Chris'.


[00:51:30]

Chris: The small version.


[00:51:32]

Dr. Cheryl Wilen: You press a button, and then when it turns green, you press another button and it's ready to go. It's nothing you really have to mess with. The engineering is just incredible on this one as opposed to the other one. On the other hand, the equivalent one for Weedtechnics is about $25,000. I think this is about $40,000. You're like, "Gulp." Right? Yeah, so that's kind of high. Here's the tank in the back here. [00:52:00] Here's the machine. Here's the tank that holds water. Here's the tank that holds the stuff that's the foam. They have two things that make the foam. One, depending on what your use is, one is organic olive oil and sugars or something like that. The other one, oh, here we go, sorry, because I just added this.


This is where they just take a bunch of stuff, potatoes, corn, wheat, and everything and a little bit of palm oil. That's one of them. But if you want to do an organic system, they actually have organic olive oil because some people are like, "Yeah." I really don't get it. You're not going to be eating the landscape, but some people want an organic line, so they do have an olive oil-based material. It's proprietary, so you have to buy it from them and that's the only thing you can use. I apologize. I don't have a price of what that extra stuff is. It looks like you have to buy it in maybe 10 gallon. [00:53:00] Maybe that's five gallon buckets to use it.


Let's see here. I think the next one is kind of cool. Let's see if we can make this work. Here's what it looks like. They put it on there. I can't say that this grass is, in fact, I doubt, actually, if this grass here… no, I take that back. They treated this. This was a demo. They treated this about two or three hours before I got there. You can see there's some damage here on the grass. I think this is fescue here. You can see there's a little bit of damage three hours later. I can't tell what that is, actually, but you can see there's some death. It's kind of folding over. Here's plantain. It really doesn't look like it's injured too much, though. It's not 100% control from what I can tell from this, but there is some. This is the kind of thing that you get. Chris was saying they didn't get a lot of foam when you had the demo.


[00:54:00]

Chris: Yeah, you had one picture on that that shows a lot more foam than what we saw. Maybe 20 [INAUDIBLE 00:54:06].


[00:54:06]

Dr. Cheryl Wilen: Let's see if I can get the video to go here.


[00:54:11]

Chris: They put it on the pavement and actually it was just a bunch of hot water and there was flecks of foam.


[00:54:17]

Dr. Cheryl Wilen: Oh, really?


[00:54:20]

Chris: I mean [INAUDIBLE 00:54:22].


[00:54:23]

Dr. Cheryl Wilen: I'm going to see if I can run it again. Not sure if this will work or not. Where is it? [LAUGHTER] It's in the background. I'm going to try something.


Chris: You might need to just move out of this.


Dr. Cheryl Wilen: I'm going to just go to that.


Chris: I had it on the desktop.


Male: You get more foam on the $100,000 pumps.


Dr. Cheryl Wilen: [LAUGHTER]


Chris: There it is.


Dr. Cheryl Wilen: Let's see if this will work.


Chris: If you just move it over to the middle.


[00:55:00]

Dr. Cheryl Wilen: It's going the wrong way?


[00:55:08]

Chris: You did the double screen. That's why.


[00:55:09]

Dr. Cheryl Wilen: I'm going to try it again here. Where is the cursor?


[00:55:15]

Chris: You just need to do a duplicate screen. Do you want me to do that?


[00:55:16]

Dr. Cheryl Wilen: Yeah, please. Chris is going to help me out here.


[00:55:44]

Chris: I hope this works.


[00:55:48]

Dr. Cheryl Wilen: I'll tell you what. Close the PowerPoint because I can open that up again. Bear with us here. [00:56:00] Nope. [LAUGHTER] You get what it sounds like. [LAUGHTER]


[00:56:06]

Male: Is it quieter than the other one?


[00:55:06]

Dr. Cheryl Wilen: It is quieter, actually, but it's still noisy, but you could use this in more places, I think.


[00:56:14]

Chris: I don't know, Cheryl. I don't know why it's not doing that. Sorry.


[00:56:17]

Dr. Cheryl Wilen: That's all right. We'll do it after I close the PowerPoint to make that happen. I've only got two more slides, and then I'll just close the PowerPoint and hopefully be able to show you this. Anyway, this was the foam steamer. That looks like horseweed or marestail there. It does have some control there. Like I said, a few hours after it was treated, now here's the fescue on the side here. That doesn't look very injured. The broadleaves look more injured, although not everything. This looks like it is khaki weed here. It's kind of weird. It's not as good, in my opinion, [00:57:00] control of the weeds as Weedtechnics one. But on the other hand, and I was kind of giving the manufacturer a little bit of tips there. I said, "You know what? It might be helpful if this were something I could use on a turf area, if you can really dial it in to control the broadleaves, but not injure the turf." So anyway, we'll see. This is really good. Somebody mentioned moss. I think this would be really good for moss control or algae control. We'll look at that video and you'll see what I mean when you see that.


I did have some observations between the two of them, if you are considering buying one. To the point about the sound, Weedtechnics, it's pretty noisy. They're going to have a new one out that's going to be electric. I don't think it's going to be a big deal. I think it's more for maybe a homeowner's association or something like that where they don't need a lot of room. [00:58:00] Because since it's electric, you've got to have a long extension cord to make it work, I think. It might be a battery, but I'm not so sure. About moving it around, the smaller one, again, it's pretty difficult, even the smallest one. I use 500 pounds and the cart and so on is not very amenable to turning and so forth, but you can do it with the hoses.


Better precise application. That's where you can get some good edging with Weedtechnics. Again, we kind of lost it because you didn't see the video, but because it's a foam, it kind of spreads out like an amoeba, so you might not be able to get as good edging and so forth that you want. There we go. Engineering we talked about. Price. More expensive, but you're getting that better engineering, in my opinion, but if it doesn't control the weeds as well as I think it should, it might not be worth it anyway.


[00:58:58]

Chris: Cheryl, did you try and go back a couple weeks later [00:59:00] for the Foamstream to do any kind of…?


[00:59:04]

Dr. Cheryl Wilen: I didn't, but unfortunately, it's some distance where they did a demo some distance from where I am, so it's not on my regular route. But yeah, I should do that. That is all I have for this part, but I really want to see if I can get you to see that. Hopefully this will work. Magical. [LAUGHTER] It just doesn't show up. All right, do you guys want to take a five-minute break and we could figure this out? How would that be? Yeah? We're going to try it again and hopefully this will work this time. You can see this is a lot of foam here. [01:00:00]


[01:00:00]

Male: That's way more than we have, right?


[01:00:02]

Dr. Cheryl Wilen: This one was the olive oil one. That's it. It's just a very short video, but I'm going to do it again just to kind of point out a couple things here.


[01:00:12]

Male: What's the temperature of the foam?


[01:00:15]

Dr. Cheryl Wilen: I don't know, really. What is it? 212? You see it spreads out more, right? If you're doing a big area, this would probably be faster than the other one. That's kind of a benefit of this one, but I mean I can't remember what the temperature is. On their website, they have a lot of information on their website. I don't want to have to talk too loud, so if you could just give me a break here. Thank you, Salvador.


At the wand, it's 208 Fahrenheit. Two inches above or at the weed, it is 147 Fahrenheit, [01:01:00] which isn't great, but that's probably enough to really cause some foliar damage. I'm sorry. I've got them backwards. They say at contact it's 203 degrees Fahrenheit, whereas the steam is 147 degrees Fahrenheit. I don't think that's accurate, to be honest. But again, I haven't put the thermocouples down there to really measure it, so not really sure. We have to get it up a little bit higher, but I mean really we want to break the cells. That's the real key is to kind of get the cells to leak and that's the kind of temperature we want to get to. This is pretty cool, actually. Where's Salvador? Is this online or they gave this to you?


[01:01:52]

Salvador: They sent it to us.


[01:01:53]

Dr. Cheryl Wilen: I'm going to have to see if I can find that and do a little bit of verification on my own for this. So anyway, to answer your question, looking at about 203 degrees.


[01:02:06]

Male: Does [INAUDIBLE 01:02:06] Foamstream, their website?


[01:02:11]

Dr. Cheryl Wilen: They do. I mean they have a really good website. Just go Foamstream.something. Yeah, you'll find it for sure. A lot of information is on their website and videos, as well. Then Chris is going to post the pictures from the work he's done.


[01:02:22]

Chris: I mean Salvador had made a few more observations to share on his trials.


[01:02:31]

Dr. Cheryl Wilen: I'm going to let you guys go.


[01:02:31]

Chris: I would just say that I would echo that that machine is really cool. I mean it had the light. It tells you when it's ready to go. You could be all the way down the path and you look back and see the green light. You know I'm ready to go. I can push the trigger. Automatic everything pretty much. The Toro [INAUDIBLE 01:02:53]. You can get on a little path. [01:03:00] But like I said, sorry about that. I keep forgetting.


It was a very cool machine. It's too bad, in a way. [LAUGHTER]. They were out demonstrating it on a path next to the slew, and there are a lot of weeds between the cracks and they tried it on some fennel. When he was doing it on the fennel, I was timing that. He was standing there for like a minute just foam, foam, foam. It still didn't get it. They tried cutting back some pampas grass.


[01:03:40]

Salvador: Pampas was cut low. Then he sprayed. How long did they spray for? They sprayed for…


[01:03:49]

Chris: I don't know. 15.


[01:03:50]

Salvador: Five, 10 minutes, something over the pampas, but we had a guy check it and the pampas was growing a foot. It looks like they fertilize it. [01:04:00] [LAUGHTER] The grass on the cracks on the edges, it was there for sure. It works very well to kill the grass, not too high. Probably four, six-inch guy. But on the fennel and pampas, didn't work. It's truly probably is more grasses or weeds to be working fine.


[01:04:19]

Chris: How about on a path, in the cracks?


[01:04:20]

Salvador: Yeah, on the path, in the cracks, it works very well. It was the idea. Even on the wall, it was taller grass. It was all dead.


[01:04:30]

Dr. Cheryl Wilen: I mean, but then its credit. I mean pampas grass, in general, is hard to control with anything. I mean I think it was pretty hard…


[01:04:38]

Salvador: This is a very tough root, so not easy to kill. [LAUGHTER] But that was my things I found out after one week and a half, so probably might damage the tissue of the plants because the oils on the foam.


[01:04:56]

Chris: Yeah, so I don't know. Like I said, there was hardly any foam. [01:05:00] It was really just hot water. Look at the path. I mean I'll bring some photos in. I'll post them. There was a lot of water sitting on the path with little pieces of foam floating on it. The purpose of the foam is to hold the heat in so that it's there longer and has a better chance of breaking down the cells, but I can't see that it's doing that. Now when it was on the bed, when he put it on the bed where there was some grass there, it held the foam a little bit better, but it was still nothing like your picture. It might have been a bad… maybe it wasn't a good mix.


[01:05:33]

Salvador: But the big grass on the top, it was dead. The grass, but not the front.


[01:05:46]

Chris: I know. I keep forgetting. Here, you can have that.


[01:05:52]

Dr. Cheryl Wilen: That pretty much is my presentation. If anybody has any questions. I know you asked a lot. Andrew, do you have one?


[01:06:00]

Andrew: In theory, could these systems be used in the rain? I know you guys don't [INAUDIBLE 01:06:05] on there, but in theory, could you use the systems in the rain?


[01:06:12]

Dr. Cheryl Wilen: Hang on a sec. Could I use the systems in the rain? I don't see why not. I mean because you're really doing a localized heat treatment. It's not like it's going to be colder, so you can do it in the winter. You can do it in the summer. I can't see why you can't do it in the rain either.


[01:06:30]

Andrew: That's a potential advantage over any kind of…


[01:06:32]

Dr. Cheryl Wilen: I mean there are advantages, obviously. You don't get drift. Beautiful. You can use it near where people are working, so there's not an exposure issue or things like that. I mean there are definitely advantages of using it over certain herbicides.


[01:06:49]

Chris: Good question.


[01:06:52]

Male: We're just using a torch on cracks. We use a big torch on cracks and [INAUDIBLE 01:07:00]. Do you see any advantage over a torch?


[01:07:05]

Dr. Cheryl Wilen: A torch, you've got to consider where I live and where I'm doing this stuff. I am not a big fan of it because anything could spark it. In southern California, a fire was started just from a guy hitting a golf club against a rock. I mean so anything is burnable. In my opinion, fire is that you should probably pretty much use it when it's misty or rainy or like today, maybe, after it's rained and you're not going to have very dry things. Those are those kind of limitations. "Hey, I just can't use it anywhere." You might be able to use it, again, like in a parking lot. I think that's fine. You don't have a lot of burnable or flammable materials. Obviously, the equipment needed is a lot less technical than what I showed you. Again, getting to the IPM part of it, it's use the right equipment [01:08:00] for the right thing the most economical way that you can think about. Hang on one sec. Yeah, because you're going to be famous now.


[01:08:08]

Male: Is it safe for rubber surfaces and children's play areas?


[01:08:20]

Dr. Cheryl Wilen: For rubber surfaces? Yeah, that's an interesting question. I don't think we did it over rubber mulch or something like that. Is that what you're talking about, maybe?


[01:08:33]

Male: Those rubber puzzle pieces that fit together.


[01:08:36]

Dr. Cheryl Wilen: Yeah, don't know. I have a feeling it would be okay, but I can't guarantee it.


[01:08:45]

Male: I have a question. Are you going to do some more studies on the foam?


[01:08:51]

Dr. Cheryl Wilen: The company that has the foam, they'd like me to do more, but I don't have the capacity to do more than what I'm doing right now. [01:09:00] To be honest, I really don't predict me doing anything with it, but it's interesting.


[01:09:07]

Chris: I think you're right. Maybe we didn't get a fair trial on pampas and fennel, although I'd love to see if we could get more foam with the other formulations.


[01:09:21]

Dr. Cheryl Wilen: Yeah, because I'm surprised because this just really was very foamy. But again, I think for something like this… all right, so it's a European machine. It comes from England. This is the equivalent to Waipuna. They bought the patent for that.


[01:09:38]

Male: I'm sorry, but I'm still seeing Waipuna. With the foam, the owner is showing the kill wasn't there.


[01:09:46]

Dr. Cheryl Wilen: Like I said, here I didn't really see it. You saw two weeks afterwards you could still see kill. I mean I think they've improved it, but I didn't really follow up myself, but maybe Chris has that information.


[01:09:57]

Male: I came in at the tail end of the Waipuna era.


[01:10:00]

Dr. Cheryl Wilen: Yeah.


[01:10:02]

Male: I remember people saying, as well, people had mixed reviews about [INAUDIBLE 01:10:05].


[01:10:06]

Male: The other problem is talk about the control over the aesthetic, right? Like keeping control of aesthetics. That was the same with the Waipuna. You could go through and there'd be still… it's just like going with glyphosate. [INAUDIBLE 01:10:18] and you still have the aesthetic one. You know what I mean?


[01:10:23]

Dr. Cheryl Wilen: There's always that issue about that. Again, sometimes glyphosate is not the right tool. It's very easy to use and cost effective and everything, but we've just been so complacent. That's what we've always used, where sometimes it's better to edge or use something else.


[01:10:00]

Male: You say they manufacture this in Europe?


[01:10:43]

Dr. Cheryl Wilen: Correct.


[01:10:44]

Male: Are they using that regularly over there or are they kind of playing around with it like we are over here?


[01:10:50]

Dr. Cheryl Wilen: That's the point I was going to get to was that… so good. Thank you for doing that. In Europe, what they have, the weather is different. It's high moisture, a lot of [01:11:00] high relative humidity, and they have a bad problem with mosses and algae growing in the streets and the sidewalks, those cobblestone places that everybody is like, "Oh, it's so cute." But it works really well for those situations because foam can just go and just kind of cover the street in a short period of time and really does a good job. I actually told this company because I do a lot of work with greenhouse nursery growers as well. They've got a big problem with liverwort moss. I said, "You know what? If they got into that market trying to control weeds under benches, I think that's where they could really do well in it, but it's not a big enough market for them." Again, it's like the difference between Europe and us here. Maybe this works somewhere else. Maybe the east coast better.


[01:11:48]

Male: I kind of have a last question. Has there been any studies on intensive agriculture where they make passes with this very frequently and sterilizing the soil [01:12:00] and that kind of dead zones?


[01:12:02]

Dr. Cheryl Wilen: Sure. The Weedtechnics actually has an ag side, the first one with the steam. They've got these really kind of sort of upside down pie plates except bigger that they can come alongside like a grape trellis area, kind of do that. Same effect. It kills the grasses and the broadleaves along there. There's that. It's not so much, again, trying to kill the weeds and the seeds in the seed bank or anything like that. It's just, again, top growth. Now there's a colleague of mine, Steve Fennimore, who does more of what you're doing or talking about about getting the steam inside the soil and really trying to raise the temperature and then sort of use it as an alternative to methyl bromide, for example.


[01:12:47]

Male: That'd be strawberries and sand.


[01:12:48]

Dr. Cheryl Wilen: I'm sorry?


[01:12:49]

Male: Strawberries and sand.


[01:12:50]

Dr. Cheryl Wilen: But the problem with that is and we've done it, and I've worked with him a little bit doing that. The problem is that uses so much water and it's so slow. [01:13:00] I think they did two acres at the farm that I worked with. Two acres took 10 hours to get to that point because you really have to have that heat in the ground with the special equipment and actually have it sit there for a little bit before you can move forward. I mean to answer your question, yes, but is it as ready for prime time as this is? No. I'm going to cut it there.