Hi, I'm Crista Conforti, I'm the IPM Coordinator for the Presidio here in San Francisco, and Chris asked me to give kind of a general update about what's going on in the Presidio IPM-wise. But really what I'm going to do is give you two different talks about focuses for me in the past handful of years. One being how do we find alternatives to Roundup? And two how do we protect our park from the plant disease Phytopthera?
So, I've got two presentations separate and this is going to count as the update to the Presidio, although it's not complete. Alright. So we're going to start with our organic herbicide field trials that we've been doing over the past handful of years, which is, of course, in reaction to our desire to reduce the use of Roundup when the IARC came out with its reclassification of Roundup, we stopped using Roundup for about two and a half years. And as we've gotten more information, have started to use it only in very specific occasions. So, we're not in a moratorium on Roundup, but we are wanting to find alternatives in an effort to really, really use it very sparingly. So, a lot of what I've been doing is evaluating the organic herbicides that are on the market. So back in 2017, we took a look at two products, Avenger and Exempt. How many here have used Avenger? What do you think of it?
Alright. How about efficacy?
Can we have a show of hands? Low, medium, high. Low efficacy raise your hand.
Medium? Yeah, Medium. Okay. So, this just kind of runs through the specifics on Avenger. The signal word is caution and it's certified organic. How does it work? It destroys the plant cunical resulting in dehydration and death. It only does this on the part of the plant that it touches. So, it really is just a top burn. And when you look at the human toxicity, it does have skin and respiratory irritant issues, but usually only with industrial strength exposure. So, it's not a huge issue for applicators. Alright. So that's Avenger.
And then we tested it against this material called exempt, which is a clove oil and salt material. I don't know if this is even still on the market, but it was a back in 2017. No signal word it's exempt from EPA registration because clove oil and salts are on the generally recognized as safe lists and it's certified organic has the same kind of mode of action. It has additional human toxicity issues in terms of it might cause nausea, vomiting, abdominal pain and can trigger asthma. So, this is just to say that, as we all know, even though herbicides might be organic, they're not without risks to the applicator.
People die from drinking too water, with the salt.
People have died. Yes. Alright, so those are the two that we wanted to test against each other back in 2017. I've just got a couple of images here. We did do a replicated plot trial with this. And I'm just showing you one plot for each. This is what the plots looked like ahead of the treatment. It's hard to tell, but that's mostly Malba grasses some plantain in the plots. And these are what we call fence line areas in the Presidio, which tend to have this kind of suite of weed species.
So this was the day after treatment. So, we did get some relatively good knock back. And then this was one month after treatment and it's hard to see, but the green growth is coming back, both the grasses and the broad leaves. But it's not terrible. So, I really did try to push our applicators to use it. And they did. But they were kind of like, "It's not great. It's better than nothing. But we really want something better than this."
Were they the same level of efficacy?
They were about the same level of efficacy. And because the Avenger was cheaper than Exempt.
It was cheaper?
Yes, it was cheaper than Exempt. So, we went with Avenger. But we didn't really see any significant difference between the two. Alright. So, then this material Weed Slayer came on the market and how many of you have experience with Weed Slayer?
Alright. It was hard to get. Like it came on the market and then it left the market really quick because there was an issue with labeling. And then so we put in an order for it. And then we waited for months and months and months until the issue with labeling was resolved. And we finally, about three or four months ago, did a field trial with it. And we decided not to do a replicated field trial instead just side-by-side Avenger and Weed Slayer. So, this is what we've (inaudible 5:47). It's clove oil, likely exempt, but it's not only clove oil. It's clove oil in one jug, plus microbes in another jug. And the manufacturer won't tell us which microbes they are. And they also recommend that you use it with a pH reducer to get your water down to a pH of about four. And they recommend that it be used with a surfactant. And the suppliers will sell all of these to you as a kit, although you could, do your own pH reducer or organic surfactant. But we bought it all together in one kind of lump sum.
Alright. So, it controls broad leaves and grasses. It's non-selective and the label is just general. It can be used in any type of landscape. It's no signal word, it is exempt from EPA registration and it's certified organic. And so, the way it works is very similar to where the other clove oils work.
You say it's exempt from registration. So, just for clarity, that means they don't have to have a single word. It doesn't mean that it's lower risk.
We're talking about GHS?
No, I'm talking about EPA labeling. So, if it's exempt from EPA registration there are no label requirements for single words.
And that's federal only?
Federal and State, both.
Well, GHS is international.
Yeah, GHS is a different system. But it is important to realize because there are some people who advertise no single word.
As a proxy for it's safe, whereas that's not necessarily true.
Sorry to interrupt.
So it works in the same way as other clove oils. However, it's got these other--it's recommended that you use it in a way that that makes it easier to travel through the plant. So, the low pH allows for better penetration beyond the cuticle and presumably the microbes facilitate more penetration and more movement through the plant. So, the manufacturers are calling it translocation. I don't know if that's actually true, but that's what they're calling it. So, it has a better movement through the plant. And so, it's actually not just killing it on the cuticle level, but presumably in more portions of the plant.
What we want is a chemical that goes down kills the root.
I know you do. Which is why we're testing this. And I'm saying it's the manufacturer is saying its translocation. I'm a little uncomfortable thinking that that's 100 percent true. Alright. And it's human toxicity, same as any clove oil material. But like I said, we don't know what the microbes are so we can't do a toxicity evaluation on that.
So we chose just one area. It's kind of a little blurry in this picture, but just one area of what I consider a landscape bed with landscape bed weeds. This is not a planted landscape bed, but it's just a weedy landscape bed, which we took a look at what was growing there. And primarily it's plantain, mallow and grasses. But we also had some bindweed, some sow thistle, some Scarlet Pimpernel, some Blackberry, and some cud weed. So again, a pretty good suite of what we generally find in our landscape beds, our roadsides. So, we kind of split that site down the middle. This is us mixing. And I put this picture in here just because, as you saw, it's got four parts to it. So, it's a little bit more complicated of a mix than your average mix, but it's totally doable.
Are these all packaged separately?
All package separately. Yeah. Alright, so after you've mixed all your materials together, we split the bed down the middle. One site got treated with Avenger, the other side got treated with Weed Slayer. And this is what it looked like before treatment. And this is what it looked like one week after treatment. And I did the Weed Slayer application. So, I was like, "Oh, God, what did I do wrong? This is not looking good." And my co-worker who did the Avenger treatment said, "Come on, Crista. Give it a minute. Don't freak out." So, this is week two where they're like, they're neck and neck. And this is week three. And I'm starting to feel better about my applicating skills. And this is week four. And I'm starting to think, "Oh, maybe Weed Slayer is really significantly better at getting to more parts of the plant. And this is week five. I'm still feeling that way. Jump ahead to week eight. And it really it does look better. It's hard to see in this picture, but I think I've got a little bit of growth coming back. But it really helps. This is yesterday. This is 14 weeks after the application and after some heavy rains. You can see it's not perfect, but in comparison, it's significantly better. Our applicators are really pleased with these results and are looking for harder tests on it because this is kind of a relatively easy test. This was a mowed area. It had blackberry in there so there were some really tough weeds. Yes, Chris?
I forgot to ask if you are okay if we ask questions.
Yeah, I am.
What kind of weeds were coming back?
It's mostly plantain and a little bit of blackberry, which I was a little bit surprised at. I don't really know how to explain it because there is some plantain in here that is 100 percent dead and not coming back. And there is some plantain in there that did come back. So maybe it was maybe that I under applied on some of the individual plants. I don't have a good explanation for why some of the plantain is gone and some of it is coming back.
Did you try it on poison oak?
Yes. Hold that thought.
Were you giving it 100 percent?
Yes. That was my aim.
Weed Slayer two percent, Avenger 100 percent?
No, Avenger is not...Is it? I can't remember. It's high. I didn't mix the Avenger. I don't remember.
And one other question. Was there any pH adjustment on the Avenger?
No. Ok, so hold that thought about poison oak. First, I want to show you...The other area of application that our applicators are always looking for ways to deal with are what we call sidewalk weeds, which we have a lot of sidewalks near buildings, near cars and weed whacking tends to break windows. And so, applicators are always wanting to use Roundup in this situation. And it's really one of those situations where we're like, no, we're not going to do that anymore. And so, they say, "Well, how are we going to control the weeds?" So, we tested it on what we call sidewalk weeds.
We've got fumaria area here, which you can see before and after. It did really well. We've also got some grasses and some oxalis which also-- that should say two weeks after but did really well. We bumped it up to a three percent solution, and three percent is the max on the label. But the bump up was not because we thought sidewalk weeds were going to be harder than the landscape bed weeds, but because we were doing it at the same time as we were doing a poison oak application. So, let me show you the poison oak application. It's a little hard to read here but this is poison oak plus blackberry up here and it's fully grown, woody, mature and it didn't do very well. It's pretty hard to see these pictures, but it browned it out and kind of gave it a little bit of a slowdown. But it really was not a full control. And it's kind of hard to see but maybe you can see here we've got browning on the edges of the leaves and general kind of chlorosis but I wouldn't say that is a good a good material if you really do need to remove mature poison oak. Does that answer your question?
As I expected. Are those Himalayan blackberries?
Well, maybe. Yes, probably. Actually, I'm not sure.
Because there are lots of blackberry species, but there's only one poison oak.
Yeah. It's either Himalayan or the California native, I'm honestly not sure. We've got both. Alright, so that's poison oak. Oh, I don't know why that's in there. Alright. So, this is for applicators what goes in. And we do very relatively small applications. So, I put it up per gallon of water because we tend to do it in two- or three-gallon backpack sprayers. And these are all the four parts that you've got to add to the tank. But it's not hard to do. However, it is kind of expensive if you think Avenger is expensive, look at of Weed Slayer. And this is a little high. I showed this number to another IPM Coordinator who's been using it. And when they do their calculations, it came out to like $2.95 or something for a thousand square feet. But that was how we're using it, that's our calculations. But again, like I said, we're not using it in large areas. And this is...it's the labor that is the major expense when we do sprays. And so, this is not a this doesn't knock Weed Slayer out of the running for us. It's an acceptable cost for us. And partially because we really do want to be moving away from using Roundup and toward using materials that are more acceptable to the general public who are using the park. It's their park and we want to be doing management in a way that's comfortable for the public. So that's why we're doing this. And that's all I got on the Weed Slayer. Does anybody have questions about that?
How much is it on oxalis?
So we only tested it on oxalis in a sidewalk and it did really well on oxalis in a sidewalk. We haven't tested it in like a larger landscape setting, but now we will have the chance to do it and we will test it.
Did you see whether it came back the following year?
So this was this year. We haven't had a chance to look at it the next year.
What species of oxalis? We have half a dozen.
When you order from the distributor, does it come in a bundle where all the stuff is together, because I saw Trifle on there? Or do you have to order from the different?
The distributor sold it to us as a bundle, but we could have chosen only to buy certain parts of that bundle. Like if you've got other suppliers.
And is there tolerance on the label to use another buffer?
I was wondering if there is a way you can maybe send those microbes to a company that will test them?
Yeah. Do you know of any labs who do that?
Soil food web. Yeah. I don't know. Do they. Do they do the species? I know they do like functional groups.
I'm not sure if they would.
I don't know.
And also, is there any testing of the soil to determine if the lower pH is affecting the soil?
We have not done that. My sense is that the amounts that we're putting down are not having a lasting impact. But no, we have not tested.
Yeah, thanks Christa. I was just wondering about your poison oak trial. It looked like it was a big thicket that went back. Were you just kind of spraying the edge of it as a trial?
Yeah. So, we actually had two areas where we tried it on poison oak. One was in the image and it was a large sort of like thicket. The other was a much lower, not a not a dense standard poison oak, but an area where it had been pulled and was coming back and they were much smaller, and we got the same result. So, I think that sort of the woodenness and the maturity were kind of not a good match for this material.
Do you know anything about the persistence of this in the soil?
Well, what I can say is that on the area where we did the landscape bed weeds, we also sprayed it in an area where there weren't wood chips at the front of the bed. And now that I go in and I look at the Avenger versus Weed Slayer area where there weren't wood chips, I'd see the same amount of seedlings coming up in both. So, my sense is that there is no persistence.
I know (inaudible) was trying the pH reducer with the Avenger and you had a big improvement, right?
Yeah. You treat the water first with Axe or Avenger or any of these products. But that was just the longer...from what I see here the Weed Slayer seems to be a bit longer results. You still get them back when you treat with Avenger and till things, but they still do come back.
Yeah, that's a good point. The pH reducer does seem to be key. So maybe comparing Avenger without pH to Weed Slayer with a pH reducer was not fair. But that was the way that we had been using it in the way that we intended to use Weed Slayer.
Is that area irrigated?
Yes. But mowed.
(inaudible) but I still see Roundup signs. Like the last one I saw was in August. But I am there like three or five times a month. And is this toward the elimination of everything which is (inaudible)?
It's intended to be used in any situation where it works. So, yes, it could replace other materials, not just glyphosate.
Is it planned?
Well, the plan is to give these tools to the applicators and the applicators want to be using more organic than not. So, when we give them these tools, they will use it. But we don't have a policy that says you must use this everywhere. We do have a policy about where you cannot use Roundup. So that's how we get at that. Yeah. And like I said, we did eliminate its use for several years, but have run into issues with that in that there are certain weeds that we have found we have not successfully controlled with the organic materials or with alternatives and situations where if we don't control weeds, our habitat restoration projects are going to not be able to establish that the native species. So, we've started to use some of it in those situations again.
I think it's really to see all the different stories we're hearing about Avenger. Like Cherly Willen at UC did their trials. I think they're all about the same effectiveness. The different burn downs but Avenger was by far the most expensive. And we heard from Kim Conti last month that they're hearing from other cities that Avenger was just out. It didn't work.
I know. Yeah.
And I wish someone would do a big scientific replicated study on all of this stuff.
I think it's hard because you've got so many different weed species. You've got so many different climates. There are so many variables that I do feel like it's in part a cultural...that it is site specific.
Yeah, I'm sure. And I'm really curious about the microbial thing, That's new. And I mean, yeah, I'd love to know what that is.
(Crosstalk among participants)
But I think we're all kind of wary. We have to be wary about the product claims, especially if it’s an exempt product. And we keep running into this over and over again. But seeing that eight-week photo. That's pretty cool.
Yeah. And really, you know, I'm looking for ways to convince our applicators that it's worth their time to learn how to use a new product and that really got them fired up. They really went and started to use it.
(To Luis) And you might have a new business idea.
Well Chris, one of the problems with some of these organics is because they're so easy to bring to market, they come, and they go.
And the distributors, you want to order them and then if it get in policy somewhere and then you can't get it. And so, Avenger seems like it's stood some of the test of time, that we've seen other products come and go and it's sort of frustrating on the end user part because you pushed so hard to get something. You get it listed so you can use it in a particular situation or scenario, and then you can't even get it.
My hope is that because Weed Slayer did have to like get over one of those hurdles immediately with this challenge that was brought against their label; and they did clear that hurdle, is that it's here to stay. But yeah, that's our experience as well.
Where are you buying it?
I knew you were going to ask me that.
I did find it on Amazon.
I don't remember who the current distributor was that we bought it from.
If you do find that info, I'm sure people will be interested.
Anything else, or should we move on to phytophthora?
Alright. So, I'm going to give you guys this sort of overarching phytopthera risk management in the Presidio talk that I gave at the SOD conference a couple of months ago. And I'll just say that I have done a very deep dove into phytopthera over the past five years. So, this is kind of like a sprawling tale that doesn't have like a neat beginning, middle and end. And I'm actually starting like right in the middle here. Does anybody know who this plant is?
This is the Raven's manzanita. This is an endangered species. There's only one wild individual left, and this is it. And five years ago, it crashed pretty significantly. And so, this this image shows you what it looked like four years ago. There's only one wild individual. We are tasked with maintaining it and making sure nothing bad happens to it. And then this. So that's the middle of the story. But let me just give you a little bit of information. As probably a lot of you know what the Presidio is. But just in general, who we are. We're a 1,400-acre urban national park. We have sixteen rare or endangered plant species there. One of our missions is to preserve and protect the resources there. So, preserve and protect those. There's some pictures down here that are hard to see of just a handful of the endangered species.
We've got two endangered manzanitas, the Franciscan manzanita and the Raven's manzanita. And the Presidio is divided up into three vegetation management zones. That means when you look at the Presidio as a whole, there are different ways that we manage the landscapes based on what zone we've allocated. We've got the landscape zone, which is all of the ornamental landscapes that people use for recreation or that are around the buildings there. We've got the native habitat zone, which is all the areas where we're doing restoration projects. So, taking out landfills and restoring to native vegetation, or taking out trees and restoring to native vegetation. And we've got our forest. So, all of this stands of trees we call our forest. So, we've got this tree vegetation management zones. And mostly what we do in those native zones is managed for weeds, weeding and is the primary thing that we do in those zones. However, maybe the second most common thing that we do in those zones is plant plants that come from nurseries. And here we are planting in the in the landscape management zone and in the forest management zone and in the native plant communities’ zone. And all of these plants are coming from nurseries. And our aim is to enhance the landscapes by planting plants from nurseries. And about five years ago. We had a little bit of a paradigm shift within our own nursery because we found fight off there in our nursery. And before that, I had always kind of felt like I probably top there is in our nursery. But if we find it, what are we going to do about it? How big a deal is it? And I and I changed my way of thinking after realizing just how much damage it could do to rare and endangered species and kind of realizing that the mission of our nursery is to enhance habitat restoration, not take it down. So, we really started to take fight off there as seriously in our own nursery. And our own nursery grows all of the plants that get planted into our habitat restoration projects. So, it was important for us to kind of focus and figure out how to stop growing, fight off threat in our nursery. And it was a major, major undertaking.
We totally renovated our shade house, meaning it used to have a weed cloth floor, but we put in permeable concrete to reduce, or eliminate the level of pooling under our tables. We did of a full clean of the greenhouses. We disinfected the greenhouses. We didn't stop using recycled pots, but we started sterilizing all of them in between uses.
What disinfectant chemical did you use?
We started by using bleach, which is not easy to use. It doesn't stay stable for very long and you have to keep everything submerged for a pretty long time to get what you need.
About an hour?
Yeah, which I think is a long time. So this is doing bleach, but we've since moved to starting to use steam and we can do that because we bought a boiler and we bought it kind of at first to heat up the potting mix that we use. We had it we had some trepidation going into this because we didn't want to heat it so much that we killed everything in the potting mix. So we bought a boiler that has an aerator that can kind of regulate the temperature so that when we pump steam into our potting mix, we're only getting it...we can get it to about 140, 150, 160 and not get it to the really high temperatures that it would go to if we weren't using this system. But because we have this steamer that we're using to pasteurize our soil, we can also use steam to heat our pots. It was not easy to figure out what temperature and how to do the pots. We melted pots.
Phytopthora flora is actually rather fragile. But the micro floras that you might want to preserve in the potting soil is the question. I was actually asking about the services of the buildings, on the floors. Steam sterilizing is fairly straightforward for Phytopthora, but you have all these other services it can land on that have major leaves. Their favorite habitat.
Are you asking about the...?
I was asking about what you use for disinfectant?
On the benches?
Can you switch to Lysol instead?
So, yes, the answer is yes. We've been using Lysol in a pressure washer. We don't do this disinfectant on the greenhouse. We do that once every two years or so. But, yes, we're using Lysol through a pressure washer. But we in the in the interim, when we're not doing the whole full clean, we use isopropyl alcohol, 70 percent isopropyl alcohol to disinfect benches between crops.
We had Steve Swain here two months ago and last month he was at the International (inaudible) of Plant, Test and Disease seminar in San Rafael, so I've heard a lot about it.
Yeah. Alright, so we disinfect pots, we pasteurize soil, and this is hard to see but this is a picture of two nursery staff standing inside a green dumpster, discarding plants that we've grown. And those plants were grown with love by our staff and by our volunteers. And it was really, really difficult to throw away those plants. But when we found Phytopthera we discarded the plants.
How do you find it?
How do you find it? Alright. Let me show you. Good question. Alright, so how are we going to do quality control? Now, we've done all those things. How do we know it's working? Alright, so has anybody heard of pear baiting? Yeah. So, it's the thing is the thing that we do at Presidio Nursery now. We take the hard-green pears and pears are used for finding Phytopthera because they have a very thick skin compared to most fruits and Phytopthera is a very strong pathogen. Phytopthera can make it through the skin of a pear, whereas most other pathogens cannot. So the idea is take a pear, put it in your sample, and if there's Phytopthera in that sample, presumably it will find the pear and make it through the skin and you'll be able to tell that it's there.
So here's what we do. We buy lots of green hard pears. They know us at Safeway. They know that we're going to ask, like, "Do you have a new shipment of pears? I need your hardest and your greenest pears."
Is it just a physical thing? It's just that they have a hard skin, like watermelon could you use for example?
Too thick, but yes. No, it's the fact that the pear has sugars in it. And so, it's going to be attractive to the to the pathogen. You could use an apple, but many pathogens can make it through the skin of an apple, whereas this is a harder fruit to break through. And so, if something makes it through, it's probably phytopthera.
So, Bartlett’s or Anjou?
So I like Anjou's. Other people use Bartlett’s. But my preference is Anjou, but you can't find them year-round.
Okay, so here is another fuzzy picture that I'll explain what we're doing here. So, this is the way that we do it in our nursery. We went through various ways of trying to get a sample to put a pear in. But this is where we landed. This is a very fuzzy picture of some pots of plants that are on a rack. And there's a plastic sheeting under the pots. And we've watered the plants and the water is coming off the plastic sheeting into a container. And we've got a pear floating in that container. So that's what we do. We're testing the effluent that comes through the irrigation, through the pots and collects into one bin. And so, we're essentially testing whole lots at once. We're not testing individual plants. So, we've identified the plant species that we're growing that are sort of the most likely to be infected with phytopthera and we test lots of those plants within our nursery as quality control.
So after you had your pear floating in your sample for a handful of days, you evaluate it for lesions. You need to get some good practice at this because it can get confusing, but it's totally doable. So here is a pear and so when we buy the green pears, usually they have a blemish or two on them. And because lots of pathogens can make it through blemishes, you've got to mark the areas that have blemishes. So that's why you've got all these sharp areas. Like these areas had blemishes before the test. So, if you get these lesions in areas that had blemishes before the test, that's not an indication of Phytopthera. That's probably an indication of something like Pythium. So that's not what you're looking for. This is what you're looking for. And it's a little bit, again, these are very stark differences. It's not always this easy to see, but Phytopthera will infect the pear anywhere, not just where the blemish was. And it'll be a gradient that doesn't look like...I don't how to explain it. It looks different. And you can't tell in these pictures. But this is mushy, and this is not. So that's another way to tell. So, once you do this, you kind of get good at it. But I'm never 100 percent sure. Like I can look at this and say, "Oh, my God, that's probably phytopthera but I would want confirmation and I can't tell you what species it is. So, when we get something like this on our pears, we say not phytopthera. When we get something like this on our pears, we say probably phytopthera and we send it to CDFA for confirmation, so that they can tell us which species of phytopthera it is.
Alright. So we've been testing our plants since our 2014 crop and this was the crop that initially it's kind of the light bulb went off and said, "Oh, phytopthera is a big deal, let's look for it and see what we have." We found four different species of phytopthera in our nursery. Not a huge percentage, but it was there. And this is a big deal to us. We definitely wanted to clean that up. So, we did all those improved best management practices and we've been testing since and we haven't had any phytopthera detections in our crops since then. These are great numbers. But at some point, we're going to find it. I don't think that we have 100 percent impenetrability for phytopthera, but the BMPs really are working. So, we're feeling good about our own nursery plants.
However, we also buy plants from commercial ornamental nurseries. This is a picture that I took in a commercial ornamental nursery and the BMPs are really not up to snuff. So, it's like, "OK, now we've cleaned up our own nursery, but we're bringing all these plants from other nurseries and we're planting them into the landscape zone, into the forest zone. Should we be worried about that?"
So we started testing the commercial nursery plants and so we're doing pear baiting and we're also doing this sort of off the shelf phytopthera test that is okay but it has the same problem as a pear in that, if you get a positive on it, it could be phytopthera, it could be Pythium, but you don't have that lesion and you really can't tell if it's phytopthera or Pythium, whereas on a pear you can. So, if we get a positive on this, we move on to the pear bait and see whether or not it's phytopthera or Pythium.
Anyway, so these are a number of lots tested. So, like I said, we test in big groups of plants of all the same species so that 298 is the number of lots. That's actually thousands of plants. And as of now, about 15 percent of the lots that I've tested have been infected. Earlier on, before we started figuring out which nurseries to work with, it was more like 30 percent. But look at all these species that we've detected and one of them was previously undocumented in the US. We are really are buying things that we don't want to buy from commercial nurseries, and it was like, "How are we going to deal with this?"
So we started to kind of look around and see whether or not we could identify growers who are growing in a manner that's kind of comparable to the way that our own in-house nursery is growing. So, we went to the Oregon State University suggestions for good growing practices and came up with sort of like a checklist questionnaire for growers. And we called up about 30 or 40 growers, did phone interviews, identified a handful of growers, or six or seven growers, that we thought might be worth visiting their site to confirm whether or not they are, in fact, doing these things. But it's been really hard to find growers that fall sort of in this green flag category. These BMP's are doable, but they're not standard in the nursery industry.
Alright, so given that it's been hard to find qualified growers, we thought, "how are we going to mitigate the risk that we take when we buy plants from nurseries?" So we kind of thrashed about to try to figure out how to evaluate our risk and landed on a method that I am not going to go into too deep, but out of Australia and Australia is way ahead of us in terms of dealing with phytopthera. But it's a method where you kind of take a look at the consequences of bringing in a pest and having it established and spread versus the likelihood of doing that. So, we applied this to our situation and decided that, Okay, we can kind of get a grip on likelihood of bringing phytopthera in on nursery plants very low if they're grown by our nursery and then the gradient kind of goes up all the way through. Okay, the risk goes slightly up if we're talking about a qualified grower, up again, if we're talking about plants from a standard grower that we have tested. The tests are not perfect. And then way up if we're talking about untested plants from a standard grower. And then the consequences go from minor, if you're planting these plants into a site that doesn't contain rare endangered species, or doesn't drain to such a site; and then it goes all the way up to sites that do have endangered species or that drain to sites with endangered species because phytopthera is carried on water.
Alright, so we decided that we wanted to stay in this yellow zone but wanted to avoid being in the red zone. So how are we going to do that? We came up with sort of this decision-making tree for project managers about whether or not they need to test the plants they're using in their project for phytopthera. So, if the plants are turf, turf is not a carrier of phytopthera, then you don't need to test your plants. If the plants were grown by a qualified grower, or under a qualified grow contract, meaning we're buying lots and lots of plants for paying you to grow them for us and we want you to grow them under these conditions, then you don't need to test your plants. But if that's not true, then the question is will the plants be planted in the native plant community zone? If the answer is yes, you have to test all your plants. If the answer is no, then you have to evaluate the topography of your site and determine whether or not it drains to the native plant community zone and if it does, then yes, you have to test all your plants. And if it doesn't, then no. And it's kind of a rigmarole to go through all of this. Project managers generally can't do it on their own. I'm involved in all of this and it slows down projects. I will tell you that.
So, if you do need to test your plants, then you test your plants and you have another set of decision-making processes to go through. Was phytopthera detected in the lot. No. Alright. You can plant your plants. If yes, then I have to answer these questions. Is this phytopthera three species rated A, B or Q by CDFA? So, those that they think are really significantly dangerous to agriculture or the state in general. If it gets one of those ratings by CDFA, then you have to discard the plant lot. If it doesn't get one of those ratings, we still have another question. Is it known to cause widespread die back in California native ecosystems? And that's a list that I keep based on information from folks in the habitat restoration world. If the answer is yes, then you have to discard your plants. And then the next question is, is the phytopthera species known to be present in the Presidio and that's a list I've been doing, I'll show you in a minute, a lot of what I call baseline testing in the Presidio. So, we have a list that we know are already present in the Presidio. If the answer is no, we haven't found it. Then you have to discard your plant lot. If the answer is yes, then you can plant your plants. So, we are planting some plants with phytopthera and this is against the advice of people like Mateo Gravilano and others who tell us that every introduction increases your risk of disease. So, this is something that I would like to get away from. But this is what we're currently doing.
Do you think they hybridize?
They hybridize, yeah. Okay, so like I said--this is a lot of information for you to look at. I thought I had put it up here in steps, but. Alright. I've been doing kind of baseline sampling throughout the Presidio and sampling before and after we put in plants in our landscapes. And so, if you look at this right here, this shows you 1, 2, 3, 4, 5 projects where I tested the landscape before we renovated it. And after we put in plants, tested plants from commercial nurseries. And I do not like these results at all. We tested plants and we'd come up with like 18 percent of my samples before renovation had phytopthera and 40 percent after renovation. Like, what is this? We're not getting anything with our testing, zero before renovation, 20 percent after renovation. And it's not good. There's only one site where I found less phytopthera after renovation. So, this this makes me feel like our testing is not buying us what we want it to buy us.
I only have one site where after going through the decision-making process, it was determined that we didn't need to test the plants before putting them in. And on that site, we have comparable before and after. And then here is what it looks like when we use Presidio nursery plants. We did see a reduction before and after. But any increase before and after on there. So, this is just to tell you that I don't think we have a real handle on managing phytopthera by testing plants from commercial nurseries. So that brings me back to this. I feel like all of this is not buying us what we want, but there is some room for getting better here.
So we've been focused on trying to find more qualified growers. As of right now, we only have two commercial nurseries that we've visited and have confirmed that they're growing practices meet what we need and that's Double Creek and Rana Creek and then our own nurseries. There are four nurseries throughout the GGNRA. So those are our qualified growers. And then we have a handful of growers who don't in their general practice meet all of our standards, but they're pretty close. And if we gave them instructions to do specific things differently for a contract grow, they could. So, these are growers that are authorized to do a qualified grow for us under specific best management practices that are not their standard practices.
And we've been making a real push. So, like I said, our own in her house nursery generally only grows for our habitat restoration projects. So, they generally only grow California natives, so they don't grow a lot of what our landscape architects are looking to put into our landscape zone. However, because of all this problem, we have started to collect propargyls and started to grow ornamental species within our own nurseries so that we can avoid this issue of trying to find clean plants from commercial nurseries. So, this is a big win for me.
Alright. So, let me just show you what we've found through our 2 or 3 or 4 years of what I call baseline testing. All of the dots are areas where we took a sample and tested it. And all of the red dots are where we have found phytopthera. And all those red dots are any species of phytopthera, but I'll tell you, we found about 20 different species of phytopthera in the Presidio. And so, it kind of looks like it's kind of everywhere, but maybe not in a couple places. But for those of us who have spent a lot of time in the Presidio, when we look at this map, we see like, "Oh!", and this is not going to be a surprise to but phytopthera shows up where there is water. So, the blue is where there is water and the yellow are where the soil is very sandy. So, in areas where it's very sandy, we are not finding it much. We are finding it in a couple of places. But I'm starting to think that maybe we need to look at this idea of phytopthera holding capacity of a site and think of it more like is this site vulnerable to phytopthera and not sort of across the board.
And then I just want to leave you with this image. So, this was the image that I started with the Raven's manzanita that crashed in 2016. And it's not all is lost. It definitely is not doing well but we do still have some green growth in there. It's not dead. We are going to be doing phosphate treatments on it to try to help it recover to whatever extent it can recover. But it's not dead. And then just some pictures of my interns who helped me do all this work. Whoo, whoo, for interns. And this is a graphic that my husband did for one of my interns. Alright. Any questions about phytopthera? Yeah.
Do you have a problem with (inaudible?)
Yeah. Well, so we find it and we find it in areas where we're having some trouble with plant specific species of plant establishment. But on the manzanita, it has not been cinamonas and phytopthera pseudocryptogea. But yeah, cinemoai is one of those that we would not plant in the Presidio because it has shown to be problematic in California native ecosystems.
First comment, wow, that was a huge undertaking I can't even imagine and regardless of the outcome and you're still trying to sort this out, the amount of information that you got out of this, that also I'm sure you're sharing with other is huge.
Interns. That's how it happens.
Also just to see the relationship with the CDFA and I'm curious how that relationship is going?
Yeah. I really enjoy working with CDFA. They're very, very responsive and very helpful and have been really a huge part of us trying to wrap our heads around how we want to explore this. And so, there are regulatory agency. And I have been sharing all of the results with them. And my hope is that they are able to take this information plus from everybody else and use it to add--So right now they're focused on agriculture. So that rating system really is focused on protecting agriculture in the state. And my hope is that they will fold in ecosystem restoration into that and add more phytopthera species in those A or B categories. And I think that's happening. But I would also like them to do more regulation of the nursery industry and try to get best management practices elevated to a greater extent. And they're struggling with that. They did start a voluntary kind of certification system that is similar to the checklist that I that I walk into a nursery with when I'm trying to see whether or not we're going to qualify a grower as a qualified grower.
My checklist that I use is somewhat bare bones. Like I'm really trying to meet the nursery, we're trying to meet sort of the people who are doing good best management practices where they are. Whereas I think the certification process that CDFA has, because they've been working with some really great pathologists who are really knowledgeable, and those pathologists convinced CDFA to have even higher standards. I think the nurseries are having a hard time meeting them. And so are not going in for this voluntary program. And so, I worry about that. But yes, CDFA is very interested in the information that we're generating by testing all these commercial nursery plants. And I continued to feed them and continue to talk to them to try to nudge that in that direction, because it's really the only way that we're going to be able to buy clean plants is if the nursery industry recognizes this as an issue. And I totally understand that the nursery industry--like the way they get their business is by having a lot of variety in their stock. So, growing a lot of variety and bringing in plants from other nurseries, which is problematic and then having low prices, that's how they make their sales. And this is on their radar. But it's not within their business plans. And so, I recognize that that's an issue. But if we're going to be able to buy clean plants, my sense is that we're going to end up paying more for them.
And when you test and send (inaudible) of phytopthera from a commercial nursery that falls into their agriculture phytopthera restricted today, do they respond to that?
Yeah, they responded the one that we found that had not yet been found in California. They did respond. Yeah.
What's the name of the State certification?
That's a good question. I don't know the name of it. I would have to look it up. Yeah.
Have you tried solarization?
We have looked into solarization and have done sort of like...there is an online calculator out of Oregon State University, where you can kind of plug in your weather information and your site, and we don't have we don't have the conditions for it to work, but it can work in areas where you can get more solar hours.
Yeah, we've used it.
There is an online calculator, I encourage anybody who wants to, to use it because it can work. Because we haven't been able to use it, we've brought our mobile boiler out into the field and tarped areas and tried to get the temperature of the soil at 12, 18 inches up to one hundred and forty degrees fahrenheit, and had a lot of trouble doing that. Of course, because steam moves up, not down. Right. And we've experimented with different ways to try to get it to move down. And it's just a major undertaking and uses a lot of diesel fuel and a lot of water. And while I know steam will kill it, but we don't have a good way to deliver it through the soil profile.
You know, this is probably way too big of a question, Don, but did you have any observations at how this compares with PUC's experiments and experiences?
PUC after their huge problem with phytopthera (inaudible), had to go and it costs them hundreds of thousands of dollars to remove plants and try to treat protected places. Because as a new introduction of phytopthera. And so, they have gone to direct seeding.
Yeah, I know. This is another thing that worries the nursery industry, like, "Are you trying to kill us?" "We want to stay in business."
They've established their own nursery.
Yeah. I haven't visited it. I've heard it's impressive. Yeah.
But you almost have to do direct seeing or something like that to be certain.
Yeah, like more exploration into which species do well in direct seeding and how long does it take after direct seeding to get to the size that would have been comparable if you had just planted a nursery ground plant? It does seem like there's going to be a fair amount of work in direct seeding.
You had a sign that was about testing sites before and after renovation. Was that on the testing on pear baiting?
No that's pear baiting.
Are things already in the ground?
Yeah. So what we do is we have a protocol for field sampling and the protocol is to walk into a site, survey it for the symptoms that might be indicative of phytopthera and focus on those plants for digging up roots and taking a root and a soil sample back to the lab and doing the pear baiting on that. So, we look for symptomatic plants. If we don't find them, then we go for woody plants, which tend to be more of an issue for phytopthera. So, we have a whole protocol for field sampling.
What's your process for destroying plants and if you find them in the field, do you remove them?
We don't. In the field we do not. We leave them in place. We could remove the plant, but we're not going to remove the contamination. So, in most cases, it just stays in place. And in a lot of cases, the plants are fine. But if the plants are not fine and we're replacing them, then we have tried to steam the soil, we have not been terribly successful. And so, we're just kind of moving toward trying to replant with phytopthera resistant plants because we don't have a good way to eliminate it in the field. But if we find it in a nursery plant before we planted it, we compost it.
What have you found is the best way to disinfect boots and vehicles?
Yeah, we use 70 percent isopropyl alcohol just because it's so stable and so easy to carry around in a squirt bottle. We buy a lot of it.
Do you even do vehicles, like tires?
We do tires with it, yeah. I mean, we brush off with a brush and then do tires with it. Yeah. Our standard is in the rainy season, try to stay on paved areas that you don't have to disinfect your tires. But if you do go and get mud on your tires. Yeah, isopropyl alcohol. It's been kind of expensive but because of stability and ease of use, that's what we're using.
Any other questions? Well, that's a really impressive amount of work you guys have been doing. Thank you, it helps everyone. (APPLAUSE)
We had some pilot testing of rechargeable landscape equipment. It went on with Public Works and Rec Parks, courtesy of the State Air Resources Board and their equipment trailer. First of all, thank you all for engaging in that. Those of you who are just getting into those pilot tests. We gathered the data from this, and I have mentioned this in a previous meeting, but we haven't really shown you the detailed results. But Jen Monae, who is my colleague at the farming environment, did the work on it and it makes sense to bring it to you so you see a little bit more about what people liked and what people didn't like in terms of rechargeable equipment. As you might remember, there are multiple reasons for doing this. One is, of course, we're moving away from the more hazardous herbicides and whenever possible. And often that means moving to more physical methods for certain situations. But there are risks to that, too. If you have gas fumes blowing your face all day, it's another 80 cases per million of cancer that can result from that according to CARBS numbers.
So it's something we want to move away from spewing gas fumes. You also want to have a lower greenhouse gas impact. And luckily, we have clean power here. So, when we use electricity in San Francisco, that's pretty low greenhouse gas impact. We have gravity fed water systems and so forth, for the most part. So, I just wanted to give that a little bit of context and I'll turn it over to you Jen.
Yeah, thanks Chris.
Oh, and I should say I'm sorry. I forgot to say it in front of our commission, but there are multiple other reasons why we want to move in this direction. And one of which is the people who are affected are people who are doing the work on the ground as an environmental justice issue. And so, it is especially important for that reason too, for worker health, for indigent communities, for poor people essentially. So that's part of the picture too.
So, as Chris mentioned there several issues that we're trying to address, reducing air pollution, and greenhouse gas emissions, and also ensuring that the alternatives we're using to herbicides are actually safe and effective. And so, to address them, last summer the Department of the Environment, along with Public Works and the Department of Recs and Park, got together and collaborated on this pilot program to test out the latest models of rechargeable landscaping tools.
So it's exciting because results are in. And they seem quite promising. So first of all, I wanted to thank the 25 people from Public Works and the Department of Rec and Parks who took their time to test out these products. Without them, the pilot wouldn't have been possible. They sampled six different categories of products, which included leaf blowers, edgers, chain saws, hedge trimmers, string trimmers and pull saws. And among them, there are seven different brands represented Echo, Greenworks, Makita, Oregon, Stihl, and Milwaukee.
What they did is, after testing out each product, they would fill out a survey and the survey looked at six different criteria. So, there is comfort of use of the products. The power of the product, how well the battery held out, because that is quite a concern for these battery powered products as well as safety and health issues and noise and quality of construction that did come up a couple of times. In addition to looking at these different qualities, we also asked for the different testers to give us an idea of whether they preferred the battery powered tools to their more traditional gas powered tools and to also provide us comments on any of these tools.
With the data that we got from them, we put it into charts like this. This is an example for the string trimmer. And as you can see, it's probably pretty well divided. Generally, on the top you'll see are the tools that had the best results and the bottom is really the tool that had the worst results. But you'll also notice that one minor issue with this pilot program was that even though we had twenty five participants helping us do this survey; because of the number of products that they were also testing out, a number of tools they're testing out, generally, there are only maybe a couple people who are testing each product and giving their feedback. So, you know, the sample sizes were pretty small. That said, we do feel pretty good about the results. Just given how strongly people often felt. You can see like where it's where it's been highlighted green. That represents either excellent or best possible results. And where it's been highlighted, red, we label that as not so great, which would be like a two out of five. And then worst possible, which is a one out of five, which is the worst possible.
So, even though there weren't that many results, people were quite opinionated about the products one way or another. And overall, you see that the rechargeable tools rank pretty well. In the far-right column, we asked, you know, are these better than the gas-powered versions? Basically, do you prefer these battery powered versions to their gas equivalent? And a lot of people actually said yes. Where they said no, it is interesting to see that actually, it seems to be isolated to like maybe one or two products that are quite strongly, no. Like the Oregon string trimmer, the Greenworks was not so great.
And again, I would mention that really when you look at it overall, there still seems to be mostly concerned about battery life. I also looked online to see if these were replicated issues in general and a lot of comments on these products websites do say, their main concern is the shortness of battery life. Wouldn't it be great if this product had that type of battery? A lot of feedback had to do with the battery. And at the end, I would actually be more than happy to share the results for the other product categories. I do have printouts of the summary of these results. They don't include tester's comments. But I can also share those with you if you want.
And what we did with the results after that was, we looked overall globally at the top brands that had the most number of products that came up as being preferred to the gas-powered versions. And the reason that we wanted to do this was really because we have a kind of a longer-term goal. Maybe I should mention this at the end. Well, a longer-term goal of asking you folks whether you'd be interested in creating a citywide contract for these rechargeable tools.
People seem to be really happy with them overall. Going back, if you looked at all the survey results, you'd see that in every category there are at least one or two products that do rate as better than the gas-powered equivalents. So, there are, you know, good battery powered equivalents to all of these tools available. And what we would like to know is, would you be interested in such a contract? It would allow for huge cost savings. We could invest in a certain number of types of batteries. So, for example, if we just bought these rechargeable tools from say Echo, (inaudible) and Milwaukee, then we would only use three different types of batteries that we could then share. Which has a lot of benefits. And that's where I want to open it up to you.
Yeah. Thank you, Jen. She did a lot of work to put the data together. And like, you know, like she said, that wasn't all the data you're looking at. The sheet that she showed you is just like a sample.
So just so you can see.
Yeah, there's a lot more. But it's a little overwhelming to try to look at all those tables in a room like this, right.
Yeah, exactly. It's a little too much to handle.
You know, we put out the offer to do a citywide contract, but we don't really know how you buy these things. And there might be some very good reasons why it doesn't make sense to have a citywide contract. It's certainly easy for me if you don't. But we would like to promote the technology any way that we can. And it might be helpful to understand how you do buy these sorts of products. Is it just a once every five years you go out and buy a whole bunch of equipment? Or is it a constant trickle of purchases? Is it something that's not suited for a citywide contract for some reason? Is it easier for you to pay it to a departmental purchasing mechanism? Does anyone have any?
I'd also be interested in knowing if you're not interested in a citywide contract, or in going from gas power to battery power tools, like why not? What are the sticking points?
Just so you know, for a citywide contract is where we would work with office contract administration. We kind of do the work to put the bids out with these specifications. And we would focus on the lines that you preferred to try to get the best price. And it would be a significantly better price. Not sure how much volume there is. So that's maybe one big sticking point. But these are expensive items. So that's on our side if we want to do a citywide contract. Anybody have any observations on this idea? And why it might or might not work?
If you have a citywide contract is there a certain amount of equipment that has to be purchased anyway?
No. The way it works is it goes out to bid and as part of the bid process you have to give the bidders an estimate of what the volume might be like. There is nothing that really holds you to this. And everyone knows we can't know in advance how much people are going to buy. But it's sort of standard practice in these contracts so that bidders have an idea of how low they can go with prices. If you have historical data on purchases, it's better. I mean, the bidders love that, but usually we don't when you go out to bid on these things.
And then for purchases it's still like any other purchase, like in any fiscal year we purchase within our individual’s budgets, we can get that at a lower price?
Yes, and it's actually usually it's easier if there is a citywide term contract that's already been negotiated. You know, you don't have to get any bids. And if you're one of those wonky unfortunate people who have to use the FFSP system, the accounting system in the city, it's a lot easier there too, because you just push a button and it knows that that term contract is there and the prices are already negotiated. Whereas I think with departmental purchasing effort, you would have to go have some bids if it's over $10,000 generally.
So what would be the downside?
Well, it takes some effort to put this together. If I don't see a lot of interest from the departments, I'm not going to do it. There may be there's some uncertainty. I mean, OCA, Office of Contract Administration has their own timelines on things and their own priorities. So, we may not get it when we want it. It may be a year down the road. Other disadvantages. I can't think of any other disadvantages. It is just a piece of work. And if it's the case that if there are departments who are likely to be buying a significant amount of these tools in the next couple of years, then it might make sense to do it. If not, you know, you can do it departmental.
As time goes by the tools are going to be better. The batteries are going to be better, can it be included in the contract?
It can be it can be structured any way. You can do it by brand with the percentage off list. You know that that's typically what they would do. You have to specify what they mean by list price. So that would make it more flexible for new products. We'd say we want Milwaukee string trimmer or whatever, what percentage can you give us off your list price? Something like that. This is probably not what we usually talk about.
San Francisco, we got some DeWalt backpack blowers that have two batteries, so it gives you a little bit more option, but they are a lot heavier, and less powerful. (Inaudible) evaluated the long-term battery life, but they're not real popular with the crew because they just don't last. It takes a lot longer and difficult especially on eucalyptus leaves you with this club sleeves because they like to lay down in front of a blower and they don't pop up at all with a DeWalt. Did you test any DeWalt?
We didn't no. The tools that we did tests were provided to us by the California Air Resources Board, and they have this landscaping trailer that's basically full of these battery power tools. And DeWalt wasn't part of them.
And then part of the difficult part of asking this question with this group is, I don't actually know who makes a decision to buy this stuff for the departments at this level. Matt, are you the person at Rec Parks, is it the section supervisor?
It's the section supervisor.
So they're actually more the people to ask these questions probably.
They will have a budget, or their manager will control the budget.
(Inaudible) I think it comes down to convenience of having the same battery that you're changing in tools.
Right. Well, I mean, so that kind of brings up some other possibilities. I'm just, you know, kind of thinking about citywide contracts, but there are other things that we could do with this information, which is I mean, just make sure that it gets distributed to the right people, the park section supervisors or whatever. I don't know what the equivalent would be at Public Works. So, you know, in a way, I'm not asking the right people this question about a citywide contract it sounds like.
I can say we're definitely interested in battery operated tools in general. We've got all Husqvarna stuff and I'm sure we will continue to buy the batteries size, pull saws, land trimmers.
I wonder if this might be just like this is sort of a question to put out through the department directors and they could just distribute to the right people and pose it that way. And you know, if they're not interested, that's fine.
I think we would be. Because we still need gas power stuff for certain big cuts and so on. But in general, the battery stuff is working good for us.
How do you buy them now?
Through West Coast Contractors.
Through a departmental...
So you do it under $10,000?
It's pretty much the same way for use. We use West Coast.
And that's not a problem.
Well, sometimes it is, but it's kind of like what they want.
Sometimes if you do a series of $10,000.
So we have to separate them out, so we are ordering over time.
I'm sorry and you're specifically buying battery powered tools under that contract?
We'll use the battery power devices just because of the noise. Pretty much at Public Works we use gas for different reasons. Most likely power. We're dealing with a lot (inaudible) and they are just better power-wise. But the battery powered line trimmers, they were good at night.
(Inaudible) Just as the equipment wears out, they are replacing with battery powered. There are already kind of doing it. They're not able to buy their whole suite all at once.
Sure, which you don't have to. But, you know, if that's the case, though, and they are doing smaller purchases then it's easier to do it through departmental contracts.
Would your contract be brand specific, or would it be through a reseller and you can buy multiple brands?
We would likely ask for the top brands that you all wanted for particular kinds of products. And so, to narrow down. And that way, you'll get better prices on those. So, okay. I think what I'm hearing is there's definite interest in the rechargeable technology...Kind of doing it already. the decision makers aren't really here right now. It is more the section supervisors and maybe I need to communicate through a different means to find an answer to that question. And in the meantime, I think it's really exciting that, you know, batteries have changed so much recently. And everything I look at, the amount of power in the new batteries is just incredible. And it's kind of an exciting time. All the possibilities are out there, whether it's scooters or skateboards or landscaping equipment. So, any case we will look back on this through a different channel to try to ask the question. Any other any other comments about the rechargeable equipment in general?
I don't remember what the comments were like on that. Thank you. OK, well, now we have we have a little time left over for the traditional problem-solving session. Thank you. (APPLAUSE) END TRANSCRIPT.