1 00:00:00,020 --> 00:00:02,820 Shimat Joseph: Okay, so let me introduce our first speaker. 2 00:00:03,640 --> 00:00:07,600 Shimat Joseph: Our first speaker is Dr. 3 00:00:07,840 --> 00:00:08,320 Shimat Joseph: Chris Marble. 4 00:00:08,780 --> 00:00:13,700 Shimat Joseph: Okay. Dr. Chris Marble is an associate professor of horticulture at the University of Florida, 5 00:00:13,940 --> 00:00:16,360 Shimat Joseph: Institute of Food and Agriculture Sciences, 6 00:00:17,400 --> 00:00:19,880 Shimat Joseph: Mid-Florida Research and Education Center, 7 00:00:20,060 --> 00:00:21,940 Shimat Joseph: located in Apopka, 8 00:00:22,100 --> 00:00:22,900 Shimat Joseph: Florida. 9 00:00:23,580 --> 00:00:23,820 Shimat Joseph: Okay. 10 00:00:24,420 --> 00:00:29,580 Shimat Joseph: His research and extension program focus on weed management in ornamental plants, 11 00:00:30,480 --> 00:00:33,580 Shimat Joseph: both in production and landscape plantings. 12 00:00:34,020 --> 00:00:39,520 Shimat Joseph: Major research and extension effort focus on developing and implementing new and innovative methods. 13 00:00:39,820 --> 00:00:50,840 Shimat Joseph: of weed management in nursery production and landscape plantings and understanding how production and maintenance practices influence weed growth, 14 00:00:51,400 --> 00:00:51,760 Shimat Joseph: reproduction, 15 00:00:52,120 --> 00:00:53,379 Shimat Joseph: herbicide efficacy, 16 00:00:54,360 --> 00:00:55,860 Shimat Joseph: and ornamental plant growth. 17 00:00:57,320 --> 00:00:57,800 Shimat Joseph: Dr. 18 00:00:57,960 --> 00:00:59,500 Shimat Joseph: Marble, the floor is yours. 19 00:01:00,399 --> 00:01:01,000 Chris Marble: All right. 20 00:01:01,399 --> 00:01:02,100 Chris Marble: Thank you very much. 21 00:01:02,420 --> 00:01:05,860 Chris Marble: Thank you all for attending and thank you all for inviting me. 22 00:01:06,259 --> 00:01:10,280 Chris Marble: I'm hoping that my screen looks good, sharing and everything. 23 00:01:10,680 --> 00:01:10,759 Chris Marble: Okay. 24 00:01:10,940 --> 00:01:13,360 Chris Marble: So we'll go ahead and get started. 25 00:01:13,640 --> 00:01:15,360 Chris Marble: So today I'm going to be talking about 26 00:01:16,000 --> 00:01:18,680 Chris Marble: Weed control in nurseries and greenhouses. 27 00:01:19,440 --> 00:01:19,700 Chris Marble: Mostly, 28 00:01:20,060 --> 00:01:23,080 Chris Marble: if you're focused on weed control in landscapes, 29 00:01:23,340 --> 00:01:30,800 Chris Marble: hopefully a lot of this will still apply to you as well. So the same principles and things like that. 30 00:01:31,000 --> 00:01:34,979 Chris Marble: But we'll talk about some of the latest research that I've done. 31 00:01:35,240 --> 00:01:41,479 Chris Marble: I'll go quickly through those results and then kind of how it's applicable in real-world scenarios. 32 00:01:41,900 --> 00:01:45,860 Chris Marble: because that's kind of what my program does is everything that we do, 33 00:01:46,040 --> 00:01:50,580 Chris Marble: it's very applied and focused on developing solutions for growers. 34 00:01:50,860 --> 00:01:57,080 Chris Marble: So the first thing that we are going to talk about here is non-chemical control options. 35 00:01:57,320 --> 00:02:00,960 Chris Marble: So rethinking some of those non-chemical control options. 36 00:02:01,119 --> 00:02:02,040 Chris Marble: Down in Florida, 37 00:02:02,200 --> 00:02:07,780 Chris Marble: I mean, we have a lot of people that are growing palms and different tropicals and things like that, but everybody is going to have, 38 00:02:08,000 --> 00:02:14,120 Chris Marble: you know, a few plants, whether you're doing hydrangea, which is kind of the poster child for herbicide sensitive plants, 39 00:02:14,319 --> 00:02:17,520 Chris Marble: or you're doing a lot of annual and perennials and things like that. 40 00:02:17,980 --> 00:02:20,400 Chris Marble: You can't use herbicides in those situations, 41 00:02:20,580 --> 00:02:24,020 Chris Marble: and so there are a lot of non-chemical tools that can be utilized, 42 00:02:24,360 --> 00:02:27,020 Chris Marble: whether or not you're using herbicides at all. 43 00:02:27,320 --> 00:02:32,360 Chris Marble: that can improve control and that's been a focus of my program over the last couple years. 44 00:02:33,120 --> 00:02:35,840 Chris Marble: But I do want to say this, that these non-chemical controls, 45 00:02:36,000 --> 00:02:37,360 Chris Marble: they're not an all-or-nothing tool. 46 00:02:37,600 --> 00:02:43,440 Chris Marble: So you don't have to incorporate these throughout the entire production system. 47 00:02:43,760 --> 00:02:50,700 Chris Marble: If you have a specific area that you're having more weed pressure or you can't use herbicides or you can't even use the same herbicides, 48 00:02:50,920 --> 00:02:58,620 Chris Marble: You know, maybe you have a block of plants or a specific group of species that you can only use maybe one or two herbicides on those. 49 00:02:58,780 --> 00:03:03,220 Chris Marble: You can incorporate some of these non-chemical controls to get better control there. 50 00:03:04,579 --> 00:03:09,019 Chris Marble: But all these different things should be part of an overall program, really, regardless of herbicide use. 51 00:03:09,420 --> 00:03:11,720 Chris Marble: So things like sanitation and prevention, 52 00:03:12,420 --> 00:03:12,959 Chris Marble: people are going to be, 53 00:03:13,220 --> 00:03:13,379 Chris Marble: you know, 54 00:03:13,780 --> 00:03:18,659 Chris Marble: putting those into play and that's going to be part of their program regardless of whether they're using herbicides or not. 55 00:03:19,000 --> 00:03:22,920 Chris Marble: But some of these things that I'll talk about, like rice hull mulch, for example, 56 00:03:23,220 --> 00:03:24,019 Chris Marble: which is what we've done, 57 00:03:24,260 --> 00:03:31,060 Chris Marble: the interest in that has really increased over recent years and so we've done a lot of work trying to answer some of the questions. 58 00:03:31,500 --> 00:03:32,959 Chris Marble: growers have had about that. 59 00:03:33,480 --> 00:03:36,360 Chris Marble: Hand weeding is always going to be needed and it can usually be improved. 60 00:03:36,700 --> 00:03:39,780 Chris Marble: So you think of something like hand weeding and it's pretty straightforward. 61 00:03:40,120 --> 00:03:43,540 Chris Marble: You know, you go through and you're cleaning out the plants when weeds break through. 62 00:03:44,220 --> 00:03:49,560 Chris Marble: But we actually did some research that was led by Joe Neal at North Carolina State, 63 00:03:50,329 --> 00:03:57,459 Chris Marble: where we looked at hand weeding frequency and how hand weeding practices can be altered to get better control and actually reduce labor. 64 00:03:57,920 --> 00:04:00,940 Chris Marble: We saw a 40 to 60% reduction in weeding cost. 65 00:04:01,100 --> 00:04:02,840 Chris Marble: by just weeding more frequently, 66 00:04:03,580 --> 00:04:05,620 Chris Marble: but not weeding more in terms of time. 67 00:04:05,860 --> 00:04:08,680 Chris Marble: So I'll talk about how we did that study real quick. 68 00:04:08,900 --> 00:04:12,060 Chris Marble: So this is a study that we did several years ago. 69 00:04:12,380 --> 00:04:14,920 Chris Marble: It was sponsored by the Southern IPM Center. 70 00:04:15,280 --> 00:04:20,960 Chris Marble: We had blocks of plants. So this is just what we did in Florida. We carried it out a little bit differently in North Carolina, 71 00:04:21,160 --> 00:04:24,100 Chris Marble: which is where Dr. Neal is at, and then Virginia, 72 00:04:24,760 --> 00:04:27,680 Chris Marble: which is where Jeff Derr did his studies at. 73 00:04:27,819 --> 00:04:31,560 Chris Marble: So they used different herbicide combinations and had a little bit different treatments. 74 00:04:32,180 --> 00:04:33,340 Chris Marble: This is what I did in Florida. 75 00:04:33,560 --> 00:04:36,500 Chris Marble: So we had two blocks of plants. 76 00:04:36,569 --> 00:04:43,259 Chris Marble: The two herbicides that we chose to use were Tower and Gemini, which are two commonly used pre-emergent herbicides. 77 00:04:43,370 --> 00:04:46,659 Chris Marble: And it was what was actually used at this particular nursery. 78 00:04:47,520 --> 00:04:52,560 Chris Marble: All we did was we had separate blocks of plants. We had several hundred plants in each block. 79 00:04:53,050 --> 00:04:55,420 Chris Marble: They were all treated with those herbicides. 80 00:04:55,780 --> 00:05:16,560 Chris Marble: Half of the plants were weeded every two weeks and then half weeded every eight weeks. So that's like a typical weeding schedule that you'll see in a container nursery where people are putting a herbicide out and then they don't really get weeded until it's time to reapply that herbicide. Then they go in, send people in to completely hand weed those and then reapply. 81 00:05:17,020 --> 00:05:26,480 Chris Marble: In this case, what we did was is there was scouting that was done every two weeks. If there were fairly large weeds there in those pots, those were going ahead and being pulled. 82 00:05:27,370 --> 00:05:32,520 Chris Marble: And then what we did was is over that the span, we repeated this over a 24 week period. 83 00:05:32,680 --> 00:05:33,040 Chris Marble: And then we, 84 00:05:33,560 --> 00:05:37,220 Chris Marble: every time that we weeded, we recorded the time that it took to weed those plants. 85 00:05:37,850 --> 00:05:43,040 Chris Marble: Then we also recorded biomass that we were collecting in those plants as they were being weeded. 86 00:05:43,220 --> 00:05:45,800 Chris Marble: So you would look at that and you would say, yeah, 87 00:05:46,080 --> 00:05:48,580 Chris Marble: obviously you're going to have less plants in the two-week interval. 88 00:05:49,100 --> 00:05:51,260 Chris Marble: These are, you know, almost perfectly clean. 89 00:05:51,720 --> 00:05:55,400 Chris Marble: That's because these are being weeded basically four times what these are being weeded. 90 00:05:55,660 --> 00:06:00,520 Chris Marble: That's what you see in these pots here. So this is about a five-gallon terracotta pot here. 91 00:06:01,100 --> 00:06:03,380 Chris Marble: And then the typical amount of weeds that will be pulled, 92 00:06:03,770 --> 00:06:07,380 Chris Marble: two-week interval versus 16-week interval from the blocks. 93 00:06:07,500 --> 00:06:17,100 Chris Marble: This has a terracotta pot back behind that. You just can't see it because of how large the weeds got and then how many weeds we actually pulled out. 94 00:06:17,880 --> 00:06:23,140 Chris Marble: This is what was really eye-opening here is the biomass and then the cost per acre. 95 00:06:23,620 --> 00:06:24,900 Chris Marble: So with the biomass, 96 00:06:25,090 --> 00:06:29,220 Chris Marble: you know, we're getting over a 9% reduction in weed biomass by weeding every two weeks. 97 00:06:29,840 --> 00:06:35,620 Chris Marble: Those weeds were never able to mature and they were never able to go to seed if they're being weeded every two weeks. 98 00:06:36,050 --> 00:06:41,300 Chris Marble: And so our pressure just continually decreased over the span of that study, whereas, 99 00:06:41,720 --> 00:06:43,040 Chris Marble: If we let the weeds go, 100 00:06:43,220 --> 00:06:44,280 Chris Marble: those are two, 101 00:06:44,520 --> 00:06:46,420 Chris Marble: you know, pretty effective pre-emergent herbicides, 102 00:06:46,620 --> 00:06:49,180 Chris Marble: but no herbicide is going to give you 100% control. 103 00:06:49,770 --> 00:06:51,680 Chris Marble: And so you would still have breakthroughs. 104 00:06:51,930 --> 00:06:56,300 Chris Marble: And as those breakthroughs occurred within eight weeks in Florida in the summertime, 105 00:06:56,740 --> 00:06:59,280 Chris Marble: you know, a lot of these weeds are going to be able to reproduce, 106 00:06:59,900 --> 00:07:02,140 Chris Marble: set seed, you know, some of these species. 107 00:07:02,520 --> 00:07:13,460 Chris Marble: somewhere between 10,000 to 100,000 seed on one plant, your pressure just continually increases. And so your herbicide has your margin of error gets smaller and smaller as that weed pressure gets higher. 108 00:07:13,640 --> 00:07:19,780 Chris Marble: So our cost per acre dramatically decreased and continued to decrease when they were weeded more frequently. 109 00:07:20,020 --> 00:07:20,520 Chris Marble: Overall, 110 00:07:20,960 --> 00:07:24,780 Chris Marble: the time savings on average is 66%. So in this case, 111 00:07:25,060 --> 00:07:26,160 Chris Marble: these pots were really weedy. 112 00:07:26,520 --> 00:07:29,780 Chris Marble: So we saved a lot of time by doing it every two weeks. 113 00:07:30,520 --> 00:07:36,500 Chris Marble: Across the board, I would say the average at all the different nurseries that this was done at, the savings was about 40%. 114 00:07:36,620 --> 00:07:36,980 Chris Marble: So, 115 00:07:37,400 --> 00:07:38,800 Chris Marble: some nurseries, 116 00:07:39,040 --> 00:07:40,320 Chris Marble: weeding by this method, 117 00:07:40,580 --> 00:07:44,700 Chris Marble: where you're not having to go through and if you have a little cotyledon-stage weeds there, 118 00:07:44,860 --> 00:07:47,520 Chris Marble: we didn't pull those because we know that we're going to get those. 119 00:07:47,760 --> 00:07:57,360 Chris Marble: We're going to be back around to those pots within two weeks, so we didn't have to meticulously weed every pot. We're trying to get the biggest ones out and then just leave and be done with it. 120 00:07:58,000 --> 00:07:58,140 Chris Marble: So, 121 00:07:58,320 --> 00:07:59,040 Chris Marble: some nurseries, 122 00:07:59,220 --> 00:08:03,740 Chris Marble: when they have implemented this, they're able to weed those blocks three to seven times faster. 123 00:08:04,640 --> 00:08:10,260 Chris Marble: by doing it this way. They're not spending a ton of time getting those small cotyledon-stage weeds out. 124 00:08:10,460 --> 00:08:13,840 Chris Marble: They're just getting the large ones that are going to go to seed within the next week or two. 125 00:08:14,060 --> 00:08:20,720 Chris Marble: And so we did this study, we found this, but then I started using it to when I do consulting trips for nurseries. 126 00:08:20,960 --> 00:08:23,000 Chris Marble: I do consulting all across the country, 127 00:08:23,160 --> 00:08:25,860 Chris Marble: and most of it's in Florida, just through my extension appointment, 128 00:08:26,020 --> 00:08:27,780 Chris Marble: but to develop cleanup protocols. 129 00:08:28,720 --> 00:08:35,140 Chris Marble: There's a lot of nurseries where they'll have blocks or sections of plants that have just become completely inundated with weeds. 130 00:08:35,659 --> 00:08:40,039 Chris Marble: And they're trying to figure out, you know, how to get those back under control without spending a ton of money. 131 00:08:40,820 --> 00:08:45,120 Chris Marble: And so what they can do is kind of incorporate this same methodology where you're going through, 132 00:08:45,600 --> 00:08:47,060 Chris Marble: you're just getting the big stuff out. 133 00:08:47,500 --> 00:08:51,420 Chris Marble: and then you're coming back and just continually hitting them. 134 00:08:52,200 --> 00:08:54,880 Chris Marble: Getting them weeded, getting a pre-emergent herbicide down, 135 00:08:55,080 --> 00:08:57,820 Chris Marble: see what breaks through, weed those again soon afterwards, 136 00:08:58,720 --> 00:09:02,140 Chris Marble: and just keep going until that pressure starts to drop off. 137 00:09:03,600 --> 00:09:06,060 Chris Marble: This is just the same results. 138 00:09:06,720 --> 00:09:11,399 Chris Marble: The publication where we kind of summarized all the results is frequent hand weeding saves money. 139 00:09:11,579 --> 00:09:14,519 Chris Marble: If you just Google that, that publication will come up. 140 00:09:15,110 --> 00:09:17,420 Chris Marble: The two authors on that are Barker and Neal, 141 00:09:17,949 --> 00:09:20,079 Chris Marble: and that paper came out in 2016. 142 00:09:20,529 --> 00:09:24,639 Chris Marble: But overall in Florida, 65% reduction in weeding costs. 143 00:09:24,820 --> 00:09:32,180 Chris Marble: This is kind of just an example of spurge and we've kind of come up with guides for different weed species whatever our nursery is dealing with. 144 00:09:32,720 --> 00:09:47,899 Chris Marble: We'll take some pictures and say you know this is about when we're training people will say this is about what you can leave this is what you need to pull so you know weeds that are this small like if it was spurge those could be left those aren't going to go to seed within two weeks. 145 00:09:48,120 --> 00:09:49,680 Chris Marble: If they're a few inches, 146 00:09:49,980 --> 00:09:52,279 Chris Marble: bigger than maybe a half dollar or so, 147 00:09:52,620 --> 00:09:57,680 Chris Marble: that's the ones that you need to pull. Those small ones can be left. It allows you to weave more quickly. 148 00:09:58,120 --> 00:09:59,620 Chris Marble: And they're not going to be perfect, 149 00:09:59,839 --> 00:10:01,560 Chris Marble: but perfect didn't name the game. 150 00:10:01,759 --> 00:10:05,639 Chris Marble: It's just keeping them under control and getting them back under control. 151 00:10:05,920 --> 00:10:13,000 Chris Marble: Another thing too with these cleanup protocols is that if you're weeding, you're getting them as good as you can, good enough basically, 152 00:10:13,460 --> 00:10:15,840 Chris Marble: and then putting the pre-emergent herbicide down. 153 00:10:16,220 --> 00:10:29,780 Chris Marble: But with different pre-emergent herbicides, there's been research over the past 10-15 years that we've seen that a lot of these pre-emergent herbicides that can be applied over the top of ornamentals have a lot of early post-emergence control. 154 00:10:29,960 --> 00:10:31,840 Chris Marble: So this is just a few examples. 155 00:10:32,140 --> 00:10:34,360 Chris Marble: So if spurge was the big issue that you're dealing with, 156 00:10:34,520 --> 00:10:37,300 Chris Marble: Using herbicides with dimethenamid-P, 157 00:10:37,480 --> 00:10:43,800 Chris Marble: which would be like tower and FreeHand, you can control spurge that's already emerged with those pre-emergence herbicides. 158 00:10:44,000 --> 00:10:49,680 Chris Marble: It's going to, even if you don't kill it, it's going to stun it pretty significantly where you're going to delay seed set. 159 00:10:49,920 --> 00:10:52,140 Chris Marble: And Indaziflam or Marengo, 160 00:10:52,300 --> 00:10:53,260 Chris Marble: good for Oxalis, 161 00:10:53,420 --> 00:10:56,320 Chris Marble: it'll also stunt Spurge, kill annual bluegrass. 162 00:10:56,920 --> 00:10:57,440 Chris Marble: isoxaben, 163 00:10:57,660 --> 00:11:03,720 Chris Marble: that's where most of this research was done with isoxaben because bittercress is very sensitive to that. 164 00:11:04,050 --> 00:11:09,640 Chris Marble: You can kill bittercress up to the flowering stage with a labeled rate of gallery or Gemini. 165 00:11:10,819 --> 00:11:12,259 Chris Marble: Oxadiazon, Ronstar G, 166 00:11:12,480 --> 00:11:17,399 Chris Marble: that's the old is Chipco G and a lot of other names, but artillery weed suppression. 167 00:11:18,459 --> 00:11:19,940 Chris Marble: Dimension also has some, 168 00:11:20,100 --> 00:11:21,300 Chris Marble: Oxalis, Bittercress, 169 00:11:21,940 --> 00:11:25,139 Chris Marble: and then your oxyfluorfen-containing products like OH2 and Biathlon. 170 00:11:25,500 --> 00:11:28,120 Chris Marble: A lot of different species are suppressed with those. 171 00:11:28,220 --> 00:11:29,640 Chris Marble: Just to kind of show you, 172 00:11:29,820 --> 00:11:31,140 Chris Marble: so this is Oxalis, 173 00:11:31,420 --> 00:11:35,320 Chris Marble: the two to four least days. This is four weeks after treatment with these different herbicides. 174 00:11:35,500 --> 00:11:37,920 Chris Marble: These are all label rates of these herbicides. 175 00:11:38,160 --> 00:11:40,500 Chris Marble: This is granular Marengo here. 176 00:11:41,420 --> 00:11:43,560 Chris Marble: But you can see the non-treated control group. 177 00:11:44,080 --> 00:11:46,440 Chris Marble: And then if we add gallery and dimension or dimension, 178 00:11:47,280 --> 00:11:49,460 Chris Marble: or we do a granular Marengo application, 179 00:11:50,000 --> 00:11:55,000 Chris Marble: getting almost 100% control of small Oxalis there. 180 00:11:55,600 --> 00:11:58,199 Chris Marble: This is a gallery in bittercress. 181 00:11:58,480 --> 00:12:00,899 Chris Marble: So you can see the non-treated control group. 182 00:12:01,220 --> 00:12:05,699 Chris Marble: This was bittercress at the 6th and 9th leaf state. So this is about to start flowering. 183 00:12:05,980 --> 00:12:08,660 Chris Marble: And then we add gallery and dimension together. We're getting, 184 00:12:09,180 --> 00:12:13,800 Chris Marble: you know, almost 100% post-emergence control with these two pre-emergence herbicides. 185 00:12:14,000 --> 00:12:24,380 Chris Marble: So you can see that if you were to just get those cleaned up good enough and get one of these pre-emergence down, you can take out some of those weeds that you missed while you were hand weeding. 186 00:12:24,860 --> 00:12:28,540 Chris Marble: And then Dimethenamid-P Broadstar also will have some control, 187 00:12:28,740 --> 00:12:32,700 Chris Marble: but you see FreeHand and Tower and the effect that it has on spurge. So, 188 00:12:32,900 --> 00:12:38,020 Chris Marble: Just some things to keep in mind if you're battling the weeds and you're trying to get areas back under control. 189 00:12:38,420 --> 00:12:45,700 Chris Marble: Choosing some of these pre-emergence herbicides that have some post-emergence activity can really be a good route to go down. 190 00:12:46,520 --> 00:12:51,940 Chris Marble: So the next thing that we did, we've done a lot of work with rice hulls. People are really interested in these. 191 00:12:52,720 --> 00:12:55,720 Chris Marble: They're lightweight and hydrophobic. They're easy to apply, 192 00:12:55,900 --> 00:12:58,680 Chris Marble: which is one of the big reasons that people like to use them. 193 00:12:58,920 --> 00:13:01,600 Chris Marble: And then they're very small particle sizes. 194 00:13:01,880 --> 00:13:09,720 Chris Marble: And what that does for you is that allows you to use lower depths and still get complete surface coverage of the substrate. 195 00:13:09,940 --> 00:13:16,100 Chris Marble: So this is just an example of that. So pine bark mini nuggets here. This is actually a 196 00:13:16,100 --> 00:13:18,779 Chris Marble: that screen to about everything. 197 00:13:19,069 --> 00:13:22,500 Chris Marble: I think it was like a three-quarters inch to a three-eighths inch size. 198 00:13:22,810 --> 00:13:31,440 Chris Marble: And then all the fines were removed and using that as a mulch. And then this is like a landscape pine bark mulch. And you can see that if you put these out the same depth, 199 00:13:31,980 --> 00:13:33,160 Chris Marble: these smaller particle sizes, 200 00:13:33,319 --> 00:13:34,740 Chris Marble: you're going to get complete surface coverage, 201 00:13:34,980 --> 00:13:36,779 Chris Marble: which is what you have to have for weed control. 202 00:13:36,990 --> 00:13:39,180 Chris Marble: Whereas with these larger particle sizes, 203 00:13:39,399 --> 00:13:44,660 Chris Marble: you've got to go three inches with some of these landscape mulches to get sufficient coverage. 204 00:13:44,820 --> 00:13:47,040 Chris Marble: just depending upon how big those particle sizes are. 205 00:13:47,220 --> 00:13:54,680 Chris Marble: So pine bark nuggets great for the landscape but in a container not going to be really the best choice unless it's a really large container. 206 00:13:55,080 --> 00:13:57,200 Chris Marble: Small containers it doesn't make a lot of sense. 207 00:13:57,519 --> 00:13:59,399 Chris Marble: This is definitely not a new concept. 208 00:14:00,260 --> 00:14:03,519 Chris Marble: A lot of people have done you know research with mulchages and nurseries. 209 00:14:03,820 --> 00:14:04,899 Chris Marble: Second speaker today, 210 00:14:05,140 --> 00:14:05,500 Chris Marble: Dr. 211 00:14:06,339 --> 00:14:08,680 Chris Marble: Bartley has done a lot of work with this as well. 212 00:14:09,620 --> 00:14:11,600 Chris Marble: But for rice hulls specifically, 213 00:14:12,120 --> 00:14:15,580 Chris Marble: a lot of questions kind of came up when people started to use these. 214 00:14:15,800 --> 00:14:15,940 Chris Marble: So, 215 00:14:16,380 --> 00:14:23,140 Chris Marble: number one, can you top dress your control release fertilizer on top of the rice hulls and are you going to get any suppression of growth? 216 00:14:23,420 --> 00:14:24,480 Chris Marble: Number two, 217 00:14:25,080 --> 00:14:27,460 Chris Marble: if you do have small weed seeds that have germinated, 218 00:14:27,620 --> 00:14:31,960 Chris Marble: can you still top dress those rice hulls on top or do they need to be weed-free pots? 219 00:14:32,820 --> 00:14:34,860 Chris Marble: Can they be combined with herbicides? 220 00:14:35,280 --> 00:14:35,900 Chris Marble: And then also, 221 00:14:36,540 --> 00:14:40,200 Chris Marble: most of the research that's been done with rice hulls has looked at greenhouse environments, 222 00:14:40,900 --> 00:14:42,260 Chris Marble: specifically on two species, 223 00:14:42,740 --> 00:14:43,800 Chris Marble: bittercress and oxalis. 224 00:14:44,420 --> 00:14:49,240 Chris Marble: And so people said, "I'm not going to put these in the greenhouse. 225 00:14:49,430 --> 00:14:50,200 Chris Marble: I want them outside. 226 00:14:50,480 --> 00:14:52,140 Chris Marble: How long are the rice hulls going to last? 227 00:14:52,720 --> 00:15:02,660 Chris Marble: And then how well are they going to work on these outdoor species like spurge, for example, that not a lot of people had done work with rice hulls, spurge or some of these other ones." 228 00:15:03,000 --> 00:15:04,200 Chris Marble: We stood out. 229 00:15:04,460 --> 00:15:10,120 Chris Marble: Horticulture Research Institute was great in funding some of this research as well as the National Horticulture Foundation. 230 00:15:10,950 --> 00:15:13,000 Chris Marble: So a shout out to them. 231 00:15:13,830 --> 00:15:16,560 Chris Marble: But this is some of the work we did with fertilizer placement. 232 00:15:17,190 --> 00:15:24,620 Chris Marble: And then we did see that, you know, if you top dress on top of rice hulls, especially at higher layers, you can get reductions in growth of some ornamentals. 233 00:15:24,820 --> 00:15:26,260 Chris Marble: So in this study, 234 00:15:26,430 --> 00:15:30,840 Chris Marble: we had coleus and Vitex. They were potted up into two-gallon pots. 235 00:15:31,120 --> 00:15:33,600 Chris Marble: Rice hulls were applied at zero inches, 236 00:15:33,790 --> 00:15:35,560 Chris Marble: so no rice hulls, 237 00:15:35,759 --> 00:15:37,180 Chris Marble: and then at one and two inches. 238 00:15:37,519 --> 00:15:42,620 Chris Marble: And then we had fertilizer that was either incorporated into the media or it was top dressed, 239 00:15:42,810 --> 00:15:45,319 Chris Marble: and that top dress was on top of that rice hull layer. 240 00:15:45,639 --> 00:15:48,040 Chris Marble: You can see with coleus in particular, 241 00:15:48,199 --> 00:15:56,660 Chris Marble: when the fertilizer was incorporated, we had significantly higher growth than if the rice hulls were top dressed on top, which you see right there. 242 00:15:56,920 --> 00:15:59,580 Chris Marble: Vitex, you also had a little bit of a growth difference. 243 00:16:00,200 --> 00:16:01,620 Chris Marble: It was significant, 244 00:16:01,900 --> 00:16:05,620 Chris Marble: but not as much so as with Coleus, which was a faster growing species. 245 00:16:05,960 --> 00:16:11,380 Chris Marble: Here you can see it across the board, incorporated versus top dress at all the different depths of rice hulls. 246 00:16:11,960 --> 00:16:14,260 Chris Marble: Definitely when you get into two inches, 247 00:16:14,600 --> 00:16:19,840 Chris Marble: much greater growth with the incorporation versus the top dress. 248 00:16:20,300 --> 00:16:23,060 Chris Marble: We looked into why that was kind of occurring. 249 00:16:23,380 --> 00:16:29,399 Chris Marble: Really, we didn't see a whole lot of differences with EC or how much of that fertilizer is actually releasing. 250 00:16:29,680 --> 00:16:38,060 Chris Marble: There's a lot of other things that we could have done. We just didn't have the funding to do it. So we just took EC measurements and looked at nitrogen content, 251 00:16:38,360 --> 00:16:38,519 Chris Marble: basically. 252 00:16:38,980 --> 00:16:42,680 Chris Marble: But this is basically what we saw with that top dress treatment. 253 00:16:43,019 --> 00:16:45,959 Chris Marble: We are having higher electrical conductivity, 254 00:16:46,180 --> 00:16:47,940 Chris Marble: especially in those first few weeks. 255 00:16:48,120 --> 00:16:52,519 Chris Marble: after potting and those rice hulls what they're doing is they're drying 256 00:16:52,759 --> 00:16:58,160 Chris Marble: very quickly after rainfall or irrigation and what does a control release fertilizer need to 257 00:16:58,420 --> 00:17:05,179 Chris Marble: release from its coating it needs moisture and so because it's drying out quicker you don't get the 258 00:17:05,360 --> 00:17:13,000 Chris Marble: same release rate we think we need to do some more research with that but that's just to say you know if you are using rice hulls 259 00:17:13,020 --> 00:17:14,800 Chris Marble: be mindful of this. 260 00:17:15,300 --> 00:17:17,079 Chris Marble: Fertilizer rates may need to change or, 261 00:17:17,380 --> 00:17:26,360 Chris Marble: you know, using rice hulls on shorter term plants where they can just be incorporated and you don't have to come back in and top dress on top of them because you could see reductions in growth. 262 00:17:27,069 --> 00:17:29,960 Chris Marble: Then we also looked at hand pulling prior to application. 263 00:17:31,160 --> 00:17:32,660 Chris Marble: With rice hulls, they might be applied, 264 00:17:32,820 --> 00:17:34,800 Chris Marble: you know, right at potting, which is what I recommend. 265 00:17:35,460 --> 00:17:36,080 Chris Marble: Or they could be, 266 00:17:36,380 --> 00:17:39,800 Chris Marble: you know, done with something like this where you have these rice hull blowers 267 00:17:39,820 --> 00:17:43,220 Chris Marble: that will be blown into pots after they've already been in production. 268 00:17:43,640 --> 00:17:47,420 Chris Marble: It depends upon how a nursery is set up, which one is going to make the most sense. 269 00:17:48,860 --> 00:17:50,200 Chris Marble: And be the easiest to do. 270 00:17:50,540 --> 00:17:54,480 Chris Marble: Stilt Pro has some cool rice hull blowers and things that you see in this photo here. 271 00:17:55,400 --> 00:17:59,900 Chris Marble: But we looked at this and we looked at several different weed species at different growth stages and we said, 272 00:18:00,310 --> 00:18:03,840 Chris Marble: "Okay, what happens if we just put rice hulls on top of these after they already emerged? 273 00:18:03,990 --> 00:18:08,300 Chris Marble: Is the rice hull still going to be effective on weed seeds that have emerged?" 274 00:18:08,320 --> 00:18:09,600 Chris Marble: So here we have here, 275 00:18:09,970 --> 00:18:11,660 Chris Marble: so this is eclipta and Phyllanthus. 276 00:18:12,040 --> 00:18:14,760 Chris Marble: We also had liverwort in this trial here. 277 00:18:15,690 --> 00:18:28,360 Chris Marble: But we had five plants per pot and then we basically put rice hulls on it at several different layers. So we had no rice hulls, then we put it on a quarter inch, a half inch, one and two inches. 278 00:18:28,720 --> 00:18:41,659 Chris Marble: And then we had two different stages of growth. We had Phyllanthus and eclipta at the two to four leaf stage and then also at the cotyledon stage where we just had maybe one true or two true leaves on there like you have here. 279 00:18:42,380 --> 00:18:45,659 Chris Marble: And so we found that when you get to a half inch of rice hulls, 280 00:18:45,880 --> 00:18:48,799 Chris Marble: you're definitely getting a big drop off of 281 00:18:48,800 --> 00:18:52,000 Chris Marble: the small stage of eclipta, we almost got 100% control. 282 00:18:52,620 --> 00:18:54,320 Chris Marble: When you get up to about one inch, 283 00:18:54,540 --> 00:18:58,680 Chris Marble: you're reducing the survivability of those weeds by over 95%. 284 00:18:58,880 --> 00:19:02,300 Chris Marble: And so if you were putting rice hulls out onto, 285 00:19:02,520 --> 00:19:05,560 Chris Marble: it's going to be best to do it to weed-free pots. 286 00:19:05,820 --> 00:19:08,200 Chris Marble: But if you had some small seedlings coming up, 287 00:19:08,640 --> 00:19:25,360 Chris Marble: and you were top dressing the rice hulls at at least an inch, you could go ahead and put those down and then just look for breakthroughs and see what came through that because you are going to kill a lot of those small weeds if they're not mature and large by that point. 288 00:19:25,520 --> 00:19:28,260 Chris Marble: We did this with bittercress and oxalis as well, 289 00:19:28,780 --> 00:19:35,320 Chris Marble: and we kind of saw the same thing where at that one-inch layer with those two species had basically 100% control. 290 00:19:35,580 --> 00:19:39,240 Chris Marble: None of those small weeds were able to emerge up through that rice hull layer, 291 00:19:39,460 --> 00:19:43,560 Chris Marble: if they had already germinated, which I'll show you that in just a second. 292 00:19:44,470 --> 00:19:45,640 Chris Marble: And here's cotyledon stay. 293 00:19:45,880 --> 00:19:48,680 Chris Marble: So this is just the example. So this is at two weeks. 294 00:19:49,220 --> 00:19:51,320 Chris Marble: after the rice hulls were applied, 295 00:19:51,960 --> 00:19:54,899 Chris Marble: and the survivability 296 00:19:56,299 --> 00:19:58,779 Chris Marble: decreases as rice hull depth increases. 297 00:20:00,490 --> 00:20:04,460 Chris Marble: So another question that we get a lot of times is how are they going to perform outdoors? 298 00:20:05,100 --> 00:20:07,400 Chris Marble: So in this study we had two different depths, 299 00:20:07,580 --> 00:20:08,840 Chris Marble: a half inch and one inch, 300 00:20:09,020 --> 00:20:21,340 Chris Marble: and then we had two seed placements. So we had rice hulls that were put above the mulch, that would be like if rice hulls were applied at potting, and then weed seeds were introduced on top of that mulch layer over time. 301 00:20:21,860 --> 00:20:24,540 Chris Marble: And then we had seeds that were placed below the mulch, 302 00:20:24,700 --> 00:20:33,800 Chris Marble: which might occur if the plants were potted and then rice hulls were blown in on top, you know, several weeks or months after the plants were out there in production. 303 00:20:34,080 --> 00:20:38,220 Chris Marble: And so we looked at species that hadn't really been looked at in the literature before. 304 00:20:38,560 --> 00:20:39,720 Chris Marble: Doveweed, crabgrass, 305 00:20:39,920 --> 00:20:43,560 Chris Marble: spotted spurge, eclipta, and long-stalk Phyllanthus. 306 00:20:44,980 --> 00:20:46,880 Chris Marble: Here's what we saw across the board. 307 00:20:47,080 --> 00:20:48,580 Chris Marble: This was really clear cut. 308 00:20:48,820 --> 00:20:51,600 Chris Marble: We're working on this paper now to have this out. 309 00:20:52,040 --> 00:20:55,420 Chris Marble: And this was easy to write up because the results were really clear cut. 310 00:20:55,580 --> 00:20:55,680 Chris Marble: So, 311 00:20:55,920 --> 00:20:58,940 Chris Marble: When we put the seeds on top of that rice hull layer, 312 00:20:59,180 --> 00:21:03,800 Chris Marble: we were getting 89% control of these weeds over a 12 week period. 313 00:21:04,100 --> 00:21:05,380 Chris Marble: If they were below, 314 00:21:05,580 --> 00:21:10,480 Chris Marble: in a lot of cases we had similar growth as we did in the non-mulched group. 315 00:21:10,990 --> 00:21:15,580 Chris Marble: So you can see here, so this is long-stalk Phyllanthus, no mulch, no herbicide or anything. 316 00:21:16,020 --> 00:21:37,340 Chris Marble: This is the seeds placed on top of the mulch where we're getting about a 9% reduction in weed growth and then below the mulch basically no suppression of the growth. When those weeds had already emerged like in the previous slides I went over we kind of smothered those weeds but then if they hadn't germinated yet they were able to germinate and grow up and emerge through the rice hull layer. 317 00:21:37,540 --> 00:21:42,140 Chris Marble: Same thing with doveweed, same thing with crabgrass, eclipta, 318 00:21:42,740 --> 00:21:44,280 Chris Marble: and spotted spurge. 319 00:21:44,520 --> 00:21:54,160 Chris Marble: The takeaway here was to apply the rice hulls as soon as possible because the way their mechanism of control is is they're drying quickly after rainfall or irrigation. 320 00:21:54,720 --> 00:22:02,320 Chris Marble: They're not holding much moisture at all and so it's not allowing those weed seeds to germinate. They don't have enough moisture to germinate. 321 00:22:02,670 --> 00:22:06,920 Chris Marble: And so you want to get those rice hulls on as soon as you can because if the weed seeds land on top, 322 00:22:07,220 --> 00:22:13,940 Chris Marble: you're going to have a lot better success with that as opposed to if they're already on the surface of the soil when the rice hulls are applied. 323 00:22:16,309 --> 00:22:19,179 Chris Marble: And then we looked at degradation just over time outdoors. 324 00:22:19,950 --> 00:22:25,000 Chris Marble: So after 12 months about 40% of what we applied remained. 325 00:22:25,200 --> 00:22:26,279 Chris Marble: In this case, 326 00:22:26,440 --> 00:22:28,279 Chris Marble: we had twice daily irrigation. 327 00:22:28,639 --> 00:22:29,960 Chris Marble: We did have hurricanes. 328 00:22:30,139 --> 00:22:31,860 Chris Marble: We weren't directly hit by the hurricanes, 329 00:22:32,260 --> 00:22:34,760 Chris Marble: but that was kind of an interesting thing. So, 330 00:22:35,279 --> 00:22:41,880 Chris Marble: Rice hulls, the big complaint of them outdoors is that they're going to blow out of the pots, and we have definitely seen that. They can definitely blow out of the pots. 331 00:22:42,120 --> 00:22:44,900 Chris Marble: But in these big storm events, 332 00:22:45,460 --> 00:22:46,419 Chris Marble: what comes with hurricanes? 333 00:22:46,720 --> 00:22:47,500 Chris Marble: A lot of rain. 334 00:22:47,650 --> 00:22:50,299 Chris Marble: And if those rice hulls are wet, they tend to stay put. 335 00:22:50,660 --> 00:22:57,059 Chris Marble: It's when we irrigate in the morning and then we have these strong winds in the afternoon where those rice hulls are dry. 336 00:22:57,320 --> 00:22:58,980 Chris Marble: That's when they're blowing out of those containers. 337 00:22:59,400 --> 00:23:03,860 Chris Marble: They're ideal for short term crops where herbicides can't be used. 338 00:23:04,020 --> 00:23:06,380 Chris Marble: Something that's going to finish in six to eight months. 339 00:23:06,900 --> 00:23:17,500 Chris Marble: Long term crops, I would probably opt for or recommend something like a pine bark mulch because it's going to last longer than rice hulls would. And you're not going to have the blowout and things. 340 00:23:17,820 --> 00:23:22,580 Chris Marble: But they provide a control similar to a standard pre-emergence herbicide rotation. 341 00:23:22,900 --> 00:23:30,860 Chris Marble: We just finished this work where we looked at rice hulls applied at different depths over a 12-month period and compared it to some standard pre-emergence herbicides. 342 00:23:31,040 --> 00:23:34,100 Chris Marble: They perform similarly as those pre-emergence herbicides. 343 00:23:35,420 --> 00:23:38,460 Chris Marble: up until about the 6-month mark. 344 00:23:38,910 --> 00:23:45,380 Chris Marble: Then the herbicides provided a lot better control because those rice hulls had degraded to a level where weeds were able to break through. 345 00:23:45,640 --> 00:23:52,500 Chris Marble: So this just kind of shows the degradation over time. So this is rice hulls applied at a half inch, one inches, 346 00:23:52,760 --> 00:23:53,380 Chris Marble: and two inches, 347 00:23:53,640 --> 00:23:55,460 Chris Marble: and then kind of how they broke down. 348 00:23:55,660 --> 00:24:00,160 Chris Marble: By the time we got to 12 months, we had about 40% of what we originally applied, 349 00:24:00,340 --> 00:24:00,500 Chris Marble: you know, 350 00:24:00,800 --> 00:24:01,920 Chris Marble: depending upon the starting. 351 00:24:02,480 --> 00:24:08,400 Chris Marble: So a good depth, you know, that I recommend for small containers is shoot for an inch or so. 352 00:24:08,880 --> 00:24:14,160 Chris Marble: That's a happy medium where you're getting good weed control and it's not, you're not reducing, 353 00:24:14,500 --> 00:24:18,200 Chris Marble: you know, potential root volume like you would if you went at two inches or something. 354 00:24:18,620 --> 00:24:23,340 Chris Marble: Another thing that we've looked at over recent years is substrate stratification. 355 00:24:23,720 --> 00:24:29,539 Chris Marble: This was kind of pioneered by Jeb Fields research who's at University of Florida now. 356 00:24:30,110 --> 00:24:37,120 Chris Marble: But this is basically filling containers and layers with different substrates with different particle sizes and physical properties. 357 00:24:38,320 --> 00:25:01,240 Chris Marble: Jeb came up with this concept and the idea that he had was he put really coarse mulch or coarse bark at the bottom of the container and had finer material at the top of the container and the idea was is that it would increase the water use efficiency and fertilizer efficiency by doing it that way. 358 00:25:01,700 --> 00:25:06,500 Chris Marble: You can look up a lot of his information to go into more detail on that. 359 00:25:07,320 --> 00:25:12,100 Chris Marble: We took that concept and I talked to Jeb and Jim Owen and some of the people that have worked with that. 360 00:25:12,450 --> 00:25:17,720 Chris Marble: And then we said we could probably flip this and see if there's a weed control benefit where we put a more coarse mulch. 361 00:25:17,920 --> 00:25:22,400 Chris Marble: or coarse bark on top, not coarse like a mulch would be, 362 00:25:22,560 --> 00:25:31,060 Chris Marble: but just a larger particle bark with some of those fines removed so that it's not holding as much moisture and then not have fertilizer in that very top layer. 363 00:25:31,930 --> 00:25:33,800 Chris Marble: But the ornamental that's pot into that, 364 00:25:34,000 --> 00:25:36,600 Chris Marble: you know, is still sufficient for those to root into it. 365 00:25:36,800 --> 00:25:40,300 Chris Marble: So this is the standard where it would just be a homogeneous mixture. 366 00:25:40,920 --> 00:25:45,180 Chris Marble: And this would be like a stratified version where you have coarser bark at the top. 367 00:25:45,400 --> 00:25:50,160 Chris Marble: The first two or three inches or so doesn't have any fertilizer in there. 368 00:25:51,000 --> 00:25:53,660 Chris Marble: And then the plants are potted in for larger liners. 369 00:25:53,880 --> 00:25:55,960 Chris Marble: The liner can still access those nutrients, 370 00:25:56,140 --> 00:26:00,740 Chris Marble: but then when weeds germinate, they have to grow for a while before they actually get down to the fertilizer layer. 371 00:26:01,460 --> 00:26:03,080 Chris Marble: And they don't have as much moisture. 372 00:26:03,600 --> 00:26:09,620 Chris Marble: The top part of the bark doesn't have a high enough moisture-holding capacity to support some weed species. 373 00:26:10,460 --> 00:26:12,140 Chris Marble: So we've looked at this. 374 00:26:12,440 --> 00:26:17,460 Chris Marble: I'm not going to go into the specific differences that we did in this study in terms of stratification. 375 00:26:17,800 --> 00:26:23,180 Chris Marble: It was basically different bark sizes and fertilization regimes and things. 376 00:26:23,500 --> 00:26:26,580 Chris Marble: The main thing here is that all of these stratified treatments, 377 00:26:26,880 --> 00:26:29,000 Chris Marble: liverwort will not grow on top of that. 378 00:26:29,740 --> 00:26:31,299 Chris Marble: Liverwort has to have nitrogen, 379 00:26:31,539 --> 00:26:33,260 Chris Marble: it has to have moisture to be able to grow. 380 00:26:33,779 --> 00:26:35,820 Chris Marble: Even if you sub-dress fertilizer, 381 00:26:35,980 --> 00:26:39,320 Chris Marble: liverwort won't grow on those containers. It will grow very minimally. 382 00:26:39,500 --> 00:26:40,559 Chris Marble: It might establish, 383 00:26:40,740 --> 00:26:49,320 Chris Marble: but it's not going to form a thick mat like it would if that fertilizer is incorporated or top-dressed. So stratification was excellent for liverwort control. 384 00:26:49,480 --> 00:26:53,460 Chris Marble: We had over 20 weeks perfect weed control when the substrates were stratified. 385 00:26:54,020 --> 00:26:55,060 Chris Marble: Bittercress, 386 00:26:55,280 --> 00:26:58,720 Chris Marble: not as good as liverwort, but we definitely did reduce 387 00:26:58,940 --> 00:27:04,800 Chris Marble: Bittercress growth by 40 to 60% with our stratified treatments, which you see all here 388 00:27:04,950 --> 00:27:09,380 Chris Marble: in between these two yellow lines. These are our industry standard treatments here. 389 00:27:10,760 --> 00:27:18,480 Chris Marble: And so now I'm going to get into the last part of the presentation is just some keys with developing a rotation and talk about some of the research that we're doing now. 390 00:27:18,720 --> 00:27:20,860 Chris Marble: So when you're using herbicides, 391 00:27:21,120 --> 00:27:34,180 Chris Marble: I can go and I can give a talk on all the different herbicides and efficacy charts and all those different things that we've looked at. But I try to give people the tools and say, you know, we know all these herbicides work. You have a lot of options, 392 00:27:34,420 --> 00:27:34,700 Chris Marble: but it's, 393 00:27:34,820 --> 00:27:37,900 Chris Marble: Picking the right herbicide for the job that you needed to do. 394 00:27:38,140 --> 00:27:40,980 Chris Marble: So developing a rotation is a big part of that. 395 00:27:41,280 --> 00:27:43,180 Chris Marble: When you're developing a herbicide rotation, 396 00:27:43,540 --> 00:27:46,300 Chris Marble: you want to look, use guides to see what all is labeled. 397 00:27:46,480 --> 00:27:49,920 Chris Marble: This is the 2017 Southeast Pest Management Guide. 398 00:27:50,120 --> 00:27:58,680 Chris Marble: I tell people to this particular guide because we went through all the herbicide labels and we showed, you know, what is labeled on what. 399 00:27:58,980 --> 00:28:01,940 Chris Marble: So which herbicides are labeled on which ornamental species. 400 00:28:02,200 --> 00:28:02,360 Chris Marble: So, 401 00:28:02,820 --> 00:28:07,320 Chris Marble: Just to kind of give you an example of how you can go about doing this for your own operation. 402 00:28:08,080 --> 00:28:08,480 Chris Marble: Gardenia. 403 00:28:09,680 --> 00:28:13,560 Chris Marble: When you have a F or C, that means it's labeled for use in field or container. 404 00:28:14,220 --> 00:28:22,840 Chris Marble: And so you can see all the different options that you have labeled for use in gardenia. A lot of plants that you have, or cultivars too, might not be in those labels. 405 00:28:23,380 --> 00:28:25,060 Chris Marble: So testing is always key. 406 00:28:25,420 --> 00:28:27,480 Chris Marble: And I recommend, you know, if you're using a new herbicide, 407 00:28:28,080 --> 00:28:32,100 Chris Marble: test it out on a small group of plants first and see if it's going to work for what you need it. 408 00:28:32,200 --> 00:28:33,399 Chris Marble: We do a lot of testing, 409 00:28:33,659 --> 00:28:33,860 Chris Marble: you know, 410 00:28:34,100 --> 00:28:36,720 Chris Marble: at my research and other people do this research, 411 00:28:36,960 --> 00:28:40,919 Chris Marble: but nothing, you're never going to get as good enough data as you do at your own nursery, 412 00:28:41,120 --> 00:28:41,500 Chris Marble: basically. 413 00:28:42,299 --> 00:28:47,159 Chris Marble: But then when you have all your different options, you want to kind of separate them out by mode of action group. 414 00:28:47,720 --> 00:28:48,200 Chris Marble: You know, 415 00:28:48,899 --> 00:28:51,120 Chris Marble: you have a bunch of 14 plus three combinations. 416 00:28:51,710 --> 00:28:52,840 Chris Marble: These are all good herbicides, 417 00:28:53,000 --> 00:28:58,899 Chris Marble: but they wouldn't be good rotation partners because they work very similarly and they're going to control the same general weed spectrum. 418 00:28:59,120 --> 00:29:01,360 Chris Marble: Same for these isoxaben combinations. 419 00:29:02,140 --> 00:29:03,360 Chris Marble: These are all good herbicides. 420 00:29:03,910 --> 00:29:05,980 Chris Marble: All of them really good on bittercress, for example, 421 00:29:06,140 --> 00:29:08,419 Chris Marble: but they're not going to be good rotation partners. 422 00:29:09,080 --> 00:29:19,299 Chris Marble: You just want to look at your herbicide options and make sure that you're choosing options from different mode of action groups and you're choosing ones that are effective for the weed that you have at that time as well. 423 00:29:19,720 --> 00:29:30,840 Chris Marble: So knowing which weeds you target, you can also go back to that guide, you can fix spotted spurge, and you can look and see what all is ranked as good for spotted spurge and say, "Okay, so during March, 424 00:29:31,080 --> 00:29:31,760 Chris Marble: June and July, 425 00:29:32,120 --> 00:29:32,179 Chris Marble: May, 426 00:29:32,350 --> 00:29:32,860 Chris Marble: June and July, 427 00:29:33,179 --> 00:29:35,120 Chris Marble: spurge is my number one problem, 428 00:29:35,380 --> 00:29:38,159 Chris Marble: so I have to have options." 429 00:29:37,700 --> 00:29:39,519 Chris Marble: for spurge in that time frame. 430 00:29:39,730 --> 00:29:41,620 Chris Marble: And so I could look here and I could say, okay, 431 00:29:41,960 --> 00:29:51,179 Chris Marble: FreeHand is a good option or Marengo is a good option. So I'm going to put those into my rotation at that time frame because I need those for spurge. That's my biggest issue at that time frame. 432 00:29:51,919 --> 00:30:01,220 Chris Marble: And so then you just kind of do that throughout the year. You figure out what your worst weeds are during your different time frames and then your different options that are labeled on those plants. 433 00:30:01,420 --> 00:30:04,740 Chris Marble: and you can kind of structure your rotation program that way. 434 00:30:05,480 --> 00:30:07,980 Chris Marble: So it's just kind of a piecemeal process. 435 00:30:08,820 --> 00:30:15,160 Chris Marble: This is just for using the example of gardenia, but gardenia is going to fall in line with a lot of those other ornamentals. 436 00:30:15,220 --> 00:30:17,740 Chris Marble: You can kind of look and group all those together. 437 00:30:18,060 --> 00:30:23,060 Chris Marble: Most of your woody ornamentals are going to be pretty tolerant to a wide range of these pre-emergent herbicides. 438 00:30:23,520 --> 00:30:29,400 Chris Marble: Just a quick herbicide update. Two herbicides to be on the lookout for. Two bare ground options. 439 00:30:30,200 --> 00:30:33,520 Chris Marble: StrataCor or pethoxamid is a new one that has come out. 440 00:30:33,700 --> 00:30:36,160 Chris Marble: Broadleaf grass sedge controller suppression. 441 00:30:37,040 --> 00:30:38,340 Chris Marble: That's a new SePRO product. 442 00:30:39,160 --> 00:30:40,060 Chris Marble: And then SureGuard Extra, 443 00:30:40,260 --> 00:30:43,400 Chris Marble: which is flumioxazin, they added pyroxasulfone to that. 444 00:30:43,600 --> 00:30:45,820 Chris Marble: for broadleaf grass control, 445 00:30:46,000 --> 00:30:47,280 Chris Marble: and it has a long residual. 446 00:30:48,260 --> 00:30:51,220 Chris Marble: You can see in this particular trial that we did, this is SureGuard Extra. 447 00:30:51,760 --> 00:30:55,140 Chris Marble: SureGuard is a really good herbicide, and I recommend it all the time, 448 00:30:55,320 --> 00:31:00,400 Chris Marble: but we have seen in a couple instances where we get longer control with SureGuard Extra. 449 00:31:00,500 --> 00:31:02,660 Chris Marble: So just two to keep in mind. 450 00:31:03,170 --> 00:31:09,680 Chris Marble: The latest thing that we are kind of doing now is looking at the efficiency of different herbicide application equipment. 451 00:31:10,130 --> 00:31:12,560 Chris Marble: So I'm on a nationwide grant. 452 00:31:13,240 --> 00:31:16,760 Chris Marble: It's a USDA funding grant. We call it the LEAP project. 453 00:31:17,040 --> 00:31:22,780 Chris Marble: We're looking at labor efficiency automation and labor engineering automation and production. 454 00:31:22,930 --> 00:31:24,820 Chris Marble: So we're trying to increase the 455 00:31:24,820 --> 00:31:29,580 Chris Marble: the adoption of different technologies and automation in the nursery industry. 456 00:31:30,300 --> 00:31:32,120 Chris Marble: With herbicide application practices, 457 00:31:32,340 --> 00:31:34,500 Chris Marble: there's a lot of different herbicide options available. 458 00:31:34,900 --> 00:31:39,140 Chris Marble: The bottleneck is often getting the herbicides out in time and at the correct rate. 459 00:31:39,640 --> 00:31:42,440 Chris Marble: That's typically due to labor issues. You might have weather. 460 00:31:42,800 --> 00:31:47,600 Chris Marble: A lot of people that I've talked to, they say, you know, we know what to do. We know what to apply. 461 00:31:47,780 --> 00:31:49,740 Chris Marble: It's just getting the herbicide out in time. 462 00:31:50,150 --> 00:31:52,340 Chris Marble: It takes too long to apply to the nursery, 463 00:31:52,560 --> 00:31:53,600 Chris Marble: depending upon how they're doing it. 464 00:31:54,040 --> 00:32:04,480 Chris Marble: And so we've started to look at these different forms of herbicide application equipment and what can be used to improve efficiency, basically. 465 00:32:05,200 --> 00:32:09,560 Chris Marble: Granular formulations are still the predominant formulations of herbicides. 466 00:32:09,900 --> 00:32:12,360 Chris Marble: We have more herbicide options with granules. 467 00:32:12,900 --> 00:32:18,820 Chris Marble: People are very familiar with those and then you have a good safety profile with a lot of these granular products. 468 00:32:19,360 --> 00:32:20,360 Chris Marble: Here's just an example. 469 00:32:21,180 --> 00:32:23,880 Chris Marble: The granules, you have a lot more options than you do with liquid. 470 00:32:24,060 --> 00:32:26,100 Chris Marble: These are just your over-the-top liquid options. 471 00:32:26,420 --> 00:32:33,640 Chris Marble: You have basically three mode of action groups, whereas with granulars you have many that you can do over the top. So, 472 00:32:33,800 --> 00:32:39,040 Chris Marble: but it's not going to be the most efficient way to apply herbicides in a lot of cases. 473 00:32:39,360 --> 00:32:41,000 Chris Marble: So, that's what we wanted to do. So, 474 00:32:41,240 --> 00:32:43,740 Chris Marble: with this project, I'm looking at herbicide application. 475 00:32:44,200 --> 00:32:49,760 Chris Marble: stuff we're looking at comparing the labor needed and the economics of things like, 476 00:32:49,980 --> 00:33:01,419 Chris Marble: you know, as simple as a, you know, a homemade shaker jar all the way up to a drone basically for granular applications and then for liquids from a backpack sprayer all the way up to air tech, 477 00:33:01,919 --> 00:33:10,279 Chris Marble: you know, air assisted boom sprayers like you see in this slide here. So we're trying to get baseline data and see, you know, for people that are using this different type of equipment, 478 00:33:10,919 --> 00:33:12,080 Chris Marble: what is the equipment cost? 479 00:33:12,320 --> 00:33:15,140 Chris Marble: and what is the return on investment for this type of equipment? 480 00:33:15,420 --> 00:33:21,460 Chris Marble: So if somebody invested in a huge, big capital investment of an air tech sprayer or something, 481 00:33:21,660 --> 00:33:27,020 Chris Marble: how quickly are they going to recoup that cost based upon their particular nursery infrastructure? 482 00:33:27,170 --> 00:33:29,520 Chris Marble: So that is what we are working on. 483 00:33:30,100 --> 00:33:35,520 Chris Marble: Another part of this is just looking at, say someone's just using a typical boom sprayer, 484 00:33:35,700 --> 00:33:39,380 Chris Marble: you can use a wide range of application volumes with that. 485 00:33:39,820 --> 00:33:40,620 Chris Marble: And so, 486 00:33:40,860 --> 00:33:47,100 Chris Marble: you know, some people might go very low application volume and make it more efficient, and then some people go very high because they 487 00:33:47,100 --> 00:33:51,120 Chris Marble: They feel that they get a lot better canopy penetration and coverage with that. 488 00:33:51,419 --> 00:34:07,120 Chris Marble: And so we've been looking at that. So this is basically the canopy penetration of liquid applied herbicides through different types of ornamentals at different application volumes ranging from 25 gallons per acre up to 200 gallons per acre. 489 00:34:07,420 --> 00:34:15,020 Chris Marble: And then you can see that the canopy penetration upon that initial application definitely increases as you go up higher. 490 00:34:15,200 --> 00:34:16,540 Chris Marble: And that's pretty obvious. 491 00:34:16,860 --> 00:34:19,179 Chris Marble: If you use 200 gallons of water per acre, 492 00:34:19,419 --> 00:34:24,620 Chris Marble: you're probably going to get better coverage and better application bottom than if you went at 50. 493 00:34:24,820 --> 00:34:26,340 Chris Marble: So that's pretty straightforward. 494 00:34:26,880 --> 00:34:29,120 Chris Marble: What we're doing now is we're taking this, 495 00:34:29,280 --> 00:34:31,980 Chris Marble: you know, what we actually saw on spray cards, 496 00:34:32,410 --> 00:34:37,020 Chris Marble: and then we're putting that in efficacy studies that we're looking to see following irrigation, 497 00:34:37,190 --> 00:34:40,280 Chris Marble: are we still getting the same efficacy at these lower application volumes? 498 00:34:40,620 --> 00:34:44,860 Chris Marble: So far, the early data that we've done suggests that you do have to, 499 00:34:45,180 --> 00:34:48,160 Chris Marble: if you do increase those application volume, 500 00:34:48,400 --> 00:34:52,660 Chris Marble: it's going to take a lot more time to make those applications and a lot more water, 501 00:34:52,840 --> 00:34:55,700 Chris Marble: but you're going to get improved control by doing that. 502 00:34:55,980 --> 00:35:01,100 Chris Marble: Next time I speak, I'll have some of that data available for that. 503 00:35:01,220 --> 00:35:03,960 Chris Marble: So we're doing a lot of this. We're still doing it at nurseries, 504 00:35:04,560 --> 00:35:07,740 Chris Marble: mostly in Florida, but really throughout the Southeast in the US. 505 00:35:07,970 --> 00:35:12,320 Chris Marble: So I'll be going out to Oregon to measure some different types of herbicide application equipment. 506 00:35:12,920 --> 00:35:15,500 Chris Marble: This is just kind of some of the data we've been doing. 507 00:35:16,160 --> 00:35:19,680 Chris Marble: So this is average of four nurseries that we took. 508 00:35:20,020 --> 00:35:24,820 Chris Marble: So we look at different herbicides that they're using, how much actual product they're doing, 509 00:35:25,190 --> 00:35:27,960 Chris Marble: how many employees that they're using to apply that. 510 00:35:28,200 --> 00:35:29,940 Chris Marble: How much area are they covering, you know, 511 00:35:30,099 --> 00:35:30,780 Chris Marble: per man hour, 512 00:35:30,980 --> 00:35:34,060 Chris Marble: and then the chemical cost of that application. 513 00:35:34,599 --> 00:35:36,980 Chris Marble: So in this case with a granular application, 514 00:35:37,240 --> 00:35:38,180 Chris Marble: you know, $5,500, 515 00:35:38,900 --> 00:35:40,960 Chris Marble: three employees per five hours, 516 00:35:41,200 --> 00:35:42,280 Chris Marble: so 15 man hours, 517 00:35:42,520 --> 00:35:44,640 Chris Marble: and covered 1.3 acres. 518 00:35:44,960 --> 00:35:47,060 Chris Marble: As opposed to a liquid application, 519 00:35:47,300 --> 00:35:50,500 Chris Marble: this was several different booms kind of averaged together, 520 00:35:50,740 --> 00:35:57,280 Chris Marble: but six-hour application time with one employee, and they covered 17 acres at about half of the chemical cost. So 521 00:35:57,700 --> 00:36:02,680 Chris Marble: You can definitely change a lot of these variables depending upon the type of equipment you use. 522 00:36:03,380 --> 00:36:08,660 Chris Marble: These liquid boom sprayers, and especially if you factor in the cost of the tractor, 523 00:36:08,880 --> 00:36:14,380 Chris Marble: much higher cost than a belly grinder spreader, but based upon your specific operation, 524 00:36:15,100 --> 00:36:20,400 Chris Marble: Is it going to make sense? Are you going to recoup that cost? In a lot of cases, the answer is yes. 525 00:36:20,740 --> 00:36:25,400 Chris Marble: You're going to recoup that cost pretty quickly by investing in that more efficient equipment. 526 00:36:26,080 --> 00:36:27,500 Chris Marble: We also did drones. 527 00:36:27,660 --> 00:36:33,500 Chris Marble: We've only done this at a couple places because relatively new technology where a lot of people weren't actually doing this, 528 00:36:33,680 --> 00:36:33,760 Chris Marble: but 529 00:36:34,020 --> 00:36:39,780 Chris Marble: a half an acre in three minutes with this at a 200 pound per acre application rate. So two passes, 530 00:36:39,990 --> 00:36:42,840 Chris Marble: putting 100 pounds in the hopper there with that drone, 531 00:36:43,040 --> 00:36:46,360 Chris Marble: and then a very efficient type of application. 532 00:36:47,240 --> 00:36:56,180 Chris Marble: So I say all that to say this, I still need collaborators. I'm still interested in speaking to people on this and taking this baseline data. 533 00:36:56,520 --> 00:37:04,400 Chris Marble: allow me to come during normally scheduled herbicide applications. 534 00:37:04,950 --> 00:37:10,280 Chris Marble: All I do is for liquids, I'll measure how much area is being treated, 535 00:37:10,560 --> 00:37:13,540 Chris Marble: put some spray cards out basically, 536 00:37:13,800 --> 00:37:17,060 Chris Marble: area treated in the amount of time, the pot size species. 537 00:37:17,600 --> 00:37:18,740 Chris Marble: accuracy of that. 538 00:37:19,310 --> 00:37:20,860 Chris Marble: I share all that with you too. 539 00:37:21,030 --> 00:37:23,620 Chris Marble: I don't publish anything without the grower's permission. 540 00:37:23,920 --> 00:37:27,520 Chris Marble: I don't put any kind of personal or business identifiers on any of this. 541 00:37:27,680 --> 00:37:29,960 Chris Marble: It's just nursery one, two, three, four, five, 542 00:37:30,320 --> 00:37:30,480 Chris Marble: etc. 543 00:37:30,880 --> 00:37:38,800 Chris Marble: But it's, you know, the more data that we can get, the better information that we can develop to give to other growers to help everybody improve, 544 00:37:38,960 --> 00:37:39,240 Chris Marble: basically. 545 00:37:39,620 --> 00:37:44,180 Chris Marble: "Rise and Tide Lifts All Ships" is kind of the motto there. 546 00:37:44,780 --> 00:37:50,540 Chris Marble: Kind of as a thank you for people that allow me to come out if they're interested and I haven't done this for them before. 547 00:37:50,900 --> 00:37:54,380 Chris Marble: I do come up with, I can come up with herbicide plans for people. 548 00:37:54,620 --> 00:38:00,260 Chris Marble: I've done this for several different people where they'll give me their crop list. I tell them what all is labeled. 549 00:38:00,620 --> 00:38:04,640 Chris Marble: and then come up with a treatment plan or some options that they could follow. 550 00:38:04,840 --> 00:38:12,120 Chris Marble: Whether they want to do a liquid program or granular or combination based upon the weed species that they have and the plants that they're growing. Because, 551 00:38:12,320 --> 00:38:13,580 Chris Marble: you know, I can give, 552 00:38:13,780 --> 00:38:16,160 Chris Marble: you know, examples of rotations and say, 553 00:38:16,320 --> 00:38:17,580 Chris Marble: you know, this is an example of rotation. 554 00:38:17,800 --> 00:38:19,280 Chris Marble: People were going to take that and they say, 555 00:38:19,740 --> 00:38:22,980 Chris Marble: this is the rotation that Chris said, you know, will work. 556 00:38:23,220 --> 00:38:29,740 Chris Marble: The stuff that I show on my slides, it could be the best rotation that you've ever used in your nursery. It could be horrible. 557 00:38:31,140 --> 00:38:40,740 Chris Marble: I've never used the same rotation for any two nurseries that I've ever consulted with or done a farm visit with. Everything is very specific to that particular operation. 558 00:38:40,980 --> 00:38:44,220 Chris Marble: There's a lot of nuance and different factors that have to go into that. 559 00:38:44,400 --> 00:38:51,599 Chris Marble: So just showing you an example of what I've done for people that have helped us out with collecting this type of data. 560 00:38:52,020 --> 00:38:54,460 Chris Marble: I also want to point out that we do offer, 561 00:38:54,620 --> 00:38:56,000 Chris Marble: we have several greenhouse 562 00:38:56,320 --> 00:38:57,860 Chris Marble: training courses at University of Florida. 563 00:38:58,280 --> 00:39:00,240 Chris Marble: I have one on weed management. 564 00:39:00,540 --> 00:39:03,760 Chris Marble: Every year I do mine about the fall to winter time frame, 565 00:39:04,040 --> 00:39:08,600 Chris Marble: but it's a four week course where I do eight different lessons. 566 00:39:08,880 --> 00:39:10,380 Chris Marble: So there's two lessons per week. 567 00:39:10,700 --> 00:39:15,220 Chris Marble: And I try to cover all different aspects of weed control and nursery production in greenhouses. 568 00:39:15,620 --> 00:39:23,240 Chris Marble: and give people the tools that they need to manage weeds more effectively and develop a program for their specific operation. 569 00:39:23,600 --> 00:39:37,300 Chris Marble: And it's offered in English and Spanish as well. So if you had Spanish speaking employees, they could take the course and we can provide all kinds of course support and answer questions and all that in Spanish as well as English. 570 00:39:37,500 --> 00:39:39,040 Chris Marble: That's all that I have. 571 00:39:39,220 --> 00:39:44,380 Chris Marble: If you're interested in learning anything more about the research that we're doing or if I can help you with anything, 572 00:39:44,700 --> 00:39:46,120 Chris Marble: feel free to reach out, 573 00:39:46,280 --> 00:39:47,720 Chris Marble: email my mobile. 574 00:39:47,880 --> 00:39:50,900 Chris Marble: That's my personal mobile phone. I give it out to everybody. 575 00:39:51,220 --> 00:39:53,480 Chris Marble: Feel free to call it or text it if I can ever help. 576 00:39:53,620 --> 00:39:54,560 Chris Marble: with anything. 577 00:39:55,140 --> 00:40:03,780 Chris Marble: Another thing that I want to point out too is with the LEAP project is we're looking for people that are still using manual irrigation, 578 00:40:04,060 --> 00:40:05,240 Chris Marble: turning valves on and off. 579 00:40:05,420 --> 00:40:10,000 Chris Marble: We're looking for people to work with to 580 00:40:11,320 --> 00:40:14,860 Chris Marble: and why people are doing that or if they've looked at different 581 00:40:15,000 --> 00:40:18,480 Chris Marble: technologies that didn't work for them in terms of irrigation controllers and stuff. 582 00:40:18,480 --> 00:40:25,640 Chris Marble: So point that out as well. But thanks to the people that sponsored a lot of the research that I shared in the talk, Horticultural Research Institute, 583 00:40:25,830 --> 00:40:33,520 Chris Marble: and then the Specialty Crop Research Initiative as well. So with that, hopefully I have time to answer any questions that anyone has. 584 00:40:33,700 --> 00:40:38,540 Chris Marble: But I really appreciate your time and attention and for the opportunity to speak today. 585 00:40:40,360 --> 00:40:41,320 Shimat Joseph: Thank you so much, 586 00:40:42,120 --> 00:40:44,100 Shimat Joseph: Dr. Marble, on these topics. 587 00:40:44,480 --> 00:40:46,400 Shimat Joseph: It's the idea of topics you discussed today. 588 00:40:46,960 --> 00:40:57,460 Shimat Joseph: I think this is time for any questions you may have. You can use the Q&A box there and type your question, and I can ask Dr. 589 00:40:57,640 --> 00:41:01,380 Shimat Joseph: Marble, and that worked out very well in the past. 590 00:41:02,460 --> 00:41:03,000 Shimat Joseph: Thank you. 591 00:41:03,620 --> 00:41:08,020 Shimat Joseph: Since we are waiting for questions, maybe let me start with one question. 592 00:41:08,700 --> 00:41:11,840 Shimat Joseph: So you showed in one of your data, 593 00:41:12,100 --> 00:41:17,940 Shimat Joseph: excellent picture that showed where you put some coarse substrate on the top and the finer one on the bottom. 594 00:41:18,240 --> 00:41:22,540 Shimat Joseph: Very interesting that you're seeing a lot of very good weed control, 595 00:41:22,920 --> 00:41:24,480 Shimat Joseph: especially some species that you indicated, 596 00:41:24,660 --> 00:41:24,800 Shimat Joseph: right? 597 00:41:25,200 --> 00:41:31,240 Shimat Joseph: So how does that translate into temperature in the pot in that particular arrangement? 598 00:41:31,839 --> 00:41:35,060 Chris Marble: So I haven't looked at temperatures with that. 599 00:41:35,950 --> 00:41:41,180 Chris Marble: So like when Jeb is doing his, he has seen cooler temperatures in the pot because 600 00:41:41,520 --> 00:41:42,340 Chris Marble: He is basically, 601 00:41:42,920 --> 00:41:45,160 Chris Marble: I'm not going to describe it better, 602 00:41:45,320 --> 00:41:47,760 Chris Marble: so somebody can just go and look at Jeb's research. 603 00:41:47,980 --> 00:41:50,340 Chris Marble: He's the substrate guru and everything. 604 00:41:50,720 --> 00:41:54,660 Chris Marble: So Jeb Fields, you can look up that information for anybody that's interested in that, 605 00:41:54,820 --> 00:41:57,820 Chris Marble: but he has seen cooler temperatures with the way he's doing it. 606 00:41:57,900 --> 00:41:59,220 Chris Marble: But for what we're doing, 607 00:41:59,390 --> 00:42:03,099 Chris Marble: we're just using it in the top, you know, two or three inches of that container, 608 00:42:03,260 --> 00:42:08,359 Chris Marble: like for a one gallon pot. So it's not a significant amount of that, of the entire pot. 609 00:42:08,819 --> 00:42:11,279 Chris Marble: So we're not really decreasing the temperature at all. 610 00:42:11,809 --> 00:42:14,299 Chris Marble: I would imagine it's not really increasing it either. 611 00:42:14,559 --> 00:42:16,119 Chris Marble: But we haven't looked at that closely, 612 00:42:16,319 --> 00:42:16,539 Chris Marble: but, 613 00:42:16,859 --> 00:42:19,440 Chris Marble: you know, 80% of that, that sub, 614 00:42:19,640 --> 00:42:19,819 Chris Marble: that, 615 00:42:20,200 --> 00:42:26,420 Chris Marble: substrate in that pot is going to be just like a typical pot would be. So I doubt there's much impact on temperature. 616 00:42:26,880 --> 00:42:29,540 Chris Marble: I don't think it's providing a benefit from that standpoint. 617 00:42:29,869 --> 00:42:30,000 Chris Marble: So. 618 00:42:31,480 --> 00:42:31,920 Shimat Joseph: Sure. 619 00:42:32,079 --> 00:42:35,260 Shimat Joseph: For definitely there is a moisture playing a big role, 620 00:42:35,460 --> 00:42:35,619 Shimat Joseph: right? 621 00:42:36,119 --> 00:42:38,400 Shimat Joseph: You know, less moisture in the top makes sense. 622 00:42:39,420 --> 00:42:39,500 Shimat Joseph: Yeah. 623 00:42:41,260 --> 00:42:42,780 Shimat Joseph: Any questions you have, 624 00:42:43,520 --> 00:42:45,000 Shimat Joseph: please type it. 625 00:42:45,520 --> 00:42:48,280 Shimat Joseph: Sometimes you need some time to think about it. 626 00:42:48,800 --> 00:42:50,880 Shimat Joseph: Digest because a lot of information was thrown at you. 627 00:42:51,820 --> 00:42:52,300 Chris Marble: Yeah, 628 00:42:52,900 --> 00:42:58,560 Chris Marble: and feel free to anybody you can read. If you think of something at some point, feel free to email me. 629 00:42:59,300 --> 00:43:01,240 Chris Marble: If you weren't able to write it down when I had the slide, 630 00:43:01,480 --> 00:43:06,180 Chris Marble: you can Google Chris Marble UF IFAS and my contact information will come up. 631 00:43:06,500 --> 00:43:06,700 Shimat Joseph: Right, 632 00:43:06,960 --> 00:43:07,079 Shimat Joseph: right. 633 00:43:07,240 --> 00:43:10,619 Shimat Joseph: Let's wait for one more minute and see if there is any questions there. 634 00:43:11,140 --> 00:43:11,880 Shimat Joseph: If not, 635 00:43:12,039 --> 00:43:15,619 Shimat Joseph: you know, we'll take a break and we'll come back at four. 636 00:43:16,559 --> 00:43:17,599 Shimat Joseph: That's what you're going to do. 637 00:43:17,799 --> 00:43:17,940 Shimat Joseph: Okay. 638 00:43:18,579 --> 00:43:22,359 Shimat Joseph: So let's take one minute and see if anybody has any more questions. 639 00:43:23,380 --> 00:43:24,859 Shimat Joseph: And you'll go from there. 640 00:43:26,320 --> 00:43:27,680 Paul Bartley: I got a comment for you, Chris. 641 00:43:28,500 --> 00:43:28,620 Chris Marble: Okay. 642 00:43:28,960 --> 00:43:39,100 Paul Bartley: Some of the work you pointed out from my time in my master's work with Charles Gillum, we had way better weed control when the weed seed was under the wood and bark mulch. 643 00:43:39,980 --> 00:43:43,620 Paul Bartley: And you had much better weed control when it was above the rice hulls. 644 00:43:43,840 --> 00:43:44,240 Chris Marble: Yeah. 645 00:43:44,640 --> 00:43:46,300 Paul Bartley: So it's just not a great... 646 00:43:49,440 --> 00:43:50,480 Chris Marble: The weight. 647 00:43:50,800 --> 00:43:53,680 Chris Marble: Your mulch was a lot heavier than the rice hulls. 648 00:43:53,900 --> 00:43:57,200 Chris Marble: We've seen the same thing with wood chips and stuff like that. 649 00:43:57,660 --> 00:44:00,980 Chris Marble: We've seen, when we did, especially like shredded, 650 00:44:01,180 --> 00:44:06,900 Chris Marble: I forgot what all y'all had in y'alls, but we did work with shredded melaleuca, 651 00:44:07,060 --> 00:44:08,020 Chris Marble: for example, which is, 652 00:44:08,300 --> 00:44:09,920 Chris Marble: they call it flora mulch down here. 653 00:44:10,800 --> 00:44:12,640 Chris Marble: It's like a shredded wood mulch. 654 00:44:12,720 --> 00:44:14,820 Chris Marble: Weeds will germinate on top of that. 655 00:44:15,060 --> 00:44:25,320 Chris Marble: It's just, it holds a lot of moisture and then it's able to germinate. But the rice hulls are so lightweight that it's not providing any kind of physical barrier to emergence. 656 00:44:25,760 --> 00:44:29,900 Chris Marble: We smothered some of them when they had already germinated like in those studies. 657 00:44:30,200 --> 00:44:35,000 Chris Marble: But wood and bark and those heavier mulches provide a much better physical barrier to 658 00:44:35,000 --> 00:44:37,400 Chris Marble: to emergents than the rice hulls do. 659 00:44:38,080 --> 00:44:44,180 Chris Marble: Rice hulls are basically working just by reducing the available moisture within that layer. 660 00:44:44,400 --> 00:44:46,520 Chris Marble: I just thought that was a fascinating interaction. 661 00:44:46,760 --> 00:44:58,820 Chris Marble: Great info to distinguish between different mulches and how they work more efficiently. They all have different mechanisms of control and so yeah what works for one doesn't necessarily work for another one. 662 00:44:59,420 --> 00:45:00,200 Shimat Joseph: Okay. 663 00:45:01,140 --> 00:45:02,500 Shimat Joseph: So it looks like we don't have any questions. 664 00:45:03,559 --> 00:45:04,640 Shimat Joseph: So thank you so much, 665 00:45:04,980 --> 00:45:05,039 Shimat Joseph: Chris, 666 00:45:05,460 --> 00:45:06,020 Shimat Joseph: for the talk. 667 00:45:06,279 --> 00:45:10,140 Shimat Joseph: And I really appreciate your time and everything. 668 00:45:10,579 --> 00:45:12,180 Chris Marble: Yeah, thank you for having me. 669 00:45:12,460 --> 00:45:12,940 Chris Marble: Yeah, 670 00:45:13,119 --> 00:45:13,420 Shimat Joseph: thank you.