Attaining Efficacy, Crop Safety, and Sustainability in Cropping Systems: What’s New in the Weed Management Toolbox?
Kanissery's presentation will cover novel and alternative approaches for tackling a problem that has troubled crop production forever – weeds. From weed identification apps to herbicide spraying robots, weed management has advanced rapidly in adopting new technologies in the last few decades. He will discuss innovative tools such as precision herbicide placement, steam application, etc., as weed control strategies in citrus orchards and vegetable production systems.
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[00:00:00.780]The following presentation
[00:00:02.250]is part of the Agronomy and Horticulture Seminar series
[00:00:05.850]at the University of Nebraska, Lincoln.
[00:00:08.790]Okay, good afternoon everyone.
[00:00:10.590]Thank you very much for joining us today
[00:00:12.270]for the seminar of Dr. Ramdas Kanissery.
[00:00:17.240]It is my honor to introduce him.
[00:00:20.926]Dr. Kanissery completed his PhD from University of Illinois
[00:00:26.100]and then he was working as a chemist in one private company
[00:00:30.270]in Maryland for a little while.
[00:00:32.850]And then he joined University of Florida
[00:00:35.940]as a weed science faculty assistant professor.
[00:00:41.340]And now his position is located at Southwest Florida
[00:00:45.450]Research and Education Center which is in Immokalee,
[00:00:49.494]a very nice growing area for vegetable crops
[00:00:52.230]and some fruit crops, particularly,
[00:00:55.050]this area is well known for palmetto production.
[00:00:58.260]About 85% of palmetto in the United States
[00:01:02.220]is being actually produced in that Immokalee area.
[00:01:06.030]Lot of vegetables and fruit production in that area,
[00:01:11.820]He has been there for last five years
[00:01:15.960]and he is affiliated with Department of Horticulture
[00:01:19.440]on main campus of Gainesville,
[00:01:21.990]but his position is located at one of the off campus
[00:01:26.640]research stations in the University of Florida system.
[00:01:32.130]He has research and extension appointment,
[00:01:35.700]so his research activities are primarily focused
[00:01:39.000]on finding out chemical and non-chemical
[00:01:41.970]weed management solutions in vegetable crops
[00:01:45.270]as well as in Florida citrus.
[00:01:48.833]Florida is the place where majority of citrus
[00:01:52.290]is being produced.
[00:01:54.630]I was also working with University of Florida
[00:01:56.850]for one and a half year as a post doctoral fellow,
[00:02:00.450]and at that time Florida had about 600,000 acres
[00:02:04.290]of citrus production.
[00:02:06.600]Now it's not been that much because of some disease issues,
[00:02:10.950]particularly HLB and citrus canker
[00:02:17.550]and citrus greening are major disease problems
[00:02:22.320]in Florida citrus production.
[00:02:23.850]And because of that, citrus production has been declined,
[00:02:27.330]but there is still,
[00:02:29.280]I think about 400,000 acres of citrus
[00:02:32.520]is still being produced
[00:02:33.870]and there is always need for weed management in citrus.
[00:02:39.780]Dr. Ramdas has really developed a very visible
[00:02:43.590]and active research and extension program
[00:02:45.960]focusing on weed management.
[00:02:47.520]And he has lot of clientele in that area
[00:02:51.600]as well as in other part of the state
[00:02:53.940]because Florida is the state
[00:02:56.430]which has lot of crop diversity.
[00:02:58.680]They produce lot of vegetables and other fruit crops,
[00:03:04.140]so this is extremely important position
[00:03:06.570]and I will let him to speak about his research program
[00:03:10.920]focusing on weed management
[00:03:12.930]in vegetable and citrus production.
[00:03:17.220]Thank you Amit for that very nice introduction.
[00:03:21.300]Usually I get introduced as, I mean,
[00:03:23.670]maybe all the weed scientist says,
[00:03:25.507]"This is the guy who heal plants for a living",
[00:03:28.440]but this is much better than that.
[00:03:32.730]What I'm gonna go do today,
[00:03:34.740]I'm gonna talk about some of the tools,
[00:03:38.310]novel and innovative approaches or tools
[00:03:41.760]in the weed management toolbox we are trying or evaluating
[00:03:45.480]and see how we can fit that into a horticulture production
[00:03:49.380]system in the Florida and learn lessons
[00:03:52.680]from it so that we can go into larger scale.
[00:03:55.600]Okay, so small projects or experiments to enhance efficacy,
[00:04:00.000]sustainability and crop safety.
[00:04:02.100]Some of the innovative or novel approaches
[00:04:04.530]based on some of student projects or small projects,
[00:04:07.860]small baby steps we are doing back in Florida.
[00:04:12.692]So Amit already mentioned this,
[00:04:15.450]I come from Southwest Florida.
[00:04:20.040]I mean, it was in the news these days
[00:04:22.320]because of Hurricane Ian for all wrong reasons,
[00:04:25.410]but there are a lot of exciting things happening there.
[00:04:28.710]We have beautiful beaches, endless summer,
[00:04:31.830]and it's a major production hub for citrus,
[00:04:36.480]not only in the state but also in the whole country, right?
[00:04:41.010]So we call this as citrus production belt in Florida,
[00:04:47.502]This is a video.
[00:04:49.110]I'm gonna take you on a trip
[00:04:51.840]to some of the parts of Southwest Florida.
[00:04:53.460]You'll be seeing a lot of new planting these days
[00:04:56.250]because we've already mentioned
[00:04:57.930]that the citrus is being demolished
[00:05:01.650]by a devastating disease known as citrus greening.
[00:05:05.640]And it's causing a lot of pre-decline,
[00:05:09.630]taking down a lot of trees,
[00:05:10.530]so we are also pushing the mature trees
[00:05:12.570]because it's not productive, so they're replanting them.
[00:05:17.580]And you might also see this,
[00:05:18.413]these are mature trees where you can see
[00:05:19.980]a lot of nice oranges.
[00:05:23.010]This is a picture of a citrus tree I took
[00:05:26.520]just a week before Ian, the hurricane.
[00:05:29.790]This is from one of our trial.
[00:05:32.160]You can see nice oranges starting to ripe on that.
[00:05:37.020]And this is the picture after Ian,
[00:05:39.000]all the fruits are on the ground.
[00:05:41.250]Not only this area,
[00:05:42.840]but the whole citrus belt in Florida,
[00:05:45.510]already suffering from disease,
[00:05:46.950]but now, another rank in the form of a hurricane.
[00:05:52.380]What this means to us, no yield data for me,
[00:05:54.900]but again, it's a very difficult situation.
[00:05:58.600](audience member faintly speaking)
[00:06:01.590]Yes, these oranges are cultivars
[00:06:04.140]mainly used for juice production
[00:06:06.240]versus California oranges are used for fresh fruit, right.
[00:06:11.820]Yeah, there will be scarcity for juice.
[00:06:15.690]Now I'm gonna talk about the weed management in citrus.
[00:06:19.680]Typically if you are, I mean,
[00:06:23.340]if you're unfamiliar with citrus production,
[00:06:25.560]we like to keep the under tree area or under canopy area
[00:06:28.800]weed free as you can see in the left
[00:06:31.440]and on the right is a weed citrus tree row.
[00:06:33.303]In the middle area between the tree rows,
[00:06:36.210]we like to keep some vegetation to keep the soil in place,
[00:06:39.720]to keep it from eroding from wind or water, right?
[00:06:43.800]This is a typical weed management system
[00:06:46.350]going on in citrus.
[00:06:48.630]This is a very clean, well managed,
[00:06:51.150]under tree area in citrus,
[00:06:53.970]the same location I photographed in about 30 days.
[00:06:58.020]You can see the weeds are coming up.
[00:06:59.610]It's thriving because growers are doing
[00:07:01.870]a lot of mitigation into the tree rows,
[00:07:03.840]a lot of fertilizers are putting out
[00:07:05.970]because basically we need to spoon feed the citrus
[00:07:08.910]to set off the effects of this disease.
[00:07:12.870]Whatever we do to boost the trees
[00:07:15.600]are gonna boost the weeds as well.
[00:07:17.910]Weed management is a major challenge
[00:07:20.610]for the producers in the area.
[00:07:23.148]Not only just weeds come up,
[00:07:25.740]we get a lot of surprises as well.
[00:07:27.177]For example, the same tree row,
[00:07:29.490]it has a lot of Spanish needle,
[00:07:31.560]the same tree row when I pictured in the next season,
[00:07:33.780]it's a new set of weed pressure now.
[00:07:36.570]The soil is enriched with a lot of weed seeds,
[00:07:40.230]we call it seed bank.
[00:07:42.150]This has that seed bank and from time to time,
[00:07:45.030]different types of weeds come up.
[00:07:46.980]It's not a weed monoculture going on there.
[00:07:49.086]I always say there is no dull day
[00:07:50.610]in the life of a weed scientist in Florida,
[00:07:52.620]because you get new weeds every season.
[00:07:54.300]And see even with other weather events
[00:07:56.160]like hurricanes or storm,
[00:07:57.870]again, you know, stimulate new species emergence
[00:08:01.440]and things like that.
[00:08:02.460]Weed management is a major challenge
[00:08:05.490]and growers are trying to cope up with the HLB
[00:08:09.240]or the citrus greening disease at the same time,
[00:08:11.430]trying to fight weeds to get the productivity going on.
[00:08:14.940]That's about citrus.
[00:08:16.440]And again, many of you may not know this,
[00:08:18.840]but Southwest Florida is a major hub
[00:08:20.580]for vegetable production.
[00:08:21.960]Also, like 70,000 acres are currently
[00:08:24.510]under vegetable production,
[00:08:26.130]tomatoes, watermelon, and other cooker wheat crops,
[00:08:28.620]bell peppers, herbs are growing there.
[00:08:31.350]And there we have a special production system going on,
[00:08:33.540]which is known as plasticulture production.
[00:08:35.190]We raise the beds and we run drip tubes
[00:08:38.520]and we put plastic mulch, something like this.
[00:08:41.040]This is a plastic mulch,
[00:08:42.660]you can see a transplants of pepper or tomatoes
[00:08:44.970]going on in the plastic mulch beds.
[00:08:47.130]This is another picture of a plastic,
[00:08:49.050]you use black or white plastic depending on what season
[00:08:52.500]we are planting.
[00:08:53.370]This is a tomatoes planted on black plastic mulch beds.
[00:08:59.010]Again, when it comes to plastic mulch production,
[00:09:01.500]weeds, definitely a major challenge
[00:09:03.630]because one of the major weed we are trying
[00:09:06.570]like you guys have a pigweed here, we have nutsedge,
[00:09:09.600]which is very tolerant to many herbicide programs.
[00:09:12.210]And not only that,
[00:09:14.160]the nutsedge such can poke the plastic mulch and come out.
[00:09:17.250]So in here, you're looking at a picture of a pepper
[00:09:20.970]or probably a tomato bed,
[00:09:22.050]which was basically taken over by the nutsedge weed.
[00:09:26.700]And also in the row middles areas as well.
[00:09:28.830]Here you can see a lot of grasses coming up
[00:09:30.660]in the row middle areas between the beds.
[00:09:33.570]This is an egg plant going on a plastic mulch bed again.
[00:09:37.517]Again, I talked about pigweed, right?
[00:09:39.690]This is a normal pigweed that we see here
[00:09:42.270]in a very early growth stage.
[00:09:43.950]But I want to bring your attention to this pigweed.
[00:09:47.220]This is about eight feet tall that I pictured the last week
[00:09:50.430]from one of my citrus grove.
[00:09:52.170]So I just want to bring this picture
[00:09:54.270]to bring that perspective,
[00:09:56.070]how much this weed can suck the moisture
[00:09:59.550]and other nutrients and other resources from the soil
[00:10:01.950]that should be otherwise available for your crop.
[00:10:05.730]We have documented, we had done several research to see
[00:10:08.520]how weed management impacts particles of production
[00:10:11.580]of citrus production.
[00:10:12.450]For example, this example data I want to show you.
[00:10:16.290]If you, you have different levels of weed control
[00:10:18.930]on the Y axis, sorry, X axis,
[00:10:21.660]weedy which is less than 10% weed control,
[00:10:24.180]and if you have a weed free or 75% weed control
[00:10:27.030]and you have Y axis average harvest weight of citrus,
[00:10:31.380]definitely if you have a well managed tree row,
[00:10:35.280]you can get at least 25% increase in the year.
[00:10:38.966]It's worth it.
[00:10:40.800]Growers understands this,
[00:10:42.090]although there is pressure from HLB management
[00:10:45.060]and things like that.
[00:10:45.893]They set aside 12%-15% of the production cost
[00:10:49.290]for fighting weeds because weeds are gonna compete
[00:10:52.200]with the crop and are gonna impact the productivity.
[00:10:55.770]Not only competition,
[00:10:56.940]several other factors such as supporting pests and diseases.
[00:11:00.240]For example, we mentioned the HLB
[00:11:03.170]or citrus greening disease.
[00:11:04.350]The vector for that disease is a psyllid
[00:11:06.630]known as Asian citrus psyllid.
[00:11:08.490]And we found, we published work very recently
[00:11:11.220]with some entomology collaborators,
[00:11:13.290]some of the common citrus weeds such as Spanish needle,
[00:11:16.020]dog fennel or primrose that's commonly found
[00:11:18.960]in citrus groves or in the tree rows
[00:11:21.510]or in the perimeter areas or ditch banks,
[00:11:23.820]they can act as a way station for this psyllid.
[00:11:28.170]If there is an insecticide program
[00:11:29.820]going on in the tree rows, in the trees,
[00:11:32.910]these guys can fly to this weeds in the perimeter areas,
[00:11:36.840]spend some time there, but they cannot reproduce.
[00:11:39.150]There's only silent feeding happening there,
[00:11:40.710]not flowing feeding, not active feeding,
[00:11:42.660]but they can spend a couple of hours
[00:11:44.400]actually up to six to 10 hours
[00:11:46.170]and come back to the citrus trees
[00:11:48.000]when that detrimental effect is gone.
[00:11:50.670]It can support a lot of pests and diseases,
[00:11:52.500]it's been well documented as well.
[00:11:55.816]When it comes to citrus or vegetables, weeds have to go,
[00:12:00.390]and growers are spending money to fight the weeds.
[00:12:03.930]But there are several challenges,
[00:12:05.490]especially from the Florida production system.
[00:12:07.860]I want bring this picture.
[00:12:08.693]This is a big picture, like a global picture,
[00:12:10.840]which shows the number of weeds that are being resistant
[00:12:16.530]and tolerant to any herbicide.
[00:12:19.230]You can see our country, it's in the red.
[00:12:22.260]We have at least hundred weeds resistant
[00:12:25.980]to any herbicides documented in US.
[00:12:28.740]Dr. Amit Jhala is an expert in working
[00:12:33.090]in the field of herbicide resistance,
[00:12:34.560]so he would know better than me.
[00:12:35.640]But this is again, luckily,
[00:12:37.860]Florida do not have a lot of resistance issues,
[00:12:39.990]but we have a lot of tolerance issues
[00:12:41.760]and it can turn into a resistance issue as well.
[00:12:44.970]Also, if you look at this figure, the resistant increasing,
[00:12:50.040]the number of resistant biotypes are increasing
[00:12:52.230]and it is forecasted to increase over time.
[00:12:56.190]But if you look at that green line,
[00:12:58.050]it shows the number of herbicide chemistries
[00:13:02.310]or active ingredients released into the market,
[00:13:07.200]In fact, after 1980, not much development in that area,
[00:13:10.590]there is not much herbicide chemistries coming up.
[00:13:13.230]This is an alarming situation.
[00:13:14.850]More resistance, less amount of chemistries.
[00:13:18.450]Apart from that,
[00:13:19.440]there is an increase in demand for food production.
[00:13:21.420]We have farm labor shortages, especially in Florida,
[00:13:24.420]with all the pandemic and things like that.
[00:13:26.910]There are issues of farm, you know,
[00:13:29.370]there is scarcity of farm labor workers
[00:13:31.710]and a rising interest in organic production.
[00:13:34.290]Altogether, I want to bring this into your mind,
[00:13:39.391]there is a need for coming up with some novel
[00:13:41.850]and alternative approaches that should be added
[00:13:44.520]to the weed management toolbox.
[00:13:45.900]We have several strategies in the weed control,
[00:13:48.030]chemical, mechanical, non-chemical,
[00:13:50.520]cultural, things like that,
[00:13:51.660]but there should be some innovation and outside box thinking
[00:13:56.100]that should happen when it comes to weed control
[00:13:58.650]in horticulture production.
[00:14:00.180]I'm gonna focus on three things here,
[00:14:01.974]efficacy, sustainability, and crop safety.
[00:14:06.660]So from the theme of efficacy,
[00:14:09.474]I'm gonna talk about some projects that we are doing
[00:14:12.450]under the huge umbrella of precision weed management,
[00:14:15.720]which include machine vision weed detection
[00:14:18.113]as well as UAS, which is a fancy name for drones,
[00:14:21.870]unmanned aerial system and making the best use of adjuvants
[00:14:26.040]to fine-tune herbicide placement and application
[00:14:28.800]in the soil system.
[00:14:30.720]Also, I'll talk about steam weeding,
[00:14:33.060]which is considered as a non-chemical alternative,
[00:14:35.310]some natural herbicides and cover crops.
[00:14:37.650]You all know cover crops is not a novel strategy,
[00:14:40.380]it's been out there forever in row crops
[00:14:42.840]and agronomic crops, but for tree productions
[00:14:45.120]such as citrus, it's an emerging practice,
[00:14:47.130]so we are learning a lot from that these days.
[00:14:50.370]And also I'll talk about some slow release carriers
[00:14:52.680]and things like that to improve crop safety.
[00:14:56.670]First, I'm gonna touch base with a small project
[00:15:00.120]we are doing in terms of automation or machine learning.
[00:15:03.960]Basically this is what we are trying to achieve here
[00:15:06.270]is a synergy between human, machine and the sprayer, right?
[00:15:11.955]This is a picture of a raised bed with a plastic mulch
[00:15:15.480]with strawberry, okay?
[00:15:17.130]Strawberries been growing Florida on plastic mulch
[00:15:20.220]raised beds as well.
[00:15:21.053]So you can see a lot of geranium weed.
[00:15:24.130]We are trying to see if you can detect this weeds
[00:15:28.680]once it grows with the crop on a plastic mulch,
[00:15:31.980]you can detect it and we can spray it.
[00:15:35.220]Basically it's a see and spray system.
[00:15:37.980]What growers does when they see,
[00:15:39.900]well they'll try they level best to apply herbicides
[00:15:42.510]under the plastic mulch and things like that,
[00:15:44.850]hoping that the weeds never come up,
[00:15:46.170]but weed shows up and there is no way
[00:15:47.700]because this, when they spray,
[00:15:50.580]it's gonna hurt the,
[00:15:53.490]when they do like a blanket spray,
[00:15:54.990]it's gonna hurt the crop as well.
[00:15:57.449]What we are trying to do is to develop a need only based
[00:16:01.980]see and spray vision based platform.
[00:16:06.780]It's a very prototype, early prototype.
[00:16:09.420]It consists of a sprayer as well as a herbicide tank
[00:16:13.020]and control box camera is the detector here,
[00:16:16.110]it has GPS and then this is, it's autonomous.
[00:16:21.210]You can actually control it from your remote control.
[00:16:27.540]We are trying to use it on the plastic mulch bed.
[00:16:31.688]When it moves through the plastic mulch beds,
[00:16:33.720]they can detect,
[00:16:34.553]we have trained the system to detect a crop from a weed,
[00:16:37.620]that is a mulch on the bed.
[00:16:40.977]For example, I want to show an example here.
[00:16:47.379]The system can detect the target, which is a weed,
[00:16:49.170]and the non-target, which is the crop.
[00:16:51.330]When it moves through the bed or even the bare ground,
[00:16:54.360]it will find the weed and just spray.
[00:16:58.290]You can see some of the sprays here, you know,
[00:17:00.283]it's again in the initial development stage.
[00:17:04.440]We hope we'll be able to test it pretty soon,
[00:17:08.220]but the whole idea or thread of the research
[00:17:10.970]is to see this weed sprayed and without touching the crop.
[00:17:19.320]This is an example system we are trying now
[00:17:21.810]in the growers' field.
[00:17:23.340]Getting success, but there is a hit or miss sometimes,
[00:17:26.070]there's a lot of small factors involved,
[00:17:29.130]especially training the system to detect the weeds
[00:17:31.680]are very difficult.
[00:17:32.760]But again, we can at least ensure
[00:17:35.460]there will be a need only based application.
[00:17:38.190]It avoids crops and spray the weeds and potentially,
[00:17:40.980]we can reduce the chemical footprint in the farm,
[00:17:44.460]but there are several chances of spray errors
[00:17:47.340]and the scalability of this type of system
[00:17:50.400]has to be evaluated very well.
[00:17:52.890]That's one example I want to show you,
[00:17:54.570]plus, I'm sure Dr. Jhala will be also working
[00:17:58.290]something like this, but I want to show this
[00:18:00.046]from a horticulture production system.
[00:18:01.440]Unmanned aerial systems or drone,
[00:18:03.150]using drone images for inferring weed management decisions.
[00:18:07.950]This is a photo of a cucumber farm in Southwest Florida,
[00:18:13.650]but can you tell it's already taken over by an annual weed
[00:18:18.360]known as parthenium.
[00:18:19.580]It is kind of resistant to many herbicides.
[00:18:22.140]You can see the plastic mulched beds, the black color,
[00:18:24.990]but it took over.
[00:18:26.550]I mean, as I said, the seeds of these weeds
[00:18:30.930]are already in the soil, in the top five inches of soil.
[00:18:34.737]When the right time come,
[00:18:36.150]when the right sunshine and moisture come,
[00:18:38.400]it start to emerge on a fine day
[00:18:41.250]and it takes over the whole farm.
[00:18:42.840]Situations like this happen, okay?
[00:18:47.220]I wanna show you again,
[00:18:48.053]this weed is kind of not responding well
[00:18:52.200]to many herbicide programs.
[00:18:53.640]You can see, we have applied several herbicide program
[00:18:57.750]and you can see the differences in efficacy, right?
[00:19:00.630]This is a visual sensor photo with the drone.
[00:19:05.063]You can see the rows with several colors,
[00:19:07.980]which means some herbicide worked well, some did not.
[00:19:11.490]Then we put the multispectral sensor, you get more data,
[00:19:14.550]for example, you get the photosynthetic activity from there.
[00:19:17.640]Here, number two, there's no or low activity,
[00:19:21.540]number one, it is green, high weed activity.
[00:19:24.240]This photosynthetic activity or vegetation vigor
[00:19:27.150]can be converted into a weed mortality
[00:19:30.300]and we actually did the ground through thing
[00:19:33.120]in some of very recently in a project.
[00:19:34.920]What we did was we looked at the drone data
[00:19:37.320]with hyperspectral images and we looked at the ground.
[00:19:41.820]I mean, what's actually happening?
[00:19:42.990]Is it actually connecting or linking?
[00:19:46.500]And surprisingly, there is a good data fit
[00:19:49.110]between the derived mortality, the drone derived data,
[00:19:52.740]as well as absurd weed mortality.
[00:19:54.870]So we're trying to see if these models can be used
[00:19:58.620]to help growers to make informed weed management decisions.
[00:20:02.730]For example, if they have a,
[00:20:04.620]I'm talking about hundreds of acres here
[00:20:06.360]to have a herbicide program going on,
[00:20:08.550]whether a herbicide program worked
[00:20:11.040]or would they have to do another pass or follow publication.
[00:20:14.430]This type of work could be utilized for that
[00:20:19.980]and this is also helpful in evaluating
[00:20:22.380]herbicide injury as well.
[00:20:23.823]We have a grower where we are working with,
[00:20:27.065]so he sprayed the herbicide and he will fly the drone
[00:20:33.690]and we can help them convert the data
[00:20:35.430]and see how much mortality is happening.
[00:20:38.340]For instance, he was planning for a follow up spray,
[00:20:41.100]but we found that he had a good acceptable amount
[00:20:43.800]of field already happening,
[00:20:45.450]so we advised him do not go
[00:20:47.340]for another pass for now, saving money.
[00:20:49.320]So things like that.
[00:20:50.340]Informed decision, weed management decisions.
[00:20:52.980]But you know, we have to work with large data sets
[00:20:55.440]and hardware and software know how,
[00:20:57.900]maybe some producers may not be able to handle
[00:20:59.820]and things like that.
[00:21:00.653]Again, this is a small project,
[00:21:02.790]small baby stuff we are doing,
[00:21:04.860]just to bring into the toolbox,
[00:21:07.350]to improve efficacy and things like that.
[00:21:10.470]Weed free row middles.
[00:21:11.940]I talked about weeds encroaching the whole bed
[00:21:14.190]and things like that.
[00:21:15.660]But the row middles, the area between the rows,
[00:21:18.120]raised beds are also very important.
[00:21:20.460]And this is a very clean row middle,
[00:21:23.310]just in 25 days you can see the weeds coming up,
[00:21:25.860]taking over the row middles.
[00:21:28.590]We have a great tool in our toolbox,
[00:21:30.150]that's our pre-emergence herbicides
[00:21:32.070]that we apply to the soil, stay in the soil,
[00:21:36.630]prevent the emergence of seed
[00:21:38.550]or suppress the weed seed emergence.
[00:21:40.237]But when you apply the pre-emergence herbicide,
[00:21:44.520]in most cases, it'll get attached or absorbed
[00:21:47.960]or bound to soil like clay or organic matter, right?
[00:21:51.997]Those are the two binding sites
[00:21:54.420]where this pre emergence herbicide.
[00:21:55.650]Most time depending on the type of the herbicide
[00:21:58.140]and things like that,
[00:21:58.973]it has to stay in that top four inches,
[00:22:00.900]which I like to call as the weed drama zone,
[00:22:03.480]that's where all the weed germination activity happens.
[00:22:05.940]It has to be there to do its job.
[00:22:08.880]But that's about normal crop production soils like this.
[00:22:12.420]This is a picture from Illinois, where I did my PhD,
[00:22:16.290]and this is what we do in Southwest Florida.
[00:22:19.290]Typically beach sand, more than 95% sand,
[00:22:22.620]no clay or less than 1% clay
[00:22:25.140]and organic matter is less than 1%.
[00:22:28.080]Whatever herbicide soil applied,
[00:22:29.610]residual or pre-emergence herbicide,
[00:22:30.890]growers and producers are applying,
[00:22:33.330]it's gonna leach to it very easily,
[00:22:35.040]so they're kind of putting money in the drain.
[00:22:37.260]This is one of the major impediment we are having now.
[00:22:40.470]Herbicides are very expensive,
[00:22:42.090]you apply and there is a lot of rainfall,
[00:22:44.760]irrigation going on,
[00:22:45.810]it will not stay in the top four inches.
[00:22:48.455]One thought process was how to improve the retention
[00:22:53.070]of sandy soils for herbicides.
[00:22:55.860]There is an accidental discovery we made,
[00:22:57.930]there's a special group of surfactants or additives,
[00:23:02.640]spray additives known as deposition agents
[00:23:05.340]or herbicide sticker.
[00:23:07.050]They are typically used to reduce the drip
[00:23:09.990]when they are applied with post-emergence herbicides
[00:23:12.810]to reduce the wind induced drift and things like that.
[00:23:17.100]We found that this type of surfactants
[00:23:19.560]because of their special chemistry,
[00:23:22.290]they can actually act as binding sites
[00:23:26.130]for these herbicides to the soil
[00:23:28.080]or they can actually reduce the leaching
[00:23:30.780]potential of the soil, especially sandy soils.
[00:23:32.970]There are several products out there, but you know,
[00:23:35.120]it has not been evaluated for this.
[00:23:37.800]We looked at some of the herbicides,
[00:23:40.320]for example, Flumioxazin is a soil applied,
[00:23:43.800]a very popular soil applied pre-emergence herbicides
[00:23:46.410]in citrus row middles.
[00:23:48.300]You can see a trial, a piece of data from a trial
[00:23:51.270]where we applied it, there's an untreated check,
[00:23:53.760]you can see the control is going down, weeds are coming up,
[00:23:56.370]that means weeds are coming up.
[00:23:58.020]Flumioxazins did a good job initially,
[00:23:59.790]but over time, it's leaching from the top soil.
[00:24:04.080]But when we mixed it,
[00:24:05.250]it's time mixed and applied with this particular product,
[00:24:09.960]which is a polyvinyl polymer,
[00:24:12.390]you can see it stayed in the soil for some time,
[00:24:16.950]This program only cost about $2 per acre for a producer,
[00:24:21.690]but it is buying him two to three weeks
[00:24:24.240]of extra weed control, right?
[00:24:27.060]This is a picture from that trial,
[00:24:28.290]you can see on the left the Flumioxazin
[00:24:30.600]without soil binding agents,
[00:24:32.370]and on the right, we have that with 0.1%
[00:24:36.390]volume per volume basis tank mixed soil binding agents.
[00:24:39.720]This type of strategies can help,
[00:24:41.880]it has potential to actually help the producers
[00:24:46.110]to get the best bang out of their buck.
[00:24:47.880]I mean, it's not adding a lot to the post production,
[00:24:51.000]but it can help enhance their weed control window.
[00:24:56.640]So that was about some strategies in the toolbox
[00:25:00.900]that we were trying to improve the efficacy
[00:25:03.420]like machine vision or need only see and spray,
[00:25:06.180]need only basis, reduce the chemical footprint,
[00:25:08.970]then drone imaging for just getting a informed decision
[00:25:14.760]for weed management decisions
[00:25:15.930]and then utilizing adjuvants,
[00:25:17.790]making use of this materials to improve the retention
[00:25:20.790]of herbicides in the soil.
[00:25:22.440]Now I'm switching my gears to sustainability,
[00:25:24.870]the theme of sustainability here.
[00:25:27.090]I'm gonna talk about thermal weed management,
[00:25:30.120]particularly using steam.
[00:25:33.510]Steam has a lot of potential to be used
[00:25:35.880]as a weed management tool.
[00:25:37.830]Because just like you get scotched or burned from steam,
[00:25:44.070]the plant tissues can be burned from the steam,
[00:25:46.260]high pressure can break the steam.
[00:25:49.950]We built a steam system here,
[00:25:53.430]which consists of basically a flow meter,
[00:25:55.680]an electric generator, water tank and water pump.
[00:25:58.860]And this steam generator was channeled into a boom system
[00:26:03.690]and the whole setup can be pulled by a truck.
[00:26:08.865]Here we are applying the steam onto the weed foliage,
[00:26:12.960]under the tree rows, very slowly,
[00:26:17.310]and that area after the stream application after a few days.
[00:26:21.510]Again, as I said, this has a lot of potential,
[00:26:25.590]but there are drawbacks as well,
[00:26:28.860]I'm gonna walk you through that,
[00:26:31.020]but this is a great tool for especially organic producers
[00:26:34.410]or somebody who wants to do a sustainable production
[00:26:37.440]in tree crops.
[00:26:39.990]Again, six hours of the steam application,
[00:26:42.480]you can see all the untreated control also
[00:26:44.370]and the bare ground, you can see the steam applied area.
[00:26:48.690]We published a paper recently,
[00:26:50.850]where we looked at different steam treatments.
[00:26:54.420]They are actually varies in the levels of their pressure
[00:26:57.773]as well as tractor speed.
[00:26:59.910]And we found when you look at the weed control percentage
[00:27:02.670]on the Y axis,
[00:27:05.670]one of our treatment like number two with the high pressure
[00:27:08.340]and low tractor speed, kind of compare or comparable
[00:27:11.790]with paraquat or the trade name Gramoxone.
[00:27:14.280]It's like a conduct type herbicide.
[00:27:16.680]You're getting a very similar result with steam.
[00:27:21.930]Another thing I want to bring to the table here
[00:27:23.820]is integrating steam with herbicide application.
[00:27:26.940]Especially I'm gonna use goat weed as a model weed here,
[00:27:30.922]which is a very slow response to glyphosate
[00:27:32.940]and paraquat application.
[00:27:34.468]This is a citrus tree row,
[00:27:36.150]where effective weed management program is going on,
[00:27:38.730]but still you can see a monoculture of goat weed.
[00:27:42.030]Everything else is controlled by glyphosate,
[00:27:44.520]but not goat weed, it's tolerant.
[00:27:47.820]We tried steam on this.
[00:27:51.237]What we did was,
[00:27:52.350]so one of the issue with goat weed is its regrowth
[00:27:55.627]from the base stem even with the paraquat
[00:27:59.010]or the contact type herbicide.
[00:28:02.040]We have the dead weed biomass
[00:28:04.140]or percentage of total biomass,
[00:28:06.420]which clearly shows how much it's gonna regrow,
[00:28:09.450]so higher this number, better the weed control.
[00:28:11.277]And we have several treatments on the X axis
[00:28:13.860]including steam alone, paraquat, very low rate,
[00:28:17.280]steam plus paraquat.
[00:28:18.390]What we did was we applied steam, made the plant weak,
[00:28:21.900]waited 24 hours and we sprayed our herbicide.
[00:28:25.470]That was steam followed by paraquat low,
[00:28:27.930]then paraquat high as a spray,
[00:28:29.730]then steam followed by paraquat high and untreated control.
[00:28:33.030]And as you can see when you compare it
[00:28:35.430]to the paraquat low earlier on, it did not kill,
[00:28:38.179]I mean, we only got a 50% kill because half of it was green.
[00:28:42.210]When you combined it with that steaming,
[00:28:44.400]it's efficacy improved.
[00:28:45.780]So this maybe a tool we can utilize
[00:28:48.390]as an integrated approach,
[00:28:49.560]maybe combine steam with a low amount of herbicide.
[00:28:55.830]This is the picture,
[00:28:56.670]you can see untreated control, really green.
[00:28:59.310]Then paraquat low rate, started to with a red
[00:29:02.040]but still it's green,
[00:29:02.970]but the steam and the steam plus paraquat low,
[00:29:06.180]actually kind of smoked the weed.
[00:29:09.120]But I did not have another picture here,
[00:29:10.587]but I want to tell you when we did further observation,
[00:29:13.650]the steam applied one shows a lot of regrowth,
[00:29:16.950]but when we combine steam with paraquat low,
[00:29:19.380]it stayed dead, so which means,
[00:29:22.290]there is a potential for combining to improve
[00:29:27.939]the management of tough weeds like goat weed.
[00:29:31.290]So again, we are trying to apply steam
[00:29:33.600]in the ditch bank, canal sites
[00:29:37.260]because we have very limited herbicide chemistries
[00:29:40.290]approved to use in the ditch banks,
[00:29:42.450]because of the reasons of leaching into the water bodies
[00:29:44.970]and things like that,
[00:29:45.960]but we found steam can be a great tool there.
[00:29:49.230]You apply steam on the ditch banks
[00:29:50.760]and you can get a very conduct herbicide type kill
[00:29:54.840]two days after application.
[00:29:57.390]My point here is, again, this is a baby step.
[00:30:01.290]Earlier we used to get, I mean, I don't know,
[00:30:04.278]I mean there are some companies that start selling steamers
[00:30:07.170]for large commercial productions,
[00:30:08.790]but it's not as, you know,
[00:30:12.150]some are not evaluated, some are not popular,
[00:30:14.460]but still we can modify the systems for using
[00:30:20.070]in a citrus orchard or peach orchard or things like that.
[00:30:23.910]It has some potential,
[00:30:24.750]especially if that's a production system
[00:30:27.150]growing under organic production.
[00:30:29.070]But one of some of the drawbacks I have to admit,
[00:30:31.530]there will be regrowth.
[00:30:33.360]I mean if it's a annual weed, you get a good kill.
[00:30:36.000]But if it's a tough weed or a peroneal weed
[00:30:38.340]such as goat weed or maybe nutsedge,
[00:30:40.453]there will be potential regrowth from there.
[00:30:43.320]And another challenge we found in this project
[00:30:46.040]is when you apply herbicides,
[00:30:48.000]you'll be going at 3.5 to five miles per hour.
[00:30:51.360]But with steam,
[00:30:52.470]the amount of exposure that the plant
[00:30:55.650]has with the steam is very important,
[00:30:57.990]it has to be like at least 30 to 45 seconds exposures.
[00:31:02.040]But to achieve that exposure,
[00:31:03.510]you have to be going very slow,
[00:31:04.800]like almost one miles per hour, which takes a long time.
[00:31:08.640]If you have acres and acres,
[00:31:10.260]it's gonna be really difficult to cover all that acre.
[00:31:12.600]But again, this is a small baby step.
[00:31:16.170]Now I'm gonna talk a little bit about a project we did
[00:31:21.930]on bio herbicide or natural herbicide.
[00:31:25.925]For those who are not familiar with this term,
[00:31:28.020]they're herbicide made from plant based products.
[00:31:32.490]They're also known as green herbicide or green products,
[00:31:34.710]for example, oils like clove oil, eugenol, soaps, vinegar,
[00:31:39.450]all good candidates to be included
[00:31:41.490]as a natural bio herbicides
[00:31:43.320]used in organic production system.
[00:31:45.630]What we did was, you know,
[00:31:48.443]Florida is popular for its network of canals
[00:31:51.780]and back waters, so that means a lot of aquatic weeds.
[00:31:56.130]It's a major pest problem in Florida.
[00:32:00.030]You can see the canals here,
[00:32:01.470]completely filled with aquatic weeds.
[00:32:04.440]We thought of recycling this aquatic weeds
[00:32:07.980]and how to make the best use of that.
[00:32:09.840]We need to remove that.
[00:32:11.970]How about we utilize it for managing terrestrial weeds.
[00:32:15.930]That's a thought process we had
[00:32:17.790]and we got a grant for this.
[00:32:19.230]And we looked at several aquatic weeds such as muskgrass
[00:32:22.740]or filamentous algae and we dried them, made powders,
[00:32:27.960]some of them we had extract, things like that.
[00:32:31.470]And we tested it on our, the best model weed,
[00:32:34.753]amaranth or pigweed, which is a very problematic weed.
[00:32:37.710]The data here shows, for example,
[00:32:40.035]muskgrass and filamentous algae,
[00:32:42.840]you have the treatment rate on the X axis
[00:32:46.740]and Y axis, the biomass.
[00:32:48.930]Compared to the control of zero grams when you increase,
[00:32:52.320]you know, the increase in the powder or the extract
[00:32:56.400]is actually reducing the emergence of this pigweed.
[00:33:01.650]And this is a lab study or a greenhouse study.
[00:33:04.999]I don't have the data,
[00:33:06.327]but I can tell you we are trying it in the field
[00:33:09.240]where we are applying this powder in the raised beds.
[00:33:12.420]It's not only increasing the organic matter,
[00:33:15.630]it's reducing the weed emergence,
[00:33:18.150]possibly due to allelopathic effects,
[00:33:20.130]because some of this algae as well as the muskgrass
[00:33:24.720]and things like that are known
[00:33:25.950]to produce allelopathic materials,
[00:33:28.440]which can suppress the germination of weed seeds
[00:33:32.490]and things like that.
[00:33:33.450]Again, this is a work in progress,
[00:33:35.387]but this is something we call adding the organic matter
[00:33:38.880]at the same time suppressing the weeds
[00:33:40.470]and it's kind of an excellent example for recycling things.
[00:33:44.010]You're kind of taking care of aquatic weeds in the canals
[00:33:47.970]and utilize it or reuse it for sustainably controlling
[00:33:54.306]the terrestrial weeds as well.
[00:33:58.530]I want to bring your attention back
[00:33:59.760]to our citrus orchard here.
[00:34:01.110]This is not a great or well managed citrus grove here.
[00:34:04.380]As I mentioned in the row middle areas,
[00:34:07.770]we try to keep some vegetation, but not as much as this.
[00:34:11.070]So we ask the growers to mow it from time to time.
[00:34:15.090]Sometimes they keep it in the back burner,
[00:34:16.920]they will not mow it and you might end up in like this,
[00:34:19.050]a lot of weed seeds coming up in the row middle.
[00:34:22.530]And this can be a source of weeds for the tree rows, right?
[00:34:28.140]One solution we are having or we are trying out
[00:34:30.720]or evaluating is the use of cover crops in the row middles
[00:34:36.450]rather than having a patch of weeds
[00:34:38.000]or a patch of vegetation.
[00:34:40.330]We all know, I don't have to talk about cover crops here,
[00:34:41.897]we are all over crop experts here,
[00:34:43.890]but it's an emerging practice in citrus production.
[00:34:46.950]I like to say it's a weed control tool
[00:34:48.600]provided by the mother nature
[00:34:49.830]because it has a lot of benefits like building soil quality,
[00:34:55.350]retaining soil from erosion,
[00:34:58.020]suppressing weed growth and improving biodiversity,
[00:35:00.720]but I'm more or less interested in how it impacts
[00:35:04.020]the weed growth in a citrus orchard in the row middle.
[00:35:08.520]Basically shade is the process here,
[00:35:10.980]shade is an natural weed killer.
[00:35:12.510]So when we select some cover crops such as radish to grow
[00:35:16.440]in the row middle, it provides a lot of shade,
[00:35:19.140]it has a lot of good canopy,
[00:35:21.690]it prevents the weed seeds from emergence,
[00:35:23.580]it keeps the light out and helps in weed suppression.
[00:35:27.480]So we had a project where we looked at multiple years
[00:35:32.190]of impacts of cover crops on the weeds.
[00:35:35.460]In most of the seasons,
[00:35:36.750]we got a data like this where there is a cover crop,
[00:35:39.480]there is an inverse relation between the weeds,
[00:35:41.460]more cover crops, less weeds.
[00:35:44.440]A very interesting, a very strong negative correlation.
[00:35:49.320]And this is a picture I gonna show you,
[00:35:51.210]on the left you have a non-cover crop row middle,
[00:35:54.960]you have all sort of nasty weeds there.
[00:35:58.140]Guinea grass, very bad, it sucks a lot of soil moisture,
[00:36:02.070]black nightshade, tolerant to many herbicides,
[00:36:05.220]geranium, things like that.
[00:36:06.990]But on the right, you have a cover crop area
[00:36:11.160]where you can see lush growth
[00:36:12.570]of daikon radish without a weed.
[00:36:15.720]Daikon radish is a great cover crop
[00:36:18.090]for Florida from our observation,
[00:36:20.130]because these are just the tip of iceberg we are seeing,
[00:36:24.510]Some of these radishes can grow three feet deep in 60 days,
[00:36:28.470]which is very helpful in holding up the soil,
[00:36:31.920]which is another problem we have in Florida, soil erosion.
[00:36:35.580]Having cover crops in the row middles,
[00:36:38.070]not only build the soil quality,
[00:36:40.500]not only reduce the weed emergence,
[00:36:43.200]but also improve the soil holding as well.
[00:36:46.110]This is a system that we are evaluating
[00:36:48.420]and the growers are liking these days.
[00:36:50.460]This is a video of how we do cover crop planting
[00:36:54.300]in the row middles.
[00:36:55.410]We use seed drill with the seeds
[00:36:58.950]and this is a germination, it's coming up,
[00:37:02.070]maybe a couple of weeks and it's a full fledged cover crops.
[00:37:06.210]In this mix, we are using sunn hemp,
[00:37:08.610]daikon radish and ryegrass.
[00:37:10.140]This is a lesson we learned,
[00:37:11.550]rather than using a single species, a mix of species,
[00:37:14.100]probably a legume and non-legumous species
[00:37:18.690]can always help to get all the good benefits of cover crops.
[00:37:23.970]And you can see nice flowers,
[00:37:25.920]which is also attracting a lot of good insects,
[00:37:28.740]pollinators and everything, so it's a win-win situation.
[00:37:32.400]Many growers are interested in this
[00:37:34.110]and this also reduce the herbicide application
[00:37:40.020]involving frequency in the row middles as well.
[00:37:43.337](audience member faintly speaking)
[00:37:46.841]We will mow it back
[00:37:49.470]and then we'll do the drilling again, seeding again.
[00:37:53.010]That's a system we are working on,
[00:37:54.180]but at some point of time we may have to try that as well,
[00:37:57.090]but right now, we have to reseed it again.
[00:38:02.430]Finally, I'm gonna switch gears
[00:38:04.830]to the crop safety aspect here,
[00:38:06.160]where I'm gonna talk about herbicide placement.
[00:38:09.318]Using slow-release carriers.
[00:38:10.830]Before that, again,
[00:38:12.120]I want to really show this picture
[00:38:14.970]of a white plastic bed with peppers.
[00:38:17.490]Can you see the peppers?
[00:38:18.510]No, because it has been taken over by the nutsedge,
[00:38:21.330]very tough weed.
[00:38:24.930]We do have a lot of tools in our toolbox
[00:38:27.240]such as pre-emergence herbicides or fumigation,
[00:38:29.820]so that growers typically apply this on the bed top,
[00:38:32.580]then put the plastic mulch.
[00:38:36.420]That's a great system, it's gonna control it actually.
[00:38:38.580]When you put herbicides on the bed top
[00:38:40.710]and cover with plastic mulch,
[00:38:42.180]it is gonna control the nutsedge,
[00:38:44.430]but we have a very dire side effect, herbicide toxicity.
[00:38:48.810]This is a picture of a bell pepper
[00:38:52.500]exposed to herbicides on the bed top.
[00:38:55.710]The herbicides again, because of the sandy soil,
[00:38:57.630]it's gonna leach into the root zone.
[00:38:59.130]So this is the cartoon I wanna show you.
[00:39:01.219]The high rate of herbicide
[00:39:03.180]when the transplants get established,
[00:39:06.090]it's gonna suck up the herbicides and cause an injury.
[00:39:10.200]What we are gonna do here,
[00:39:12.832]we thought about how we can help the herbicide
[00:39:16.440]again stay in the bed with a slow release,
[00:39:20.340]rather than going into the root zone.
[00:39:22.620]And one candidate we are evaluating here
[00:39:25.350]are known as hydrogels or water granules or you know,
[00:39:29.550]sometimes they're known as polymer granules.
[00:39:32.940]They're actually typically using added agriculture,
[00:39:36.060]where they can absorb water and become big
[00:39:40.380]like 200 times their size and slowly release the water back.
[00:39:44.430]What we did was we had this hydrogel mixed with herbicides.
[00:39:51.690]They absorbed the herbicides in due cause of time
[00:39:54.900]and then we put it under the bed.
[00:39:57.840]The hope was it will release herbicide back,
[00:40:00.600]filling the nutsedge tubers
[00:40:02.070]or preventing their emergence at the same time,
[00:40:05.430]will keep the herbicide active ingredient
[00:40:07.142]and come into the root bowl zone.
[00:40:11.490]This is how we apply it, we mix the herbicide hydrogel,
[00:40:15.180]you can see the gel kind of expanded
[00:40:17.250]with herbicide active ingredient
[00:40:19.080]and put under the plastic, put the mulch.
[00:40:20.820]This is a picture where we open the mulch and show you,
[00:40:22.617]you can see the plant pore and everything and it worked.
[00:40:26.460]In our case, initial results are very encouraging
[00:40:29.730]as you can see here.
[00:40:31.020]Untreated control, can see the weeds coming up,
[00:40:34.050]but on the left, we have the hydrogel based application,
[00:40:37.830]it's pretty clean, no weeds,
[00:40:39.900]and the plants were looking healthy as well.
[00:40:42.360]More pictures, herbicide and hydrogel carrier applied beds.
[00:40:45.560]In the background, you can see the control
[00:40:47.460]where nutsedge is taking over.
[00:40:50.310]Let's look at some data here.
[00:40:52.440]In the study we had a control, untreated control,
[00:40:55.470]then we had a spray, herbicide was sprayed.
[00:40:59.520]Low standard rate spray,
[00:41:01.500]then we mix low rate of herbicide with hydrogel
[00:41:04.380]and a high rate of herbicide with hydrogen.
[00:41:06.660]When it comes to the nutsedge density or weed management,
[00:41:09.630]all the spray treatments or hydrogel based treatments,
[00:41:11.880]it worked very well,
[00:41:12.713]because this herbicide we are using is metolachlor,
[00:41:15.352]it's very good nutsedge suppression agent.
[00:41:17.160]It's a great pre-emergence herbicide.
[00:41:19.500]But when we look at the plant vigor
[00:41:21.720]after one and a half months,
[00:41:23.340]it's the direct sprayed bed had a related significantly
[00:41:29.280]low vigor when compared to our hydrogel based application.
[00:41:34.146](audience member faintly speaking)
[00:41:38.610]Yeah that is spray, spray is just blanket spray,
[00:41:43.073]The other one was low rate of herbicide with hydrogen
[00:41:45.390]and high rate with hydrogen.
[00:41:47.070]We looked at the plant vigor here
[00:41:48.870]and then we looked at the bell pepper yield
[00:41:51.240]and you can see it's clearly and compared to spray,
[00:41:54.390]our hydrogen based application even the lower rate,
[00:41:57.330]had a acceptable amount of marketable weight,
[00:42:03.630]which means, yeah, the dire spraying of herbicide
[00:42:06.600]may have something to do with the producing the vigor,
[00:42:09.660]probably it's gonna linger up to the productivity.
[00:42:12.330]This type of strategies are something
[00:42:13.920]that we need to evaluate,
[00:42:15.210]so that improves or safen the herbicide application.
[00:42:18.360]And without herbicides,
[00:42:19.320]it's very difficult to grow in plasticulture production,
[00:42:22.920]because nutsedge is gonna take over at some point of time.
[00:42:25.140]There are some pros I already mentioned to you,
[00:42:29.190]but there are cons, there is risk of carry-over toxicity.
[00:42:31.680]We need to evaluate, actually see if that herbicide,
[00:42:34.500]it's a slow release,
[00:42:35.610]so there is a chance that active ingredient
[00:42:37.080]gonna stay in the soil for a longer time.
[00:42:38.550]So next season what happens
[00:42:40.710]if there is gonna be a carry-over toxicity.
[00:42:43.410]And again there is always a dilemma of scalability.
[00:42:46.860]We are doing it in small couple of acres,
[00:42:49.200]so we can hand spread it or we spread it
[00:42:50.850]from fertilizer spreader or something like that,
[00:42:53.070]this hydrogel mixture,
[00:42:54.390]but when it comes to hundreds or five hundreds of acre,
[00:42:56.910]how can we do that?
[00:42:58.020]Those top are things we need to keep in mind.
[00:43:01.659]Metolachlor, it's metolachlor, dual magnum.
[00:43:06.260]And same idea, we are also bringing
[00:43:08.850]into container production,
[00:43:09.990]which is also a small niche program
[00:43:13.140]or niche industry in Florida,
[00:43:15.540]where we grow a lot of trees,
[00:43:19.020]especially lime trees and lemon trees in containers.
[00:43:21.690]And one of the issue we're having
[00:43:22.790]is the weeds coming in the container.
[00:43:25.680]And once it's very difficult to spray the containers
[00:43:28.200]in the greenhouse or screenhouse,
[00:43:29.550]it's gonna cause a lot of environmental implications rift
[00:43:32.400]and things like that.
[00:43:33.510]We are mixing herbicides, pre-emergence herbicides
[00:43:35.550]and adding to the container.
[00:43:37.410]You can see a clear difference here,
[00:43:39.540]there is less weeds on the left and more weeds on the right.
[00:43:43.980]This has some potential, but again,
[00:43:45.720]one more thing I want to,
[00:43:47.400]this hydrogel is originally used
[00:43:49.382]as a water retention medium.
[00:43:51.070]Apart from leasing herbicide,
[00:43:53.370]it's also keeping the moisture good in the containers.
[00:43:57.030]The plants are, I'm not showing the data here,
[00:43:58.980]so the containerized plants are showing better vigor also.
[00:44:03.782]Another on point project as a next step,
[00:44:06.227]we are trying to coat fertilizers with herbicides.
[00:44:09.960]Some of the fertilizers are slow release granules,
[00:44:12.750]so we can do the same way, mix, coat it with herbicides.
[00:44:16.230]And we have a trial where we apply
[00:44:18.690]several types of herbicides, coat it on fertilizers,
[00:44:21.690]apply it on the bed and we'll put plastic on that
[00:44:24.900]and we'll see.
[00:44:26.100]I'd like to call, my student coined this name,
[00:44:28.470]weeding by feeding.
[00:44:30.510]It actually feeding the plant at the same time,
[00:44:32.460]we are achieving a kind of weed control strategy.
[00:44:37.080]I'm gonna sum up my seedling talk here.
[00:44:38.910]We talked about several aspects, a lot of information.
[00:44:42.180]We talked about automation and machine learning,
[00:44:45.000]there is great potential there.
[00:44:46.290]Detecting the weeds versus crop, applying the herbicide,
[00:44:49.380]that will definitely reduce the herbicide input.
[00:44:51.450]But there are several challenges, scalability,
[00:44:53.760]things like that.
[00:44:54.870]Drones or UAS are great sources and tools
[00:44:58.440]for getting images that can be converted
[00:45:00.450]into a weed mortality and that can be used
[00:45:03.660]for helping growers to make informed decisions.
[00:45:07.200]Adjuvants has a lot of potential,
[00:45:08.610]there's a new group of adjuvants that they can be used
[00:45:11.490]for enhancing the retention of herbicides in soils
[00:45:14.250]such as sandy soils.
[00:45:15.990]And steaming, thermal weed control
[00:45:18.480]has a lot of potential as well,
[00:45:20.010]but needs to be really evaluated
[00:45:22.323]to look at the regrowth and things like that.
[00:45:26.490]And natural herbicide,
[00:45:27.960]we talked about the recycling aquatic weeds
[00:45:30.600]and use the phenomenon of allelopathy
[00:45:33.660]for controlling terrestrial weeds
[00:45:35.010]and also adding organic matter.
[00:45:37.080]Cover crops, not a new system,
[00:45:39.960]but really emerging system in tree production,
[00:45:43.260]is giving initial results are really great,
[00:45:45.570]growers are excited about this.
[00:45:47.640]And talked about hydrogels as a potential herbicide
[00:45:50.820]carrier for real slow release
[00:45:52.650]and safening the herbicide use on plastic mulch bags.
[00:45:58.080]I like to thank my team here
[00:46:01.560]at Southwest Florida Research Education Center
[00:46:03.570]and my collaborators and several funding agencies
[00:46:06.540]for funding this small projects.
[00:46:09.630]And this is a picture of a weed garden
[00:46:13.050]we have at our station.
[00:46:14.550]It's a live demonstration garden
[00:46:17.610]of different types of weeds in Southwest Florida
[00:46:20.880]that's found in horticulture production system.
[00:46:23.640]We invite growers to come take a look, touch it,
[00:46:26.790]smell it, maybe eat it and see how it looks.
[00:46:31.710]One thing I want to say, maybe Amit will also agree,
[00:46:36.390]the weeds thrive out in the field,
[00:46:38.640]but when we try to put it in a pot, it doesn't wanna grow.
[00:46:43.230]That's all I have, thank you very much.
[00:46:44.610]Thank you for inviting me, I'm so honored.
[00:46:47.340]The light reflectance, yeah.
[00:46:50.850]Because dark soils,
[00:46:52.993]Is gonna absorb all the light,
[00:46:54.990]no light reflectance.
[00:46:57.288]So is there an advantage
[00:46:59.460]to having vegetation under there?
[00:47:02.300]So the question was, again,
[00:47:03.900]it was regarding the light reflectance.
[00:47:07.260]In Florida, we have sandy soils, which is white mostly,
[00:47:10.320]so it's gonna reflect more.
[00:47:12.000]But I think when you talk about the under canopy,
[00:47:16.050]it is, again, it's shade,
[00:47:18.330]because depending on the age of the tree,
[00:47:22.320]we get different levels of shade.
[00:47:26.580]This is something I have to mention,
[00:47:28.890]well, it's very difficult to control very young citrus weeds
[00:47:32.040]because weeds are gonna come up a lot,
[00:47:33.690]but when the canopy start building up
[00:47:36.360]like five, six to 10 years of age, it's rather easy.
[00:47:41.310]The under tree area will be more shade and it's easy.
[00:47:54.120]Erosion if you use clean cultivation,
[00:47:57.990]it strikes me that those soils are pretty mobile.
[00:48:01.260]Yes, so the question is about how cultivation
[00:48:04.920]is gonna impact the erosion, yes.
[00:48:06.450]We don't actually promote, I mean, encourage the growers
[00:48:10.974]to do a lot of cultivation,
[00:48:13.290]especially because of the flooding, I mean, the erosion
[00:48:16.200]related to rainfall and things like that.
[00:48:18.330]It's a very loose soil, it's gonna go away.
[00:48:21.930]Wind, even wind can take some of the sand particles away.
[00:48:27.789](audience member faintly speaking)
[00:48:31.950]That steaming treatment
[00:48:33.930]it takes what time?
[00:48:35.091]Oh, oh sorry.
[00:48:36.027]So the question was regarding combining herbicide
[00:48:40.740]It's not mixing, it's not a time mixing.
[00:48:42.930]It's like we steam first, apply the steam,
[00:48:46.260]and then let the weeds get weakened,
[00:48:49.770]then follow it up separately with the herbicide application.
[00:48:53.040]It's not combined anywhere, you cannot combine,
[00:48:56.352]but you have to apply the steam, wait for a day or two,
[00:49:01.410]then apply the paraquat or whatever herbicide.
[00:49:06.276](audience member faintly speaking)
[00:49:09.856]The question was about how we can combine in a tank,
[00:49:12.180]but it's 214 degree Fahrenheit,
[00:49:18.360]it's gonna disintegrate the herbicide for sure.
[00:49:21.270]It's boiling the herbicide basically, we dunno.
[00:49:25.620]You mentioned the word fumigation.
[00:49:28.740]Tell us about it.
[00:49:32.880]Okay, so the question was describe fumigation
[00:49:36.720]in a plasticulture production system.
[00:49:39.782]What we do, when we pull the beds,
[00:49:42.420]when we make raised beds, we inject a fumigant,
[00:49:45.847]which is a liquid high pressure liquid,
[00:49:48.300]we'll inject into the bed, so it will be turned into a gas.
[00:49:52.950]And what it does, it desiccate all the weed seeds
[00:49:56.820]or soil borne pathogens or tubers and things like that.
[00:50:00.450]Then we immediately we put the plastic mulch,
[00:50:03.210]then we'll give two to three weeks to the gas to go
[00:50:07.320]and when it's safe for the plants to come in,
[00:50:12.630]Soil sterilization using gassing
[00:50:15.000]and the product we are using
[00:50:16.380]are high pressure fumigant liquid.
[00:50:19.658](audience member faintly speaking)
[00:50:25.430]The question was what are the side effects
[00:50:26.760]of fumigation on beneficial organisms?
[00:50:29.010]Yes, there can be.
[00:50:30.330]Some of the evaluations shows that fumigations
[00:50:32.970]can be really nasty on good bugs.
[00:50:45.210]Yes, there is a term for that, biological control.
[00:50:50.850]Yeah, true, it's a added advantage, right?
[00:50:59.732](audience member faintly speaking)
[00:51:03.845]Instead cover crop.
[00:51:07.909](audience member faintly speaking)
[00:51:09.672](audience member faintly speaking)
[00:51:10.793]Got it, yeah.
[00:51:12.780]The question was instead of a cover crop,
[00:51:14.707]can we do some cash crop, right?
[00:51:17.370]So yeah, that's a great system we are thinking about,
[00:51:20.130]but to convince growers, it's very difficult.
[00:51:22.170]Because they have really fixed,
[00:51:24.180]their aim is to just have these trees,
[00:51:27.870]bring it back from HLB or the citrus greening,
[00:51:30.360]so they may not have time to think about another cash crop,
[00:51:33.540]but it's a great system.
[00:51:34.410]If you can get a successful system going there,
[00:51:37.290]it's an additional benefit the growers can get.
[00:51:39.750]Maybe some vegetables or cowpea or green grams,
[00:51:42.270]something like that, yeah.
[00:51:44.880]Or even short season cover, yeah, system.
[00:51:48.924](audience member faintly speaking)
[00:51:51.270]Yes, for the containers, the nursery production, yeah.
[00:52:03.990]The question was how are we gonna apply
[00:52:05.503]a hydrogel herbicide mixture, right?
[00:52:08.070]We are applying it by, if it's a small trial,
[00:52:10.950]we use it our hands and everything,
[00:52:13.170]but if it's a large trial, we use fertilizer spreader.
[00:52:17.134]It'll be applied from a, we'll put it in the fertilizer,
[00:52:22.290]you know, weed and feed entire, something like that.
[00:52:25.500]We modify that spreader so that we'll spit out hydrogel
[00:52:29.100]onto the side of the bed,
[00:52:31.800]like a side dress application.
[00:52:35.940]Oh yeah, that depends on what product we are using.
[00:52:38.730]Usually when we buy a hydrogen product,
[00:52:41.130]you can get it from Amazon or small packets,
[00:52:44.310]so they will let you know what is that.
[00:52:47.781]It depends on the granular size, size of the granule,
[00:52:50.640]so they will say this much hydrogen per acre
[00:52:53.880]or per square feet, whatever.
[00:52:55.470]We'll use that rate.
[00:53:06.600]No, it'll, so the question was can we apply hydrogel
[00:53:11.280]through a sprayer?
[00:53:12.210]It's gonna clog the sprayer.
[00:53:13.602]So what it does, whatever moisture is available,
[00:53:16.230]it'll absorb it and well,
[00:53:18.510]some granule can become 200 times its size.
[00:53:26.850]But it's a cool thing.
[00:53:28.560]To be honest with you, when you apply hydrogel on a bed top,
[00:53:32.970]it looks like diamonds on the black bed top, very beautiful.
[00:53:42.810]Something like that, yeah.
[00:53:44.280]It's silica based, yeah.
[00:53:56.580]It's a great question.
[00:53:58.057]So Joe was asking how much growers are concerned
[00:54:01.570]about weed management when compared to the HLB.
[00:54:04.293]Now, weed management is the back burner now,
[00:54:06.600]it's all about HLB.
[00:54:08.730]Even when you have to say weed management,
[00:54:12.240]we have to say controlling weeds in HLB affected crop.
[00:54:16.380]You have to bring in that term HLB somewhere
[00:54:19.050]to get their attention.
[00:54:21.210]Because we can't blame them, it's so devastating.
[00:54:34.721](audience member faintly speaking)
[00:54:48.600]Yeah, so the question was how about some of the techniques?
[00:54:51.720]I mentioned it, watermelon.
[00:54:54.090]Yes, I do work in watermelon,
[00:54:55.650]but watermelon these days are grown on a bare ground
[00:55:02.130]to reduce the production cost because watermelon, again,
[00:55:05.230]it's a spreading crop, yeah.
[00:55:09.750]I mean, we don't see a lot of it emergence on the back,
[00:55:12.750]but whatever is, my projects are more or less focused
[00:55:15.150]on the row middle areas,
[00:55:16.290]which is kind of similar for the other row middle work
[00:55:18.840]I have published.
[00:55:29.039]Yeah, we do have seedless, it's a big industry.
[00:55:32.640]As I said, I mentioned about tomatoes,
[00:55:34.800]85% comes from our area, likewise watermelon,
[00:55:38.460]we are a big industry for all specialty watermelons,
[00:55:41.910]regular watermelons, all sort of things.
[00:55:43.380]But one thing I really get involved with watermelons
[00:55:46.680]is the crop injury.
[00:55:49.395]There are some herbicides that's allowed to apply
[00:55:51.810]on top of watermelons,
[00:55:53.430]but depending on the weather conditions,
[00:55:55.800]the vines get injured very easily.
[00:55:57.570]So that's where my focus is like managing the injury.
[00:56:08.250]Any questions from the online?
[00:56:14.610]All right, that's it and thank you again.
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