Video 5 - 2020 Virtual Nebraska Soybean Day and Machinery Expo
Deloris Pittman
Author
12/21/2020
Added
37
Plays
Description
Considerations for Early-Season Weed Control in Soybeans (PRE-Emergence Herbicides and Cover Crops)
Rodrigo Werle, Assistant Professor & Extension Weed Specialist, University of Wisconsin-Madison
Considerations for Mid-Season Weed Control in Soybeans (Post-Emergence Herbicides and Drift Management)
Rodrigo Werle, Assistant Professor & Extension Weed Specialist, University of Wisconsin-Madison
Searchable Transcript
Toggle between list and paragraph view.
- [00:00:14.930]So that, we're gonna move on.
- [00:00:18.590]Next topic is gonna be weeds.
- [00:00:23.300]And there are two faculty members
- [00:00:27.120]at the University of Wisconsin
- [00:00:29.820]that are going to share with us
- [00:00:34.500]their information and experience associated
- [00:00:38.070]with the different aspects of weed control.
- [00:00:40.750]Now they do have a Nebraska connection
- [00:00:45.280]and that Dr. Rodrigo Werle was an extension specialist
- [00:00:51.900]for some time at West Central Research and Extension Center
- [00:00:55.820]at North Platte.
- [00:00:56.830]And Nick Arneson who's a weed science outreach specialist
- [00:01:01.740]at UW Wisconsin was in the plant pathology department
- [00:01:07.690]on campus here in Nebraska.
- [00:01:09.470]So they have a good idea of Nebraska's growing conditions
- [00:01:13.800]and challenges associated with weed management
- [00:01:17.320]and things like cover crops and all that.
- [00:01:19.623]So with that I'm gonna welcome Rodrigo
- [00:01:24.627]and Nick and turn it over to them.
- [00:01:30.400]Good afternoon everybody,
- [00:01:32.340]it's an honor to be here today as weed scientist specialists
- [00:01:38.000]in the West Central Research and Extension 2016/2017,
- [00:01:42.360]but prior to that, I got my master's and my PhD at UNL.
- [00:01:47.300]So it's great to be here today,
- [00:01:50.020]I wanna thank you Keith for the opportunity to be here
- [00:01:54.688]for everything that you do for agriculture
- [00:01:56.970]for being a great mentor to me,
- [00:01:59.380]and also to Nick who's gonna be be speaking next.
- [00:02:03.157]We are very thankful to you.
- [00:02:05.010]You have been a tremendous mentor
- [00:02:07.400]in my professional years you have played a big part of it.
- [00:02:10.620]So I appreciate the opportunity.
- [00:02:12.420]So without further ado,
- [00:02:13.845]I think we're probably 10 minutes behind,
- [00:02:15.600]as some of you know I like to talk fast,
- [00:02:17.750]so let's get this going.
- [00:02:19.910]We have three talks scheduled for the next hour here.
- [00:02:24.290]I'm gonna give two of them.
- [00:02:25.930]First one is gonna be considerations
- [00:02:27.610]for early-season weed control.
- [00:02:29.500]My next talk is gonna be consideration for mid-season
- [00:02:33.100]weed control.
- [00:02:34.100]And then the last talk Nick is gonna give a talk
- [00:02:37.210]on considerations for late season weed control.
- [00:02:41.067]If you're on Twitter make sure you follow us
- [00:02:43.057]@WiscWeeds.
- [00:02:45.528]@WiscWeeds is our handle on Twitter
- [00:02:48.180]and throughout my presentation here
- [00:02:49.680]Nick is gonna be sharing some links on the chat
- [00:02:52.400]so just so you all have the other resources available.
- [00:02:56.140]Okay? Before I start,
- [00:02:58.100]I want to acknowledge our sponsors
- [00:03:00.610]and also our research team
- [00:03:02.870]for the great work that they do
- [00:03:05.837]without our sponsors and without this amazing team,
- [00:03:08.700]I couldn't be here today presenting to you all.
- [00:03:12.850]So as an outline for my first talk
- [00:03:14.960]I'm gonna talk about three different series of studies.
- [00:03:18.220]The first one looking at cover crops
- [00:03:20.490]so cover crop management as a strategy for weed control.
- [00:03:24.300]And then we gonna visit crops from our research
- [00:03:26.900]and looking at residual control of waterhemp
- [00:03:30.020]and giant ragweed.
- [00:03:31.810]It is my understanding into the presentation
- [00:03:34.870]from artemisiifolia L. Amaranth palmer
- [00:03:37.650]has become a major problem in the state of Nebraska
- [00:03:41.450]and I'm familiar with that 'cause I've seen
- [00:03:43.590]that happening over the years.
- [00:03:45.970]But what I wanna say here is that
- [00:03:47.450]most of the things that I'm gonna be talking about
- [00:03:49.527]for waterhemp also apply to Palmer amaranth.
- [00:03:52.000]So hopefully the information I have to provide
- [00:03:54.300]I'm gonna be providing here today
- [00:03:56.220]is useful for those who are also struggling
- [00:03:58.550]with Palmer amaranth.
- [00:03:59.890]And then I'm gonna wrap things up talking about
- [00:04:02.410]the research conducted by one of our graduate students
- [00:04:05.626]looking at some bioassay in the greenhouse
- [00:04:08.670]really need data.
- [00:04:10.930]So I'm gonna start with this soil management study
- [00:04:15.000]that we conducted.
- [00:04:16.410]This study is being led by a graduate student Kolby Grint
- [00:04:20.976]and Kolby is actually from Nebraska,
- [00:04:22.360]he received his bachelor's in agronomy at UNL.
- [00:04:25.990]And he's doing his master's degree here with us.
- [00:04:28.520]For Kolby's trial we are looking at rotations.
- [00:04:31.470]And we're looking how soil management practices
- [00:04:34.870]and PRE-emergence herbicides,
- [00:04:36.330]in fact, weed control and crop productivity.
- [00:04:40.570]In terms of soil management practices
- [00:04:42.570]Kolby has evaluated six different practices.
- [00:04:45.360]Tillage which is quite popular in Wisconsin,
- [00:04:48.380]70% of our acres receive some form of tillage.
- [00:04:52.440]We also have a no-till treatment
- [00:04:54.580]and then we have four different cover crop
- [00:04:58.360]termination strategies here in Wisc Weed.
- [00:05:01.354]So the studies I'm gonna be focusing on today
- [00:05:03.240]are studies that come from corn
- [00:05:05.240]and going to soybeans
- [00:05:06.560]this is where I see a lot of promise for cover crops.
- [00:05:09.277]Our cover crop treatments are terminated
- [00:05:11.430]at four different times and spread if you would.
- [00:05:14.240]15 days before planting,
- [00:05:16.136]at planting,
- [00:05:17.860]and then 15 days after planting
- [00:05:19.990]and termination is usually conducted or done
- [00:05:24.200]always glyphosate.
- [00:05:25.970]Before one of our treatments
- [00:05:27.260]given that we're in Wisconsin,
- [00:05:28.650]there is state we chop the rye before planting.
- [00:05:32.818]This are four termination for cereal rye.
- [00:05:36.090]So here's just a picture of Kolby's trial.
- [00:05:39.230]It's a large trial that we have
- [00:05:40.650]and we intend to conduct this trial for multiple years.
- [00:05:43.520]We are going into the third rotation here.
- [00:05:48.340]So here's a picture of third week May
- [00:05:50.330]when we're planting our soybeans.
- [00:05:51.417]And this is by far my favorite scenario there.
- [00:05:54.240]Here we have a big amount of cover crop biomass
- [00:05:56.440]going in green with our soybeans
- [00:05:58.730]and then we're terminating here
- [00:06:00.500]after planting or a few weeks afterwards,
- [00:06:03.170]here's a picture of a treatment
- [00:06:05.040]that was terminated in 15 days before planting.
- [00:06:08.020]Here's tillage which is quite popular in Wisconsin.
- [00:06:11.020]And this is our little tool scenario.
- [00:06:12.500]So again, we're looking at weed control
- [00:06:14.400]and crop productivity.
- [00:06:16.830]The one thing that I wanna point out
- [00:06:17.960]and I'm gonna walk through this live rather fast here
- [00:06:21.340]is that the best levels of mid-season weed control
- [00:06:24.660]were achieved when we had high amount of cover crop biomass
- [00:06:29.250]combined with PRE-emergence herbicide.
- [00:06:32.270]Okay. So I have a lot of cover crops,
- [00:06:34.260]suppressing weeds but PRE-emerge herbicides.
- [00:06:37.220]The one challenge that we have in Wisconsin
- [00:06:39.370]is that the cereal rye cover crop does not grow very fast.
- [00:06:42.790]So if we terminate that at planting,
- [00:06:44.560]we have about a 500-700 pounds of dry matter of breaker
- [00:06:50.100]whereas if we wait another two weeks
- [00:06:51.900]is when we see the big genre.
- [00:06:54.110]And remember, if you wanna see good weed suppression
- [00:06:56.590]from cover crops,
- [00:06:57.670]you wanna let that cover crop grow.
- [00:06:59.230]You wanna be terminating
- [00:07:00.360]and when is reaching the reproductive stage.
- [00:07:03.197]'cause this is when it has
- [00:07:04.420]this is the time when the cover crop has
- [00:07:06.500]high CN race will take longer to decompose
- [00:07:09.500]and it's gonna be doing a good job suppressing weeds.
- [00:07:12.740]Okay. So high amount of biomass
- [00:07:14.770]combined with the PRE-emergence herbicide program.
- [00:07:17.250]This is one when we're seeing outstanding levels
- [00:07:19.550]of weed control.
- [00:07:21.630]The one question that I get from producers
- [00:07:24.320]when I described this scenario here,
- [00:07:25.793]this is gonna go back to the speak for here.
- [00:07:28.200]When I'm telling the producer,
- [00:07:29.320]don't kill this cover crop
- [00:07:30.760]no go green planted
- [00:07:32.110]and then you spray you pre,
- [00:07:33.900]the question that we typically get is
- [00:07:35.450]what happens with the pre-emerge herbicides?
- [00:07:38.520]Are they gonna stay, hang up during this
- [00:07:41.700]all this amount of residue?
- [00:07:43.550]So we've done some studies over this past two years.
- [00:07:45.790]We have eight side years of data,
- [00:07:47.350]and I'm just gonna show
- [00:07:48.183]some of our preliminary results here.
- [00:07:50.130]So thanks for zone.
- [00:07:51.240]While we do 30 days after planting the soybeans
- [00:07:54.270]we collect soil cores from zero to three meters in depth
- [00:07:58.333]from each one of our plots
- [00:08:00.090]and then we submit those samples to South Dakota Ag Labs
- [00:08:03.410]and we evaluate the herbicide concentration.
- [00:08:06.040]And what we've learned here
- [00:08:07.390]over this past couple years is that
- [00:08:09.260]usually the tillage treatment
- [00:08:10.570]where you have no crop residue
- [00:08:12.710]on top of the soil surface
- [00:08:15.100]it is where you get the highest amount of herbicide in soil
- [00:08:18.270]30 days after application.
- [00:08:20.350]However, when we're comparing no till cover crop
- [00:08:23.270]early terminated termination
- [00:08:25.210]then the late terminated cover crops
- [00:08:28.020]those terminated 15 days after planting,
- [00:08:31.250]the amount of herbicides in soil 30 days afterwards
- [00:08:34.970]was the same.
- [00:08:36.060]One thing that I want to point out here is that
- [00:08:37.580]this studies are being conducted in Wisconsin,
- [00:08:40.000]silt loam soil
- [00:08:41.090]and all the times that we conducted this study
- [00:08:43.890]within three to four days after the planting,
- [00:08:46.310]we received a decent amount of precipitation, you know,
- [00:08:49.580]half an ace if not more.
- [00:08:51.360]Every time we conducted this study
- [00:08:52.950]we had a lot of rainfall in the spring in Wisconsin.
- [00:08:55.930]And why is that important?
- [00:08:56.763]While as you're spraying PRE-emergence herbicide
- [00:08:59.210]in a scenario like this
- [00:09:00.780]you wanna make sure you get enough rainfall in there
- [00:09:03.660]for that herbicide to get into the soil activated
- [00:09:06.600]where it needs to be, okay?
- [00:09:08.530]So this is what we actually considered
- [00:09:10.470]when looking at this results here.
- [00:09:12.820]The next question that I get asked the producers
- [00:09:15.490]when we walk through those crops or when I see weeds
- [00:09:17.808]it's like as is
- [00:09:18.757]what is the impact on use?
- [00:09:20.530]I'm not showing four new data here,
- [00:09:22.220]I'm gonna focus on soybean yield.
- [00:09:24.333]And that's one of the reasons why I really liked the system,
- [00:09:26.670]you know planting green
- [00:09:27.710]and then terminating afterwards
- [00:09:29.840]is because we see no impact,
- [00:09:31.890]but at least in our studies in Wisconsin,
- [00:09:33.600]we have a summary eight site years of data
- [00:09:36.340]out of the eight site years, only one site year
- [00:09:38.304]we did see a little bit of a reduction in soybean yield
- [00:09:42.770]when the cover crop was late terminated.Okay?
- [00:09:45.147]And from both of our studies here
- [00:09:46.860]the yield is flat.
- [00:09:48.670]So having a cover crop here there is no till
- [00:09:50.950]we did not see yield reduct.
- [00:09:52.810]So not seeing yield reduction
- [00:09:54.740]seen immense levels of weed control
- [00:09:57.100]the Waterhemp.
- [00:10:00.520]Since we're talking about PRE-emergence herbicide here
- [00:10:03.780]I'm gonna switch gears,
- [00:10:05.320]and I want to talk about the studies that we've conducted
- [00:10:08.030]in 2018, 2019,
- [00:10:10.850]and also 2020
- [00:10:12.140]at multiple locations here in Wisconsin.
- [00:10:15.360]We started this studies to showcase to our producers
- [00:10:19.230]the importance of effective
- [00:10:21.630]PRE-emergence herbicide programs.
- [00:10:24.230]Okay? So here I have data from Lancaster
- [00:10:27.310]which where we have a little lower waterhemp pressure
- [00:10:30.420]and here I have the data from Brooklyn, Wisconsin,
- [00:10:32.613]This is a non-farm research site.
- [00:10:35.390]We worked with a group of producers deal Brian brothers
- [00:10:38.170]and they have a pretty heavy waterhemp infestation.
- [00:10:41.900]The way we look at this data here in blue
- [00:10:44.100]we have herbicides with one site of action
- [00:10:47.240]from multiple sites of action.
- [00:10:48.730]So we have Group 2 herbicides, ALS chemistry.
- [00:10:51.870]We have Groups 5, photosystem two,
- [00:10:55.279]we have PPO herbicides
- [00:10:57.120]and here we have our group 15 herbicides.
- [00:10:59.770]In green I have pre-mixes
- [00:11:02.270]that contain two sites of action.
- [00:11:04.900]And then in red I have pre-mixes that contain
- [00:11:07.740]three sites of action.
- [00:11:08.880]And I just wanna remind you that
- [00:11:10.030]this data is available
- [00:11:11.580]and Nick is already sharing in the chat.
- [00:11:13.930]So you can download and evaluate this data later on.
- [00:11:17.310]But what's my point here?
- [00:11:18.600]For waterhemp ALS resistance is widespread,
- [00:11:21.870]the same is true for Palmer Amaranth
- [00:11:23.420]so when you spray the ALS chemistry by itself
- [00:11:25.770]you don't see effective levels of control
- [00:11:28.020]like you wanna see, okay?
- [00:11:29.400]So this is the dash line
- [00:11:30.960]90% control 25 days afterwards.
- [00:11:33.410]This is where you wanna be at. Okay?
- [00:11:35.600]One herbicide that does quite well
- [00:11:37.700]for small seeded weeds
- [00:11:39.280]including Palmer and waterhemp is Metribuzin
- [00:11:41.870]And that's why Antrobus Metribuzin
- [00:11:43.780]has skyrocketed over the past few years.
- [00:11:46.900]One thing that I wanna say is
- [00:11:48.210]when folks are adopting Metribuzin
- [00:11:49.840]you've gotta make sure to use the appropriate rate
- [00:11:52.130]even their soils.
- [00:11:53.130]Don't cut short under rate,
- [00:11:54.780]'cause if you do, you do not see
- [00:11:56.620]effective levels of weed control.
- [00:11:59.060]Our Group 14 herbicides sulfentrazone
- [00:12:02.020]followed by flumioxazin
- [00:12:03.910]tend to do a little better job
- [00:12:05.070]better job than saflufenacil
- [00:12:07.130]or Sharpen by itself.
- [00:12:09.670]And then here we have the Group 15s
- [00:12:11.976]and all we did in this study with the Group 15s
- [00:12:13.710]we did a kind of a full rate and a half rate.
- [00:12:16.360]So here I have Warren half rate ,full rate.
- [00:12:20.070]Next I have dual half rate,
- [00:12:22.300]full rate outlook,
- [00:12:24.140]half rate, full rate
- [00:12:26.050]and then residual rate full rate.
- [00:12:29.000]The level of waterhemp control
- [00:12:30.760]varies according to the Group 15 herbicide
- [00:12:33.100]And every time we use the reduced rate,
- [00:12:35.420]we dropped the levels controlled
- [00:12:36.840]trying to convey this matters.
- [00:12:38.570]Yeah, you gotta put a PRE-emergence out there
- [00:12:40.610]but don't cut on the rates 'cause if you do
- [00:12:42.527]you'll see reduced levels of weed control.
- [00:12:45.507]The one thing that we learned from the study here is
- [00:12:47.340]that every time you combine two active ingredients
- [00:12:50.250]that's when you enhance levels of weed control.
- [00:12:53.400]For instance, here, I have the combinations
- [00:12:55.220]of a Group 14 and a group 2 herbicide
- [00:12:59.210]exceeding those herbicides by themselves.
- [00:13:02.220]Here I have a herbicide that did quite well,
- [00:13:04.120]which is in this case here,
- [00:13:05.330]it's 40 Supreme, which is a mixture of so propoxycarbazone
- [00:13:08.574]flucarbazone Imidazolinone.
- [00:13:09.970]So when you're combining two effective herbicides
- [00:13:12.920]by enzymes, you know, as a pre-made series
- [00:13:15.200]that enhanced level of control, okay.
- [00:13:17.670]So as farmers prepare for weed control at 2021
- [00:13:20.000]this is the time to be studying this types of data sets
- [00:13:22.850]and select the right PRE-emergence of herbicide program.
- [00:13:27.627]Our Rock co farm programs have become very water eccentric.
- [00:13:30.394]In the state of Wisconsin giant ragweed is also a problem.
- [00:13:33.980]And back then I know giant ragweed
- [00:13:36.270]was a problem in Nebraska, little Sandal.
- [00:13:38.552]One of my mentors during my time at UNL
- [00:13:39.944]did a lot of research.
- [00:13:42.046]But one thing that I want to point out
- [00:13:44.438]is that giant ragweed in Nebraska
- [00:13:45.620]behaves differently than giant ragweed in Wisconsin.
- [00:13:48.940]Giant ragweed in Nebraska merge
- [00:13:50.560]is earning the season for only like a couple of weeks
- [00:13:53.140]for us in Wisconsin It starts germinating in April
- [00:13:55.610]and it goes all the way through June July
- [00:13:58.508]is when Wisconsin we had this giant ragweed
- [00:13:59.990]with an extended emergence window
- [00:14:01.650]which makes it very difficult.
- [00:14:03.450]So we conducted the same study
- [00:14:04.890]for ragweed at a Rock County farm.
- [00:14:07.020]And all we've learned here
- [00:14:08.210]is a little different than waterhemp.
- [00:14:09.800]So as you can see I'm gonna go back
- [00:14:11.420]for waterhemp lots of effective options.
- [00:14:14.400]Those options are not as effective for giant ragweed.
- [00:14:17.150]And that's due to the nature of this weed
- [00:14:19.560]with a very large seed size.
- [00:14:21.870]Okay. As I said, ALS chemistry is not very effective
- [00:14:25.460]pursued classic first rate for waterhemp
- [00:14:28.470]because of resistance before giant ragweed
- [00:14:30.920]and many other large weed abruptly,
- [00:14:33.370]weed seed that we have in our seed bags
- [00:14:36.270]ALS chemistry is very effective.
- [00:14:37.700]So some of our farms are starting to walk away
- [00:14:40.460]from ALS chemistry further PRE-emergence herbicide program,
- [00:14:43.560]but then all of a sudden they start missing
- [00:14:45.340]because then they start getting more manse orders ,
- [00:14:47.400]more ragweeds and some water species
- [00:14:49.230]that used to be controlled by this chemistry.
- [00:14:51.540]So ALS chemistry (mic drowns out the speaker)
- [00:14:53.952]would do the trick for the big weeds
- [00:14:55.380]but they're still very helpful
- [00:14:57.010]for other weeds that we have in our seed farm.
- [00:14:59.370]And that's the one thing I wanna convey here.
- [00:15:02.370]So transitioning into the last portion of this first talk,
- [00:15:05.460]I wanna talk about the bioessay study
- [00:15:07.720]that was conducted by a Victor Ribeiro.
- [00:15:10.290]Victor was a masters student
- [00:15:12.140]and visiting masters student in our program.
- [00:15:14.460]He's here with us on the line today.
- [00:15:17.620]So what Victor did,
- [00:15:18.810]he went to this site where we did this studies
- [00:15:21.460]that I just presented.
- [00:15:22.720]And he collected soil samples
- [00:15:24.370]at 0,10,20,30,40 and 50 days after treatment.
- [00:15:30.050]And he collected soil samples from zero to 10 centimeters
- [00:15:33.470]or zero to three inches in depth.
- [00:15:35.550]And he brought the samples into the greenhouse
- [00:15:37.620]and conducted his bioassay.
- [00:15:40.524]As his bio indicator species
- [00:15:41.870]we had cereal rye, radish,
- [00:15:43.574]Palmer Amaranth, giant Foxtail.
- [00:15:47.340]Because of we have limited time here,
- [00:15:48.980]I'm gonna to focus on his Palmer Amaranth
- [00:15:50.950]and giant foxtail results.
- [00:15:53.950]But the intent of this study here was to evaluate over time,
- [00:15:57.300]which herbicides did the best job
- [00:15:59.890]controlling the weeds that we evaluated
- [00:16:01.790]which were Palmer Amaranth and giant foxtail
- [00:16:04.740]and also evaluate which herbicides would be least harmful
- [00:16:08.780]to our cover crops that then can be seeded
- [00:16:11.220]after soybean harvest.
- [00:16:13.770]So in terms of results here
- [00:16:15.280]the way I went in to look at this figures
- [00:16:16.970]one of a bid figure here, but it's very informative.
- [00:16:19.490]We have 11 herbicides
- [00:16:21.370]from four different sites of action.
- [00:16:23.840]Here's the data for Palmer Amaranth,
- [00:16:26.080]here's the data for giant foxtail,
- [00:16:28.500]data for radish
- [00:16:29.930]and then data for cereal rye.
- [00:16:32.830]Here what Victor used as an explanatory variable
- [00:16:35.670]is accumulated only three days from zero to a thousand,
- [00:16:39.280]which is somewhat which represents the zero to 50 days
- [00:16:42.680]after treatment. Okay.
- [00:16:44.557]And the way he plotted this, he's looking at percent biomass
- [00:16:48.220]as compared to the non treated control of the plots
- [00:16:50.610]that didn't have herbicide.
- [00:16:52.110]So when you're talking about Palmer amaranth
- [00:16:53.557]and giant foxtail we wanna see herbicides
- [00:16:55.950]reducing the biomass of the weed as much as possible
- [00:17:00.170]and having a small, slow period.
- [00:17:02.930]You don't wanna see the herbicide degrading fast.
- [00:17:04.820]You wanna see good weed control over time.
- [00:17:07.140]So for Palmer Amaranth
- [00:17:08.640]the most effective herbicides here
- [00:17:11.170]were pyroxasulfone
- [00:17:14.050]and sulfentrazone they provided similar results
- [00:17:16.720]but group 15 herbicides.
- [00:17:18.920]And sulfentrazone Spartan
- [00:17:21.760]followed by S-metolachlor
- [00:17:23.780]which is dual and full mesotrione
- [00:17:26.410]which has Valor.
- [00:17:27.570]So this four herbicides were the most effective herbicides
- [00:17:30.490]from Victor's bioassay
- [00:17:31.937]from a Palmer amaranth control standpoint.
- [00:17:34.900]And then metribuzin was the fifth one.
- [00:17:37.440]So my recommendation for folks out there
- [00:17:39.560]if you're selecting a PRE-emerge and herbicide programs
- [00:17:42.140]looking at Palmer amaranth, waterhemp control
- [00:17:44.890]make sure you have one of this herbicides
- [00:17:46.930]as part of your pre-program
- [00:17:48.400]and if possible combined two of them
- [00:17:50.700]at adequate field rates. Okay.
- [00:17:52.910]So again Flumioxazin Semicarbazone,
- [00:17:55.690]pyroxasulfone ,S-metolachlor
- [00:17:58.300]and metribuzin.
- [00:18:01.090]The other thing that I wanna point out is
- [00:18:02.440]that this Group 15 herbicides,
- [00:18:03.950]both of them are zidua and dual
- [00:18:05.570]not only they did great work in Palmer amaranth
- [00:18:07.660]but they were also very effective on giant foxtail.
- [00:18:10.760]So selecting good herbicides,
- [00:18:12.180]their understanding of the weed
- [00:18:13.760]then pressure that they have in your seedbed
- [00:18:15.670]can be very helpful.
- [00:18:17.350]So let's take away from the first presentation here
- [00:18:19.620]before I run out of time.
- [00:18:22.188]Cereal rye can be a promising component
- [00:18:25.890]of weed control programs.
- [00:18:27.412]It doesn't have to be grown everywhere.
- [00:18:28.620]I know time is, you know,
- [00:18:30.420]sometimes there's not enough time in the fall
- [00:18:32.230]to get everything planted but our growers can be strategic.
- [00:18:35.130]If there are some acres where they're struggling
- [00:18:37.210]with Palmer, with waterhemp and radish you know
- [00:18:40.400]give it some thought.
- [00:18:41.830]PRE-emergency herbicide at the foundation
- [00:18:43.450]as they start thinking 2021 weed control programs
- [00:18:46.820]make sure you have a good PRE-emergence herbicide program.
- [00:18:51.000]And then every time you're considering your weed control
- [00:18:53.850]make sure you have non-chemical strategies.
- [00:18:56.430]And I'm gonna talk a little bit more about that
- [00:18:58.730]in my next talk.
- [00:19:00.310]Make sure we use integrated weed management strategies.
- [00:19:03.390]So we take some of the selection pressure away,
- [00:19:05.910]the base, which waterhemp and Palmer amaranth
- [00:19:09.050]are involved in resistance is somewhat scary.
- [00:19:12.200]So keep that in mind.
- [00:19:13.450]So with that I'm gonna stop here.
- [00:19:15.680]Keith I'll stop sharing
- [00:19:17.210]and then I'll
- [00:19:18.996]if there are questions
- [00:19:19.829]how we handle this part now Keith.
- [00:19:23.030]Yeah. So if you have questions for Rodrigo
- [00:19:27.407]please put them in the chat box
- [00:19:29.330]and I'll take a look here real quick.
- [00:19:35.830]I don't see anything right now regarding
- [00:19:39.690]your comments up till now Rodrigo.
- [00:19:43.000]Excellent.
- [00:19:45.160]Yeah. So folks on the line here if you have a question,
- [00:19:47.247]feel free to add into the chat.
- [00:19:49.820]Keith do you want me to keep going here?
- [00:19:51.930]Yeah. That'd be fine.
- [00:19:54.460]Wonderful.
- [00:19:55.580]So I'm gonna bring my presentation back here.
- [00:20:00.210]And I'm gonna switch gears
- [00:20:01.470]so we covered early season weed control.
- [00:20:03.640]Use of cover crops, termination of cover crops
- [00:20:06.805]and the importance of PRE-emergent herbicide programs.
- [00:20:09.080]Now I'm gonna switch
- [00:20:10.150]and we're gonna talk mid-season
- [00:20:11.900]or post-emergence weed control.
- [00:20:15.700]For this talk here,
- [00:20:16.850]I'm gonna go through again three series of studies.
- [00:20:21.070]The data is gonna is, is available in the chat.
- [00:20:23.900]Nick is sharing that
- [00:20:25.808]it's also available in the resources
- [00:20:27.720]that the Ro has put together.
- [00:20:29.490]So the first one we're going to talk about
- [00:20:31.434]burndown control of waterhemp and giant ragweed,
- [00:20:34.762]we're again gonna talk about
- [00:20:36.184]a layered residual approach study
- [00:20:38.320]that we conducted in this past couple of years.
- [00:20:42.050]And I'm gonna wrap things up talking about
- [00:20:44.870]tank-mix with PPO-inhibitors.
- [00:20:49.120]One thing that I want to see here
- [00:20:50.380]I think we're gonna start to see a lot of liberty
- [00:20:54.460]being used out there and glyphosate
- [00:20:57.950]will glyphosate this one herbicide
- [00:20:59.247]and we're not seeing widespread cases of resistance.
- [00:21:03.930]There hasn't been official cases of resistance yet
- [00:21:07.524]and it's now a common herbicide across the platform.
- [00:21:10.760]So the L LGT 27, your enlist soybeans
- [00:21:14.590]and your extend flex platform
- [00:21:16.960]now allows for post-emergence applications
- [00:21:19.575]that glyphosate.
- [00:21:20.510]It tends to be a very effective herbicide of ragweed
- [00:21:23.000]but we need to make sure
- [00:21:24.710]we take care of the disturbance side
- [00:21:26.340]so we don't quickly select for resistance.
- [00:21:28.590]So this is how I'm gonna wrap things up.
- [00:21:31.750]So this is a study in the burndown studies
- [00:21:33.873]that we conduct after we talk to our growers in Wisconsin
- [00:21:38.290]about pre-emergence,
- [00:21:39.250]the next question is, okay
- [00:21:40.500]now we're in season the winter breaking through
- [00:21:42.530]in my corn and soybeans,
- [00:21:44.040]how do we control them post emergence?
- [00:21:46.410]So in order to address that question
- [00:21:47.980]we established a series of studies
- [00:21:50.670]comparing 20 different herbicides
- [00:21:52.960]herbicides that can be used in corn
- [00:21:54.890]and soybeans from multiple sites of action.
- [00:21:57.780]So you have your Group 2 ,Groups 4, growth regulators
- [00:22:01.210]Group 6,9 and 14 and 27.
- [00:22:05.690]On the left here I have waterhemp control
- [00:22:08.890]14 days after application
- [00:22:10.607]and this weeds were three inches
- [00:22:12.750]when we sprayed them.
- [00:22:13.760]Remember the three inch mark
- [00:22:15.140]we don't wanna let those weeds grow to more than that.
- [00:22:18.040]And why is this hard to control them?
- [00:22:19.757]We've got to spray them small. So that's what we did here.
- [00:22:21.580]So on the left is waterhemp
- [00:22:23.360]on the right is giant ragweed.
- [00:22:25.620]Given this is soybean talk,
- [00:22:27.070]I'm gonna focus on the soybean herbicide.
- [00:22:28.890]So ALS chemistry because of resistance
- [00:22:31.430]in both specie and waterhemp
- [00:22:33.887]and giant ragweed we don't get effective controls
- [00:22:36.410]in our trials.
- [00:22:37.710]Here I wanna talk about the, you know
- [00:22:39.520]the three herbicides,
- [00:22:40.610]if you would we can now use in soybeans
- [00:22:42.970]like Clethodim, 240 colleen
- [00:22:46.040]and glyphosate
- [00:22:48.117]these three herbicides are the most effective herbicides
- [00:22:50.506]for control both waterhemp
- [00:22:52.380]and giant ragweed in our trials.
- [00:22:54.440]These are important tools they are now available
- [00:22:56.710]to our soybean producers,
- [00:22:58.230]we gotta take good care of them.
- [00:23:01.170]And this is the time of the year
- [00:23:02.270]when I started getting these questions
- [00:23:04.110]from our producers.
- [00:23:04.970]They're right now deciding which seeds to plant
- [00:23:08.040]and with the seed decision comes a trade decision, right?
- [00:23:10.880]Are we gonna go the came early roundup?
- [00:23:12.300]Are we gonna go a 2,4-D roundup?
- [00:23:14.070]Or are we gonna go Gramoxone roundup?
- [00:23:17.010]And then they asked me which one should I go?
- [00:23:18.710]Which one is the best?
- [00:23:20.360]So instead of telling them what to do
- [00:23:22.190]what I asked Ryan to do
- [00:23:23.760]Ryan and bird research technologists in our program
- [00:23:26.700]I asked me to compile all the data that we have
- [00:23:29.400]offered this past growing season.
- [00:23:31.010]So here has got all the data for Dicamba.
- [00:23:33.953]You know, he sprays them with soybeans
- [00:23:37.170]are about the V3 V4 post-emergence
- [00:23:39.450]the weeds are the right size.
- [00:23:40.890]So we do everything by the book in our research route.
- [00:23:43.770]Okay. So here's dicamba 240 glyphosate
- [00:23:48.290]and here's a tank mix that is allowed in the enlist system
- [00:23:51.150]which is a 240 Coleen plus glyphosate.
- [00:23:55.280]And as you can see here, 14 days
- [00:23:57.080]after application of that control is somewhat equivalent.
- [00:24:00.130]Okay? With this thing makes your leading
- [00:24:02.580]to a little higher control
- [00:24:04.030]but across the board if you can spray
- [00:24:05.880]according to the best management practices
- [00:24:08.570]for each one of those herbicides
- [00:24:09.700]you can get excellent levels weed control.
- [00:24:12.410]What Ryan did he started applying the data a little more.
- [00:24:15.290]And then he was able to come up with a strategy
- [00:24:18.110]where for some of the posts applications
- [00:24:19.780]the results weren't as good.
- [00:24:21.340]So what he did, he broke down by levels
- [00:24:24.150]of PRE-emergence herbicide program.
- [00:24:26.400]And he combined levels of post emergence weed control
- [00:24:30.450]across the various herbicides.
- [00:24:32.440]So here's a scenario in our research trials
- [00:24:34.832]where we don't have a PRE-emergence herbicide applied
- [00:24:37.387]and this is a very bad idea. Okay?
- [00:24:40.120]Getting this under control is very, very challenging
- [00:24:42.270]as you most know, and this is waterhemp, okay?
- [00:24:45.300]This is a fair herbicide program
- [00:24:46.900]I didn't want to invest a whole lot.
- [00:24:48.210]I put a pre it's better than this
- [00:24:50.180]but there are a lot of weeds breaking through. Okay?
- [00:24:52.900]So fair, a good herbicide program
- [00:24:55.270]about 80 to 90% reduction in waterhemp density.
- [00:24:59.000]And this is where I want our farmers to be
- [00:25:01.047]I want them to be using an excellent herbicide program.Okay?
- [00:25:04.610]So as you can see here the waterhemp density
- [00:25:06.700]really decreased as you enhance the quality
- [00:25:09.820]of your pre-program.
- [00:25:11.360]What happens in this scenario,
- [00:25:13.430]you have fewer weeds to control post emergence
- [00:25:15.930]and then when you have a scenario like this
- [00:25:17.960]the levels of post-emergence weed control
- [00:25:20.740]14 days after that post application
- [00:25:23.330]now towards the end of the season is enhanced. Okay?
- [00:25:27.610]So it is important that we start strong
- [00:25:29.900]so we can finish strong
- [00:25:31.380]and we can help this technologies last longer
- [00:25:34.220]because if we lose them because of resistance
- [00:25:36.550]and other factors,
- [00:25:38.100]it isn't clear how we're gonna handle
- [00:25:39.730]this weeds post emergence. Okay?
- [00:25:43.160]So now I wanna switch gears a little bit
- [00:25:45.380]and I want to talk about this trial here
- [00:25:47.290]which is gonna lead me to the next one
- [00:25:49.870]because of some of the observations we took
- [00:25:52.120]from this study here.
- [00:25:53.480]So this is what we're recommending
- [00:25:55.420]for farmers dealing with waterhemp and Palmer amaranths.
- [00:25:58.780]Layered residual approach, right?
- [00:26:00.890]So you put a PRE-emergence at the time of planting,
- [00:26:04.050]and then when the weeds are breaking your pre-emerge
- [00:26:06.150]herbicide program about three, four to five weeks
- [00:26:08.760]into the growing season you come with your post program.
- [00:26:11.660]This was an LL GT 27 soybean cultivars
- [00:26:14.800]so we used vital liberty as our main post program.
- [00:26:20.053]And what we did, we compared that
- [00:26:22.278](motor engine roars)
- [00:26:23.790]with the addition of Group 15 herbicides
- [00:26:26.540]or Magnum, dual ultra Magnum outlook residual, right?
- [00:26:30.413]This is a recommendation you spray your Glyphosate
- [00:26:33.697]and a Group 15 to retain.
- [00:26:35.560]And when we do that we do see an enhanced
- [00:26:38.510]level of control when compared to the Glyphosate post only.
- [00:26:43.110]But what really got our attention
- [00:26:44.600]is when we brought Flexstar
- [00:26:47.170]dimethenamid into the tank mix.
- [00:26:49.070]So we actually combine
- [00:26:50.880]because of our treatment structure here,
- [00:26:52.420]we combine the Glyphosate and Flexstar,
- [00:26:54.980]and we were really surprised with the level of control
- [00:26:57.820]that we obtained.
- [00:26:58.880]And here's a similar set of treatments where we have
- [00:27:02.089]Glyphosate plus prefix.
- [00:27:03.710]Prefix is for metsulfuron plus dual
- [00:27:06.800]and here's Blazer ultra,
- [00:27:08.080]which is flumethasone of Flexstar plus warrants.
- [00:27:11.920]So here we have three sites of action
- [00:27:14.169]Glyphosate, flumethasone burning the water habits average.
- [00:27:18.310]Remember that flumethasone has soil residual activity
- [00:27:21.040]so when you combine them with a group 15
- [00:27:22.960]now you have two herbicides in the season
- [00:27:25.090]providing a residual weed control.
- [00:27:27.830]So we were really surprised about the start here.
- [00:27:30.590]We brought agronomist
- [00:27:31.530]and they were also surprised.
- [00:27:32.720]The next question that we got is
- [00:27:34.350]what happens to my soybean
- [00:27:35.890]when I start mixing the service sites.
- [00:27:38.600]And that's what we did this past year.
- [00:27:40.520]In 2020, we intend to replicate this studies in 2021.
- [00:27:45.280]This study here was conducted at three sites,
- [00:27:48.440]two sites in Wisconsin,
- [00:27:49.937]and a site in Western Illinois with Dr. Mark Bernard.
- [00:27:54.200]And here are some of the results that we obtained.
- [00:27:56.460]So for the first part here
- [00:27:58.033]we're gonna talk about waterhemp control.
- [00:28:00.160]So we put a pre down
- [00:28:02.440]with the pre level of control was 20 to 50%.
- [00:28:06.521]14 days after the post application
- [00:28:09.490]we tested four different BPOs
- [00:28:11.670]Cobra, Flexstar,
- [00:28:14.610]Cadet, Resource,
- [00:28:16.800]and then we compared identical phosphinate.
- [00:28:19.010]So phosphinate ,Flexstar and Cobra
- [00:28:22.670]provided the equivalent levels of control,
- [00:28:24.720]they perform better than cadet and resource.
- [00:28:28.560]The one thing that I want to point out is that
- [00:28:30.000]when we combine this BPO's with phosphinate
- [00:28:33.250]every time the control enhanced
- [00:28:36.230]and the control for the tank mix of resources
- [00:28:39.480]in liberty and Cobra and liberty
- [00:28:42.410]was equivalent to the tank mix of at least one
- [00:28:46.240]and liberty.
- [00:28:47.200]So when we combined two herbicides
- [00:28:48.980]that have activity post emerges with glyphosate there,
- [00:28:52.124]that's when we saw enhanced levels of control.
- [00:28:56.320]Here's crop injury going from zero to 30
- [00:28:59.570]the higher the injury you know,
- [00:29:01.812]the higher the number here to higher the injury.
- [00:29:05.230]And the one herbicide that caused all of injury
- [00:29:07.140]and most of us are familiar with this.
- [00:29:09.410]It was Cobra.
- [00:29:10.280]So Cobra caused about 30% injury
- [00:29:12.760]14 days after the application. Okay.
- [00:29:15.580]As compared to the other herbicides.
- [00:29:17.920]We then took this blocks to yield.
- [00:29:21.630]And the cobra that caused about 30% injury,
- [00:29:24.080]did not impact yield. Okay?
- [00:29:25.730]So the yield is equivalent to the other treatments.
- [00:29:28.990]However, when we combine all this BPO glyphosate
- [00:29:32.809]for this Cobra mix for the flexstar mix
- [00:29:34.997]and for the cadet mix,
- [00:29:36.250]we did see a downward trend.
- [00:29:38.170]A reduced yield when we combine the full rate of the PPO
- [00:29:42.460]with the glyphosate
- [00:29:44.270]however that trend was not observed
- [00:29:46.560]for the herbicide resource.
- [00:29:48.470]So let me combine resource,
- [00:29:50.280]which is a PPO herbicide
- [00:29:51.370]glyphosate be enhanced waterhemp control
- [00:29:54.170]we did not impact soybean yield.
- [00:29:56.560]And the same was true when we compare
- [00:29:59.010]the same system instead of tank mixing with the PPO
- [00:30:02.150]we tank mix it with 240 Coleen.
- [00:30:04.150]And remember that this soybeans
- [00:30:05.870]we're in the list soybeans. Okay.
- [00:30:08.970]So I'm running a short of time here.
- [00:30:11.890]I talked about tank mixing herbicides.
- [00:30:14.050]It's a promising strategy to postpone resistance
- [00:30:16.560]and enhanced levels of weed control.
- [00:30:18.470]We're seeing some promising results.
- [00:30:20.170]We're gonna continue to study that
- [00:30:23.040]before I wrap things up here,
- [00:30:24.310]I just wanna switch gears real quick.
- [00:30:26.420]And I wanna talk about dicamba
- [00:30:28.797]So dicamba has been re registered
- [00:30:30.940]for the next five years.
- [00:30:33.270]One of the requirements now is that growers add
- [00:30:36.800]a volatility reducing agent to the tank mix.
- [00:30:41.290]And the reason why that's required is to reduce
- [00:30:44.330]dicamba volatility in applications in soybeans.
- [00:30:49.330]Okay? So this is gonna be mandatory now.
- [00:30:51.700]I know there are some products
- [00:30:53.480]that are coming down the pipeline
- [00:30:54.720]or some announcements to be made.
- [00:30:56.610]One of the products that we had the chance to work with
- [00:30:59.270]is VaporGrip Xtra which is already
- [00:31:02.820]part of the formulation of Xtendamax
- [00:31:05.790]and fexapan, okay.
- [00:31:08.250]And the tape herbicide
- [00:31:09.690]already have VaporGrip in them.
- [00:31:11.503]What we are learning in our trials
- [00:31:13.340]is when you bring an additional VaporGrip
- [00:31:15.940]into the spray solution,
- [00:31:17.920]that helps reduce volatility.
- [00:31:19.830]And we have a bunch of data that's available on that.
- [00:31:22.830]How it helps it helps buffer the reduction pH, okay.
- [00:31:27.740]And this is one of the main reasons
- [00:31:29.110]why we see the reduce volatility
- [00:31:31.630]and Nick is gonna be sharing some information
- [00:31:33.310]with you all.
- [00:31:34.143]So again, this is a requirement moving forward
- [00:31:37.010]one of the products,
- [00:31:38.470]and I'm not endorsing this product
- [00:31:39.560]but this is one product that we tested.
- [00:31:42.240]And we did see a significant reduction in volatility.
- [00:31:46.900]So to wrap things up here,
- [00:31:48.580]we talk about chemistry a lot
- [00:31:50.700]but we need to think outside of the job
- [00:31:53.490]our options inside of the job are getting very limited.
- [00:31:57.540]Okay? So when I heard
- [00:32:00.010]our producers out there to bring more agronomy
- [00:32:03.130]into their program, okay?
- [00:32:05.200]This is what Nick is gonna talk about next.
- [00:32:07.010]We got to stop spreading the weed seed from farm to farm.
- [00:32:11.770]This is something I talked about today.
- [00:32:12.973]We want to bring competition into our systems, right?
- [00:32:16.090]We want to bring what we call darkness.
- [00:32:17.810]We want to bring the canopy as much as possible
- [00:32:20.750]to minimize the opportunities for weeds to grow and Savage.
- [00:32:24.570]Here's a study that we're conducting.
- [00:32:27.800]This is the student Nikola Arsenijevik
- [00:32:30.229]from our program.
- [00:32:31.062]He is looking at management practices of soybeans
- [00:32:34.147]and how that impacts canopy development.
- [00:32:36.590]And one that has a big impact is rows base.
- [00:32:39.610]So that is our mid maze soybeans.
- [00:32:41.630]This picture was taken on July 2nd,
- [00:32:44.440]30 inch, same sitting range,
- [00:32:47.180]15 inch okay?
- [00:32:48.270]some cadet soybeans
- [00:32:50.030]view from above, view from the bottom
- [00:32:52.860]15 inch soybeans
- [00:32:54.170]from above, from the bottom.
- [00:32:55.930]If you're a big weed plant growing
- [00:32:57.660]where are you likely to be more successful?
- [00:33:00.010]Right. So think about that.
- [00:33:01.910]So here I leave my contact information.
- [00:33:04.110]I'm probably running short on time to take questions
- [00:33:07.030]Keith will be happy to take them.
- [00:33:09.280]Folks can check our work on Twitter @WiscWeeds
- [00:33:12.880]or check our blog was WiscWeeds.info.
- [00:33:15.520]So Keith, one more time.
- [00:33:16.670]Thank you for the opportunity.
- [00:33:18.170]Great to be here today.
- [00:33:19.450]And also this information that I presented here today
- [00:33:22.973]will be helpful for Nebraska producers
- [00:33:25.800]as they move into the 2021 growing season.
- [00:33:30.560]Thank you, Rodrigo.
- [00:33:31.590]I do have a questions seen in the chat box,
- [00:33:38.511]based on your experience in Nebraska
- [00:33:41.870]and now based on your experience in Wisconsin,
- [00:33:45.770]do you see in terms of private and commercial applicators
- [00:33:50.680]in terms of weed control,
- [00:33:52.750]do you see anything that you wish you
- [00:33:57.169]you can get growers in Wisconsin
- [00:33:59.600]to adapt the growers in Nebraska are doing
- [00:34:03.400]and vice versa?
- [00:34:05.520]Yeah. So that's an excellent question Keith.
- [00:34:08.010]I think our time in Nebraska,
- [00:34:09.690]prepared us and wanna see us big nine
- [00:34:12.967]for the research that we do here was nice.
- [00:34:16.690]You know, I remember when I was in graduate school
- [00:34:20.180]palmer amaranth was a problem of the West, right?
- [00:34:22.260]West part of Nebraska
- [00:34:24.030]the problem now is still palmer amaranth
- [00:34:26.744]according to a survey is the number one weed.
- [00:34:28.910]So the weed is moving across the state.
- [00:34:30.870]When I was in graduate school at Nebraska
- [00:34:33.033]I remember our mentors there,
- [00:34:35.510]the Winc Science we were doing lot of research
- [00:34:37.510]with waterhemp, they were 2012, 2013.
- [00:34:40.570]We went for field days with you
- [00:34:41.850]and several other resistance management field dates
- [00:34:44.390]with the marketing board,
- [00:34:46.180]talking about the value of pre and later residual qualities,
- [00:34:51.897]and where we were in 2012
- [00:34:54.553]and 2013 in Nebraska
- [00:34:55.440]where we were at in, in Wisconsin.
The screen size you are trying to search captions on is too small!
You can always jump over to MediaHub and check it out there.
Log in to post comments
Embed
Copy the following code into your page
HTML
<div style="padding-top: 56.25%; overflow: hidden; position:relative; -webkit-box-flex: 1; flex-grow: 1;"> <iframe style="bottom: 0; left: 0; position: absolute; right: 0; top: 0; border: 0; height: 100%; width: 100%;" src="https://mediahub.unl.edu/media/15221?format=iframe&autoplay=0" title="Video Player: Video 5 - 2020 Virtual Nebraska Soybean Day and Machinery Expo" allowfullscreen ></iframe> </div>
Comments
0 Comments