Weed Control in High Plains: Current Challenges and Future Outlook
The use of herbicides and herbicide-resistant (HR) crops have allowed to reduce or eliminate tillage for weed management, thereby benefitting soil and water conservation in the semi-arid High Plains. However, the widespread adoption of glyphosate-resistant crops, repetitive use of herbicides with the same mechanisms of action, and lack of diversity in production practices resulted in evolved resistance to herbicides in major cropland weed species, including horseweed, kochia, Palmer amaranth, common waterhemp, and Russian thistle. Managing HR weeds is complex and varies both within and between regions. Further complicating management is lack of community-wide concern and unified approach to management, lack of flexibility in government programs, and current commodity prices makes it difficult to change. This seminar will illustrate some of these challenges and will also highlight novel weed control strategies that may fit well in the no-till cropping systems of the High Plains for controlling HR weeds.
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[00:00:00.800]The following presentation
[00:00:02.250]is part of the Agronomy and Horticulture Seminar Series
[00:00:05.840]at the University of Nebraska-Lincoln.
[00:00:08.250]Okay, so let me do a quick introduction here.
[00:00:12.510]My name is Steve, Steve Knezevic,
[00:00:14.360]and it's my pleasure to introduce Dr. Kumar.
[00:00:19.580]Dr. Kumar and I've known each other,
[00:00:22.260]pretty much from day one he arrived to K-State.
[00:00:24.900]And I've been a K-State graduate so I keep in close touch
[00:00:29.510]with the folks down in Kansas.
[00:00:35.000]And I was the one who actually invited him to come
[00:00:37.590]and share some of his experiences
[00:00:39.260]from that part of the State.
[00:00:41.370]So Dr. Kumar actually came to K-State in 2017.
[00:00:47.420]His office is actually at the ARC,
[00:00:51.610]Agricultural Research Center, that's in Hays, Kansas,
[00:00:54.550]which is, those of you who like geography,
[00:00:56.470]just straight South of Kearney.
[00:00:58.650]And then prior to coming to Kansas,
[00:01:03.090]Dr. Kumar was a postdoc in Bozeman in Montana.
[00:01:07.920]Actually at Huntley, a research station in Montana,
[00:01:12.307]and then he did his PhD prior to that at Bozeman
[00:01:16.360]and his masters at Baton Rouge in Louisiana.
[00:01:21.510]And currently his program's been working on all kinds
[00:01:25.600]of issues with weed control and weed biology,
[00:01:30.410]on problematic species.
[00:01:32.560]And then working on integrated weed management strategies
[00:01:35.890]for dry land in Western Kansas and High Plains regions.
[00:01:41.200]So, I guess with that,
[00:01:42.760]I'm gonna stop and I'm gonna turn the floor to Dr. Kumar
[00:01:47.130]and we're looking forward to your presentation, Sir.
[00:01:51.140]Good afternoon, everyone.
[00:01:54.130]Today, I'm gonna give a little bit of overview
[00:01:58.674]on "Weed Control Issues in High Plains,"
[00:02:01.250]or no-till trial and production systems in terms of,
[00:02:06.290]what are the challenges folks have been seeing here,
[00:02:08.840]in the High Plains region?
[00:02:11.570]Especially the Central Great Plains,
[00:02:14.840]in terms of weed control.
[00:02:16.670]So I'll be going over some of the research projects
[00:02:20.160]we have been doing over the years,
[00:02:22.030]and gonna highlight some of the previous work been done
[00:02:25.670]in the region,
[00:02:26.503]as well as relating to some historical data,
[00:02:30.230]what we have seen in the past and what we can learn
[00:02:33.900]for the future weed control plans,
[00:02:37.230]if you're gonna look forward in the future.
[00:02:40.110]So stick with me and I have plenty to cover,
[00:02:43.050]so, we'll go from here.
[00:02:49.160]So, first of all,
[00:02:49.993]I would like to introduce about the region,
[00:02:54.220]the Great Plains of North America.
[00:02:56.280]It's a prominent region going through
[00:03:00.643]the center of the continent, North America.
[00:03:03.250]And some of the features I have listed down here,
[00:03:06.260]very prominent features of the region.
[00:03:09.610]It, the agroecosystem is a semiarid,
[00:03:12.290]means it has hot summer days
[00:03:14.740]with the cold and dry winters.
[00:03:17.620]The precip, or of the annual rainfall,
[00:03:20.330]is highly variable in this region.
[00:03:22.900]If you go from east to west,
[00:03:25.000]there's a day/night difference
[00:03:26.230]in terms of annual precip we receive.
[00:03:28.892]I have listed down some of the literature mentioned
[00:03:31.750]in the east you can get, some places,
[00:03:34.470]less than 760mm.
[00:03:36.960]Annual rainfall while in the western side,
[00:03:39.420]in Western Texas or Western Montana,
[00:03:42.420]the rainfall could be as low as like 300
[00:03:45.367]or 380mm in some years.
[00:03:48.650]So, along with those rainfall patterns
[00:03:52.350]and weather conditions,
[00:03:53.640]the soil is also shallow in natures.
[00:03:57.010]Most of the soils in the Great Plains
[00:03:59.660]is low in soil organic matter content
[00:04:02.810]and because of that, it's highly prone to wind erosion.
[00:04:07.570]And because of those soil characteristics,
[00:04:10.770]the soil conservation practices were adopted,
[00:04:14.320]such as the fallow production,
[00:04:16.760]as well as a minimum tillage
[00:04:18.180]or no-tillage production systems,
[00:04:20.830]for decades to conserve this soil,
[00:04:23.220]or the soil with the low organic matter,
[00:04:26.150]as well as the lighter soil.
[00:04:29.220]So to conserve the soil folks have been
[00:04:32.530]following these conservation practices,
[00:04:34.990]or soil conservation practices.
[00:04:37.560]So if we look at the region,
[00:04:39.090]we can divide this region in three different sub regions.
[00:04:42.250]This is a, like you see in the map here,
[00:04:45.230]this is a more, we call as a Northern Great Plains.
[00:04:48.290]And then we have a Central Great Plains
[00:04:50.067]and Southern Great Plains.
[00:04:52.240]So I'm gonna focus on the Central Great Plains,
[00:04:54.340]where we are based in Western Kansas,
[00:04:57.300]Western Nebraska or Eastern Colorado area.
[00:05:01.130]And talk about some of the research activities
[00:05:04.520]we have been doing in this region.
[00:05:08.770]A little more on this region,
[00:05:10.960]the Great Plains regions.
[00:05:12.730]This whole region is accounts for more than 60%
[00:05:15.790]of total wheat production in the US.
[00:05:18.310]And predominant rotations are two years
[00:05:20.670]or three year rotations.
[00:05:22.550]Like winter wheat-fallow is predominant
[00:05:24.650]in Northern Great Plains.
[00:05:27.510]While three-year rotations like wheat-summer crop-fallow
[00:05:31.520]is more common in Central and Southern Great Plain.
[00:05:36.070]And as I said,
[00:05:37.150]most of the weed control in these no-till fallow phase
[00:05:40.800]is mainly achieved with the use of herbicides,
[00:05:43.630]because tillage is a very minimal
[00:05:45.720]and no-till production is predominant.
[00:05:48.120]So weed control is generally and historically been achieved
[00:05:51.630]by use of herbicides or chemicals.
[00:05:54.740]Little bit on the history of chemical era or herbicide era,
[00:05:59.860]how it started.
[00:06:01.040]It started with the discovery
[00:06:02.540]of chlorophenoxy acetic herbicides in early 1940s,
[00:06:08.230]when 2,4-D was discovered and commercialized.
[00:06:11.930]And it was pretty effective,
[00:06:14.100]was providing pretty good control.
[00:06:15.920]Still provides pretty good control,
[00:06:17.590]broadleaf weed control in grasses like wheat.
[00:06:21.460]With that discovery,
[00:06:22.470]it actually gave a rise to a new crop protection industry,
[00:06:25.820]or what we call herbicide industry.
[00:06:28.970]A push in many herbicides were developed
[00:06:31.730]during the next 50 years.
[00:06:34.300]It was also known as a golden era of herbicides
[00:06:37.700]and several new mode of actions were discovered,
[00:06:40.170]and were commercialized for folks to use
[00:06:43.290]in different cropping system or different situations.
[00:06:46.870]And part of the history is also the last
[00:06:49.770]herbicide mode of action, which was HPPD-inhibitors,
[00:06:53.900]where our herbicides like mesotrione belongs to.
[00:06:58.420]That was the last herbicide mode of action
[00:07:01.000]that was commercialized and that was 1980.
[00:07:03.950]Since then we don't have any new herbicide mode of action
[00:07:08.240]came into the market.
[00:07:09.320]So you can imagine that we have been using
[00:07:13.280]all those chemistries,
[00:07:15.250]there's no new herbicide side of action or mode of action
[00:07:19.470]into the market since 1980s.
[00:07:24.360]Along with those herbicide discoveries,
[00:07:26.170]herbicide-resistant crops were developed as well.
[00:07:30.460]if we see the first non-transgenic herbicide system crop
[00:07:34.150]was atrazine-resistant canola and that was in 1984.
[00:07:39.240]However, the first transgenic or GMO,
[00:07:42.580]or genetically modified crop,
[00:07:44.490]was bromoxynil-resistant cotton,
[00:07:47.010]or glyphosate-resistant canola,
[00:07:49.540]and then corn and cotton later on.
[00:07:52.560]So those were the first commercial successes
[00:07:55.100]were like glyphosate-resistance or Roundup Ready crops,
[00:07:59.010]like canola, cotton, soybean and corn during the mid 90s.
[00:08:03.290]That was the highest success we have achieved
[00:08:05.960]with the transgenic crops or GMO crops.
[00:08:10.750]So, I pulled up some of the data,
[00:08:15.000]as per the survey been done with the USDA
[00:08:18.031]and NASS during 2012 and 2016.
[00:08:22.290]And they had found about 160 million acres of fallow fields
[00:08:27.130]were treated with glyphosate during those four years.
[00:08:30.630]An interesting point was during those same years,
[00:08:33.230]about 85% of the total glyphosate use
[00:08:35.830]was also applied to GR crops or Roundup Ready crops
[00:08:40.280]like soybean, corn and cotton.
[00:08:43.150]So you can imagine that glyphosate use
[00:08:46.010]was not only on fallow situation,
[00:08:48.020]but also were used on those Roundup Ready crops.
[00:08:52.110]So the use was increased exponentially during that time,
[00:08:56.680]having glyphosate used on GR crops
[00:08:58.810]occurred on the same acreage,
[00:09:00.700]basically where we had a fallow phase
[00:09:04.010]and then we had a Roundup Ready crops
[00:09:06.228]in the subsequent years.
[00:09:08.370]So that has caused a lot of selection pressure,
[00:09:11.600]or increased selection pressure on the weeds
[00:09:14.700]to evolve resistance to glyphosate.
[00:09:18.920]So, with those historical background,
[00:09:22.080]two things happened in the Great Plains,
[00:09:23.850]in terms of weed control practices:
[00:09:26.430]First was adoption of soil conservation practices
[00:09:29.890]with the ease of chemical weed control.
[00:09:32.230]With the chemical industry came into existence
[00:09:34.790]and with the new herbicide mode of actions
[00:09:36.790]came into the market,
[00:09:38.650]this was easy transition from tillage-based weed control,
[00:09:44.570]to no-tillage-based weed control.
[00:09:46.970]And then the second thing was the widespread adoption
[00:09:49.550]of glyphosate-resistant crops, in mid 90s,
[00:09:51.996]as I said, soybean, cotton or corn,
[00:09:57.200]those crops were heavily successful,
[00:10:00.630]being adopted by growers.
[00:10:02.690]So these two major changes or events,
[00:10:06.190]also led to two major impacts in terms of weed control.
[00:10:10.230]There was a major weed species shift,
[00:10:11.980]from large-seeded to small-seeded weeds.
[00:10:15.450]If you see, historically,
[00:10:16.840]some of the areas we see in Central Great Plains,
[00:10:21.120]we used to have large-seeded weed species.
[00:10:25.020]Now we see more of small-seeded weed species,
[00:10:27.750]like things like kochia and Palmer,
[00:10:30.350]but historically it used to be like,
[00:10:32.760]velvetleaf or other large-seeded weed species.
[00:10:39.100]And the second thing happened was the evolution
[00:10:41.100]of herbicide resistance.
[00:10:42.040]As I said, the selection pressure has increased,
[00:10:45.050]over the years,
[00:10:45.980]because of fallow phase as well as adoption
[00:10:49.661]of transgenic crops like Roundup Ready crops,
[00:10:54.820]resulted in evolution of herbicide-resistant weeds.
[00:10:57.340]So these two major impacts happen right here,
[00:11:01.240]in Central Greater Plains or in High Plains,
[00:11:03.840]as well as other sub regions of the Great Plains.
[00:11:08.060]So moving on to some confirmed cases
[00:11:09.900]of herbicide-resistant weeds.
[00:11:11.310]This is the map of US
[00:11:12.960]and you can pretty much see the Great Plains
[00:11:15.690]or Central Great Plains in number of species
[00:11:19.588]they have documented in terms of herbicide resistance.
[00:11:23.830]And being in Kansas, I always focus on Kansas,
[00:11:28.760]and this is probably the highest number of cases
[00:11:32.240]being reported from Kansas,
[00:11:34.200]15 species: 12 broadleaf, 3 grasses.
[00:11:37.350]And you can see six different herbicide groups
[00:11:41.390]resistance in those 15 species been documented so far.
[00:11:45.360]And there are multiple cases of herbicide-resistance
[00:11:48.600]in species like kochia, Palmer, horseweed, and waterhemp.
[00:11:53.160]So, all these events happen because of increasing use
[00:11:57.680]of those herbicides over and over in our cropping system.
[00:12:03.960]So moving on to some specific examples here,
[00:12:06.630]in terms of weed species we are dealing with
[00:12:09.040]in High Plains.
[00:12:10.310]First one is the kochia or Bassia scoparia.
[00:12:13.980]This is kind of my favorite weed
[00:12:16.040]because I did my PhD on this species, I like it,
[00:12:20.650]but this is a very aggressive, very invasive,
[00:12:23.780]highly or widely-spread species in High Plains
[00:12:27.020]and other regions of Great Plains.
[00:12:29.500]So basically it's a native to temperate region
[00:12:32.960]European and Asia.
[00:12:34.980]And was introduced in North America in early 1900s.
[00:12:40.110]The features this species carries is unique,
[00:12:44.170]in terms of biological features.
[00:12:46.410]It is a C4 plant, it emerge early.
[00:12:49.560]It's one of the early emerger actually, in the spring,
[00:12:53.960]when nothing is coming from the ground,
[00:12:56.370]kochia starts emerging like mid-February
[00:12:59.350]or sometime early February in the spring,
[00:13:04.050]or even before spring.
[00:13:06.290]And it has a high rapid growth
[00:13:09.340]and it can cause a high crop yield loss
[00:13:11.810]if it is interfering with the crops,
[00:13:14.610]like sugar beet in Northern Plains,
[00:13:17.200]or sorghum or soybean or any other crop in High Plains.
[00:13:24.240]In terms of other features it is a protogynous,
[00:13:26.800]means female part of the flower matures early,
[00:13:30.730]and it can lead to cross pollination or outcrossing.
[00:13:35.100]That also led to high genetic diversity within
[00:13:37.720]and between the field populations.
[00:13:41.680]It is a prolific seed producer.
[00:13:43.120]A single kochia has been reported to produce
[00:13:46.390]more than a hundred thousand seeds.
[00:13:47.840]And those seeds can tumble across the landscape
[00:13:52.740]through the winds, strong winds in the fall.
[00:13:55.830]So all these features or characteristics
[00:13:59.430]make this weed species highly problematic.
[00:14:03.240]And one of the major challenge species
[00:14:07.250]for the producer in the region.
[00:14:11.420]Some of you might have seen this graph before,
[00:14:14.630]but this is a status of glyphosate-resistant kochia
[00:14:18.550]in throughout the Great Plains.
[00:14:20.950]And this was 2007 when the first report
[00:14:25.010]came from Western Kansas.
[00:14:26.320]Actually my predecessor, Dr. Phil Stahlman,
[00:14:29.510]was the first scientist who discovered this first report.
[00:14:34.430]And within four, five to six years,
[00:14:37.810]it was documented across through all the Great Plains.
[00:14:41.490]So glyphosate-resistance in kochia population
[00:14:45.050]has been widely-spread throughout the Great Plains.
[00:14:49.310]Like 10 States, they have documented cases,
[00:14:51.820]and then there are three provinces in Canada even,
[00:14:55.440]they have documented glyphosate-resistance
[00:14:57.580]in this species.
[00:15:00.540]Some of the earlier surveys been done by Dr. Stahlman
[00:15:03.840]and Dr. Westra in Colorado,
[00:15:06.210]they have found widespread resistance to glyphosate,
[00:15:10.410]as you see in this map in the Western Kansas
[00:15:12.690]and Eastern Colorado and then little bit
[00:15:15.330]on the Western or Southwestern side of Nebraska,
[00:15:19.300]in terms of glyphosate-resistant kochia
[00:15:21.740]in different crops and different cropping systems.
[00:15:27.230]Later on, there was other surveys being done
[00:15:30.040]in Eastern Colorado,
[00:15:32.190]looking at the glyphosate and dicamba resistance.
[00:15:34.990]And we have been also doing some recent survey
[00:15:38.470]from Western Kansas, Western Oklahoma and Northern Texas,
[00:15:42.690]and one of my graduate student is working on this survey,
[00:15:47.520]looking at the status of multiple herbicide resistance
[00:15:52.120]in those kochia line.
[00:15:53.410]If you see in this map here on the right,
[00:15:56.130]he has characterized about 82 populations screening results
[00:16:00.720]in terms of multiple resistance,
[00:16:02.510]and most of these population had survived
[00:16:05.780]field use rates of glyphosate
[00:16:07.520]and field use rate of chlorsulfuron.
[00:16:10.230]Along with that he also found four ways,
[00:16:13.370]or five-way resistance like chlorsulfuron,
[00:16:17.260]glyphosate, atrazine, dicamba and fluroxypyr resistance,
[00:16:21.800]when he screened those lines with the post applied
[00:16:24.750]of those chemistries at field use rate.
[00:16:27.360]So things have become more challenging
[00:16:29.930]with the use of alternate chemistries.
[00:16:32.850]We have been seeing more and more cases
[00:16:34.740]of multiple-resistance kochia in the region.
[00:16:39.500]So the next weed species I'm gonna talk about,
[00:16:41.640]which has recently become major issues.
[00:16:44.731]Kochia was number one issues and then in recent years,
[00:16:48.480]Palmer amaranth, which is also called Amaranthus palmeri,
[00:16:53.391]a member of pigweed family,
[00:16:55.090]has become also highly problematic
[00:16:58.410]for producers in the regions.
[00:17:00.430]So, not like kochia, it is a dioecious species,
[00:17:04.070]kochia is a monoecious,
[00:17:05.670]meaning that Palmer amaranth has a separate
[00:17:10.082]male and female flowers, on separate plants.
[00:17:14.090]And it is also somewhat annual,
[00:17:15.760]but compared to kochia it comes late,
[00:17:18.080]late spring through late summer.
[00:17:19.810]And it has extended emergence throughout the season.
[00:17:23.860]Very aggressive, just like kochia,
[00:17:25.610]in terms of growth and competitions,
[00:17:27.960]and can cause significant yield reductions.
[00:17:31.230]Prolific seed production,
[00:17:32.870]it can produce even more seeds than kochia.
[00:17:35.650]A single female plant has been reported to produce
[00:17:39.130]more than half million seeds per plant,
[00:17:41.880]if you allow them to grow
[00:17:45.260]and produce with no crop competition.
[00:17:49.220]So you can see all these features,
[00:17:51.440]all these biology of these weird species,
[00:17:54.110]make these weird species are more and highly problematic
[00:17:58.680]for the producers.
[00:18:02.327]In terms of herbicide resistance,
[00:18:04.600]status of Palmer amaranth in the Great Plains,
[00:18:06.890]you see here a map on the left.
[00:18:10.500]These are the cases being reported from Kansas,
[00:18:13.480]Nebraska, Oklahoma and Texas.
[00:18:16.640]And there are population being reported
[00:18:18.780]with glyphosate ALS is pretty common
[00:18:22.260]among this real population in Palmer amaranth.
[00:18:25.830]Along with those, there are reports on resistance
[00:18:30.090]to PS II inhibitors, HPPD inhibitors,
[00:18:32.880]and very recently, resistant to synthetic auxins,
[00:18:36.920]things like 2,4-D and dicamba.
[00:18:40.370]As well as there is a case of PPO inhibiting herbicide
[00:18:45.610]has also control failure on Palmer amaranth
[00:18:49.010]in Kansas recently.
[00:18:51.700]On the right side I have provided a map of Kansas
[00:18:54.920]and you see the blue and the red triangles here?
[00:18:58.880]These are Palmer amaranth collections
[00:19:01.040]we have screened so far.
[00:19:02.390]This is kind of the first-level screening, field use rate.
[00:19:06.750]We tested for glyphosate and you can see the widespread
[00:19:12.080]presence of glyphosate resistance,
[00:19:14.420]in Palmer amaranth population
[00:19:16.040]in Central and Western Kansas here.
[00:19:19.310]On the Eastern side, these dots, or the circular dot,
[00:19:23.640]represent the waterhemp sample we screened
[00:19:26.250]with the field used rate, and we have seen,
[00:19:30.080]100% of those populations were surviving
[00:19:33.900]the field use rate of glyphosate.
[00:19:36.530]So widespread presence of glyphosate resistance
[00:19:40.210]in Palmer amaranth and the waterhemp in the State of Kansas.
[00:19:46.960]So it's not only single herbicides
[00:19:49.220]that has been showing resistance in Palmer amaranth,
[00:19:51.780]but we have some lines being reported
[00:19:54.000]with multiple resistance.
[00:19:56.190]We have few Palmer amaranth populations from Barton County,
[00:20:00.550]Pratt County and Kiowa County,
[00:20:02.300]these are all South-Central Kansas,
[00:20:05.040]where we have reported four to five-way resistance
[00:20:09.170]in those populations.
[00:20:11.530]And you can see some of the picture here,
[00:20:13.240]the picture in the middle is Palmer amaranth
[00:20:16.020]from one of the populations surviving 18 fl oz rate
[00:20:19.740]of the 2,4-D which is a field use rate of 2,4-D.
[00:20:23.070]And the same plant on the right side was able to produce
[00:20:26.260]seeds in the greenhouse,
[00:20:27.440]and we are doing further work on understanding
[00:20:30.450]the mechanisms and inheritance and fitness,
[00:20:33.720]and all kind of biological studies on that population.
[00:20:39.910]So the point is,
[00:20:40.930]it's not only a resistance to one herbicide,
[00:20:44.290]but multiple herbicide resistance has become evident
[00:20:48.030]and common in Palmer amaranth in the State of Kansas
[00:20:51.100]and in the neighboring states in the region.
[00:20:55.320]Moving on to other glyphosate-resistant weeds,
[00:20:57.630]we talk about kochia, Palmer amaranth,
[00:21:00.710]we have other species like horseweed,
[00:21:04.100]it's widespread resistance to glyphosate ALS inhibitors.
[00:21:08.290]Russian thistle is another species,
[00:21:10.230]has not been documented for glyphosate resistance
[00:21:13.160]in the State of Kansas or Colorado,
[00:21:16.210]but has been reported from Montana,
[00:21:18.620]Washington and Oregon in the Northern side of it.
[00:21:22.450]So there could be a potential or future evolution
[00:21:25.550]in that species in the High Plains region as well.
[00:21:30.330]And then glyphosate resistant waterhemp on the Eastern side
[00:21:33.450]of the region like Eastern Nebraska, Eastern Kansas.
[00:21:37.890]We have seen glyphosate resistance
[00:21:39.770]in those population quite common.
[00:21:44.320]Little bit on the mechanism sides.
[00:21:46.100]I've been talking about those resistance
[00:21:48.810]and major mechanisms are target-site based,
[00:21:52.680]either target-site or non-target-site based resistance.
[00:21:56.300]And some of you already know that target-site resistance
[00:22:00.320]is quite common for causing resistance to ALS inhibitors.
[00:22:06.510]And there are a few cases that have also shown a mutation,
[00:22:12.210]or point mutation in target-site,
[00:22:14.100]causing resistance to glyphosate
[00:22:15.850]and other herbicide site of action as well.
[00:22:19.710]The second mechanism is a non-target-site,
[00:22:22.160]either altered absorption or altered translocation
[00:22:26.690]of the molecules could be a factor or could be a mechanism.
[00:22:30.440]And the recent one is the enhanced metabolism,
[00:22:33.380]which has become more common in multiple resistance,
[00:22:36.607]or multiple herbicide resistance populations
[00:22:40.270]of Palmer amaranth.
[00:22:41.740]We are seeing more enhanced metabolism based mechanism.
[00:22:45.660]This is all about resistance
[00:22:47.460]and what is the status right now,
[00:22:49.520]what's happening in those species.
[00:22:52.050]So before I joined here at K-State,
[00:22:54.060]my predecessor was able to hold
[00:22:56.370]original stakeholder listening session,
[00:22:58.480]organized by Weed Science Society of America.
[00:23:01.830]So he organized some sessions,
[00:23:03.950]and the main goal with those sessions in the region,
[00:23:07.360]in the Great Plains region,
[00:23:08.610]was to gain understanding of the diverse
[00:23:11.550]stakeholders awareness, concerns,
[00:23:13.750]and management of herbicide resistance,
[00:23:15.530]and become familiar with the original differences
[00:23:17.700]and solutions, what we need to do in the futures,
[00:23:20.850]what we are missing right now.
[00:23:22.480]Where is the state of weed control right now,
[00:23:25.180]and wanted to take the feedback or input,
[00:23:28.250]from the stakeholders, including farmers,
[00:23:32.130]crop consultants and industry personnel on those sessions.
[00:23:36.670]So basically there were seven sessions were held
[00:23:40.800]and one of those session was held in Great Plains,
[00:23:44.130]And some of the top priorities they discussed,
[00:23:47.140]or brought it up, throughout those discussion section,
[00:23:50.350]was they felt that there needs to be increased funding
[00:23:54.480]for university and ARS field research,
[00:23:57.360]applied weed science research from those session.
[00:24:02.340]And a second point was to educate more growers
[00:24:07.290]and give some concise electronic formats,
[00:24:10.090]not just in-person educations, but give some materials.
[00:24:15.390]Come up with some material that they can
[00:24:17.330]be distributed electronically.
[00:24:21.110]Others teams came out of those discussions,
[00:24:24.430]were education of urban citizens.
[00:24:28.230]The people in cities,
[00:24:29.580]they need to be more aware of what folks
[00:24:32.490]in the rural communities are struggling with,
[00:24:34.380]in terms of herbicide resistance and how that has been
[00:24:37.740]changing the food supply and the food chain.
[00:24:40.480]And then science based labeling of herbicide
[00:24:42.890]was also another top priority was discuss.
[00:24:47.400]Basically the main theme out of those discussion session
[00:24:51.900]was the system approach
[00:24:52.950]to herbicide resistance management,
[00:24:54.530]more diversity, including integrated weed management,
[00:24:58.040]or non-chemical methods of weed control
[00:25:00.910]need to be researched and implemented in those regions.
[00:25:05.600]So those were pretty good discussion points
[00:25:09.540]from those listening session was discussed.
[00:25:11.960]And I talked to Phil and it was pretty good,
[00:25:15.830]decent discussions and input from growers,
[00:25:19.520]and other stakeholders that helped folks like me
[00:25:23.850]to really think about, when you go beyond in the future,
[00:25:27.630]what we gonna do in terms of controlling
[00:25:30.680]these multiple herbicide resistant weed populations
[00:25:33.410]in the region.
[00:25:35.540]So when I think about the future outlook of weed control
[00:25:38.400]with all these issues of weeds,
[00:25:40.530]like herbicide resistance,
[00:25:41.960]multiple herbicide resistance,
[00:25:43.660]we have no-till folks cannot do whole lot of tillage.
[00:25:47.320]So I listed down some of the points
[00:25:49.450]I can think of we need to look into,
[00:25:52.440]and we are looking into,
[00:25:54.270]but need to implement more widespread in the regions.
[00:25:58.390]And those five points I can come up with is:
[00:26:01.630]first one is, everybody knows commercialization
[00:26:04.280]of new transgenic crops.
[00:26:05.950]Things like we all know we have now,
[00:26:11.190]three-way stack trade technologies,
[00:26:13.350]like Xtend beans or Enlist systems or GT27 Soybean,
[00:26:18.870]they are already in the markets.
[00:26:20.530]How are we gonna use that systems or those new systems
[00:26:24.050]to help us controlling those herbicide resistant
[00:26:28.770]That could be a one thing to think about,
[00:26:32.050]in terms of how we can make this viable options
[00:26:35.450]in the longer term and learn from our past,
[00:26:38.390]from Roundup Ready systems, that what mistake we have made,
[00:26:42.130]so that we can correct it,
[00:26:44.170]and we can use these technologies for longer time.
[00:26:48.525]And the second thing I could see is underutilized tools,
[00:26:52.120]which we have not implemented or adopted widely,
[00:26:56.330]and has not been explored also, are the cultural practices.
[00:27:00.100]Things like cover crops, crop rotation,
[00:27:02.220]competitive crop cultivars,
[00:27:04.470]need to determine the germination emergence modeling
[00:27:08.150]of all major dominant weed species,
[00:27:11.000]to make our weed control plans.
[00:27:15.630]or we need to fine-tune some of the agronomic practices
[00:27:18.470]we are following or have adopted,
[00:27:22.070]and how we can change those in terms of planting dates,
[00:27:24.830]seed rates, row spacing.
[00:27:26.870]What are those in terms of optimizing our weed control
[00:27:30.640]going into the future with those
[00:27:32.430]new stack trade technologies,
[00:27:34.330]especially if you are gonna make those technologies
[00:27:37.540]viable and sustainable for longer term.
[00:27:40.990]So, third one was the mechanical methods of weed control,
[00:27:44.880]called harvest weed seed control.
[00:27:47.430]And then strategic and occasional tillage.
[00:27:50.120]And the fifth one is the utility of precision ag tools.
[00:27:53.580]So I'm gonna go over a little bit in some of these
[00:27:59.210]futures outlook, or future methods of weed control,
[00:28:03.010]I can think of for the region.
[00:28:05.340]And some of those we are touching base,
[00:28:08.010]in terms of doing some projects,
[00:28:10.060]and gonna highlight some of the results
[00:28:12.842]from the future perspective going forward.
[00:28:17.700]So, first one is the cover crops,
[00:28:19.820]integrating cover crops for weed suppression
[00:28:21.860]in no-till dryland central Great Plains.
[00:28:26.213]This is a pretty typical field we see in early spring.
[00:28:30.000]Wheat stubble or milo stubble coming up
[00:28:32.440]with the tons of kochia on the ground.
[00:28:35.510]You see like a mat of kochia coming.
[00:28:38.600]So when I think of those fallow fields,
[00:28:40.690]I think of replacing that fallow with something
[00:28:43.550]like a cover crops.
[00:28:46.100]What cover crops can do probably can suppress those weeds
[00:28:50.600]and probably we don't need to spray that many times,
[00:28:54.280]as we are spraying right now to keep those fallow phases,
[00:28:57.550]or fallow periods, weed-free.
[00:29:01.150]So thinking of that, integrating cover crops in our systems,
[00:29:04.260]I can think of two fallow periods if we are thinking about
[00:29:07.970]three year rotations.
[00:29:09.120]Let's say here, winter wheat,
[00:29:11.480]grain sorghum, and fallow rotations.
[00:29:13.630]So after winter wheat there is a fallow period,
[00:29:16.650]until we plant our grain sorghum.
[00:29:18.860]And there is another fallow period
[00:29:20.310]after grain sorghum harvest,
[00:29:21.910]until we plant our winter wheat next year.
[00:29:25.270]So these are the two windows where can fit our cover crops,
[00:29:28.380]fall cover crops or spring cover crops.
[00:29:32.419]And there has been this little bit work done
[00:29:34.180]by colleagues at K-State, in Western Kansas,
[00:29:36.880]and probably in Western Nebraska also.
[00:29:40.000]And this work has been done in actually Colby,
[00:29:44.780]as well as HB Ranch, there is another satellite site,
[00:29:48.070]with the K-State here, about 35 miles west of Hays.
[00:29:53.470]And the cropping system folks,
[00:29:55.460]they have come up with these spring-planted cover crops.
[00:29:58.520]They planted spring peas, oat-triticale mixture,
[00:30:01.850]or oat-triticale-peas mixture,
[00:30:04.290]and wanted to compare with the weedy-fallow plants,
[00:30:07.010]how much suppression they can see in terms of weed control,
[00:30:10.290]or weed suppression.
[00:30:11.930]And if you look at those data points,
[00:30:14.950]these are pretty interesting data points here,
[00:30:18.490]from those spring-planted cover crops.
[00:30:20.850]Any crop they planted helped to suppress those
[00:30:24.260]total weed dry weights.
[00:30:25.500]And the major species here was kochia
[00:30:27.800]and glyphosate resistant kochia.
[00:30:30.090]Compared to weedy-fallow,
[00:30:31.270]you can see significant reduction in those plots,
[00:30:34.830]in terms of weed dry weights at the end of the season.
[00:30:40.050]Here is the picture I took one of the plots
[00:30:42.930]they had in HB Ranch.
[00:30:44.740]On the left side you can see spring oat-triticale mixture
[00:30:48.210]and on the right side is a fallow,
[00:30:50.780]nothing, just left like a fallow plot.
[00:30:54.430]And you can see just growing a cover crop,
[00:30:58.320]how much suppression we can achieve
[00:31:00.120]in terms of weed suppression, like kochia here,
[00:31:03.040]major species, not any herbicide they applied,
[00:31:07.290]just they terminated this cover crop and that's it.
[00:31:10.360]So, good suppression they could could get,
[00:31:14.660]with spring-planted cover crop.
[00:31:16.950]And how about the fall-planted cover crop?
[00:31:18.880]This is a project been started with one of my PhD student
[00:31:22.600]is working on this, looking at the fall-planted cover crop.
[00:31:26.410]And he used the the four-way mixtures,
[00:31:28.530]like triticale, winter peas,
[00:31:33.647]He planted in May, oh, sorry, September 2020,
[00:31:37.440]and then terminated in next year in next spring,
[00:31:41.030]with the different programs.
[00:31:42.580]He used glyphosate,
[00:31:43.890]or glyphosate with the soil residual program,
[00:31:47.120]like Degree Extra.
[00:31:48.660]And wanted to see what it does in terms of combining
[00:31:52.250]cover crop with the residual herbicide program,
[00:31:55.530]for weed control in subsequent crop.
[00:31:58.530]And he had a chemical fallow plots also,
[00:32:00.670]which he maintained with glyphosate and Degree Extra
[00:32:03.930]at the time of sorghum planting.
[00:32:06.070]And those plots were planted with the sorghum on June, 2021.
[00:32:12.670]And he collected a bunch of data on weeds,
[00:32:14.910]weed density, weed biomass on monthly internal,
[00:32:19.370]and here's some data,
[00:32:21.000]the preliminary data he received last year.
[00:32:24.350]Pretty interesting and exciting that,
[00:32:27.810]at the early termination, at the time of termination,
[00:32:31.470]he found a significant suppression
[00:32:34.590]of those total weed density,
[00:32:37.230]especially with those two programs,
[00:32:39.500]either glyphosate or glyphosate with the Degree Extra.
[00:32:42.759]At termination and 30 days after termination,
[00:32:46.160]though there was no difference among treatments
[00:32:49.050]at the later evaluation timing.
[00:32:52.469]This is the picture of kochia at the chemical fallow
[00:32:56.330]and the right side picture showing fall-planted cover crop
[00:32:59.110]at the time of termination,
[00:33:00.950]suppressing those kochia seedlings under the canopy.
[00:33:04.540]And the biomass we could receive at the time of termination
[00:33:07.700]was 1,500 kilogram per hectare.
[00:33:10.190]Not whole lot like we can see in the eastern side,
[00:33:13.820]but enough to cause some suppression in the early season,
[00:33:17.260]as you see here in the data.
[00:33:20.090]Similarly, the total weed biomass reductions.
[00:33:23.090]You can see a significant difference among those programs,
[00:33:31.260]compared to chemical fallow plots.
[00:33:33.910]Especially during the late season in sorghum.
[00:33:38.530]And here is the picture that can and tell you
[00:33:40.700]exactly what was going on.
[00:33:42.520]The chemical fallow on the left side
[00:33:44.500]at 80 days after termination.
[00:33:46.900]And this is a,
[00:33:48.180]the right side plot was fall-planted cover crop,
[00:33:51.290]terminated with the Roundup and Degree Extra.
[00:33:54.370]You can see pretty good suppression of Palmer amaranth
[00:33:58.050]from right side compared to the left side.
[00:34:02.920]He also took some emergence counts and found that,
[00:34:06.040]using some of the residual herbicide program
[00:34:08.390]at the time of termination,
[00:34:10.170]can also help in shifting the Palmer amaranth emergence,
[00:34:13.800]or what he found was almost 135 days difference,
[00:34:19.880]in terms of 90% of cumulative emergence of Palmer amaranth
[00:34:24.537]in a plot where he put glyphosate,
[00:34:28.970]along with the Degree Extra at the time of termination,
[00:34:32.300]in comparison to chemical fallow plots.
[00:34:34.580]So it's not only the suppression
[00:34:36.180]or growth suppression of those weeds,
[00:34:39.850]but also the emergence shift we also observed
[00:34:42.870]with using cover crop and herbicides.
[00:34:47.100]Similarly, another graduate student,
[00:34:50.100]has been looking at the termination timing.
[00:34:52.750]This is work been done in central Kansas,
[00:34:54.813]this is the Great Bend site.
[00:34:57.560]And the cover crop he was using was cereal rye.
[00:35:01.710]So in terms of terminating early,
[00:35:05.560]when he terminated late, mid April versus mid May,
[00:35:09.490]he found significant difference in terms of density,
[00:35:13.890]where he had a Palmer amaranth density in that site.
[00:35:17.230]Significant difference at three weeks after post,
[00:35:20.100]as well as at the time of harvest
[00:35:23.170]for Palmer amaranth densities,
[00:35:24.950]just delaying the cereal rye termination.
[00:35:28.960]So again, we are looking into cover crops,
[00:35:33.560]fitting into cover crops into our system,
[00:35:35.690]so these are the things, the planting methods,
[00:35:38.770]and time of planting, termination timing.
[00:35:41.030]These are all gonna be the deciding factor,
[00:35:45.460]how much weed biomass
[00:35:47.190]or how much weed suppression we gonna get,
[00:35:49.800]if you're gonna use those cover crops in our system.
[00:35:52.260]So this is a pretty cool to look at,
[00:35:57.320]from agronomic side of it, that what is the best,
[00:36:00.500]and what is the optimum time of termination
[00:36:03.100]of those fall-planted cover crops,
[00:36:05.090]when you're gonna go with the summer crops like a soybean,
[00:36:07.510]in this particular example.
[00:36:10.100]And how much water will be left there
[00:36:12.140]for the subsequent crop to make it to a good yield.
[00:36:17.810]Again, some of the barriers I listed,
[00:36:19.680]some of those, as you know,
[00:36:21.320]that most cover crops require soil moisture
[00:36:23.480]in already moisture deficient environments.
[00:36:25.400]So that'll be the major hurdle to adopt,
[00:36:27.580]or widespread adoption of the cover crops.
[00:36:30.552]Lower the crop yield, at least initially,
[00:36:33.120]however, may be offset by lower herbicide costs,
[00:36:35.640]so we're gonna look into the economic side also
[00:36:37.750]by using a cover crops.
[00:36:39.870]If we are reducing the herbicide applications
[00:36:42.250]in those system and how much economically we are saving,
[00:36:46.340]for weed control using the cover crops.
[00:36:49.090]And then agronomic consideration, as I said,
[00:36:51.480]there is a lot to do in terms of research wise.
[00:36:55.300]We need to determine the cover crops species selection,
[00:36:57.950]seeding rates, seeding and termination time,
[00:37:01.930]as well as establishment challenges
[00:37:03.720]and method of terminations.
[00:37:06.540]As I mentioned, economic considerations,
[00:37:09.920]economic analysis are needed.
[00:37:11.480]Are we gonna leave it as a cover crop,
[00:37:13.720]or we gonna graze it, or we gonna hay?
[00:37:16.170]All those factors gonna determine how profitable
[00:37:19.990]is this method of weed control,
[00:37:22.060]and how widespread it can be among the growers.
[00:37:26.445]And the last point I made it is,
[00:37:28.090]a more complex management is required.
[00:37:30.430]When we think about cover crops
[00:37:31.970]we also need to think about the sensitivity
[00:37:35.270]of those cover crop species to our commonly-used
[00:37:38.590]herbicides in the systems.
[00:37:40.360]And there has been quite a bit of work being done,
[00:37:42.340]in Nebraska, and I'm hoping to do some work here,
[00:37:47.040]in Western Kansas as well in terms of,
[00:37:50.270]using these cover crops, how they are sensitive,
[00:37:52.570]how much injury we can see in those cover crops species
[00:37:57.260]when we are following these,
[00:38:00.270]wheat summer crop fallow rotation,
[00:38:02.320]and we are using those conventional herbicide program
[00:38:05.790]in those cash crops.
[00:38:10.250]Moving on to the next tactic we are looking at
[00:38:12.790]in High Plains in Western Kansas especially,
[00:38:15.540]is the harvest weed seed control.
[00:38:18.670]When I see, when I came here in 2017,
[00:38:21.440]I got a chance to go throughout Central and Western Kansas
[00:38:26.080]to see some of the fields,
[00:38:27.270]because we were collecting Palmer amaranth,
[00:38:29.020]we were doing a Palmer survey.
[00:38:31.010]And these are the pictures I took from a grower field
[00:38:33.500]in Central Kansas at the time of sorghum harvest,
[00:38:38.070]as well as the soybean harvest.
[00:38:39.890]And I saw that there is a lot of Palmer
[00:38:42.360]and other weeds growing and producing seeds.
[00:38:45.860]So I thought that would be a good opportunity to use
[00:38:48.360]this harvest weed seed control for managing
[00:38:51.840]big weed seed bank in a longer term.
[00:38:55.900]Some of you already know what is harvest weed seed control.
[00:38:58.980]This is basically a new integrated
[00:39:01.450]weed management concept in the US,
[00:39:03.560]but has been discovered in Australia,
[00:39:05.670]has been widely adopted for grass weed control
[00:39:09.250]in Western Australia.
[00:39:11.190]But for US cropping systems,
[00:39:12.910]it's a new method of weed control.
[00:39:15.800]And success of this harvest weed seed control,
[00:39:18.450]mainly rely on the tendency of weed species to retain seeds.
[00:39:22.130]How much seed or how many seeds they will retain
[00:39:25.030]and they will not shatter,
[00:39:26.670]will determine the success.
[00:39:28.540]How much we gonna destroy
[00:39:30.943]or how much we gonna deplete the seed bank in that years.
[00:39:36.210]So the previous studies in the Midwest,
[00:39:38.610]they have found that more than 90% of seed retention,
[00:39:41.590]Palmer amaranth and waterhemp can have
[00:39:44.770]at the time of soybean harvest.
[00:39:46.840]However, we don't know about the Great Plains,
[00:39:50.010]what is the seeds sheltering from those Palmer amaranth
[00:39:54.320]at the time of different crop harvest,
[00:39:56.210]like sorghum or soybean or corn.
[00:39:59.460]So there is a need to do some of the early studies,
[00:40:03.360]the seed retention studies for those species,
[00:40:05.900]to see the fit of this tactic in the region.
[00:40:10.410]So basically two major methods
[00:40:12.670]under harvest weed seed control:
[00:40:14.770]Chaff lining and Weed Seed Destructor.
[00:40:17.516]And we have actually bought a unit here,
[00:40:22.712]in Agricell Center in Hays,
[00:40:25.810]a Redekop seed destructor from Canada,
[00:40:29.700]that can go to a John Deere combine, S series combine.
[00:40:34.290]This is a part of a project,
[00:40:35.733]a USDA project we got funded between K-State
[00:40:39.740]and Iowa State and University of Arkansas,
[00:40:43.020]to look at the seed destruction,
[00:40:44.730]or harvest weed seed control,
[00:40:48.689]on pigweed seed bank management.
[00:40:50.960]We are looking at Palmer amaranth in High Plains
[00:40:53.800]and Arkansas folks are looking in Palmer amaranth in Iowa,
[00:40:58.560]we'll be looking in waterhemp.
[00:41:00.810]So this unit we got last year just fitted on the combine
[00:41:05.030]and we just wanted to try,
[00:41:07.410]and one of the grower near Hays,
[00:41:10.360]had a milo field infested with the lot of pigweeds.
[00:41:13.740]So they invited us to bring this combine and try that.
[00:41:17.910]So, we took this unit there and make some passes there,
[00:41:25.720]and collected some samples out of the seed destruction
[00:41:30.370]behind the combine.
[00:41:31.980]And wanted to see how much seed destruction it can do,
[00:41:34.840]especially when you are running this unit in a milo field.
[00:41:39.190]So this is our very preliminary results.
[00:41:41.180]We captured some samples from those passes
[00:41:44.430]and what we found we actually could categorize those seeds
[00:41:48.090]in four different categories.
[00:41:50.660]We got full seeds, slightly cracked,
[00:41:53.570]moderately cracked and fully pulverized.
[00:41:57.020]But if you add them up,
[00:41:58.610]we saw 95% of those total seeds we capture
[00:42:02.100]from behind the combine were destructor.
[00:42:05.560]Although they were under slightly cracked,
[00:42:08.170]or moderately cracked or fully pulverized category,
[00:42:12.040]but we found 95%.
[00:42:13.930]That was pretty significant number we found in those sample.
[00:42:17.410]So, we're gonna look at this more in this year,
[00:42:21.100]when our grant will be fully executed
[00:42:24.730]and the project is gonna be in the field,
[00:42:28.010]looking at the soybean harvest.
[00:42:30.210]And we gonna also look at a other
[00:42:32.980]harvest weed seed control tactic, which is a chaff lining,
[00:42:36.660]to see how much it can effect on the Palmer amaranth
[00:42:41.020]emergence and germination,
[00:42:42.930]as well as the overall population dynamics,
[00:42:45.940]of Palmer amaranth in soybean rotation
[00:42:48.060]and soybean soybean rotation.
[00:42:51.980]The chaff lining,
[00:42:52.900]this is another project, a separate project,
[00:42:55.880]being funded from USDA-NIFA,
[00:42:58.430]I'm a part of that with the CSU
[00:43:00.550]and Oklahoma State University.
[00:43:03.210]And exploring the simulated chaff,
[00:43:05.680]wheat and sorghum chaff lining on wheat population dynamic,
[00:43:09.570]like seed germination, seedling emergence.
[00:43:12.380]So we did not, or we don't have a chaff liner,
[00:43:15.450]the commercial scale chaff liner,
[00:43:17.300]but we were able to modify our combine
[00:43:20.270]to collect some of the chaff and simulate that chaff
[00:43:24.190]in wheat stubbles.
[00:43:25.830]And what we have found so far in Hays and Tribune,
[00:43:30.540]that having a chaff line treatment
[00:43:32.850]can suppress the weed germination,
[00:43:35.440]or weed counts can be affected
[00:43:38.490]with the chaff lining treatment.
[00:43:40.360]Here you see on the right side,
[00:43:42.000]this is a high chaff line treatment,
[00:43:44.870]which we simulated considering that wheat field had
[00:43:49.010]a hundred bushel yield, versus we had a low chaff,
[00:43:52.090]where we have wheat yield of about 50 bushel wheat yield.
[00:43:56.480]So how much chaff we can get out of that 50 bushel
[00:43:59.530]versus 100 bushel.
[00:44:00.950]And we simulated that by putting those chaff lining
[00:44:04.270]on the field.
[00:44:05.880]And we found that in Hays and Tribune,
[00:44:08.040]both sides, having a chaff line,
[00:44:09.900]especially the high chaff line,
[00:44:12.710]reduced the emergence count of different wheat species,
[00:44:15.630]especially the downy brome, as you see in the picture.
[00:44:19.050]We could see clearly see there's some suppression,
[00:44:22.110]in terms of emergence of those downy brome,
[00:44:25.270]as well as a prostrate pigweed or the wild raddish in Hays,
[00:44:31.440]versus having a Foxtail and downy brome suppression
[00:44:34.510]in Tribune side.
[00:44:35.940]So there is a potential having a chaff lining treatment
[00:44:38.950]also in place,
[00:44:40.891]which will basically collect all the weed seeds
[00:44:44.500]and go to put all the weed seeds in that chaff,
[00:44:47.460]in a narrow row behind the combine.
[00:44:50.140]And you can manipulate that chaff lining to control weeds,
[00:44:55.760]for the subsequent year.
[00:44:57.540]So we gonna, as I said,
[00:44:58.500]we gonna look at the commercial scale chaff liner this year,
[00:45:01.950]with that new USDA and NIFA grant,
[00:45:04.810]comparing with the Harvest Weed Seed Destructor,
[00:45:09.370]side-by-side comparison with the conventional harvester,
[00:45:13.300]that how much seed destruction or chaff lining can do,
[00:45:17.730]in terms of weed seed bank management or Palmer amaranth
[00:45:20.690]in High Plains.
[00:45:24.500]Moving on to a strategic tillage.
[00:45:26.040]Another way of looking the weed control issues
[00:45:28.850]is the strategic tillage.
[00:45:30.280]I know, as I mention, this was,
[00:45:33.360]soil conservation practices were adopted,
[00:45:35.480]because of soils are of shallow
[00:45:37.300]and wind erosion is a major issue.
[00:45:40.540]But some of the colleagues here at K-State
[00:45:42.710]and Colorado State,
[00:45:43.840]they have looked at some of the strategic tillage practices,
[00:45:48.530]like no need to till every year,
[00:45:51.230]but maybe till once in three years,
[00:45:53.900]and what it does in terms of weed control.
[00:45:56.910]And there are reasons to do that because
[00:45:59.870]it also help correcting the soil,
[00:46:02.190]in terms of reducing, with the no-till practice,
[00:46:08.060]the soil pH is reducing, or is going low and low,
[00:46:11.610]becoming more acidic.
[00:46:13.200]And one pass we have found that can reduce,
[00:46:16.310]or can at least correct the soil, in terms soil pH.
[00:46:19.980]But from weed management perspective,
[00:46:22.740]we have also seen that there is a benefit
[00:46:25.460]of doing that practice, of strategic tillage,
[00:46:28.930]maybe once in three years,
[00:46:30.340]especially during the fallow phase,
[00:46:32.390]that you can control some of the weeds.
[00:46:34.770]Some of the data has been published from K-State.
[00:46:37.163]They have done this over three year,
[00:46:40.060]three locations in Western side of the State,
[00:46:43.280]and they did this strategic tillage in different rotations.
[00:46:46.770]Like wheat fallow,
[00:46:48.140]or wheat, sorghum fallow,
[00:46:49.410]or wheat, wheat, continuous wheat.
[00:46:51.800]And they found wherever they had a strategic tillage,
[00:46:54.550]they had a benefit of reducing the weed emergence
[00:46:57.910]in those plots, compared to no-till plots.
[00:47:01.630]Again, we have to be very cautious what we are gonna do,
[00:47:05.260]with the strategic tillage,
[00:47:06.420]but that is another potential tool
[00:47:08.656]we need to think about it,
[00:47:10.681]especially for the future weed control
[00:47:13.270]when we are struggling with multiple herbicide resistant
[00:47:16.230]kochia and Palmer amaranth, and other species.
[00:47:20.949]I'm gonna touch base,
[00:47:21.790]not gonna go too much into details
[00:47:23.760]on the precision ag tools.
[00:47:26.010]I think this is pretty obvious to everyone
[00:47:28.910]that technology has been improved.
[00:47:32.578]Over the last decade,
[00:47:34.140]there is a latest advancement in sensors and weed detection.
[00:47:39.980]There has been some work been done on detecting
[00:47:43.140]kochia and Palmer amaranth from crops,
[00:47:46.520]as well as detecting them from resistance,
[00:47:51.100]versus susceptible population.
[00:47:53.910]So these studies have already been done.
[00:47:57.400]It's actually needs to be implement on a larger scale
[00:48:01.600]when we can do a field map,
[00:48:03.850]for early detection of herbicide resistant weed population
[00:48:07.900]in High Plains.
[00:48:09.220]So that's where I'm thinking to use some of these tools,
[00:48:11.950]which already developed, already available,
[00:48:14.570]how we can implement and help, can get help,
[00:48:18.020]in terms of managing those herbicide resistant
[00:48:21.660]or multiple herbicide resistant weed population.
[00:48:25.060]Especially when our input cost as going up,
[00:48:30.320]how we can reduce that input cost
[00:48:32.120]by using these technologies,
[00:48:34.020]and doing some site specific weed control.
[00:48:37.940]On similar lines,
[00:48:39.010]you might have seen there are new technologies,
[00:48:41.860]new sprayer technologies coming.
[00:48:44.310]WeedSeeker has been on the market for last decade,
[00:48:47.740]or more than decade.
[00:48:49.170]And then new John Deere See & Spray system
[00:48:52.050]has already been on horizon to be used.
[00:48:55.750]I think those technologies are also potential tool,
[00:48:59.100]we will be looking into in High Plains
[00:49:01.910]and integrating with our other methods of weed control,
[00:49:05.670]to make it our economical and sustainable weed control
[00:49:09.550]practices for producers here.
[00:49:12.140]So, the last message I would like to give today,
[00:49:16.010]I think there is a new paradigm of weed management tactics
[00:49:19.020]and we need to think beyond,
[00:49:22.020]what we have been thinking so far.
[00:49:23.780]This is where we are on the left side,
[00:49:26.220]been relying too much on herbicides
[00:49:28.250]and very little on other weed control methods,
[00:49:31.300]especially cultural methods
[00:49:33.430]and mechanical methods and precision ag.
[00:49:35.870]And we need to shift this paradigm towards the right side
[00:49:39.590]and start using other methods of weed control,
[00:49:42.250]especially cultural practices.
[00:49:43.700]I think that these tools are underutilized,
[00:49:46.630]especially like cover crops or crop rotations,
[00:49:49.480]those are underutilized tools we need to explore more
[00:49:52.767]and need to adopt more going in the future.
[00:49:56.680]As well as using some advanced technologies,
[00:49:59.590]precision ag technologies, along with herbicides,
[00:50:03.020]along with other methods of weed control,
[00:50:05.510]so that we can make as a sustainable
[00:50:08.930]and more economical weed control in coming in the future.
[00:50:14.600]This is my last slide,
[00:50:15.590]I would like to acknowledge my students,
[00:50:20.410]graduate student, visiting scholar,
[00:50:22.280]and my collaborators, here at K-State
[00:50:24.660]and in neighboring states,
[00:50:27.470]been helping me supporting me
[00:50:29.040]in all these research projects.
[00:50:32.000]And I would like to acknowledge different commodity groups,
[00:50:35.840]as well as, the USDA and NIFA and Herbicide Industry
[00:50:41.030]to support all these projects
[00:50:43.980]and for the future support as well.
[00:50:48.630]I think I have little time to take some questions.
[00:50:53.140]We'll be happy to entertain any question you guys have.
[00:50:57.580]What about some of the other alternative methods
[00:51:02.510]that you have not mentioned,
[00:51:05.420]and you probably know where I'm heading with my question,
[00:51:08.370]because we did have some discussions before
[00:51:10.680]about using things that, flaming, flame weeding?
You had any experience,
[00:51:17.990]have you heard of anybody doing anything
[00:51:19.930]in you are part of Kansas or, you know?
[00:51:24.460]That is a good question, Steve.
[00:51:25.990]And I think we discussed briefly
[00:51:28.190]on bringing that flaming approach in the system.
[00:51:34.950]I have been approached by some of the organic growers
[00:51:37.420]in Western Kansas,
[00:51:38.970]especially using that technique
[00:51:41.540]for weed control in sorghum.
[00:51:44.780]And I have not looked at it
[00:51:46.440]and I know you have done quite a bit of work,
[00:51:49.000]a lot of work actually.
[00:51:51.180]And a part of that, I was thinking,
[00:51:55.260]when you think about the flaming,
[00:51:58.920]if you have a chaff lining in our systems,
[00:52:01.330]and if it helps suppressing some of those weeds,
[00:52:04.300]as I mentioned in Hays and Tribune we have observed
[00:52:07.370]some of the reduction in emergence counts.
[00:52:11.790]I think managing that chaff lining through flaming,
[00:52:14.910]could be another possibility where I can see
[00:52:17.510]a fit of that method of weed control.
[00:52:20.610]Other than that,
[00:52:21.443]I think there's other potential opportunity,
[00:52:24.640]depending on where we gonna use this and what situation.
[00:52:30.400]Vipon, can you hear me okay?
[00:52:34.160]So Vipon, is there any study on effect
[00:52:36.790]of tillage on kochia control because it is early emerging
[00:52:40.590]and in some of our Kansas border,
[00:52:45.730]in south central part of the State,
[00:52:48.630]now kochia is becoming a problem weed
[00:52:52.050]and so sometimes growers are asking me like,
[00:52:54.830]tillage will be useful before planting corn and soybean?
[00:53:00.590]Yes, there has been some work been done.
[00:53:04.180]I think it is from Nebraska, actually.
[00:53:07.280]And they have found some good results.
[00:53:11.160]Strategic tillage, which I was referring to,
[00:53:13.580]is not like a conventional tillage.
[00:53:16.470]Strategic tillage or occasional tillage is basically,
[00:53:19.080]a single pass, three to four inch deep,
[00:53:22.420]once in three year when you have this three year rotation,
[00:53:25.560]like wheat, summer crop, fallow.
[00:53:27.530]And during fallow time,
[00:53:30.040]in the summertime you can do a one pass
[00:53:32.150]with the Fallow Master.
[00:53:34.360]That we are trying to quantify the impact
[00:53:37.360]of that single pass versus two pass,
[00:53:41.640]before wheat harvest or after,
[00:53:44.400]before wheat planting or after wheat harvest.
[00:53:47.510]There is a need to look at that impact, that side of it,
[00:53:51.990]like what it does on the seed bank of kochia,
[00:53:54.750]you know, glyphosate resistant kochia.
[00:53:57.550]In terms of conventional tillage, yes, there has been work.
[00:54:01.570]And I think that says that if you till that ground,
[00:54:06.020]and if the seed is buried to depth of,
[00:54:08.650]more than 10 centimeter or so,
[00:54:11.720]you can reduce some of the emergence of Palmer,
[00:54:16.200]But here in, Western Kansas or Northwest Kansas,
[00:54:20.470]that probably not the case.
[00:54:23.630]You can do conventional tillage,
[00:54:26.750]but there is another way to look at it as a strategy tillage
[00:54:30.600]for suppressing those weeds.
[00:54:34.020]I see there is a question in the chat.
So the question is,
[00:54:37.550]would you have any estimate of the cost
[00:54:40.480]of the seed-grinding attachment for a combine?
Yes, this is again,
[00:54:46.890]early thing for the US agriculture,
[00:54:51.780]and it's pretty costly right now.
[00:54:54.440]We got some educational discount,
[00:54:56.990]but right now the Redekop Seed Destructor,
[00:54:59.580]what we got is basically $75,000 a unit with two mills.
[00:55:06.360]And that's pretty costly,
[00:55:09.130]but over the time I can expect that cost will go down,
[00:55:13.310]because there are other manufacturer
[00:55:15.310]also coming into the market,
[00:55:16.750]making those seed destructor
[00:55:19.640]and probably the cost will go down in the future.
[00:55:23.300]So is that an import from Canada or Australia?
[00:55:26.510]Or is that why it's so expensive or?
[00:55:28.750]It is import from Canada.
[00:55:34.870]Because they are making very few units right now,
[00:55:37.430]and they're mostly giving to the researchers.
[00:55:40.290]As being a part of Grow team,
[00:55:42.130]I could get the educational discount.
[00:55:45.390]But for general public,
[00:55:47.340]I think they're still selling $75,000 unit.
[00:55:51.240]So, staying on the same topic,
[00:55:54.380]you shared some of the statistics on the,
[00:55:56.987]and I wrote down 28% of the old seeds were
[00:56:03.630]So have you actually done germination
[00:56:05.500]of those cracked seeds to see, will they generate at all?
[00:56:09.260]Will they survive winter?
[00:56:10.630]And you know what I mean, so.
[00:56:11.510]Yeah, I'm very curious, just like you, Steve.
[00:56:14.970]I've been working on that.
[00:56:17.140]We haven't got to that point yet.
[00:56:20.180]As I said, we collected the sample this fall,
[00:56:22.770]like November, towards the end of November.
[00:56:25.350]And we process that,
[00:56:27.280]cleaning them and separating them and counting them,
[00:56:29.850]all those kids were working on that.
[00:56:32.150]But germination, we haven't looked at yet.
We're gonna look at it.
[00:56:36.100]And we have flagged those passes,
[00:56:38.370]where we made those passes in the grower field.
[00:56:40.970]We're gonna go back and take some emergence counts as well,
[00:56:44.400]in the summer towards May, June,
[00:56:47.720]when the Palmer starts coming here.
[00:56:49.780]So, again, this is very preliminary kind of,
[00:56:53.800]numbers I showed there.
[00:56:56.120]We're gonna do more comprehensive data collection this year
[00:56:59.600]when we have the full fledge study going on.
[00:57:03.430]So is there an option of maybe burning those,
[00:57:07.820]whatever comes out of the combine,
[00:57:09.530]and you drop it on the ground and then you turn the lighter
[00:57:13.120]and burn those passes or strips,
[00:57:15.710]or whatever you wanna call them, or?
[00:57:17.750]Yeah, chaff lining, as I said,
[00:57:20.290]I see that could be a potential to look at it,
[00:57:27.200]Because when you put a chaff,
[00:57:28.760]you have a 30 feet or 35 feet header,
[00:57:31.660]putting all the chaff on the bag in a two feet row,
[00:57:34.550]like a wind row.
[00:57:36.043]A lot of chaff, especially the crops like sorghum,
[00:57:40.420]it's plenty of chaff right there.
[00:57:42.340]And you cannot plant throughout that chaff line,
[00:57:46.350]so you will have an issue.
[00:57:48.500]So, managing that chaff lining will be another way
[00:57:51.980]to look at it.
[00:57:52.813]And I think, the flaming can help.
[00:57:57.990]And other thing, there are other things,
[00:58:01.340]possible things can be done as well.
[00:58:05.140]But we have put together a proposal on that as well,
[00:58:08.300]looking at the managing those chaff line with herbicides,
[00:58:12.600]like a spot treatment,
[00:58:14.100]because all the weed seeds out there sitting,
[00:58:16.760]and when they're coming in the spring,
[00:58:18.390]you probably need to kill those with some spot treatment
[00:58:22.740]or burning, you know?
[00:58:24.870]Or just leaving it as such and see how much
[00:58:30.020]problem it caused to the next crop, in terms of emergence.
[00:58:33.860]Yeah, I see, just for the benefits of all the people
[00:58:37.340]that are still connected,
[00:58:40.230]speaking of flaming and the chaff lining,
[00:58:42.470]I probably would not use flaming in there,
[00:58:44.830]because you don't wanna run a tractor
[00:58:47.310]and then to turn those chaffs on fire,
[00:58:52.030]and then the fire, depending how fast it's moving,
[00:58:55.050]it may catch up with you if you're in front of the fire,
[00:58:58.730]with either a 4,0 unit,
[00:59:00.210]or actually there are now as wide as 16 row
[00:59:04.400]flamers out there.
[00:59:06.805]And so, anyway.
[00:59:10.680]That could be a potential hazard.
[00:59:13.400]And especially in High Plains,
[00:59:15.410]with the high wind,
[00:59:17.290]that could be dangerous thing.
[00:59:19.633]But I don't-
[00:59:20.790]Again as I said-
So when I said flaming,
[00:59:22.850]I was thinking more of doing it in the crop.
doing it in the crop,
[00:59:26.990]when the crop is up and all those things.
[00:59:32.000]Okay, I guess if that's all for today, again,
[00:59:36.040]I wanna say thank you for, to Dr. Kumar,
[00:59:39.730]for sharing his experiences from Kansas here and-
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