Buffalograss and Turfgrass Breeding Project

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08/06/2020 Added

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Keenan Amundsen - Buffalograss and Turfgrass Breeding Project

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[00:00:00.201](soft music)
[00:00:12.190]I'm Keenan Amundsen, turfgrass geneticist
[00:00:14.660]at the university of Nebraska Lincoln.
[00:00:17.760]I wear two hats in our unit.
[00:00:19.890]One is to provide bioinformatics support to students
[00:00:23.110]and other faculty and the other is
[00:00:25.300]as a turfgrass geneticist and breeder.
[00:00:27.980]For this 2020 Nebraska virtual turfgrass field day talk,
[00:00:32.250]I'm going to share with you information
[00:00:33.960]about our buffalograss breeding efforts.
[00:00:40.810]To start, I'm going to discuss why I like buffalograss
[00:00:44.950]and its value to the industry.
[00:00:47.870]I'll discuss buffalograss performance
[00:00:49.880]and expectations you may have as a turfgrass manager.
[00:00:53.910]I'll cover some of the common management challenges.
[00:00:57.160]I'll also describe our breeding objectives
[00:00:59.390]and breeding schemes.
[00:01:01.800]The reason for covering the technical aspects
[00:01:04.570]of our breeding efforts is because some
[00:01:07.330]of the traits we're selecting
[00:01:08.900]for impact how future buffalograss cultivars can be used
[00:01:13.050]as a turf.
[00:01:17.050]Taking a historical view,
[00:01:18.780]our buffalograss breeding project got started
[00:01:21.160]in the mid 1980s.
[00:01:23.760]Ed Kinbacher was a plant and range scientist
[00:01:27.880]and had a fondness for buffalograss
[00:01:30.017]which led to him collecting several wild accessions
[00:01:33.850]throughout the Midwest.
[00:01:35.920]Bob Sherman saw the value in those lines for use as a turf.
[00:01:39.890]and Terry Reardon began evaluating the material
[00:01:43.000]in the field.
[00:01:44.710]This collection formed the basis
[00:01:46.880]of our early germplasm collection.
[00:01:52.480]If you've heard me talk about buffalograss before,
[00:01:55.750]this is no surprise
[00:01:57.660]but one of the things that I find most fascinating
[00:02:00.020]about buffalograss is that it's a dioecious species,
[00:02:03.950]having separate male and female plants.
[00:02:06.950]Only about 5% of flowering plants are dioecious,
[00:02:10.170]making buffalograss somewhat unique in the plant world.
[00:02:14.210]The morphology of female and male buffalograss were
[00:02:17.530]so different that early taxonomic classification
[00:02:20.870]placed the male and female lines in separate genera.
[00:02:25.550]So the female lines were classified as antephora axiliflora
[00:02:30.710]and the males were sesleri dactyloides.
[00:02:40.210]Buffalograss is subdioecious
[00:02:42.990]so that means that it's primarily unisexual male or female
[00:02:47.220]but there are monoecious lines
[00:02:49.187]and those with perfect flowers.
[00:02:52.960]The monoecious type with separate genders on the same plant
[00:02:56.970]much like corn, for example,
[00:02:59.900]is what helped taxonomists reclassify buffalograss
[00:03:02.930]into a single genera.
[00:03:07.630]Common types of buffalograss generally have a open canopy,
[00:03:12.130]they have long internodes on the stolons
[00:03:15.760]and they don't really make for a very attractive turf.
[00:03:21.260]Early selections were identified
[00:03:23.210]that did have a dense canopy
[00:03:25.520]and their turf potential was identified
[00:03:30.270]and those early lines were also recognized
[00:03:32.890]for their fine leaf texture, good green color,
[00:03:35.650]exceptional heat, drought and cold tolerance
[00:03:39.270]and stoloniferous growth.
[00:03:42.230]After years of plant breeding,
[00:03:45.260]many of the modern varieties have superior turf performance
[00:03:48.770]and exceptional visual and functional quality.
[00:03:53.940]The basis for any breeding program is its germplasm.
[00:03:58.820]Our buffalograss germplasm collection consists
[00:04:01.250]of more than 1800 individual clones
[00:04:04.470]that are periodically evaluated for a number
[00:04:07.380]of important turf and production traits.
[00:04:15.550]When I started at UNL, I was amazed by the amount
[00:04:18.270]of variability represented in our collection.
[00:04:21.000]So this is actually the first picture that I took here
[00:04:23.910]at UNL representing the buffalograss collection
[00:04:27.330]and you can see that there's a wide variability in color,
[00:04:31.770]gender expression, canopy density, texture,
[00:04:36.520]lots of different traits
[00:04:38.396]and that really appealed to me as a breeder.
[00:04:45.150]Now we're still adding to our germplasm collection.
[00:04:48.400]That's pretty important.
[00:04:49.430]I don't think we have all
[00:04:51.460]of the buffalograss ecotypes represented in our collection
[00:04:56.690]and just over the past couple of years,
[00:04:59.580]one of my graduate students,
[00:05:00.720]Collin Marshall collected new buffalograss accessions
[00:05:04.310]throughout the West and Southwest portions
[00:05:06.530]of the Great Plains region.
[00:05:08.830]The picture on the left shows a map with pinpoints
[00:05:12.120]of where Collin had collected
[00:05:14.150]some new buffalograss accessions
[00:05:16.380]and on the right are some of those selections
[00:05:19.040]that he made growing in the field here in Lincoln.
[00:05:24.760]So one of the first steps when breeding
[00:05:28.780]for anything really is to evaluate some
[00:05:31.750]of those early selections
[00:05:33.730]and then after we identify some that have traits
[00:05:36.700]of interest, whether it's good production traits,
[00:05:40.080]good seed production, good canopy density,
[00:05:47.180]stoloniferous growth, rapid growth,
[00:05:50.200]good abiotic or biotic stress tolerance, any trait really.
[00:05:55.890]We essentially follow two main breeding strategies
[00:05:58.660]for developing new buffalograss cultivars.
[00:06:01.710]One is synthetic varieties and those are developed
[00:06:05.130]by identifying sexually compatible male and female lines
[00:06:08.730]that share similar phenotypes
[00:06:11.470]and then several male and female lines are grouped together
[00:06:15.670]that again, share a lot of those same phenotypes
[00:06:18.827]and those are allowed to intermate
[00:06:20.510]to form a synthetic variety.
[00:06:24.190]The other method
[00:06:25.023]that we employ is phenotypic recurrent selection
[00:06:29.810]and that's a breeding strategy whereby we make selections
[00:06:33.260]for a certain trait or traits within a population of plants,
[00:06:37.170]often derive from select male and female combinations.
[00:06:41.600]We generally select the top performing lines
[00:06:44.130]and advance those to the next generation
[00:06:46.780]repeating the selection process.
[00:06:49.020]After a few breeding cycles,
[00:06:51.160]the trait of interest is often fixed in those populations.
[00:06:57.050]Towards the final breeding stages we then evaluate
[00:06:59.540]for turf and production performance.
[00:07:02.170]The plots in the middle of this photo were selected
[00:07:04.550]for early green up through the breeding process.
[00:07:08.360]This picture is taken in mid May
[00:07:10.480]and it's easy to see that the majority
[00:07:12.420]of the entries were still dormant at this time.
[00:07:21.420]Gender expression again, since buffalograss is dioecious
[00:07:25.168]is something that we need to consider
[00:07:28.280]throughout the breeding process.
[00:07:30.470]It's really an important trait for us when breeding
[00:07:32.720]because we need both males and females present
[00:07:37.270]in order to make crosses
[00:07:39.083]and so that's somewhat of an unusual trait
[00:07:41.820]that we really need to focus
[00:07:42.960]on when we're developing new buffalograss lines.
[00:07:48.990]Our breeding program is focused on developing both seeded
[00:07:52.450]and vegetative buffalograss types.
[00:07:55.750]Regarding the seeded types,
[00:07:57.050]some of the traits we're most interested
[00:07:59.330]in are culm length,
[00:08:02.930]so that's basically the length of the stem and the reason
[00:08:08.020]that that's important is that the female inflorescence,
[00:08:11.140]the female flower is low to the ground
[00:08:14.020]and a relatively short culm
[00:08:16.650]and that makes harvest by a combine pretty challenging
[00:08:21.440]and so by selecting four lines that have longer culm length
[00:08:27.080]it gets the seed higher up into the air
[00:08:29.000]and it helps with how easy those lines are to harvest.
[00:08:34.670]Now, we're also exploring the use of hermaphrodites
[00:08:37.690]because they develop seeds above the canopy
[00:08:40.830]where the male inflorescence typically develops
[00:08:44.880]but one of the challenges in working
[00:08:46.630]with those hermaphroditic types is that they're fairly rare
[00:08:50.170]and they don't occur that frequently.
[00:08:57.500]Another trait that we're interested in
[00:08:58.900]for our seed producers is increasing the number
[00:09:01.270]of burs per inflorescence
[00:09:08.160]and that obviously I think that should make sense
[00:09:11.930]if there are more burs, there's more seeds
[00:09:14.450]and that leads to higher production.
[00:09:16.600]One of the challenges though
[00:09:18.100]and one of the problems in doing this is we need
[00:09:20.200]to consider what the end turf looks like.
[00:09:24.950]So in our seed production fields,
[00:09:27.110]we want large bur clusters to maximize seed production
[00:09:32.140]but then when those seeds are harvest,
[00:09:33.520]we don't want the progeny from that
[00:09:35.140]to also develop those large seed clusters
[00:09:38.620]because that's what's gonna occur in someone's lawn
[00:09:41.020]and you don't wanna walk on those big knots of burs
[00:09:45.527]and so we try to develop those lines in such a way
[00:09:48.930]that they produce a lot of seed in their production fields
[00:09:51.520]but that doesn't carry over into the turf.
[00:09:59.080]Bur size is also important.
[00:10:01.050]Larger burs have more caryopses.
[00:10:04.200]They're also easier to separate
[00:10:05.965]from other plant debris during harvest and cleaning
[00:10:10.160]and then they also tend to have higher germination rates
[00:10:16.210]and so seed size then is pretty important
[00:10:18.870]for seeded buffalograss lines.
[00:10:22.210]In terms of sod characteristics,
[00:10:23.990]we're also breeding for traits.
[00:10:26.510]Important for our vegetative producers who produce both sod
[00:10:29.470]and vegetative plugs.
[00:10:31.260]Some of the traits we're most interested
[00:10:33.060]in are the stoloniferous nature of buffalograss,
[00:10:36.540]how well the stolons knit together,
[00:10:39.260]the internode length of the stolons.
[00:10:41.970]The picture towards the bottom,
[00:10:43.990]for example shows a buffalograss line
[00:10:46.280]with very short internodes,
[00:10:50.070]they're really probably about a centimeter long
[00:10:55.890]and we're also interested
[00:10:56.970]in how well the stolons knit together to form a turf
[00:11:00.790]and how quickly a turf forms from plugs so
[00:11:03.320]that establishment rate is pretty critical.
[00:11:07.670]Sod strength is also important
[00:11:09.380]to make sure sod holds together when being cut
[00:11:12.180]or transported but also contributes to how well
[00:11:15.270]that turf knits together and forms a good turf stand.
[00:11:21.780]So those are some of the traits that we're interested
[00:11:24.940]in breeding for that are specific
[00:11:26.460]to either the seeded or vegetative types
[00:11:28.780]but in a general sense we're also interested
[00:11:31.500]in some other traits,
[00:11:34.100]so we're interested in chinch bug resistance.
[00:11:36.610]This picture shows some containers
[00:11:42.210]with some clear plexiglass tubes that are used
[00:11:46.440]to hold the chinch bugs in place
[00:11:49.240]and then we can evaluate how many basically feed
[00:11:52.860]on the turf, how many survive after a period of time
[00:11:55.250]and those types of things and how well that turf survives
[00:11:57.770]after exposure to those chinch bugs
[00:11:59.460]and so it gives us an idea of tolerance,
[00:12:02.290]of certain chinch bug tolerance of some of those lines.
[00:12:09.390]We're also interested in shade tolerance,
[00:12:11.080]shade as I'm sure you know is an important part
[00:12:14.340]of any landscape and buffalograss isn't generally known
[00:12:20.010]for shade tolerance but we've identified several lines
[00:12:24.510]that actually perform quite well when exposed to shade.
[00:12:30.910]Leaf spot disease is really one of the only diseases
[00:12:34.940]that really impacts turf, it's caused by a disease complex
[00:12:39.760]so there's number of different pathogens
[00:12:42.090]that cause the disease
[00:12:45.700]but we're also interested and do quite a bit
[00:12:47.640]of work identifying buffalograss lines that are tolerant
[00:12:51.940]or resistant to leaf spot disease.
[00:12:59.880]Traffic tolerance is certainly an important trait for us
[00:13:01.843]with buffalograss, buffalograss is not known
[00:13:05.460]for tolerating traffic
[00:13:06.860]but some of the newer varieties do stand up really well
[00:13:10.320]to traffic and so the picture on the left is a study
[00:13:15.700]where we were using a Brinkman Traffic Simulator
[00:13:20.090]to basically apply traffic stress
[00:13:22.600]to a number of buffalograss accessions
[00:13:24.850]and see how they perform
[00:13:25.900]and from that research we were able to identify a number
[00:13:28.070]of lines that could tolerate that traffic.
[00:13:32.950]Early and late season performance
[00:13:35.950]are also important traits for us.
[00:13:39.370]This picture was taken during the onset
[00:13:41.490]of dormancy in the fall and in the upper right corner
[00:13:44.590]of this picture you can see two bright, vibrant green plots
[00:13:48.340]and those are the ones that stayed green practically a month
[00:13:51.070]after everything else went dormant
[00:13:54.430]and so by identifying lines that stay green later
[00:13:57.730]in the fall or green up earlier in the spring,
[00:14:01.410]we can extend that growing season of buffalograss
[00:14:03.370]and that's certainly something that we're interested in
[00:14:06.180]as long as we don't sacrifice winner survivability.
[00:14:14.500]Now I wanna spend just a few minutes reviewing some
[00:14:16.820]of the management recommendations for buffalograss.
[00:14:21.220]So this is a study that was done actually before I started
[00:14:25.970]but it's a really good illustration showing
[00:14:27.940]that buffalograss does respond to fertility applications
[00:14:33.900]and based on some early research done by Kevin Frank
[00:14:40.188]who did his graduate work here at UNL
[00:14:44.850]but is now a faculty member at Michigan State University.
[00:14:48.110]Kevin found that two pounds
[00:14:49.880]of nitrogen per thousand feet is sufficient
[00:14:52.560]to maintain turfgrass quality for buffalograss.
[00:14:57.070]Quality improvements were observed with higher N rates
[00:15:01.150]but they were fairly marginal gains after two pounds.
[00:15:08.510]and also, so we recommend two pounds N
[00:15:14.430]per thousand square feet
[00:15:17.220]and we also recommend that that be applied
[00:15:19.320]in split applications.
[00:15:21.410]The N applications should be applied
[00:15:23.300]when buffalograss is actively growing
[00:15:25.580]and so late May after buffalograss
[00:15:28.080]or as buffalograss is coming out of dormancy
[00:15:30.700]and then also in mid July
[00:15:32.580]that's when the buffalograss is going to be able to use
[00:15:34.960]that nitrogen most effectively.
[00:15:38.960]If you're seeding buffalograss,
[00:15:41.010]seeds tend to germinate when soil temperatures is
[00:15:44.670]around 60 degrees
[00:15:47.620]and so there's a range depending on where you are
[00:15:50.550]in Nebraska or elsewhere in the Midwest region,
[00:15:53.610]where you might wanna grow buffalograss
[00:15:56.856]and so keep that in mind and seeding it's important
[00:16:00.460]to seed early in the spring
[00:16:02.650]as opposed to later in the season,
[00:16:05.660]like we might do with cool season grasses
[00:16:08.260]because the earlier seeding dates give buffalograss plenty
[00:16:12.550]of time to establish before the onset of winter,
[00:16:17.670]where the seedlings might be more susceptible
[00:16:19.930]to winter injury.
[00:16:23.100]Our recommended seeding rate is still two pounds
[00:16:25.610]of burs per thousand square feet.
[00:16:29.270]There can be a range in some
[00:16:31.230]of our plots where we really try
[00:16:34.000]to get buffalograss established more quickly.
[00:16:37.690]We'll seed at a higher rate.
[00:16:38.930]We've seeded as high
[00:16:39.950]as four pounds per thousand square feet,
[00:16:41.880]and the buffalograss we can get a stand established
[00:16:46.100]within a month or so.
[00:16:47.690]It grows really quickly if you seed at a really high rate.
[00:16:51.230]Now, of course that's doubling your seeding rate,
[00:16:52.860]doubling your cost and so that's certainly a factor.
[00:16:57.860]So for vegetative establishment,
[00:17:01.960]when you're establishing sod,
[00:17:03.910]you can expect some transplant shock
[00:17:06.550]but the buffalograss will recover.
[00:17:08.970]A lot of customers when they are not familiar
[00:17:11.710]with buffalograss, they'll observe that initial shock
[00:17:14.210]and they'll be afraid that they completely lost their stand.
[00:17:18.150]We encourage you to maintain that soil moisture
[00:17:20.940]and the buffalograss will recover.
[00:17:22.950]It tends to shock a fair bit when
[00:17:25.300]it gets root pruned during the harvest period.
[00:17:29.900]So we encourage you to keep the canopy wet
[00:17:35.810]for evaporative cooling and provide soil moisture
[00:17:39.080]to encourage that plant growth.
[00:17:40.510]You wanna be careful not to over water as
[00:17:42.380]that can obviously lead to other types of problems.
[00:17:45.050]So just maintain adequate moisture
[00:17:47.440]and buffalograss should grow well from sod.
[00:17:51.140]Vegetative plugs are kind of a fun way
[00:17:54.090]to establish buffalograss.
[00:17:56.669]You can use a soil auger and
[00:17:59.780]it's basically the way that we establish all of our plots
[00:18:03.230]because it's a way we can maintain genetic integrity
[00:18:05.580]and other things when we're working with cloned lines.
[00:18:11.210]We will plant buffalograss at one foot spacing.
[00:18:15.270]There is a fair bit of bare soil
[00:18:18.000]when you establish a buffalograss turf from plug
[00:18:22.210]so you wanna consider erosion and weed control
[00:18:26.650]but for the most part,
[00:18:27.620]similar to seed you can get a stand pretty quickly,
[00:18:31.930]clearly tighter spacing, much like seeding
[00:18:35.020]at a higher rate is gonna give you a turf stand more quickly
[00:18:39.500]Obviously there's more
[00:18:41.350]or the costs increase with that increased density
[00:18:44.060]so that's a factor
[00:18:46.490]for vegetative plug establishment as well.
[00:18:50.840]Weeds are probably our number one test for buffalograss.
[00:18:53.360]So it's important to maintain a fairly weed-free stand,
[00:18:56.700]especially during establishment,
[00:18:59.960]either through seed or plugs.
[00:19:03.240]One of the advantages that I like about buffalograss,
[00:19:06.720]I still view Roundup glyphosate-based products
[00:19:09.580]as a fairly safe herbicide
[00:19:12.500]and that can be safely applied to buffalograss
[00:19:15.880]when Buffalo grass is dormant
[00:19:19.050]and generally we recommend making those applications
[00:19:22.350]in the fall rather than in the spring,
[00:19:25.140]you get some early growth,
[00:19:27.330]even if it's not so visible in the spring
[00:19:30.310]and you can really damage the plants
[00:19:31.980]and so we tend to make those applications in the fall.
[00:19:41.240]I wanted to end with this study.
[00:19:42.660]This is one that I know we've talked about
[00:19:44.400]in other talks and so you may have seen this before
[00:19:48.040]but this is really one of my favorite studies
[00:19:50.810]in recent years of buffalograss.
[00:19:53.523]It is sponsored by the U.S. Golf Association
[00:19:56.140]and Cole Thompson, Bill Kreuser
[00:19:58.560]and I evaluated fairway mowing height management
[00:20:04.570]of creeping bentgrass, Kentucky bluegrass and buffalograss.
[00:20:09.610]Pesticides, fertilizers
[00:20:11.300]and different irrigation was applied
[00:20:13.720]and that created several of these smaller subplots.
[00:20:18.440]So this entire plot in the bottom right,
[00:20:21.980]it was planted Kentucky bluegrass.
[00:20:24.400]This bottom middle plot for example was planted
[00:20:27.350]to buffalograss and then the left was creeping bentgrass.
[00:20:30.670]Creeping bentgrass, it was topdress,
[00:20:33.310]so that's why it looks a little funny there
[00:20:37.060]but what was most interesting was
[00:20:38.620]that buffalograss shown in the bottom middle again,
[00:20:42.600]really doesn't show much response to any of the treatments,
[00:20:48.270]whereas Kentucky bluegrass and creeping bentgrass,
[00:20:53.880]you can see pretty significant differences.
[00:20:56.210]So for example, this is a low maintenance plot
[00:21:00.010]of Kentucky bluegrass and you can see evidence,
[00:21:02.220]quite a bit of disease,
[00:21:04.050]it's not a very uniform dense canopy.
[00:21:06.460]The one to the left is a higher maintenance plot
[00:21:08.640]and you can see that it's performing quite a bit better.
[00:21:13.890]The buffalograss plots, they don't look as nice
[00:21:18.130]as kind of the high managed Kentucky bluegrass
[00:21:22.810]but what's nice is even the low input plots
[00:21:27.800]of buffalograss really look about the same
[00:21:31.150]as the high end ones
[00:21:33.090]and so that suggests that you can get away
[00:21:34.930]with much lower levels
[00:21:36.810]of management inputs, management costs
[00:21:41.300]in maintaining a buffalograss fairway compared
[00:21:45.050]to bentgrass or bluegrass.
[00:21:48.930]Obviously, ultimately it's going to depend
[00:21:51.000]on your expectations and the expectations
[00:21:53.970]of folks playing on that surface but
[00:22:03.173]if your budget and if resource conservation is a priority
[00:22:09.730]for your operation, you might wanna consider buffalograss.
[00:22:15.470]I'm gonna stop there
[00:22:16.730]and hopefully some of the information I presented
[00:22:19.400]on our buffalograss project is interesting or useful to you.
[00:22:23.370]If you have additional questions, feel free
[00:22:25.560]to reach out using the contact information provided here.
[00:22:32.421](soft music).

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Buffalograss and Turfgrass Breeding Project

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