CW Podcast: Corn Planting and Early Growth Stages
On this month’s Nebraska CropWatch podcast, Extension Educator Michael Sindelar talks with Extension Weed Specialist Amit Jhala about spring burndown herbicide applications. Jhala talks about what weeds species need to be controlled now and with spring burndown applications. He also addresses burndown challenges and how to overcome them, as well as herbicide modes of action used for burndowns.
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[00:00:00.000](upbeat guitar music)
[00:00:02.910]Welcome to CropWatch Podcast,
[00:00:05.370]a production of Nebraska Extension.
[00:00:12.870]Welcome to the CropWatch Podcast.
[00:00:14.840]I'm Michael Sindelar, a Cropping Systems Extension Educator.
[00:00:18.470]Today we'll be talking about corn,
[00:00:20.130]specifically, early season corn.
[00:00:22.170]I'll be joined today by Dr. Roger Elmore.
[00:00:25.180]Dr. Elmore, would you like to introduce yourself?
[00:00:29.670]Roger Elmore, I'm the Extension Cropping Systems Agronomist
[00:00:33.610]based here at the University of Nebraska in Lincoln.
[00:00:40.060]Over the years I've worked in irrigated corn
[00:00:42.820]and soybean production systems,
[00:00:46.220]specializing in growth and development
[00:00:49.030]of both of those crops, but also in cover crop research.
[00:00:58.230]We'll kinda start, before we even
[00:00:59.690]put anything into the ground,
[00:01:01.580]how much does hybrid selection really impact yield?
[00:01:06.870]That is probably the biggest factor of all
[00:01:11.170]in terms of productivity,
[00:01:14.690]that hybrid selection.
[00:01:16.890]I know there's a lot of dollars that go into that,
[00:01:20.350]but choosing the right hybrid is obviously
[00:01:23.810]the very first step you need to make
[00:01:26.010]in terms of production system,
[00:01:27.970]and probably one of the most important.
[00:01:30.320]So do your homework on them.
[00:01:32.680]Look at all the data you can get,
[00:01:34.930]look at the company data, the descriptions of the hybrids
[00:01:39.090]and what they're good at and what they aren't good at,
[00:01:42.180]and always choose a handful of hybrids.
[00:01:46.100]Don't put all your eggs in one basket.
[00:01:49.600]And then, make sure you look at some third-party data, too.
[00:01:53.080]Mix the data sources together and choose that way.
[00:01:58.780]It's also probably wise if you're trying out a new hybrid
[00:02:01.300]for the first time to try it on a small area
[00:02:03.390]to see how it works for you,
[00:02:05.150]how it works in your production system.
[00:02:08.760]Alright, that's good information.
[00:02:13.170]Now we have our hybrid picked out.
[00:02:15.740]What's the importance of seed bed preparation,
[00:02:18.670]and what are we looking to do so that we can have success?
[00:02:23.300]It's easier, probably, Michael,
[00:02:24.980]to talk about what doesn't work,
[00:02:29.290]and the answer to that is mudding corn in never works.
[00:02:34.310]It works, but that's a sure bet
[00:02:37.350]on reducing yield and yield potential.
[00:02:40.830]When that seed is in the bag, it's got 100% yield potential.
[00:02:45.630]As soon as you drop it in the ground,
[00:02:47.790]you start lowering that yield potential.
[00:02:50.890]The easiest way to lower that yield potential quickly
[00:02:53.590]is to put it in a lousy seed bed.
[00:02:56.290]I don't care whether you're conventional till or no-till,
[00:02:59.460]mudding-in corn does not work.
[00:03:03.460]You kinda talked about what not to do, for a seed bed,
[00:03:07.370]what about planting rate or seeding rate?
[00:03:10.670]What are we looking for, what works, what doesn't work?
[00:03:15.410]Yeah, the thing I know about corn,
[00:03:20.350]over the years, over the last 50-60 years,
[00:03:22.870]we've progressively been breeding corn
[00:03:25.060]for higher and higher seeding rates.
[00:03:28.357]I think it really is good for people
[00:03:31.150]to continually look at pushing the population window.
[00:03:35.260]I would do that with on-farm research.
[00:03:37.390]We've got a really good on-farm
[00:03:38.830]research program here at UNL.
[00:03:41.800]It's not hard to do that, there's a lot of support for it.
[00:03:44.740]You can do it on your own, if you want.
[00:03:46.410]But do some comparisons of seeding rates.
[00:03:49.990]If you're already planting 30,
[00:03:52.220]I'd really advise you to try some at 35,000.
[00:03:56.490]And do some side-by-side strips with replication
[00:04:00.130]to see how that works for you.
[00:04:02.110]How do your hybrids respond to that higher seeding rate?
[00:04:05.320]Your seed companies also will know
[00:04:07.750]better what seeding rates those hybrids will tolerate,
[00:04:12.552]but in general if you're still planting
[00:04:13.970]the same seeding rate you did, say, five or 10 years ago,
[00:04:17.600]you probably aren't keeping up with the ability
[00:04:20.010]of our new hybrids to respond to those higher populations.
[00:04:24.800]Before I go on here, the calibration
[00:04:28.010]of that planter is pretty important.
[00:04:30.460]I know those monitors may be telling you
[00:04:32.410]how many seeds you're dropping, but double-check 'em.
[00:04:36.890]Make sure they're right.
[00:04:40.780]So how would somebody double-check
[00:04:42.680]their planter calibration?
[00:04:44.180]Would they actually go out and dig up rows,
[00:04:47.810]see if they're dropping
[00:04:48.643]what their monitors are telling them,
[00:04:50.980]or are there other, easier methods?
[00:04:53.900]I'm not sure of an easy method,
[00:04:56.700]other than waiting for emergence to occur,
[00:04:59.940]and then it's too late.
[00:05:01.410]I recall one situation where
[00:05:05.010]a calibration wasn't done until emergence,
[00:05:08.700]and it was very clear there were hundreds, thousands,
[00:05:12.520]per acre of doubles and triples and quads.
[00:05:16.120]Seeds coming up, just like the old hill drop system,
[00:05:19.160]where all those seeds are packaged together,
[00:05:21.130]and it was a planter problem.
[00:05:23.320]And unfortunately, most of the corn
[00:05:24.750]was planted by the time that corn emerged.
[00:05:27.800]So I think you've gotta do some digging out there, Michael.
[00:05:30.910]Right, that's good to know.
[00:05:34.480]We've talked about putting the seed in the ground,
[00:05:37.300]what about emergence?
[00:05:38.680]What are we looking for at emergence
[00:05:40.550]to know if things are going good
[00:05:42.230]or if things are not going well?
[00:05:45.290]The best-case scenario,
[00:05:47.900]I could talk worst-case scenario, here, too,
[00:05:50.190]but let's talk best-case.
[00:05:51.950]This case is when every plant
[00:05:53.630]comes up exactly the same time.
[00:05:56.190]I'm talking within a matter of half a day
[00:05:58.210]or a day of each other.
[00:06:00.620]That's the best-case scenario.
[00:06:02.710]The worst-case scenario is when they come up
[00:06:05.070]over a period of five days to a week, neighboring plants.
[00:06:09.930]The time I see that, there's a lot of reasons for that.
[00:06:12.540]Mudding-in corn will do that for you.
[00:06:14.880]Those slick sidewalls that we
[00:06:16.710]talk about when we mud corn in.
[00:06:19.940]Variable seeding rate will do that to you.
[00:06:23.200]Shallow, sometimes those shallow-planted seeds
[00:06:25.530]come up later than the deep-planted seeds.
[00:06:28.200]I've seen it.
[00:06:31.936]That will affect yield, because those neighboring plants
[00:06:36.540]will see a late-emerging plant,
[00:06:38.600]those neighboring taller plants
[00:06:40.140]will see that later-emerging plant as competition.
[00:06:44.160]They will see it as a weed, and they start responding
[00:06:47.670]almost immediately to that late-comer that's coming up.
[00:06:51.860]It'll be competitive rather than working synergistically
[00:06:55.770]or together to promote yields.
[00:06:59.220]What does soil temperature play into that,
[00:07:02.000]and how can we monitor that to make sure that
[00:07:04.740]soil temperature's not what's nipping us?
[00:07:09.770]Variability in residue will affect that soil temperature,
[00:07:14.680]and soil type will vary it,
[00:07:15.980]and make that a low-vary soil temperature, too.
[00:07:19.170]So uniformity of soil temperature
[00:07:21.850]is one of those things that go along
[00:07:23.740]with uniformity of emergence, you're right.
[00:07:27.040]So you want uniformity in as many of those characteristics
[00:07:29.770]as you can get for that uniform emergence.
[00:07:33.080]When I'm talking uniformity of emergence,
[00:07:35.155]I'm thinking more plants side-by-side,
[00:07:38.590]though, than from 100 yards away.
[00:07:41.900]That's not quite as critical as the plants
[00:07:43.950]that are immediately bordering or neighboring
[00:07:48.077]the plants that we're talking about.
[00:07:50.910]So soil temperature, it's a good point.
[00:07:54.310]Uniformity in that are important.
[00:07:57.150]That's one thing that drives the strip till folks.
[00:08:01.055]It does warm up a little faster under those strips.
[00:08:06.350]A ridge till used to do that as well,
[00:08:07.930]if you're still ridge tilling.
[00:08:10.005]Those ridges dry off, warm up faster.
[00:08:13.760]That would promote more uniform emergence
[00:08:16.410]in early season growth.
[00:08:18.520]And that's the bottom line to, I think, good yields.
[00:08:21.960]Alright, well, you brought it up,
[00:08:23.780]let's talk a little bit about early season growth.
[00:08:26.970]What are the important growth stage,
[00:08:29.230]and why are those stages important?
[00:08:32.750]I think every growth stage
[00:08:34.720]or development stage is important.
[00:08:39.340]The V1 to V3, and you're relying on the seed
[00:08:44.330]at that point for nutrition in that plant,
[00:08:48.580]so that's where that seed is important
[00:08:51.420]in providing that early season development.
[00:08:53.900]From V3 to V5, sometimes, if the soils are cold and wet,
[00:08:58.600]those plants, V3 would be when
[00:09:01.127]the collar of the third leaf is visible.
[00:09:05.886]V3 to V5, then, fifth leaf collar's visible.
[00:09:09.940]That plant, if it's cold and wet,
[00:09:11.700]can go into kind of an ugly duckling stage,
[00:09:15.940]where the plants are turning yellow,
[00:09:17.990]and pretty chlorotic, and you think the sky is falling.
[00:09:24.940]But that's that transition time
[00:09:26.940]between a seed and the root system
[00:09:30.345]and photosynthesis in terms of nutrition.
[00:09:34.330]That's also the time that ears per plant
[00:09:36.950]are being developed, so it's a critical time
[00:09:40.690]in terms of every plant producing the right number of ears.
[00:09:45.320]Which is usually one, in our case.
[00:09:47.570]So, you heard it here.
[00:09:48.940]Every growth stage is important.
[00:09:51.105](upbeat guitar music)
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