June 17, 2024 • 24 mins
Join Dr. Rowland Tsimba, National Research and Agronomy Manager, Wade, and Matt as they sit down to discuss optimal plant populations and the impact this has on crop yield and quality.
The team brings a global perspective to the discussion by comparing maize planting strategies in the United States and New Zealand. They highlight the importance of managing plant populations for silage versus grain and the value of tailoring planting decisions to your farm's environmental and soil conditions. This podcast will equip you with practical insights to make informed planting decisions in the upcoming spring.
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Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:04):
G'day and welcome to Feed for Thought, a regular
podcast from Pioneer coveringeverything from farm systems to
crops and products and much,much more.
Speaker 2 (00:15):
Welcome to Feed for Thought.
My name's Matt Delly and, asalways, we like to delve into
all things farm systems andmaize in particular and today,
coming off the back of a maizeseason, we tend to look back on
things and what factors we mightbe considering for next season,
and one of the factors is plantpopulations.
And so, as always, I've got mysidekick, wade Bell, with me,
(00:38):
and we've got a special guesthe's pretty familiar to the
podcast Smartest guy in the roomby far.
If it was a smarter person, itwould have Bianca, because
obviously, she runs the shiparound here.
Welcome, roland.
Back to the podcast.
Speaker 3 (00:53):
Thank you, Matt.
Yeah, I'm not sure I'm thesmartest guy in the room, but
I'll take it anyway.
Maybe the most modest.
Speaker 2 (01:00):
Yeah, true.
So I suppose, Roland, this isour chance to reflect on the
season that's been and thenstart looking forward to next
year.
Around plant populations whatis the optimum planting
population?
Speaker 3 (01:14):
Yeah, that's a really difficult question to answer
because….
Speaker 2 (01:17):
That's why I asked it first.
Speaker 1 (01:19):
He's trying to prove how smart he is.
He's trying to prove that he'sa little smarter than anyone
else.
Speaker 3 (01:23):
Yeah, there's no optimum population which is
standard anyway.
Optimum population will dependon a range of things, obviously.
The first one is the hybridthat you're dealing with.
Certain hybrids will have agreater tolerance to stress
compared to others, so thosehybrids will obviously have a
(01:43):
higher optimum population.
And the other thing that willdetermine your population is
maturity.
Shorter season hybrids tend tohave a higher optimum population
compared to longer seasonhybrids, but we can delve into
that a little bit later, if youlike.
The other one is more theenvironment where you're
(02:05):
planting in.
If you're planting in a coolerenvironment where temperatures
tend to be lower I'm justrepeating myself coolant, lower
temperature, same thing you tendto want to have a lower
population.
And the reason for that issimilar to why we plant higher
(02:26):
populations for the shortermaturity hybrids, in the sense
that in cooler environments yourplants tend to be shorter,
smaller, your leaf areas aresmaller, so to capture more
radiation you need to push upyour populations.
And the other one is if you'replanting in high fertility soils
(02:48):
, you also want to increase yourpopulations.
And if you're planting in lowfertility soils or sandy soils,
again you want to lower yourpopulations because you don't
want to put a lot of pressure inthose situations.
The other one, which we don'tusually talk a lot about, is a
(03:09):
planting diet.
If you're planting quite earlyand by early I'm talking about
mid-September through topossibly early October in most
parts of the North Island youwant to be pushing up your
population slightly higher thanwhat we normally recommend is
(03:29):
your optimal population.
And the main reason for that isare you planting earlier than
where we normally would beplanting?
So your plants again are goingto be smaller.
On the other hand, if you'replanting late and what do I mean
by late?
I'm talking maybe aftermid-November, especially in the
(03:51):
southern parts of the NorthIsland you want to lower your
populations.
And the reason why we lowerpopulations is not necessarily
because of plant size, but it'slargely because your plants are
likely to run out of seasonduring the later part of a grain
(04:12):
field.
So when they run out of seasonthey will struggle for sunshine
hours, or solar radiation to bemore specific.
So you don't want your plantsto compete for solar radiation.
Hence why we want to lower yourpopulations a little bit.
Yeah.
Speaker 2 (04:32):
See, that's why I asked that because it's a
complex question and it's noteasy to answer.
Speaker 1 (04:37):
Yeah, I was actually going to say, as I was listening
to that, because, matt, you'vebeen in the area manager role,
yes, and I'm sure you've beentackled with the question about
lowering plant population.
Given everything that I'veheard Roland say he's talked a
lot about optimum why would youplant below optimum at low
populations?
Why were growers wanting to godown that pathway?
Speaker 2 (04:58):
There's definitely a few myths or a few things, I
suppose, thrown away Everyone.
As we plant lower population,we get a bigger cob right.
So everyone wants to take thecob to the bar and show off that
they've got the biggest cob,and so they say, oh, that must
mean better quality.
I've got a bigger cob, moregrain, better quality, and
(05:19):
you're just trying to sell memore seed, matt.
Speaker 1 (05:22):
So those are some of the Saving some money yeah.
Speaker 2 (05:24):
So those are some of the things.
People would kind of bet backAny truth to that.
Speaker 3 (05:33):
I had a few answers, roland, but I reckon you've got
some bitter ones.
It's quite interesting you saythat, because I get that same
question quite a lot, and one ofthe things that we get or I get
is someone who works for seedcompanies that we promote higher
populations because we want tosell more seed.
The truth is that we do notpromote higher populations, we
(05:56):
promote optimum populations.
Every time we talk aboutpopulations, we are talking
about maximizing the potentialof the crop that you're growing.
The hybrids that we have todayhave been designed to perform
better if you plant them to theright population, because,
(06:18):
unlike the old hybrids that weused to have maybe 30, 40 years
ago, which did not have a goodstress tolerance, the newer
hybrids that we have today havegot fantastic stress tolerance,
which means that they can handlestress.
Speaker 2 (06:37):
So it's not necessarily like a bigger plant
or anything.
It's actually the fact that wecan stack more plants in there.
Speaker 3 (06:44):
I was deliberately trying to avoid answering that
question about bigger cobs,because I it's one of the topics
I don't usually want to talkabout, but because you have
insisted, I will address that,so obviously shot there, I knew
that so that's a good start ifyou planted a lower population,
lower than optimum population,what you're going to get is a
(07:06):
big cob, a flesh looking cob, abigger plant and most people
love it and the plant also looksquite healthy, but at the end
of the day, that's not going topay your bills.
What you, what you end up with,is a cob or a crop that's not
going to yield to its optimum.
(07:28):
So, ideally, the hybrids thatwe have are designed to flex,
but that flex is limited.
The flex we get from hybrids ormice is not sufficient to
compensate for the loss in yielddue to a lower than optimum
population.
(07:48):
That's the theory, and if youwant me to delve a little bit
deeper into where or why thishappens, I can do that, but I
don't think you guys want to gothere.
Speaker 1 (08:04):
Well, no, actually maybe elaborate.
There's a couple of things Iwant you to elaborate on.
One is about the flex, becauseoften we talk in jargon and
terms that make sense to us, butyou know there'll be a lot of
listeners that'll go what thehell are you talking about?
When you're talking about flex,you've got kind of a simple…
it's not Wade in the gym.
Yeah, if you've got a kind of asimple explanation of what flex
(08:30):
is all about, okay, cool yeah.
Speaker 3 (08:32):
So you can call it any way you like, but I'm going
to try and introduce anotherfancy word that you guys might
like.
The actual word that we use iscalled plasticity.
Speaker 2 (08:47):
So if you, think of the plastic.
Let's stick with flex.
Speaker 3 (08:52):
So the reality is that maize has got the ability
to flex, which is calledplasticity.
So if you plant below theoptimal population, the carb, as
well as the plant itself, isgoing to increase a little bit.
But there is a limit as to howbig or how much plasticity a
(09:16):
plant can have.
So because of that, that is themain reason why the plant is
not able to compensate for theyield loss due to a lower
population, because it can onlyflex so much.
Because in general, the size ofa maize plant is genetically
determined, so it is not goingto go any bigger than what it is
(09:42):
genetically made up to be.
Speaker 1 (09:45):
So it's a diminishing curve, type A hundred percent.
A hundred percent, yeah, andI'll pick up on something that
satisfies my understanding.
Are you still with us there?
Speaker 2 (09:55):
Plasticity yeah, I got it.
Speaker 1 (09:57):
You're still all good .
You also mentioned stresstolerance and how stress
tolerance has impacted optimumplanting populations.
Do you want to just expand onthat a little bit and maybe even
the link between what thatmeans, say here in New Zealand,
when we might be comparing with,say, population data overseas?
Speaker 3 (10:18):
Yeah.
So in terms of stress tolerance,that's again another open-ended
question because I can tackleit in different ways but
generally, in terms of a massbreeding, most of the breeding
is focused on stress tolerance.
I know that most people wantbreeders to focus on increasing
(10:40):
yield, but that's not how itworks, because when you look at
the world we live in today,there is climate change, so what
that means is that we now havean environment which is
unpredictable we don't reallyknow what the weather is going
(11:02):
to do, so breeders are focusedon breeding for a product or a
hybrid that is able to toleratestress much, much better or that
has got more resilience, andhence why breeders focus on
stress tolerance.
So because of that, what hashappened is, in the old days,
(11:28):
maize hybrids used to be barrenor to where they would fail to
produce a cob if you pushed upthe population.
But because focus has been onstress tolerance.
But they would fail to producea cob if you pushed up the
population, but because focushas been on stress tolerance.
What that means is that thenewer genetics that we have
today are unable to produce acob, even under high populations
(11:51):
, and hence the reason why youfind that the newer genetics we
have tend to have higherpopulation optimal compared to
the old hybrids and I canactually confidently say this
because we do population trialsevery year.
(12:11):
We test most of our newergenetics or newer hybrids before
we commercialize them, tounderstand what the optimum
population for those hybrids are.
Speaker 2 (12:20):
So, roland, are they planting old hybrids in the
States and stuff?
Because they seem to.
The feedback is that they'vegot lower.
I know they're not planting oldhybrids, but they've got lower
populations over there.
Why are they planting at lowerpopulations overseas?
Speaker 3 (12:36):
Yeah, that's a pretty good question, especially
coming from your man.
Speaker 1 (12:40):
Oh, he's going up in Roland's estimations.
This is so good, it's good thatyou're getting grief from me
and from the guests.
Speaker 2 (12:51):
I'm loving it.
Speaker 3 (12:52):
So yeah.
So if you look at New Zealand,I think if there's one thing
that we should be proud ofunfortunately it's not something
that we did, but we arefortunate to have this Our
environment is perfect for maize.
We have a moderate environmentcompared to what they have
(13:13):
overseas.
If you look at the amount oftime that our crop is sitting in
the paddock, it's much, muchlonger compared to the States.
You look at the diseasepressure that we have in New
Zealand, it's much, much lowerthan in the US, and I will
(13:35):
probably delve a little bit moreabout what I mean by a moderate
environment and why that isparticularly important, and this
will also try to explain why weare getting higher yields with
slightly higher populations thanwhat we used to achieve in the
(13:56):
old days.
So your yield this again, thisis something that we don't talk
about Yield is, or largely is,determined by your radiation or
your sunshine hours.
To keep it nice and simple forme, yeah, well done.
So the more radiation that aplant intercepts, the more yield
(14:20):
the plant is going to achieve.
So if you then look at it fromthe perspective of New Zealand
versus the US, for instance, ourcrops are in the soil or
paddock for a much longer timecompared to the US.
As a result, they have got moretime to intercept radiation and
(14:44):
consequently radiation is notan issue for us because we've
got more time, whereas for othercountries, such as the US or
even Australia, wheretemperatures are much hotter,
there is a short time periodwhere your crops need or are in
the soil.
Therefore they've got a limitedamount of time to intercept
(15:09):
that radiation.
So we just happen to befortunate that we are in a
moderate environment, and thisis why we tend to plant at much
higher populations compared toeverywhere else.
It's just because of ourenvironment.
Speaker 1 (15:22):
What about things like and I guess you could argue
it's a stress as well, butwe've had, in seasons gone by,
wind damage or you get, and sopeople go, wow, shit, there's a
solution to that.
Just lower population andpopulation or get stronger
plants and they'll be able towithstand that, you know?
Does that just fall under thestress kind of tolerance
(15:42):
umbrella, or is that justsomething completely separate
consideration?
Speaker 3 (15:46):
Absolutely so.
When we talk about optimalpopulations, we are talking
about adjusting your populationsas well, if you're in those
environments that are notconducive to achieve those
higher populations that thosepeople who are in the best
environments can achieve.
So if you're in wind-transsituations, absolutely you want
(16:07):
to lower your populations.
Speaker 2 (16:09):
What about if you plant in a different direction?
So if you go north, southversus east west, does that make
a difference?
Roland Cheers, you said itpretty well, matt east west,
does that make a difference?
Speaker 3 (16:15):
Roland Cheers.
You said it pretty well, Matt.
I get to see the look on.
Speaker 2 (16:18):
Roland's face.
Speaker 3 (16:20):
He's getting more and more disappointed with you, do
you?
Speaker 1 (16:23):
really want me to answer this.
That was a planty question,mate, and you know it, you know
it.
Speaker 2 (16:28):
It is good, but I've heard that a number of times, so
I just thought.
Speaker 3 (16:32):
I'd throw it out there.
Okay, I'll leave wage to us.
Speaker 2 (16:38):
He's smart enough not to.
But one thing is our grain isstill growing the same plant
right.
Why do we reduce ourpopulations in general for grain
?
Or, if you're the same, hybrid,why are we planting at 10,000,
15,000 less?
Speaker 3 (16:53):
So it's basically more to do with the duration of
the crop growth cycle.
Your maize grain is in thepaddock for much, much longer
compared to maize silage.
And remember, when you'regrowing maize silage, your focus
is largely on total biomass,but when you're growing maize
(17:14):
grain, your focus is on thegrain.
So one of the things you wantto focus on is to have the best
grain possible, bigger grain,and please don't confuse bigger
grain with bigger ears.
We're just talking about idealgrain size, which is consistent
(17:35):
with the ideal population, andthe other thing, again, is more
with, because your crop is inthe soil for much longer.
If there are going to be anychallenges or stresses, those
stresses are likely to beexperienced in grain crops,
compared to silage, because thegrain plant will have to sit in
(17:55):
the soil or paddock for a muchlonger period.
Speaker 2 (17:58):
So standability and all that comes into it, root
strength, all comes into itlater on.
Speaker 1 (18:03):
I want to loop around .
This is probably my lastquestion, ronan.
I want to pick up on thingsthat I've heard you say and then
gone.
I'm not sure I completelyunderstand or maybe listeners
Leaf area index and therelationship between plant
population and leaf area.
Look again, it's terminologythat we use within Pioneer, but
what's the relationship thereand what are you trying to
(18:25):
achieve with leaf area index?
Speaker 3 (18:28):
What is?
Speaker 1 (18:28):
it and what are you trying to achieve?
Speaker 3 (18:30):
Yeah, so probably keep it nice and simple.
I may not necessarily talkabout leaf area index, because
it's probably a little bit tootechnical, but maybe if we just
focus on a total leaf area.
So ideally, what we are talkingabout is, when you go back to
the point I made earlier, thatyour yield comes from the sun.
(18:52):
So the challenge is how do weharvest the sun?
And we want to harvest as muchof it as possible.
So the way we can do that is byincreasing the total amount of
the solar panels in the maizeplant, and the solar panels are
(19:13):
the leaves, and that's where theconcept of leaf area index
comes into play.
So the more leaves we have, themore sunshine we can harvest or
solar radiation we can harvest,and there is a direct
relationship between the amountof sunshine or solar radiation
(19:36):
that the plant has interceptedor absorbed and the yield.
There is a direct correlation.
So hence why we focus or wetalk about leaf area index, and
just on that, I'm sure you guyshave spent a bit of time in the
field as well.
(19:58):
The live area index is a verydifficult concept to understand,
but there is a very simple waythat every person who deals with
mice can actually use or canapply to figure out whether they
have got the right populationor not.
So what I usually recommend isthat if they have a chance to go
(20:23):
to the maize paddock afterpollination during the day maybe
after midday or thereabout andjust look through the crop
underneath the canopy you wantto make sure that there's not a
lot of sunshine going past thecanopy, hitting the soil.
(20:47):
As soon as you see a lot ofsunshine hitting the soil
surface, that's usually anindication that you are not
utilizing that radiation, wastedenergy, yep.
So ideally you want a minimumof five percent of your ground
having some sunlight.
Speaker 1 (21:08):
Yeah, so does that, and then does that link back
then to population.
So that's something, what thatyou put in the the bank, put in
the memory for future seasons ifyou're growing in that area
under the similar conditions.
Speaker 3 (21:21):
Absolutely.
Once you get to that stage, youcan't really do anything about
it.
So it's more for next year andthat's what we want to encourage
people.
We want to encourage people toactually start doing this
themselves, because, in as muchas we do have people on the
ground, we have got our areamanagers as well as merchant
(21:42):
reps to help people understandhow or what is the right
population for their conditions,but they may not necessarily
have all the knowledge that isrequired to get the absolute
perfect population for yourconditions.
Speaker 2 (21:58):
Well, I think it's probably a good place to start
wrapping, but one of the firsttake homes that I've probably
got is I understand why Roland'sgot doctor in front of his name
and not in front of mine.
I've been put well on my place,so thanks for that, Roland, but
I think, winding it back toright at the start, it's about
(22:19):
understanding the environmentthat we're going into for a set
two and utilising as you justfinished with, then actually
utilising the people around toget to that understanding that
what is the optimum for us.
Wade any key take-homes fromyourself.
Speaker 1 (22:36):
Well, the interesting one for me.
You know you did dispel acouple of myths.
Or you know, like those reasonsthat you hear that might be,
they sound like sensible reasonsto perhaps reduce population.
You know, because you go,everybody likes to save some
money.
Or, you know, grow a higherquality crop.
But I think that's a little bitshort-sighted in terms of you
know what you're, what farmersand growers are generally trying
(22:57):
to achieve.
You know they want the highestpossible yield and you know
sometimes just that that thoughtof saving a little bit up front
is actually not going to be,it's going to be insignificant
in the scheme of the, theoverall performance of the crop.
So it's kind of nice to dispelthat to some degree.
And the other point that I thatI picked up there was just the
(23:18):
whole link between you know,each hybrid having an optimum
recommendation and thenmodifying for for the
environment that you're, thatyou're planting it into.
So you know, I think what Iwould like to think is that
listeners go away from today orfrom from listening to this
episode and go.
Oh, actually, those are somekey questions that I can ask my
professionals that give me thatadvice and tailor it for my
(23:42):
situation, my farm, my paddock,so it's not just set the planter
and go for the season.
Speaker 2 (23:48):
Okay, sounds good.
Roland, is there anything you'dlike to say just before we sign
off, because this might be yourlast time after you've given me
so much grief, oh great.
Speaker 3 (23:58):
I think the question that you guys didn't ask me,
which I get asked, is if Iincrease my populations, the
quality is going to drop, and Imust say that we have actually
been doing quite a lot of workin that space as well, and we do
not see any consequentialchanges in the quality unless
(24:19):
you start planting atridiculously high populations.
Speaker 2 (24:23):
You might have just got another invite there,
because I reckon that'd be quitea cool topic actually
understanding quality and howthat's impacted by population,
nutrient, everything else so youmight have just snuck in there.
Mate Opened the door.
Yeah, well done, well played,well played.
But anyway, mate, thank youvery much.
It's always a pleasure to haveyou on FIFA Thought For everyone
(24:44):
that's tuned in.
Make sure you like andsubscribe.
We continue to spread this farand wide and we'd like your
feedback, actually because thispodcast here was generated out
of some feedback we had aroundpopulations and people wanting
to know more.
So make sure you send thatthrough in whatever channel or
format you like.
Get in touch and we'll lookforward to you.
(25:04):
So thanks again, gents, andwe'll catch up with you all
again soon.
Speaker 3 (25:07):
Thanks, mate, thanks for having me.
Cheers, cheers, cheers, cheers.
G'day and welcome to Feed for Thought, a regular
podcast from Pioneer coveringeverything from farm systems to
crops and products and much,much more.
Speaker 2 (00:15):
Welcome to Feed for Thought.
My name's Matt Delly and, asalways, we like to delve into
all things farm systems andmaize in particular and today,
coming off the back of a maizeseason, we tend to look back on
things and what factors we mightbe considering for next season,
and one of the factors is plantpopulations.
And so, as always, I've got mysidekick, wade Bell, with me,
(00:38):
and we've got a special guesthe's pretty familiar to the
podcast Smartest guy in the roomby far.
If it was a smarter person, itwould have Bianca, because
obviously, she runs the shiparound here.
Welcome, roland.
Back to the podcast.
Speaker 3 (00:53):
Thank you, Matt.
Yeah, I'm not sure I'm thesmartest guy in the room, but
I'll take it anyway.
Maybe the most modest.
Speaker 2 (01:00):
Yeah, true.
So I suppose, Roland, this isour chance to reflect on the
season that's been and thenstart looking forward to next
year.
Around plant populations whatis the optimum planting
population?
Speaker 3 (01:14):
Yeah, that's a really difficult question to answer
because….
Speaker 2 (01:17):
That's why I asked it first.
Speaker 1 (01:19):
He's trying to prove how smart he is.
He's trying to prove that he'sa little smarter than anyone
else.
Speaker 3 (01:23):
Yeah, there's no optimum population which is
standard anyway.
Optimum population will dependon a range of things, obviously.
The first one is the hybridthat you're dealing with.
Certain hybrids will have agreater tolerance to stress
compared to others, so thosehybrids will obviously have a
(01:43):
higher optimum population.
And the other thing that willdetermine your population is
maturity.
Shorter season hybrids tend tohave a higher optimum population
compared to longer seasonhybrids, but we can delve into
that a little bit later, if youlike.
The other one is more theenvironment where you're
(02:05):
planting in.
If you're planting in a coolerenvironment where temperatures
tend to be lower I'm justrepeating myself coolant, lower
temperature, same thing you tendto want to have a lower
population.
And the reason for that issimilar to why we plant higher
(02:26):
populations for the shortermaturity hybrids, in the sense
that in cooler environments yourplants tend to be shorter,
smaller, your leaf areas aresmaller, so to capture more
radiation you need to push upyour populations.
And the other one is if you'replanting in high fertility soils
(02:48):
, you also want to increase yourpopulations.
And if you're planting in lowfertility soils or sandy soils,
again you want to lower yourpopulations because you don't
want to put a lot of pressure inthose situations.
The other one, which we don'tusually talk a lot about, is a
(03:09):
planting diet.
If you're planting quite earlyand by early I'm talking about
mid-September through topossibly early October in most
parts of the North Island youwant to be pushing up your
population slightly higher thanwhat we normally recommend is
(03:29):
your optimal population.
And the main reason for that isare you planting earlier than
where we normally would beplanting?
So your plants again are goingto be smaller.
On the other hand, if you'replanting late and what do I mean
by late?
I'm talking maybe aftermid-November, especially in the
(03:51):
southern parts of the NorthIsland you want to lower your
populations.
And the reason why we lowerpopulations is not necessarily
because of plant size, but it'slargely because your plants are
likely to run out of seasonduring the later part of a grain
(04:12):
field.
So when they run out of seasonthey will struggle for sunshine
hours, or solar radiation to bemore specific.
So you don't want your plantsto compete for solar radiation.
Hence why we want to lower yourpopulations a little bit.
Yeah.
Speaker 2 (04:32):
See, that's why I asked that because it's a
complex question and it's noteasy to answer.
Speaker 1 (04:37):
Yeah, I was actually going to say, as I was listening
to that, because, matt, you'vebeen in the area manager role,
yes, and I'm sure you've beentackled with the question about
lowering plant population.
Given everything that I'veheard Roland say he's talked a
lot about optimum why would youplant below optimum at low
populations?
Why were growers wanting to godown that pathway?
Speaker 2 (04:58):
There's definitely a few myths or a few things, I
suppose, thrown away Everyone.
As we plant lower population,we get a bigger cob right.
So everyone wants to take thecob to the bar and show off that
they've got the biggest cob,and so they say, oh, that must
mean better quality.
I've got a bigger cob, moregrain, better quality, and
(05:19):
you're just trying to sell memore seed, matt.
Speaker 1 (05:22):
So those are some of the Saving some money yeah.
Speaker 2 (05:24):
So those are some of the things.
People would kind of bet backAny truth to that.
Speaker 3 (05:33):
I had a few answers, roland, but I reckon you've got
some bitter ones.
It's quite interesting you saythat, because I get that same
question quite a lot, and one ofthe things that we get or I get
is someone who works for seedcompanies that we promote higher
populations because we want tosell more seed.
The truth is that we do notpromote higher populations, we
(05:56):
promote optimum populations.
Every time we talk aboutpopulations, we are talking
about maximizing the potentialof the crop that you're growing.
The hybrids that we have todayhave been designed to perform
better if you plant them to theright population, because,
(06:18):
unlike the old hybrids that weused to have maybe 30, 40 years
ago, which did not have a goodstress tolerance, the newer
hybrids that we have today havegot fantastic stress tolerance,
which means that they can handlestress.
Speaker 2 (06:37):
So it's not necessarily like a bigger plant
or anything.
It's actually the fact that wecan stack more plants in there.
Speaker 3 (06:44):
I was deliberately trying to avoid answering that
question about bigger cobs,because I it's one of the topics
I don't usually want to talkabout, but because you have
insisted, I will address that,so obviously shot there, I knew
that so that's a good start ifyou planted a lower population,
lower than optimum population,what you're going to get is a
(07:06):
big cob, a flesh looking cob, abigger plant and most people
love it and the plant also looksquite healthy, but at the end
of the day, that's not going topay your bills.
What you, what you end up with,is a cob or a crop that's not
going to yield to its optimum.
(07:28):
So, ideally, the hybrids thatwe have are designed to flex,
but that flex is limited.
The flex we get from hybrids ormice is not sufficient to
compensate for the loss in yielddue to a lower than optimum
population.
(07:48):
That's the theory, and if youwant me to delve a little bit
deeper into where or why thishappens, I can do that, but I
don't think you guys want to gothere.
Speaker 1 (08:04):
Well, no, actually maybe elaborate.
There's a couple of things Iwant you to elaborate on.
One is about the flex, becauseoften we talk in jargon and
terms that make sense to us, butyou know there'll be a lot of
listeners that'll go what thehell are you talking about?
When you're talking about flex,you've got kind of a simple…
it's not Wade in the gym.
Yeah, if you've got a kind of asimple explanation of what flex
(08:30):
is all about, okay, cool yeah.
Speaker 3 (08:32):
So you can call it any way you like, but I'm going
to try and introduce anotherfancy word that you guys might
like.
The actual word that we use iscalled plasticity.
Speaker 2 (08:47):
So if you, think of the plastic.
Let's stick with flex.
Speaker 3 (08:52):
So the reality is that maize has got the ability
to flex, which is calledplasticity.
So if you plant below theoptimal population, the carb, as
well as the plant itself, isgoing to increase a little bit.
But there is a limit as to howbig or how much plasticity a
(09:16):
plant can have.
So because of that, that is themain reason why the plant is
not able to compensate for theyield loss due to a lower
population, because it can onlyflex so much.
Because in general, the size ofa maize plant is genetically
determined, so it is not goingto go any bigger than what it is
(09:42):
genetically made up to be.
Speaker 1 (09:45):
So it's a diminishing curve, type A hundred percent.
A hundred percent, yeah, andI'll pick up on something that
satisfies my understanding.
Are you still with us there?
Speaker 2 (09:55):
Plasticity yeah, I got it.
Speaker 1 (09:57):
You're still all good .
You also mentioned stresstolerance and how stress
tolerance has impacted optimumplanting populations.
Do you want to just expand onthat a little bit and maybe even
the link between what thatmeans, say here in New Zealand,
when we might be comparing with,say, population data overseas?
Speaker 3 (10:18):
Yeah.
So in terms of stress tolerance,that's again another open-ended
question because I can tackleit in different ways but
generally, in terms of a massbreeding, most of the breeding
is focused on stress tolerance.
I know that most people wantbreeders to focus on increasing
(10:40):
yield, but that's not how itworks, because when you look at
the world we live in today,there is climate change, so what
that means is that we now havean environment which is
unpredictable we don't reallyknow what the weather is going
(11:02):
to do, so breeders are focusedon breeding for a product or a
hybrid that is able to toleratestress much, much better or that
has got more resilience, andhence why breeders focus on
stress tolerance.
So because of that, what hashappened is, in the old days,
(11:28):
maize hybrids used to be barrenor to where they would fail to
produce a cob if you pushed upthe population.
But because focus has been onstress tolerance.
But they would fail to producea cob if you pushed up the
population, but because focushas been on stress tolerance.
What that means is that thenewer genetics that we have
today are unable to produce acob, even under high populations
(11:51):
, and hence the reason why youfind that the newer genetics we
have tend to have higherpopulation optimal compared to
the old hybrids and I canactually confidently say this
because we do population trialsevery year.
(12:11):
We test most of our newergenetics or newer hybrids before
we commercialize them, tounderstand what the optimum
population for those hybrids are.
Speaker 2 (12:20):
So, roland, are they planting old hybrids in the
States and stuff?
Because they seem to.
The feedback is that they'vegot lower.
I know they're not planting oldhybrids, but they've got lower
populations over there.
Why are they planting at lowerpopulations overseas?
Speaker 3 (12:36):
Yeah, that's a pretty good question, especially
coming from your man.
Speaker 1 (12:40):
Oh, he's going up in Roland's estimations.
This is so good, it's good thatyou're getting grief from me
and from the guests.
Speaker 2 (12:51):
I'm loving it.
Speaker 3 (12:52):
So yeah.
So if you look at New Zealand,I think if there's one thing
that we should be proud ofunfortunately it's not something
that we did, but we arefortunate to have this Our
environment is perfect for maize.
We have a moderate environmentcompared to what they have
(13:13):
overseas.
If you look at the amount oftime that our crop is sitting in
the paddock, it's much, muchlonger compared to the States.
You look at the diseasepressure that we have in New
Zealand, it's much, much lowerthan in the US, and I will
(13:35):
probably delve a little bit moreabout what I mean by a moderate
environment and why that isparticularly important, and this
will also try to explain why weare getting higher yields with
slightly higher populations thanwhat we used to achieve in the
(13:56):
old days.
So your yield this again, thisis something that we don't talk
about Yield is, or largely is,determined by your radiation or
your sunshine hours.
To keep it nice and simple forme, yeah, well done.
So the more radiation that aplant intercepts, the more yield
(14:20):
the plant is going to achieve.
So if you then look at it fromthe perspective of New Zealand
versus the US, for instance, ourcrops are in the soil or
paddock for a much longer timecompared to the US.
As a result, they have got moretime to intercept radiation and
(14:44):
consequently radiation is notan issue for us because we've
got more time, whereas for othercountries, such as the US or
even Australia, wheretemperatures are much hotter,
there is a short time periodwhere your crops need or are in
the soil.
Therefore they've got a limitedamount of time to intercept
(15:09):
that radiation.
So we just happen to befortunate that we are in a
moderate environment, and thisis why we tend to plant at much
higher populations compared toeverywhere else.
It's just because of ourenvironment.
Speaker 1 (15:22):
What about things like and I guess you could argue
it's a stress as well, butwe've had, in seasons gone by,
wind damage or you get, and sopeople go, wow, shit, there's a
solution to that.
Just lower population andpopulation or get stronger
plants and they'll be able towithstand that, you know?
Does that just fall under thestress kind of tolerance
(15:42):
umbrella, or is that justsomething completely separate
consideration?
Speaker 3 (15:46):
Absolutely so.
When we talk about optimalpopulations, we are talking
about adjusting your populationsas well, if you're in those
environments that are notconducive to achieve those
higher populations that thosepeople who are in the best
environments can achieve.
So if you're in wind-transsituations, absolutely you want
(16:07):
to lower your populations.
Speaker 2 (16:09):
What about if you plant in a different direction?
So if you go north, southversus east west, does that make
a difference?
Roland Cheers, you said itpretty well, matt east west,
does that make a difference?
Speaker 3 (16:15):
Roland Cheers.
You said it pretty well, Matt.
I get to see the look on.
Speaker 2 (16:18):
Roland's face.
Speaker 3 (16:20):
He's getting more and more disappointed with you, do
you?
Speaker 1 (16:23):
really want me to answer this.
That was a planty question,mate, and you know it, you know
it.
Speaker 2 (16:28):
It is good, but I've heard that a number of times, so
I just thought.
Speaker 3 (16:32):
I'd throw it out there.
Okay, I'll leave wage to us.
Speaker 2 (16:38):
He's smart enough not to.
But one thing is our grain isstill growing the same plant
right.
Why do we reduce ourpopulations in general for grain
?
Or, if you're the same, hybrid,why are we planting at 10,000,
15,000 less?
Speaker 3 (16:53):
So it's basically more to do with the duration of
the crop growth cycle.
Your maize grain is in thepaddock for much, much longer
compared to maize silage.
And remember, when you'regrowing maize silage, your focus
is largely on total biomass,but when you're growing maize
(17:14):
grain, your focus is on thegrain.
So one of the things you wantto focus on is to have the best
grain possible, bigger grain,and please don't confuse bigger
grain with bigger ears.
We're just talking about idealgrain size, which is consistent
(17:35):
with the ideal population, andthe other thing, again, is more
with, because your crop is inthe soil for much longer.
If there are going to be anychallenges or stresses, those
stresses are likely to beexperienced in grain crops,
compared to silage, because thegrain plant will have to sit in
(17:55):
the soil or paddock for a muchlonger period.
Speaker 2 (17:58):
So standability and all that comes into it, root
strength, all comes into itlater on.
Speaker 1 (18:03):
I want to loop around .
This is probably my lastquestion, ronan.
I want to pick up on thingsthat I've heard you say and then
gone.
I'm not sure I completelyunderstand or maybe listeners
Leaf area index and therelationship between plant
population and leaf area.
Look again, it's terminologythat we use within Pioneer, but
what's the relationship thereand what are you trying to
(18:25):
achieve with leaf area index?
Speaker 3 (18:28):
What is?
Speaker 1 (18:28):
it and what are you trying to achieve?
Speaker 3 (18:30):
Yeah, so probably keep it nice and simple.
I may not necessarily talkabout leaf area index, because
it's probably a little bit tootechnical, but maybe if we just
focus on a total leaf area.
So ideally, what we are talkingabout is, when you go back to
the point I made earlier, thatyour yield comes from the sun.
(18:52):
So the challenge is how do weharvest the sun?
And we want to harvest as muchof it as possible.
So the way we can do that is byincreasing the total amount of
the solar panels in the maizeplant, and the solar panels are
(19:13):
the leaves, and that's where theconcept of leaf area index
comes into play.
So the more leaves we have, themore sunshine we can harvest or
solar radiation we can harvest,and there is a direct
relationship between the amountof sunshine or solar radiation
(19:36):
that the plant has interceptedor absorbed and the yield.
There is a direct correlation.
So hence why we focus or wetalk about leaf area index, and
just on that, I'm sure you guyshave spent a bit of time in the
field as well.
(19:58):
The live area index is a verydifficult concept to understand,
but there is a very simple waythat every person who deals with
mice can actually use or canapply to figure out whether they
have got the right populationor not.
So what I usually recommend isthat if they have a chance to go
(20:23):
to the maize paddock afterpollination during the day maybe
after midday or thereabout andjust look through the crop
underneath the canopy you wantto make sure that there's not a
lot of sunshine going past thecanopy, hitting the soil.
(20:47):
As soon as you see a lot ofsunshine hitting the soil
surface, that's usually anindication that you are not
utilizing that radiation, wastedenergy, yep.
So ideally you want a minimumof five percent of your ground
having some sunlight.
Speaker 1 (21:08):
Yeah, so does that, and then does that link back
then to population.
So that's something, what thatyou put in the the bank, put in
the memory for future seasons ifyou're growing in that area
under the similar conditions.
Speaker 3 (21:21):
Absolutely.
Once you get to that stage, youcan't really do anything about
it.
So it's more for next year andthat's what we want to encourage
people.
We want to encourage people toactually start doing this
themselves, because, in as muchas we do have people on the
ground, we have got our areamanagers as well as merchant
(21:42):
reps to help people understandhow or what is the right
population for their conditions,but they may not necessarily
have all the knowledge that isrequired to get the absolute
perfect population for yourconditions.
Speaker 2 (21:58):
Well, I think it's probably a good place to start
wrapping, but one of the firsttake homes that I've probably
got is I understand why Roland'sgot doctor in front of his name
and not in front of mine.
I've been put well on my place,so thanks for that, Roland, but
I think, winding it back toright at the start, it's about
(22:19):
understanding the environmentthat we're going into for a set
two and utilising as you justfinished with, then actually
utilising the people around toget to that understanding that
what is the optimum for us.
Wade any key take-homes fromyourself.
Speaker 1 (22:36):
Well, the interesting one for me.
You know you did dispel acouple of myths.
Or you know, like those reasonsthat you hear that might be,
they sound like sensible reasonsto perhaps reduce population.
You know, because you go,everybody likes to save some
money.
Or, you know, grow a higherquality crop.
But I think that's a little bitshort-sighted in terms of you
know what you're, what farmersand growers are generally trying
(22:57):
to achieve.
You know they want the highestpossible yield and you know
sometimes just that that thoughtof saving a little bit up front
is actually not going to be,it's going to be insignificant
in the scheme of the, theoverall performance of the crop.
So it's kind of nice to dispelthat to some degree.
And the other point that I thatI picked up there was just the
(23:18):
whole link between you know,each hybrid having an optimum
recommendation and thenmodifying for for the
environment that you're, thatyou're planting it into.
So you know, I think what Iwould like to think is that
listeners go away from today orfrom from listening to this
episode and go.
Oh, actually, those are somekey questions that I can ask my
professionals that give me thatadvice and tailor it for my
(23:42):
situation, my farm, my paddock,so it's not just set the planter
and go for the season.
Speaker 2 (23:48):
Okay, sounds good.
Roland, is there anything you'dlike to say just before we sign
off, because this might be yourlast time after you've given me
so much grief, oh great.
Speaker 3 (23:58):
I think the question that you guys didn't ask me,
which I get asked, is if Iincrease my populations, the
quality is going to drop, and Imust say that we have actually
been doing quite a lot of workin that space as well, and we do
not see any consequentialchanges in the quality unless
(24:19):
you start planting atridiculously high populations.
Speaker 2 (24:23):
You might have just got another invite there,
because I reckon that'd be quitea cool topic actually
understanding quality and howthat's impacted by population,
nutrient, everything else so youmight have just snuck in there.
Mate Opened the door.
Yeah, well done, well played,well played.
But anyway, mate, thank youvery much.
It's always a pleasure to haveyou on FIFA Thought For everyone
(24:44):
that's tuned in.
Make sure you like andsubscribe.
We continue to spread this farand wide and we'd like your
feedback, actually because thispodcast here was generated out
of some feedback we had aroundpopulations and people wanting
to know more.
So make sure you send thatthrough in whatever channel or
format you like.
Get in touch and we'll lookforward to you.
(25:04):
So thanks again, gents, andwe'll catch up with you all
again soon.
Speaker 3 (25:07):
Thanks, mate, thanks for having me.
Cheers, cheers, cheers, cheers.
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