Corn pollination, atrazine herbicide use, and July insect updates

Dr. Jeff Coulter, U of M Extension Agronomist, updated us on the current status and outlook of corn pollination. Significant progress across much of the state should be occurring in the next week, though because of variable planting dates, it is difficult to generalize how upcoming hot weather will affect the overall crop across the state. Currently projected highs in the lower 90s should not cause significant pollination issues.Seth Dibblee, Environmental Scientist with the EPA, was on to discuss current news with atrazine. Atazine is a widely used post-emergence herbicide with about 33% of planted acres having an application in 2021. Currently, there are water quality concerns with atrazine that the EPA is proposing to address by adding restrictions to reduce runoff, such as disallowing use on saturated soil. A public comment period is open until Sept. 6, 2022 at: Dr. Anthony Hanson also gave a quick update on insects in early July. So far, soybean aphid hasn’t reached economic thresholds across much of the state, but populations are starting to increase in some areas. Whether it’s soybean aphid or other insects, be sure to check the insecticides are actually approved. Chlorpyrifos application , even if it’s in possession from a previous year, is no longer allowed for any agricultural use.

Transcripts are auto transcribed. If you need more accurate transcripts of an episode for ADA purposes, please contact Anthony Hanson -

Welcome to the University of Minnesota as

strategic farming field notes Program.

I'm Anthony Hansen, Regional Extension Educator

in integrated pest management.

Support for this program is also provided by

the Minnesota Corn Research and Promotion Council,

as well as the Minnesota Soybean

Research and Promotion Council.

Unfortunately, recording for July 30th,

2022 isn't available due

to some technical issues that we had.

So here's just a quick summary of what

was covered at the webinar for that day.

And we will have online postings

on some of the text
and what we covered.

To start off, we had Dr.
Jeff Coulter on to talk

about what's going on
with corn pollination.

A bit of a current
status update,

and then also what might be

happening in the coming weeks,

especially junit overall been

a pretty dry month
and fairly warm to

to the point that we are
actually coming ahead

of average on growing degree
days for corn so far.

So some fields that
were planted on time,

we're seeing pollination
occurring already or

just starting to in about
the next week or so.

But because of variability,

we had to planting date.

There are definitely some
fields that are going

to be further
behind than others.

But overall with
the temperatures

were expected to see coming up,

pollination should be rolling
along pretty well without

any significant issues with
too much heat occurring,

since we're going to be in about

the lower nineties or
so, we are, however,

starting to see some
drought conditions

start to merge in some
areas of the state.

And this could delay or affect

pollination in terms of

final yield that we
will see in the crop.

So very much depends

on what part of the
safe people are in

and what their
fields are looking

like for drought conditions.

We also had Seth Ghibli with

the Environmental
Protection Agency

on to talk about atrazine.

This is a broad
spectrum herbicide

that is beginning
a look again in

terms of water quality issues

and potentially being
able to mitigate those.

So currently the EPA is

proposing some restrictions
to the use of atrazine,

mostly to prevent run-off.

So there is a 60 day
comment period open to

the public that closes on
September 6th at 2022.

So he suggested that if

atrazine restrictions are
going to affect anyone,

that they should check out

the public comment period
and submit their comments so

they can work them into

any recommendations
that are coming out.

And just as a quick final note,

we are starting to see
some insect issues either

continue across the state or

starting to see some just
emerging a little bit.

So first off, the big question
that comes up quite a

bit around this time of
year is soybean aphid.

And we are seeing some across

the state infested and soybeans,

but generally not
at high numbers.

There are however,
a few pockets of

the state where populations
are increasing.

Now it's going to
be pretty early

to be treating for
soybean aphid,

but keep an eye on those
populations as they start

to grow more in later July.

Alfalfa weevil has also been

a concern for some
growers across the state,

especially around
Central Minnesota.

Now some growers
have seen damage,

especially in their
first and sometimes

second cutting alfalfa weevil.

But if you are considering
an application now,

be sure to actually go
out and check the field

that the alfalfa weevil
is still present.

Larvae can cause
damage in the field,

but adults are going
to be dormant this

time of year and
they're not feeding

are causing significant
damage either.

Now normally this
time of year you're

only going to find adults.

You're usually not going
to be concerned about

alfalfa weevil or treating
for it any further.

However, there have
been some reports

and parts of the state
that growers are

finding very early instar larvae

are very young ones that
have been laid recently.

Well, that's not typical for
what we see with that past.

But there may be some issues

with either new strains coming

in or some other
environmental conditions

that a delayed
emergence of this one.

So just be sure to go
out there and Sculpt.

If you do find larvae,

check that they're actually at

threshold levels because you
don't want to be spraying

when that species is

on its way out for
the season instead,

and you're not
getting a return on

investment of the insecticide.

And also just a general
reminder that court purify us.

We've had questions
about that as well.

It is not allowed for
any agricultural use,

even if you did have it on
hand for a previous year.

This is definitely come up a few

times and questions
that I've gotten.

So whether it's
alfalfa weevil or

upcoming applications
potentially for soybean aphid.

Be sure that you're following

current Pesticide Regulations.

Avoid ones that are no longer

allowed such as core pure PFOS,

but then also double-check
and the label

that it's actually approved

for application on that crop

because of field school on the
St. Paul campus next week,

our next episode of

field notes will be
on the 27th of July.

So stay tuned for that episode

and we'll see you
in about two weeks.

Corn pollination, atrazine herbicide use, and July insect updates
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