ROCHELLE, Ill. — Always use protectant or so the saying
Todd Robran of DuPont Crop Protection is not necessarily a
“I’m not an advocate of just treating every acre with a
fungicide,” he said.
Robran is a portfolio manager for fungicides and insect
control. He spoke at a recent field day at DuPont’s Midwest Research Farm near
“I think that’s been done before. Customers get frustrated.
They don’t always see a positive yield response, and they think the fungicide
failed them,” he said.
Robran was speaking to an audience mainly consisting of
DuPont Crop Protection representatives from around the Midwest and a handful of
local farmers and agribusinessmen.
“If we target the right acres to give growers the best
response on that application, they’re going to be much more pleased with their
fungicide choice. They’re going to be more pleased with their seed selection and
overall and most importantly — we’re going to help them bring a few more dollars
to their bottom line,” he said.
Robran and Dr. Bond McInnes, fungicide technical manager for
DuPont, talked about using fungicides to both control and treat diseases in
soybeans and corn. The focus was on Aproach fungicide, one of DuPont’s new
Robran said that while Aproach can act as a protectant, it
also can help stop the spread of white mold spores.
“Obviously, Aproach can’t take the brown tissue and turn it
green again. When you come across an inevitable application delay, Aproach’s
curative activity will help stop those spores that are on the leaves that may
have germinated, but not yet formed a lesion, keep that leaf clean and help
protect that plant longer,” he said.
If there is an issue that worries soybean growers in the
Midwest this year, it’s going to be white mold.
“A lot of concern here as we look at how this year is
shaping up, soybean white mold, that question comes up a lot. Soybean white mold
is a very difficult disease to manage,” Robran said.
He noted that Aproach is one tool that growers can use.
“Wider row spacing, we’ve all heard that. Monitoring plant
populations is another way to help manage that disease,” he said.
Robran said that the application timing is important.
“Here in northern Illinois, we’re targeting soybean white
mold. We’re going to recommend nine ounces of Aproach, at an R1 to R2
application timing. We’re targeting a little bit earlier than what we
traditionally have sprayed our fungicides, and that is due to the way soybean
white mold develops in the canopy,” he said.
McInnes said that white mold is a special headache because
it can overwinter in the soil.
“This is an organism, schlerotinia, that has a long life in
the soil. It overwinters as sclerotia, looks like little rat turds in the soil,”
McInnes said that rotation isn’t really a solution, since
the organism can survive through the winter.
Reducing populations is not really a solution as that also
brings yield drops, he said. That’s why management of the crop and timely
application of a fungicide becomes key.
Robran said the reason for the earlier application of
Aproach is to stop the disease from becoming established.
“When we make our recommendations to apply at R1 to R2, the
reason we’re making it a little bit earlier is that pathogen needs petals to
survive. As the soybean petals start to fall off, that’s what the sclerotia and
the disease feeds on to infect the plant,” he said.
Robran and McInnes said the recommendation is for two
applications of Aproach.
“It’s a very difficult disease to manage to we make these
applications prior to the disease being established in the field or at least
being established in most of the field. We look at an R1 to R2 application
timing and we’ll come back with our second application, another nine ounces in
10 to 14 days later or at about R3 application timing,” Robran said.
He said Aproach also can be used on soybeans that don’t have
white mold to protect against other fungal diseases.
“If white mold isn’t a concern for you, for whatever reason,
you’re coming out of a field that’s been in corn for five years, there we’ll
just recommend six ounces of Aproach at R3, our standard recommendation,” he
In corn, Aproach can help maximize the protectant properties
of a fungicide by moving quickly through the canopy.
“If you look at that corn canopy and it gets bigger and
turns to the reproductive stages, and you want to maximize that fungicide
activity, you’ve got to get through that canopy. How do you do it? You get a
product like Aproach with quick uptake, moves through the canopy and has that
translameter, it means it moves through the growing tip or even if you hit on a
developing plant like that, if you hit a stalk, it actually moves to the next
node and can protect that next leaf,” McInnes said.
He touted Aproach’s ability to redistribute to maximize
protection for the plant and thus maximize green leaf area and sunlight use.
“It has the ability to redistribute, protect that leaf
tissue. Not only is it growing up, but back into that canopy, really important
on our soybeans because those organisms start at the bottom and move up toward
the canopy and also in our corn. We’ve got to maximize that disease control, and
we’ve got to maximize the green leaf area there,” he said.