AUBURN, MARCH 12---In
one respect, cotton producers have never had it so good.
Thanks to boll-weevil eradication and genetically
altered cotton, two of the biggest bullies of cotton -- boll weevils
and caterpillars -- have been effectively cut down to size. Even so,
a few pint-sized predators remain.
"We’re
moving from an era in which there were a couple of dominant pests
into one in which we have five or six less dominant pests,"
says Dr. Ron Smith, an Alabama Cooperative Extension System
entomologist. "None of these are nearly as dominant as those we’ve
encountered in the past, but all of them can cause yield reductions
in cotton."
In the past, producers relied on broad-spectrum
insecticides such as pyrethroids to combat these pests. These
chemicals, in addition to eliminating the targeted pest, offered one
other advantage.
"In the process of cleaning the insects
targeted by the chemicals, we also cleaned up a lot of other pests
at the same time," Smith says. "That’s why we referred
to chemicals as ‘broad spectrum’ insecticides."
However, under stringent new guidelines outlined in
the Food Quality Protection Act of 1996, broad-spectrum pesticides
such as pyrethroids and phosphates will become increasingly
unavailable to producers. Instead, producers will have to rely on
newer classes of insecticides that are designed to be both
"target specific" (designed to eliminate only one insect)
and safer for the environment.
While many of these newer insecticides are highly
effective against pests, they will require producers to think and
act in an entirely different way.
"In the past, producers went out with more of a
preventative approach, applying a broad-spectrum chemical at
predetermined intervals within the growing season to knock out a
wide range of pests," Smith says. "But in the future, we’ll
be taking a more reactive approach, targeting specific chemicals to
specific pests only when they’re detected in the field."
The wide array of pesticides available under the new
approach will afford producers far more adaptability. It also will
reduce the risk of insecticide resistance – a recurring concern
under the old approach. On the other hand, the sheer number and
variety of chemicals also means growers will have to become more
knowledgeable about pesticides than ever before.
"We’re moving into a new era – a more
expensive era in which growers no longer will have the luxury of
making preventative applications," Smith says. "They’re
going to have to know what the problem is in the field and target
their spraying just to that insect."
This will involve monitoring each field on a regular
basis in order to determine which pest is at an economically
damaging level. Once that determination is made, growers, working
from a list of up to 10 different chemistries, must decide which one
is best suited to eliminating this particular pest while leaving the
other pests alone.
Needless to say, the demand for highly trained
cotton scouts will be more important than ever.
"In the old days, it was easy to focus on one
dominant pest in the field, knowing that when you reacted to one
pest using broad-spectrum chemicals, you would be taking care of
others as well," Smith recalls.
"However, this new approach will require a
trained professional who can go into a field and look for the pest
that is most likely to pose a threat during that particular week in
the growing season," he adds.
"That’s where experience will count.
Inexperienced scouts are simply not going to be what a grower needs.
It’s going to require an experienced person who can guide an
inexperienced scout through the field."
Unlike many broad-spectrum insecticides, which
tended to work immediately on contact with the pest, many of these
newer chemicals are slower-acting stomach poisons – far less
dangerous to birds and aquatic life but far more costly to
producers.
"We will have to do a better job of applying
these chemicals and making sure they’re ingested," Smith
says.
The slower-acting nature of these new chemicals also
will affect the way fields are monitored after spraying.
"With this new approach, some of these pests
are likely to linger for a few days after these applications,"
Smith says. "So, a good rule of thumb is to wait a few days
before returning to the fields to evaluate.
Producers also aren’t going to have to spray their
cotton as often, Smith says.
"In the past, growers typically made
applications at certain intervals," he says. "In the
future, he may go 2, 4 even 6 weeks without applying any
chemicals."
(Source: Dr.
Ron Smith, Alabama Cooperative Extension System entomologist,
334-844-6394.)