Too Early To Think About Cutworms?
JACKSON, TENN.
I’ve had a couple of calls
related to the use of insecticides
for cutworms.
No-till and late burndown applications
that allow weeds to
persist in the field are factors
that increase the chances of
cutworm infestations. It is
best to maintain a clean seedbed for at least two
and preferably three weeks prior
to planting. This will go a long
way in eliminating the chances
of cutworm problems, but it is
sometimes easier said than
done.
A relatively low rate of a
pyrethroid insecticide is commonly
suggested to prevent cutworm
damage. However, I do
not recommend including an
insecticide with herbicide applications
that are made more
than two weeks in advance of
planting. Tank mixing an insecticide
with an early burndown
application does not make much
sense. Cutworms you kill would
have probably ‘cycled out’ before
you planted anyhow. And because
you cannot expect much
residual control, there is the possibility
of reinfestation between application and
planting. The best time to make this application
is just before or at planting (or within a day or
two after planting).
A few other points for your consideration:
• No insecticide seed treatments should be expected
to provide substantial control of cutworms.
• Although Bt corn and cotton traits provide
some protection against cutworms, planting
into fields that are heavily infested is a risky
business. Herculex, VT3 Pro, VT2 Pro and
SmartStax corn can reduce cutworm injury,
and I would expect the same from the Viptera
technology. In cotton, WideStrike will suppress
cutworm injury better than Bollgard II. However,
large larvae are much less susceptible to
Bt toxins. So, if populations are high enough, I
suspect any Bt technology can be overwhelmed.
• Ammo 2.5 EC and its generic equivalents
(e.g., Up-Cyde) are not labeled for use in corn or
soybean.
• Pounce 3.2 EC and its generic equivalents
(e.g., Arctic) are not labeled for use in cotton. Δ
DR. SCOTT STEWART: IPM Extension Specialist,
University of Tennessee