Where’s the bugs? That has been the primary question we have gotten over the past week or so. Most calls are folks reporting light insect pressure and just checking to make sure they aren’t missing anything or aren’t the only ones not seeing much. Thankfully, that is the case for the majority of the cotton across the state. There are pockets of plant bugs and stink bugs here and there, but its been relatively quiet overall.
Another big topic is whether or not to “throw something in
the tank” when making a trip in cotton at the 4th or 5th
week of bloom. In most years, that is good timing to take care of plant bugs,
especially for the cost of a pyrethroid. However given what we know about
pyrethroids appearing to flare cotton jassids, I would be hesitant to stir
anything up right now. This leaves organophosphates (acephate or Bidrin) as
options to clean up stink bugs. This year, as light as pressure has been, I
think we can pass on that 3rd week of bloom “automatic” shot and try
to buy another week or two. As I once heard my colleague at Missouri, Chase
Floyd, say, “any day we don’t have to spray is a good day.” Keep kicking the
can down the road and try to make sure we are getting the biggest bang for the
buck we can on inputs this year. If there is enough pressure to treat, another
good option is Vertento. We talked about it some in our last blog (link).
On the label, the use of an oil-based surfactant or a NIS with at least 75%
surface active agent is recommended.
Cotton Jassid Update: Populations continue to be VERY low
across Alabama. Populations are becoming more easy to find in some areas of
Georgia, but no fields have reached treatable levels yet. The current counties
where cotton jassid have been confirmed in Alabama include: Elmore (June 11),
Lee (June 29), Henry (July 7) and Autauga (July 20). A single jassid was found
in a sweep-net sample at the Prattville research unit. Last year, the first
jassid found there was on September 3. What does that mean? Other than the fact
we found jassids there six weeks later last year, we do not know. It could mean
they build up numbers quicker, or they could end up building late, similar to
last year. Only time will tell. One thing we do know is that the only way to
know if jassids are present is to scout fields weekly.
To see an up-to-date map on cotton jassid detections across
the Cotton Belt, you can check out the Stop two-Spot Cotton Leafhopper
(Stop2SCL) website here (https://stop2scl.org/cotton/)
Soybean Update
We have gotten a few reports of redbanded stink bugs (RBSB)
requiring treatment in soybeans in south Alabama and seen a few in central
Alabama as well. RBSB are more aggressive feeders and more difficult to control
than our traditional stink bugs complex. Threshold is 4 RBSB per 25 sweeps. The
best option for control is Bifenthrin + acephate, but in some cases either
alone or either plus imidacloprid can knock them back. Additionally, Endigo ZCX
is a good option. It just depends on the pressure and how long the beans have
to do. Treatment for RBSB can be terminated at R7 except under adverse
environmental conditions.
Overall defoliator (soybean looper and velvetbean
caterpillar) pressure has been light so far. We will see how the storm in the
gulf will impact those numbers in the next 7 to 10 days.
As always, if we can ever be of any help, or if you would
like to provide input on the situation in your area, please don’t hesitate to
reach out to your local Extension Agent or myself (Scott Graham: 662-809-3368)
and Ron Smith (334-332-9501). For more information on thresholds and
insecticide recommendations, visit the Alabama Cotton IPM Guide (IPM-0415). To stay up-to-date on the Alabama cotton insect situation,
subscribe to the Alabama Cotton Shorts Newsletter,
Alabama Crops Report Newsletter and Podcast,
and the Syngenta Pest Patrol Hotline.
