Overall, things have been quiet, but that likely is largely
due to the rains. A lot folks are finishing up planting and getting started on
replants. Thankfully, the thrips model is still suggesting very low pressure. I
would expect our seed treatments to carry us through the thrips window.
We do still have the possibility of some oddballs, like
slugs, cutworms or threecornered alfalfa hoppers. Keep scouting and monitoring
fields evaluating emergence and stands in this late planted cotton and don’t let
anything threaten to reduce them.
June typically means plant bugs in Alabama. We will likely
start picking them up in our oldest cotton that is squaring soon. All the rains
we have had the last 7 to 10 days may complicate early season plant bug
decisions. Daisy fleabane (plant bugs primary spring host) will likely persist
for a while longer this month. This sometimes causes a “trickle” effect where
adult plant bugs infest cotton over an extended period of time. This may mean
that we see lower “subthreshold” numbers for a couple of weeks. At a certain
point, we will probably want to pull the trigger if that is the case. While the
primary goal of plant bug management is to preserve 80% of the first position pinhead
squares, we also want to stop egg deposition and the number of nymphs that will
hatch out in the next two weeks.
 |
| Adult tarnished plant bugs on a sweep-net. |
The best way to detect adult plant bugs is to use the
sweep-net. Threshold is an average of 8 adult plant bugs per 100 sweeps.
Monitoring pinhead square retention is an excellent way to see what injury is
being done in the field. Since a cotton plant puts on a new node every ≈3 days,
monitoring the upper 2-3 nodes tells us what has happened since the last time
the field was scouted. As mentioned above, threshold is to not allow retention
to fall below 80%.
With that in mind, we have a few options for control
of adults in pre-bloom cotton:
1.Imidacloprid:
Many trade names. Imidacloprid is the most economical option we have for plant
bug control. While imidacloprid does not provide 100% control (closer to
60-65%) at the highest labeled rates, it generally provides enough to get
populations under threshold and preserves square retention
2.Thiamethoxam:
Centric, Hub WDG. Thiamethoxam is another neonicotinoid that provides good
control of adult plant bugs. Our general recommendation is 2 oz/A. While a
little more costly than imidacloprid, this material provides better control.
Another option is Endigo ZCX, which is a premix of Centric (thiamethoxam) and
lambda-cy. Endigo ZCX at 3.5 oz/A provides the equivalent rate of Centric (2
oz/A) and lambda-cy (1.5 oz/A). While the added lambda-cy may be more likely to
flare mites, this pre-mix may be a little more economical than Centric alone.
3.Sulfoxaflor:
Transform (1.5 oz/A) provides the best control of plant bugs of all currently
registered materials. For that reason, we like to wait to use it when immature
plant bugs are present. Waiting for Transform can help to delay resistance and
manage adults more economically.
4.Other options: Acephate (0.5
lb) or pyrethroids (highest labeled rate) are options for
adults but are not generally recommended. The reason for this is multi-fold. 1.
Resistance management. We prefer to use neonics (imidacloprid or thiamethoxam)
on adults and then switch to the “harder” chemicals (Ops/pyrethroids) after
bloom when targeting immature plant bugs and/or stink bugs. 2. These classes of
chemicals tend to be harsher on beneficials, which could lead to outbreaks of
spider mite (however, we can and have flared spider mites with neonics sprayed on
7-day intervals). 3. Aphids, while neonics are generally good on aphids, OPs
and pyrethroids are not as reliable.
**Note: Pyrethroid resistance has been documented in NW and
SW Alabama in recent years. Pyrethroids should be monitored closely for
efficacy if used in all cotton growing regions of Alabama.
The good news is that things are still quiet on the cotton
jassid front. To date, no active populations have been observed in “the real
world” in 2026. We, along with our colleagues in FL, GA and SC are monitoring
the situation closely.
Cotton Scout Schools kick off this week:
- June 2 - 8 a.m. at the Wiregrass REC in Headland
- June 4 - 8 a.m. at Milstead Gin in Shorter
- June 9 - 8 a.m. the Tennessee Valley REC in
Belle Mina
- June 18 - 10 a.m. at Grant Farms in Uriah
- June 25 - 10 a.m. at McCord’s Fire Department
Station #1 in Centre
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.
