Ben Hill County Ag

Cotton Weed Control June Update

Cotton weed control (Culpepper)

Weather has certainly challenged the management program. The intense and often
overwhelming rainfall in recent weeks has greatly limited our ability to be timely with weed
management programs throughout Georgia. Below are a few discussion points to address
common questions/concerns.

1. Preemergence (PRE) herbicides in 2018 have been priceless providing excellent earlyseason
control. Even after Palmer amaranth eventually emergences through the PRE
herbicides, its growth has been slowed providing a more timely first POST application.
UGA Cotton Team Newsletter
June, 2018
For growers who removed the PRE from their system…………..horrible decision. As we
move into June, the PRE herbicide is just as important as ever because weeds emerge and
grow more quickly in June and July than in April or May. As always, apply two active
ingredients that are effective on Palmer amaranth and get the rates right for your soil type
and production practice thereby avoiding cotton injury.

2. Postemergence (POST) herbicides are currently preforming exceptionally well in
controlling emerged weeds; including Roundup and our labeled dicamba and 2,4-D
products. It is worth mentioning that the performance of Liberty was hampered in late
May because of consistently cloudy weather but since the sun has returned to South
Georgia the herbicide is back to performing as expected and occasionally a little better
than expected.

3. Pigweed is big in many fields so keep in mind a systems approach including sequential
POST applications and a layby containing products like diuron offer the best opportunity
for success. CRITICAL to success is the time interval between your two POST applications;
intervals vary within a given technology. Go to gaweed.com to view cotton weed
management programs and intervals between POST applications (or call your extension
agent)……….if you are off a few days between sequential POST applications it could have
dramatic consequences.

4. As mentioned above, herbicides are currently performing exceptionally well. Of course,
that is good for weed control but it is not so great for cotton injury. UGA research has
consistently shown most cotton postemergence herbicide mixtures can cause twice as
much injury when applied in saturated soil conditions as compared to ideal soil
conditions. Don’t forget that research suggests that it is best to avoid herbicide damage
to cotton past the 8-leaf stage if any way possible……yes, use the layby rig!!