Cotton lint on soil following crop destruction from drought stressed crop in 2012.
The drought of 2011 and 2012 has certainly had a major negative impact
on cotton in the local area this year.
Yields this year were such that many producers are having their crop
adjusted out by Crop Insurance as the economics of the situation indicated that
it was more economical to collect insurance on the adjusted crop yield and
destroy the remaining crop, rather than harvest the poor crop.
As
the cotton harvest nears completion, it is important not to forget about
destroying those cotton stalks as soon as the crop has been removed or
terminated to aid in reducing costs for the Boll Weevil Eradication Program
(BWEP). This year there has not been one
boll weevil caught in Nueces County, although there have been some caught just
to the south recently. Good progress has
been made on this front, so let’s keep it that way.
The
cotton stalk destruction deadline for Nueces County remains September 1, 2012.
In its native habitat cotton is a perennial shrub that
may survive for many years. The perennial habit of cotton allows it to regrow
following harvest, and provides the potential for development of hostable fruit
(squares and bolls) for boll weevil feeding and reproduction. Under good
environmental conditions, cotton plants can generate hostable fruit in three to
four weeks. Additionally, the
destruction of the cotton stalks will also preserve soil moisture for the
following season.
When field
conditions and weather are favorable for tillage, stalks can be shredded and
then disked to destroy the intact plant. Stubble stalk pullers can also be used
to uproot the stalk. These mechanical methods are generally successful, but
some stalks may survive these operations. Also, many growers are implementing
reduced tillage systems which do not allow for primary tillage operations,
causing producers to evaluate new methods for stalk destruction.
There has
been much interest in alternative cotton stalk destruction throughout the South
Texas area in recent years. While many producers still use various tillage
methods to destroy their cotton stubble, be aware that there are other choices
available. Regardless of the method chosen, the primary purpose of destroying
cotton stalks remains the same and that is to prevent cotton fruiting sites (squares or bolls) that
are a food source for the boll weevil.
These fruiting sites will allow the boll weevil to reproduce and
increases its winter survival rate.
Several
herbicides have been registered for cotton stalk destruction. Herbicides
available include, but are not limited to 2,4-D (ester and amine formulations)
and several dicamba products (Weedmaster, Clarity, Banvel). For these products
to be legal for cotton stalk destruction, the label must contain a section
addressing “crop stubble” or specify cotton as the target pest following
harvest.
Based on
most recent field research, it appears the low-volatile, amine salt
formulations are equally as effective as the ester formulations for cotton
stalk destruction, and minimize problems associated with off-target drift. The
first application should be at the rate of one pound of active ingredient/acre
(eg. 1 qt. of a 4 lbs. a.i./gal. formulation). Generally, a second application
of 0.5 to 1.0 lb. a.i./acre will be necessary for control of any live stalks
and emerged cotton seedlings.
To obtain
optimum results, cotton stalks should be shredded (6 to 8 inch height) and the
spray application should be made soon after shredding. Best results are
achieved if the herbicide is applied the same day as the shredding operation.
To achieve optimum effectiveness, some growers have mounted spray booms
directly on their flail shredders and are banding their herbicide during the
shredding operation, and achieving excellent results. Note that thorough
coverage is essential, and should be in the range of 5 to 10 gallons
water/acre. Also, the addition of surfactant at the rate of 0.5% v/v (2
qts./100 gals. water) is recommended. Research
has should that there is essentially no difference in killing regrowing cotton
plants with 2,4-D between treating shredded stalks within one day, treating 2
weeks after shredding, or standing stalks.
However, other products are less effective on standing stalks.
If a hormone
herbicide like 2,4-D is used, remember that there is always the potential for
off-target drift that might affect other susceptible crops in the area. So, be careful and monitor local
environmental conditions that could promote the off-target movement of the
product. With all of the lint on the
ground this year, a significant rain event will likely generate sprouting
cotton seedlings in many fields, possibly allowing floating lint/seed to be
washed into ditches and creeks, so we all need to be aware of this potential
problem and destroy these seedling when they begin to emerge. If we do not
receive a good rain this summer or fall, we should expect to be fighting
volunteer cotton in these fields next spring.
For additional information on managing volunteer cotton, refer to http://varietytesting.tamu.edu/cotton/#harvesting
At this web site scroll down to the Weed Section and
then select the link for Managing Volunteer Cotton in Grain Crops.
As we work to wrap up another cotton crop, it is
important to remember that without an effective cotton stalk destruction
program here in South Texas, boll weevil eradication cannot be accomplished!
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