Howdy everyone!
Texas A&M AgriLife
Because cotton is a perennial plant that we have adapted for annual cropping systems, the cotton plant can continue to grow even after harvest aid applications. This potential for regrowth mandates post-harvest stalk destruction to prevent development of new leaves and bolls for insect habitat and feeding. In the southern and eastern portions of the state, stalk destruction is more necessary as the warm, wet climate can ensure cotton regrowth; in the northern regions, the cold temperatures and frost will kill cotton before new fruit is produced.
Mechanical
Stalk destruction should occur as soon as field and weather conditions allow after harvest. Stalks are routinely shredded and then disked or plowed under for complete destruction. Stalk pullers can also be used to uproot stalks.
Chemical
(The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination
is intended and no endorsement by Texas AgriLife Extension and Texas A&M University is implied. Always consult the label)
We are now past the spray ban date for 2,4-D this year. As a reminder, this year, the Texas Department of Agriculture (TDA) granted the temporary suspension of the 2,4-D application rule (Section 7.53(oo)(2)) in Wharton County, which allowed for the ground application of 2,4-D herbicides by permit on the west and east sides of the Colorado River in Wharton County after Thursday, September 1, 2023; and the aerial application of 2,4-D herbicides by permit on the west side of the Colorado River in Wharton County after Friday, September 15, 2023 (application of 2,4-D products with a permit on the east side of the Colorado River in Wharton County are already permitted after September 15, 2023 under rule 7.53(oo)(1)).
For Enlist, (2,4-D tolerant) cotton, 2,4-D is no longer an option to chemically destroy cotton stalks. For cotton growers with Enlist (2,4-D tolerant) cotton, they will now have the choice of using either dichlorprop or dicamba to control cotton stalks. TDA has approved a 24(c) Special Local Need label for a dichlorprop-containing product called Duplosan by NuFarm. This product will be equally effective on cotton varieties with the XtendFlex or Glytol LibertyLink traits. AgriLife Extension data shows that this product will be more effective than dicamba for controlling Enlist cotton.
The label rate for Duplosan is 32-48 fl oz/acre. It should be applied to stalks with some leaf regrowth in order for the chemical to successfully translocate to the roots and shoots. For best practices, shred stalks to 6-8 inches and then follow with the herbicide application as soon as possible. Some growers choose to mount spray booms directly on their shredders to band the herbicide during shredding, which can achieve excellent results. Thorough coverage is essential for herbicide efficacy.
Please note that Duplosan is an ester formulation which may volatilize and affect nearby susceptible plants. This product is a state limited use pesticide that requires a pesticide applicator license or direct supervision of a licensed pest applicator for purchase or application of this product. The 24(c) label will expire December 31, 2023.
Links:
Texas Boll Weevil Eradication Program
Have a great week,
Sarah Marsh
IPM Extension Specialist
