2012-03-28 / Fields & Yields

Options offered for cotton weed control

By Peyton Sapp Burke Co. Extension Coordinator

Farmers know how important weed control is for your cotton crop. Palmer Amaranth continues to make growers sharpen their skills and look for more effective ways to control weeds. This plant continues to amaze us. Dr. Stanley Culpepper, UGA Weed Scientist, provided agents with recent experimental data showing that a pigweed seed that germinates on May 15th or later has the potential to reach 6 inches of height in 7 to 8 days! Early season weed control is critical.

One herbicide of choice for starting clean is Valor. It pro- vides good weed control while hopefully minimizing crop damage. There are three basic tried and true options for using Valor. Option 1: First: apply Valor at 2 oz./A; Second: wait 7 or more days; Third: implement strip tillage operation followed immediately by planting and pre-emergence herbicides.

Option 2: First: run your strip till operation; Second: apply Valor at 2 oz./A; Third: wait >30 days (less than 30% plant residue) or >21 days (more than 30% plant residue) plus one inch of rain; Fourth: plant into the previously run strip followed immediately with preemergence herbicides.

Option 3: First: apply Valor at 3 oz./A; Second: wait 60 days or more (a label is being developed to reduce this time interval, contact your local extension agent for the latest); Third: implement strip tillage operation followed immediately by planting and pre-emergence herbicides. Significant rains, water erosion, wind erosion, lack of activating rainfall, or any type of tillage will reduce control by Valor. DON’T FORGET TO CLEAN YOUR SPRAY TANK!!!!!

There are several options when using Reflex herbicide in your cotton weed control also. Reflex can be applied PRE behind the planter press wheel; PPI prior to planting; or PPI followed by PRE application. Crop injury and effectiveness of control varied quite a bit depending on irrigation, timing of application, incorporation method, etc.

A “one dimensional” weed control program is not an option for farmers anymore. Deciding on a proven herbicide program is critical. Farmers can look for more information coming soon in the next Burke County Ag Newsletter. If you would like more information on cotton weed control options, contact the Burke County Extension Office at 706-554-2119.

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