Conventional Cotton Herbicide Control: One Approach

Editor's Note: Rusty Harris, Extension Agent in Worth County, Georgia, developed the following systems approach for his farmers who want to grow cotton that lacks herbicide resistance traits:

This program should provide adequate control of palmer amaranth, ipomea morningglory species, yellow nutsedge, bristly starbur, and tropic croton.

Timing of herbicide application and activation of soil herbicides are critical to success.

·      Burndown (Pre-plant)

o     Glyphosate+2,4-D

o     Add diuron for residual pigweed control

§       Diuron will likely DECREASE control of large grasses and increase time to kill cover crop

§       Increasing rate of glyphosate when mixing with diuronmay help to offset antagonism on grasses

·      Pre-emergence (PRE behind presswheel)

o     Reflex + Cotoran + Gramoxone   ***you MUST be sure all weeds are DEAD at this time or else!!

o     Add Prowl for residual grass control

o     Apply trifluralin Pre-Plant Incorporated (PPI) in conventional tillage systems followed by PRE treatment

·      Early Postemergence (EPOST 4 true leaf stage)

o     ALS resistant pigweed:  Cotoran + MSMA directed **Cotton must be at least 3” tall

o     ALS susceptible pigweed: Staple + NIS broadcast

·      Mid-Postemergence (8-10 nodes)

o     Envoke + NIS ***DO NOT mix with other adjuvants than NIS; DO NOT tank-mix with plant growth regulators; Application to cotton under stress (very dry, wet, or cool) may cause injury

o     Use Staple + Envoke tank mixture to control smallflower morningglory if Staple was not used earlier in the program

·      Layby (Approximately 10-12 nodes)

o    Diuron +  MSMA or Suprend + MSMA ***Use at least 2 pt/Acre Diuron if soil type allows to control emerged pigweed; ET at 0.5-1.0 oz per acre or Aim at 0.5-1.0 oz/ac will increase control of large morningglory and tropical spiderwort. Adding Dual will increase residual tropical spiderwort control.