More Tobacco Weed Control With Layby Herbicides

(Updated: May 15, 2024, 5:32 a.m.)

Layby applications of herbicide can be considered to boost weed control up to 50% depending on weed pressure and herbicide selection.  The cost of one layby herbicide application is believed to be worth 2-3 hours of weeding per acre in certain situations.

Layby herbicides are most effective during wet seasons.   Applications are often directed to the row middles in 16-20 inch bands using drop nozzles.  These products are rainfall dependent and should be applied after a layby cultivation.

These are the four options for layby weed and grass control.
  • Devrinol – Devrinol is an excellent choice as a layby herbicide because it is good against Palmer amaranth and uses a different mode of action than other tobacco herbicides.  It is a good complement to an earlier application of Spartan plus Command.  Devrinol can be used more than once during a season but a reduced rate at layby is recommended (1.0 - 2.0 quarts per acre) if this product was also used before (PRE-T) or after transplanting (post-over-the-top).  Note:  This product has been seen to carryover to small grains.
  • Prowl – Some growers may consider this product due to its pigweed and grass control. Avoid applying Prowl to tobacco buds to prevent injury.  Prowl H2O is the most popular formulation.  Note:  Some buyers object to the use of this product so check before using!
  • Poast – This product is solely a contact product and offers no residual. It must be used on grasses less than 6 inches tall and has a 42-day PHI.  Add 2 pints per acre of crop oil or 1 pint of Dash HC spray adjuvant according to label directions.  Poast can be applied over-the-top or directly in a band. If the crop is tender, avoid mid-day applications.  Two applications can be made during a season.
  • Aim 2EC – This product must be applied using a shielded or hooded sprayer to emerged, actively growing weeds (less than 4 inches) in the row middles prior to layby. It is also labeled after first harvest when nozzles are directed underneath the crop canopy.  Damage will occur if it directly contacts tobacco. Additional sprayer clean out is necessary of tanks, spray lines, and nozzles when using this product.  Aim is a good choice for morning glory pressure, but does not offer any residual control of any weed species.