The herbicides registered for use in lettuce are limited and it best to kill as many weeds as possible prior to planting. Weed seeds don’t all germinate at the same time but germinating as many as possible followed by tillage or early postemergent herbicides is effective. Fumigants, flooding and solarization kill weed seeds although most preemergent herbicides only work after the seeds have germinated. Almost any herbicide can be used preplant that is registered for “fallow” conditions as long as the preplant and preharvest intervals are observed. The following table summarizes the most commonly used herbicides for ground preparation in lettuce.

To contact Barry Tickes go to: btickes@ag.arizona.edu.

For questions or comments on any of the topics please contact Marco Pena at the Yuma Agricultural Center.
College of Agriculture, The University of Arizona, Tucson, AZ.