Growers often want soil applied herbicides to be active during the growing season of the crop it was applied to and then be gone. This is not often possible and it is often necessary to estimate the potential for crop injury when sensitive crops are planted. In lettuce, for instance, Kerb (Pronamide) will normally be active for 2 to 9 months, Prefar (Bensulide) for 4 to 12 months and Balan (Benefin) for 4 to 6 months. This will depend upon many factors including soil type, rate, time of application, environmental conditions, irrigation type and amount and other factors. This link will connect you to a chart that lists estimates of the time intervals that are likely needed before planting many of the common crops grown in Arizona. http://cals.arizona.edu/crops/vegetables/advisories/docs/HerbicidePersistence.pdf. (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.