Field studies were conducted near Oxnard, CA and in two locations near Salinas, CA in 2002 and 2003 to evaluate efficacy and safety of six herbicides in celery. s-metolachlor at 0.6 and 0.7 kg ai/ha and flufenacet at 0.5, 0.6, and 0.7 kg ai/ha PRE were safe to celery and controlled 81 to 94% of yellow nutsedge at densities < 20 plants/m2. At yellow nutsedge densities > 20 plants/m2, the most efficacious treatments were 1.1 kg/ha of s-metolachlor or 0.7 kg/ha of flufenacet, which reduced nutsedge densities by 71 or 53%, respectively; however, both resulted in slight injury to celery. All other herbicides generally did not injure celery and none reduced marketable crop yield. Flumioxazin pretransplant (PRE) at 0.1 and 0.2 kg ai/ha controlled broadleaf weeds near 100% at all locations, suggesting that it can be an effective alternative to standard linuron and prometryn, which are applied post-transplant (POST) in celery.
