Kerb: 10 years after 9/11

By Marco Pena, UA research specialist

UA weed scientist and Area Agriculture Agent Barry Tickes has conducted several trials to determine the best application method of Pronamide herbicide (Kerb) in lettuce.

Tickes’ studies in 2000, one year before the 9/11event, demonstrated that when the product is applied after planting and before sprinkler irrigation in the low desert that it is often leached below weed seeds prior to germination. The result was lost efficacy.

In one experiment, Tickes stopped the sprinklers and sprayed plots with a CO2 backpack in the mud. This showed that Kerb applications should be delayed up to six days after starting sprinklers for late season plantings. This delayed application at the time required that aerial applications be made. With the terrorists attacks 10 years ago all air traffic was suspended.

PCAs asked if the product could be chemigated (sprinkler applied). Tickes conducted several trials in the Yuma area to answer this question.

Surprisingly the trials revealed that the product performed better chemigated than applied by air. Today, most Kerb in Arizona is chemigated and applied in delayed applications. This method is extensively used in California.

To review the data from this research, read Timing Kerb Applications in Lettuce and Evaluation of Kerb Applied by Sprinkler Irrigation to Lettuce both written by Tickes.

Contact Pena: (928) 782-3836 or marcop@ag.arizona.edu