While there have been few new herbicides developed for vegetables over the past 20 years, new formulations of old products have slowly become available. Some of these new formulations have been developed after active ingredients have come off of patent as a means of differentiating and improving new products. Five of the most notable vegetable herbicides that new formulations have been developed for are Kerb, Dacthal, Prowl, Goal and Select. For the first time since Kerb 50W was registered in 1964, it will be available as a liquid Suspension Concentrate (SC). This formulation contains 3.3 lbs. of Pronamide per gallon. 1.25 pt. to 2.5 pt. is equivalent to 1.0 to 2.0 lb. of the old 50W. The label otherwise is the same. Dacthal (DCPA) was first registered as a 75WP (wettable powder) in 1958. A Flowable (F) formulation was first sold about 10 years ago. The Flowable contains 6 lbs. of the active ingredient per gallon and 1.0 pt. of the 6F is equivalent to 1.0 lb. of the old 75WP which is still available. Prowl was first registered in 1975 as an emulsifiable concentrate (EC). A water based encapsulated formulation (H2O) was developed and registered about 7 years ago. The active ingredient, Pendimethalin, of the H2O formulation is encapsulated in a polymer coating that swells and ruptures when diluted with water. It requires much more agitation to stay in suspension than the EC formulation. The original formulation contains 3.3 lbs. of active ingredient per gallon while the H2O formulation is a little more concentrated and contains 3.8 lbs. per gallon. Goal was first registered in 1979 as an emulsifiable concentrate. A water based flowable formulation, GoalTender, was registered about 5 years ago. This newer formulation has increased crop safety and less potential lift-off from codistillation with water. The older 2XL formulation contained 2 lbs. per gallon of active the ingredient, oxifluorfen, while the newer formulation contains 4 lbs. per gallon and requires half the rate of the 2XL. Select was first registered in 1991 as an emulsifiable concentrate. It was registered at the same time in California as Prism. Select contained 2 lbs. per gallon of the active ingredient clethodim and required half of the rate of Prism which contained 1 lb. per gallon. Several other formulations became available when this product came off of patent that contained 1-2 lbs. active ingredient per gallon. Select Max was registered about 5 years ago. This product contains 1 lb. per gallon of the active ingredient and does not require the addition of a crop oil concentrate adjuvant that is required with the other formulation.

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.