Historical use of Herbicides in Lettuce
The history of herbicide use in lettuce is a tale of adapting old herbicides to new and changing production practices. It can be divided into three time periods. The Early Period of the late 1950’s to the mid-1960s was a time of seeing a few herbicides that were only partially effective and had marginal crop safety. The herbicides used at that time were Vegedex (CDEC), IPC (Propham) and Dacthal (DCPA).Cultivation and hoed weeding were often necessary. The Post 1962 period was characterized by the introduction of more active and selective preemergent herbicides. These are the same three that are still used today, 55 years later!
Benefin (Balan) was introduced in 1962, Bensulide (Prefar) in 1968 and Pronamide in 1969.These herbicides have changed little although how we them has been modified by the increased use of sprinkler irrigation, precision planting and changing lettuce types. The Post 1984 Period was a time when the postemergence grass herbicides were introduced. These included Fluaziflop (Fusilade)1983, Sethoxydim (Poast)1984 and Clethodim (1987). These herbicides are mostly used as rescue treatments where the preemergent herbicides have failed.