Bensulide (Prefar) was the most promising of the preplant herbicides tested for selective weed control in melons. It is not yet registered, however, and is not recommended by the University of California. Of the postplant herbicides tested, trifluralin (Treflan) and nitralin (Planavin) gave commercial weed control with considerable safety, when incorporated with a rolling cultivator after planting. Trifluralin is registered for use in curcurbits (except for watermelon) at the “lay-by” or 3-to 4-leaf stage of development. Planavin is not registered—and neither chemical is recommended for use by the University of California at this time.

Farm Advsors R. King, San Joaquin County, and H. Kempen, Kern County, cooperated in the field work. Financial assistance was received from the Eli Lilly Chemical Company. Equipment and technical assistance was received from Dr. Lloyd Warner, Mr. Paul Steenwyk, and U.C. Field Stations staff.