Select (clethodim) and BAS-620 (BASF Corporation) at 0.1, 0.125, and 0.188 lb AI/A gave near complete control (99%) of watergrass at 8 days after treatment of the early application in watermelons and cantaloupes. Poast (sethoxydim) and Fusilade DX (fluazifop-p-butyl) offered nearly similar effective control of the watergrass with control ranging from 93 to 98%. Poast demonstrated a rate response with decreasing efficacy with decreasing rates of application. Fusilade and Poast at the high rate were comparable to Select and BAS-620 at the high rate. In lettuce, Select and BAS-620 performed similarly on large volunteer wheat with 97% control at about 3 weeks after treatment. Fusilade provided an acceptable level of control at 86% control. Poast did not provide any visible control of the volunteer wheat. Differences existed in the performance of the grass herbicides and optimal performance could be obtained with proper timing of application at effective rates and using effective adjuvants.

A field test was conducted to evaluate and determine the safety of halosulfuron on typical rotational crops such as lettuce, broccoli, spinach, onion, alfalfa, barley, field corn, and melons after an initial application on cantaloupes. Halosulfuron at 0.05 or 0.1 lb AI/A applied on cantaloupes did not detrimentally affect crop stand establishment, height, or whole plant fresh weights when alfalfa, barley, spinach, lettuce, onion, and broccoli were planted at approximately 4 to 5 MAT. Cantaloupes and field corn planted at 1 YAT were not affected in establishing a stand and in growing during the early season as height or vine lengths were measured. At 15 to 16 MAT, lettuce, onion, and broccoli were not affected in establishing a stand. Watermelon planted at 1 YAT exhibited slight stand reduction and crop injury with halosulfuron applied PREE. Alfalfa planted after PREE applications indicated slightly depressed height and yield compared to POST treatments and the untreated check. Spinach planted where POST applications were made on cantaloupes tended to show a slight reduction in fresh weight at 15 to 16 MAT. Halosulfuron does not appear to be a major deterrent to typical crop rotational schemes in the diverse desert agricultural systems.

Azafenidin (Milestone®, Dupont) and flumioxazin (Valor®, Valent)) caused cantaloupe injury that was very marginal between acceptable (<15%) and unacceptable (>15%). Flufenacet (Bayer), isoxaben (Gallery, DowAgroSciences), and thifensulfuron (Harmony®, Dupont) at the rates tested caused severe crop injury. Isoxaben provided very good weed control (>90%), azafenidin provided acceptable control of only lambsquarters at 88% and less than acceptable (85%) control of pigweeds, purslane, and grasses, and flumioxazin at the higher rate of 0.05 lb AI/A tended to offer slightly better weed control than the lower rate but overall it was marginally acceptable. Bensulide (Prefar®) combined with flumioxazin caused negligible crop phytotoxicity and better than 93% control for purslane, pigweeds, lambsquarters, and grasses. Combinations of herbicides offered slightly improved weed control compared to herbicides applied alone. Crop injury increased for combinations with dimethenamid (Outlook®, Frontier®, BASF) and s-metolachlor (Dual Magnum®, Syngenta).

Three rates of Stinger (Clopyralid) were evaluated for weed control, crop safety and soil persistence in broccoli. Efficacy tests indicated that 0.25 pt./A was ineffective in controlling volunteer alfalfa; while 0.5 pt produced marginal control and 1.0 pt. produced excellent control. No injury was noted at any rate. 140 days after treatment, injury was moderate to severe to alfalfa, moderate to tomatoes, cotton, carrots and lettuce and slight to onions.

Halosulfuron applied alone gave marginal to good control of common lambsquarters and common purslane, respectively, but did not provide control of the pigweeds. Acceptable control of 85% of the limited population of purple nutsedge was observed. Rimsulfuron applied alone gave good control of the pigweeds, lambsquarters, purslane, and marginal control of nutsedge. Weed control was effective until the late season evaluation at 9 WAT. The combination of halosulfuron and rimsulfuron gave similar results of the rimsulfuron applied alone, however, nutsedge control was not evaluated due to insufficient populations. Halosulfuron treated melons showed the least injury among all of the herbicide treatments applied alone. Rimsulfuron caused marginally unacceptable injury at 18% compared to flumetsulam, thifensulfuron, MKH-6561, and flufenacet which caused unacceptable injury ranging from 20 to 68%.