Sandea at 0.03 lb AI/A combined with rimsulfuron at 0.02 lb AI/A gave exceptionally good control of prostrate pigweed and lambsquarters at 98% and 96%, respectively, when applied postemergence (POST) in cantaloupes. Sandea applied POST in a tank-mix with increasing rates of rimsulfuron showed marginally acceptable to unacceptable crop injury. All POST applications of Sandea following preemergence (PREE) herbicides or applied alone provided 90% or better control of lambsquarters. Sandea and Strategy gave unacceptable control of pigweed and lambsquarters at 60-70% relative to the standard, Prefar. Sandea applied alone POST was less effective against pigweed than lambsquarters. A treatment of a PREE herbicide followed by Sandea was not as efficacious as the Sandea plus rimsulfuron tank-mix applied POST to control both pigweed and lambsquarters.

Three tests were conducted to compare delayed applications of Kerb applied by air with those applied through the sprinklers. Early (6-5-02) season and mid (10-20-02) applications made through the sprinklers were significantly more effective than those applied by air. The late season (11-17-02) application was made too early and the weed control was poor demonstrating the need for proper timing regardless of the application technique. It was concluded that chemigation can be an effective technique for making delayed applications of Kerb to lettuce in the low deserts.

Broccoli and red table beets emerged and established a stand in Sandea treated plots at 0.5 or 1.0 oz product/A. Table beets planted into the beds treated with Sandea did not exhibit significantly different rates of emergence and stand establishment relative to the untreated check. The broccoli that emerged and established a stand did not show any significant differences or numerical trends between the untreated check and the two Sandea treatments during any of the observation dates. Spinach, the third indicator crop, did not emerge adequately in the test site.

Callisto at 0.24 lb AI/A applied PREE gave a similar level of control of prostrate pigweed as did Dual Magnum, Outlook, and Prowl. POST applications of Callisto at 0.188 lb AI/A were equivalent to the higher rate of 0.24 lb AI/A. Callisto, Distinct, and Clarity provided excellent POST control of pigweed. Callisto applied POST was the same as PREE followed by POST sequentially. Aim provided marginally acceptable control of pigweed.

Sandea, Valor, and Outlook offered promising results in different combinations applied preemergence (PREE). The combination of Prefar plus Sandea gave 95% control of pigweed and continued to control lambsquarters at 90% late in the season. Prefar combined with Valor gave acceptable pigweed control and lambsquarters were controlled at acceptable levels at 88 and 86%, respectively. Outlook combined with Valor was safe and gave good early pigweed control and later control of lambsquarters. Strategy alone at either 1.0 or 2.0 pt/A did not provide acceptable levels of weed control and no significant crop injury was observed.

Nicosulfuron, quinclorac, triflusulfuron, MKH-3586, pyraflufen, and tribenuron applied PREE appeared to be safe on the lettuce crops while demonstrating variable activity against weeds. Head lettuce and romaine were not as tolerant to POST herbicides compared to PREE herbicides. Sulfosulfuron, MKH-3586, rimsulfuron, ethametsulfuron and pyraflufen applied POST caused various degrees of injury on the lettuces that were less injurious than other treatments. Thifensulfuron, nicosulfuron, and quinclorac applied PREE or POST showed acceptable broccoli tolerance. Ethametsulfuron exhibited adequate safety when applied POST on broccoli. Thifensulfuron, nicosulfuron, and quinclorac applied PREE also showed spinach tolerance. Similar to head lettuce and romaine spinach was not as tolerant to POST herbicides compared to PREE herbicides.