• Postemergence Weed Control in Cantaloupe Study

      Umeda, K.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      The postemergence (POST) herbicide treatments did not cause any crop stand reduction following applications. Bentazon (Basagran®) at 0.50 lb AI /A caused marginally acceptable injury on the cantaloupe leaves. At 2 weeks after treatment (WAT), the amount of injury decreased and cantaloupe treated with Basagran at 1.0 lb AI/A showed marginally acceptable injury symptoms. Halosulfuron (Monsanto) at 0.05 to 0.10 lb AI/A caused slightly more injury (10 to 17 %) with increasing rates. Basagran at 1.0 lb Al/A gave good control ( >90 %) of morningglory and was marginal in controlling morningglory at 0.75 lb AI/A Halosulfuron at 1 WAT was marginal in controlling morningglory but improved to give acceptable control at 2 WAT. Fewer and smaller plants were removed by hand-hoeing from Basagran and halosulfuron treated plots compared to the untreated check.
    • Preemergence Herbicide Combinations for Onion Weed Control Study

      Umeda, K.; Gal, G.; Strickland, B.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      DCPA (Dacthal®) at 9.0 lb AI /A, the commercial standard herbicide, slightly reduced the number of plants and shortened the plant height compared to the untreated check. Preemergence (PREE) herbicide treatments that caused injury as height reduction similar to Dacthal included pendimethalin (Prowl®), propachlor (Ramrod®), metolachlor (Dual®), dimethenamid (Frontier®), ethofumesate (Nortron®), and benefin (Balan®). Visual observations did not indicate significant stand reduction or crop injury compared to plant counts. Treatments that caused minimal visible crop injury (<10 %) were Ramrod, Balan and lower rates of Frontier and Nortron. Moderate to acceptable injury (15 %) was observed on onions treated by Prowl, Dual, Frontier, and Nortron. Treatments that significantly reduced crop stand were Prefar at 6.0 lb AI /A, lactofen (Cobra®), thiazopyr (Visor®), and some combinations of the three herbicides. Combination treatments that caused marginally acceptable injury included Prowl plus Dual, Nortron plus Prowl, Prefar plus Nortron, Nortron plus Frontier, Ramrod plus Frontier, Ramrod plus Nortron, and Ramrod plus Balan. Early weed control ratings showed that Prowl at 0.5 and 0.75 lb Al/A, Nortron, Cobra, Visor applied alone gave acceptable control (>85 %) of London rocket (Sisvmbrium irio), sowthistle (Sonchus oleraceus), and sweetclover (Melilotus officinalis). Prowl at 0.75 lb AI/A and Cobra gave season -long control of all weeds. Early weed control ratings of combination herbicide treatments demonstrated that Prowl or Nortron combined with other herbicides gave acceptable weed control. Prowl at 0.50 lb AI /A plus Ramrod, Nortron, or Dual at the lower rates slightly improved weed control compared to each of the herbicides applied alone.
    • Relative Susceptibility of Red and Green Color Forms of Green Peach Aphid to Insecticides

      Kerns, D. L.; Palumbo, J. C.; Byrne, D. N.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      Field populations of green peach aphid, Myzus persicae (Sulzer), were collected from five produce fields near Yuma, Arizona. Three of the fields sampled contained both red and green-colored forms, while the remaining two fields contained only green-colored green peach aphids. Red-colored aphids were consistently more resistant to dimethoate and lambda-cyhalothrin, and usually more resistant to endosulfan than green-colored aphids collected from the same field. Slight differences in susceptibility to imidacloprid suggest that development of resistance is a possibility and justifies close resistance monitoring. Susceptibility to imidacloprid was not influenced by color form. We detected little or no differences in susceptibility to acephate, mevinphos or bifenthrin.
    • Sweet Corn Herbicide Weed Control Study

      Umeda, Kai; Gal, G.; Strickland, B.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      Season-long near complete weed control in sweet corn was achieved with preemergence (PREE) herbicide applications of pendimethalin (Prowl®), metolachlor (Dual®), or thiafluamide/metribuzin (Axiom®) followed by postemergence applications of bentazon (Basagran®) or dicamba (Banvel®). Basagran applied alone POST gave very good control ( >93 %) of lambsquarters (Chenopodium album) and purslane (Portulaca oleracea) but did not adequately control tumble pigweed (Amaranthus albus). Prowl applied alone PREE gave acceptable control of most weeds. POST applications of prosulfuron/primisulfuron (Exceed®) caused moderate corn injury by shortening internodes and overall plant height and slight foliar chlorosis.
    • Tank Mixing New Insecticide Chemistries with a Pyrethroid Insecticide for Control of Lepidopterous Pests in Head Lettuce, 1997

      Kerns, David L.; Tellez, Tony; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      Confirm, Success and Proclaim were evaluated for lepidopterous insect control in lettuce with and without the addition of Mustang 1.5EW. Success and Proclaim used alone were highly efficacious toward cabbage looper and Heliothinae and did not appear to benefit greatly from the addition of Mustang. However, Confirm's activity towards Heliothinae was significantly improved by the addition of Mustang. Additionally, on large framed plants where coverage is difficult, Confirm benefitted from the addition of a pyrethroid for control of loopers.
    • Watermelon Herbicide Weed Control Study

      Umeda, K.; Gal, G.; Strickland, B.; Oebker, Norman F. (College of Agriculture, University of Arizona (Tucson, AZ), 1999-02)
      Bensulide (Prefar®), clomazone (Command®), sulfentrazone (FMC), and halosulfuron (FMC) treatments applied preemergence (PREE) gave very good weed control of prostrate pigweed (Amaranthus blitoides), lambsquarters (Chenopodium album), and common purslane (Potulaca oleracea) at 5 weeks after treatment (WAT). Bentazon (Basagran ® and halosulfuron applied postemergence (POST) alone were marginally effective at less than 85% against the pigweed species at 2 WAT and controlled lambsquarters and common purslane. POST treatments following PREE treatments were highly effective to control most weeds. Watermelon injury was acceptable for Command and halosulfuron treatments. Basagran caused slight injury when applied POST on the watermelons. Carfentrazone was not effective against the weeds present in this test site and was safe on the crop. The greatest number of marketable watermelons were harvested from plots having treatments that provided effective weed control. Command plus Prefar PREE followed by Basagran POST and Prefar PREE followed by halosulfuron POST treated watermelons yielded high numbers of marketable fruit.