• Swather Applied Trilogy® Effects on Twospotted Spider Mite Populations and Resultant Alfalfa Yields and Quality

      Rethwisch, Michael D.; Luna, Manuel; Williams, Michael; Saenz, Amanda; Reay, Mark; Grudovich, Jessica; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Trilogy® was applied via swather at cutting in April to alfalfa infested with twospotted spider mites. Data from samples obtained at 12 days after application noted somewhat reduced spider populations as a result of Trilogy® application, although new growth was thought to be re-infested from previously cut alfalfa which was in contact with new growth. Western flower thrips later became very prominent in plots and resulted in greatly reduced spider mite populations. Trilogy® treatment resulted in increased yields thought due to larger stem diameters as a result of fewer spider mites early in study. Very slight increases were also noted for alfalfa quality parameters as a result of Trilogy® application. Economic analysis indicated that Trilogy® applied via swather in this experiment resulted in a net increase in alfalfa valued at $2.12/acre.
    • Comparison of Baythroid® 2 and Renounce 20® WP for Fall Alfalfa Insect Control

      Rethwisch, Michael D.; Williams, Michael; Luna, Manuel; Reay, Mark; Van Dyke, Joe; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Two formulations of the insecticide active ingredient cyfluthrin (Baythroid® 2, Renounce® 20WP) were compared for fall alfalfa insect control, as was a lower active ingredient rate of both chemistries that included dimethoate. Differences in formulation effects of cyfluthrin were noted for cowpea aphids, spotted alfalfa aphids and alfalfa caterpillars at one day post treatment. At four days post treatment formulation significant differences were evident for numbers of bigeyed bugs, while at seven days after application formulations differed in numbers of spotted alfalfa aphids. Usage of dimethoate with a lower rate of cyfluthin resulted in less control of threecornered alfalfa hoppers throughout the study, improved initial control of spotted alfalfa aphids and clover leafhoppers, an increase in leafminer flies at four days post treatment and reductions in numbers of bigeyed bugs and spiders on this sample date, as well as significant reductions of lygus bugs later in the study compared with cyfluthrin only treatments.
    • Evaluation of Herbicides for the Control of Littleseed Canarygrass in Wheat – 2005

      Tickes, Barry; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Three herbicides, Puma, Achieve and Osprey, have been registered for the control of Littleseed Canarygrass in the last five years. Another, Pinoxaden, is being developed and should be registered in the next few years. These herbicides were compared for weed control and crop safety. All produced very good to excellent levels of control although crop injury, especially when tank mixed with broadleaf herbicides, was significant.
    • Evaluation of Various Insecticides for Late Winter/Early Spring Insect Control, 2004

      Rethwisch, Michael D.; Grudovich, Jessica; Bennett, Steven; Reay, Mark; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Nine insecticides were applied on March 10, 2004, to alfalfa that had been water stressed prior to irrigation on March 6. These actions were thought to have resulted in treatments means with less distinct differences than usually noted for these treatments at 7-14 days post treatment. All pyrethroid treatments as well as Lorsban® and Steward® treatments resulted in significant reductions of alfalfa weevil larvae at four days post treatment. The Trilogy® treatment did not result in acceptable control of this pest. Significant increases in adult alfalfa weevils were noted at 10-14 days post treatment in pyrethroid treated alfalfa, perhaps due to increased production of certain plant volatiles in response to this class of insecticides. Low numbers of blue alfalfa aphids were noted in this study partially due to insecticide control as well as numerous beneficial insects. Fewest damsel bugs were noted from alfalfa treated with MustangMAXTM and Warrior® insecticides.
    • Small Grains Variety Evaluation at Arizona City, Coolidge, Maricopa, and Yuma, 2005

      Ottman, Michael J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.
    • Evaluation of AuxiGro® WP and Foliar Fertilizers on Bermudagrass Seed Production

      Rethwisch, Michael D.; Reay, Mark; Grudovich, Jessica; Ramos, D. Michael; Wellman, Jessica; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      AuxiGro® WP was evaluated for effects on bermudagrass seed production in the Palo Verde Valley of far eastern California. Four rates of this product, in addition to a 4 oz./acre rate with two fertilizers were tested, as were the fertilizers only to separate treatment effects. Highest yields from subplot harvests were noted from the 2 and 4 oz./acre rates of AuxiGro® WP, and germination percentages from these treatments and resultant pure live seed were also numerically higher (81-99 lbs./acre) than that noted from untreated bermudagrass, although most plant parameters did not result in statistical difference.
    • Comparison of Hydra-Hume™, Asset® RS, and SuperBio® AgBlend on Late Spring and Early Summer Alfalfa Yields and Quality

      Rethwisch, Michael D.; Reay, Mark; Perez, Rigo; Wellman, Jessica; Ramos, David; Grudovich, Jessica; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Asset® RS, HydraHumeTM and SuperBio® Ag Blend were evaluated during several sequential alfalfa harvests for their effects on alfalfa yields and quality. Addition of Hydra-HumeTM or AgBlend when applied via chemigation appear to have slightly increased hay yields over the three cutting period by 0.12-0.22 tons/acre respectively when compared with an area of the field that received 10-34- 0 but was a different soil type. Addition of Asset® RS to Hydra-HumeTM did not provide any additional consistent yield increase in this study. Addition of Asset® RS resulted in increased hay quality as measured by protein levels, acid detergent fiber, total digestible nutrients, neutral detergent fiber and relative feed value. These parameters were often statistically different than the Hydra-HumeTM treatments. It is unknown if application of Asset® RS would result in similar or greater quality and yeild response alone or on another soil type. Different results for all products may occur if heavier soils are used for experimentation rather than sandy soils, as nutrient availability is affected by soil type and pH.
    • Alfalfa Variety Performance at Tucson, 2003-2004

      Ottman, Michael J.; Smith, S. E.; Fendenheim, D. M.; Comeau, M. J.; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      New alfalfa varieties are constantly being introduced into the marketplace. The number of varieties available for low-elevation desert areas in Arizona in the non-dormant and very non-dormant class is close to 50. New varieties are introduced each year and unbiased yield comparisons are helpful to the grower to base the decision of whether or not to sow a new variety. The study reported here is part of the on-going effort to evaluate alfalfa variety performance in Arizona. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1267.pdf.
    • Evaluation of Two Velpar® Formulations on Alfalfa, 2005

      Rethwisch, Michael D.; Tickes, Barry R.; Luna, Manuel; Dulmage, Alexandra; Ottman, Michael J. (College of Agriculture, University of Arizona (Tucson, AZ), 2005-12)
      Two formulations of Velpar® (DF, L) were evaluated over multiple alfalfa varieties to compare the potential phytotoxic effects this product. Treatments were made April 15, with yield and stem data collected on May 10. Both Velpar® formulations resulted in yellowed alfalfa within three days of application, with symptoms disappearing by 21 days post treatment. Yield data indicated increased yields from alfalfa treated with Velpar®, due to increased numbers of stems. The reason for the stem increase associated with Velpar® usage is unknown.