• Pest Management and Yield Enhancement Qualities of Particle Film Technologies in Citrus

      Kerns, David L.; Wright, Glenn C.; Wright, Glenn; Gibson, Rick (College of Agriculture, University of Arizona (Tucson, AZ), 2002-11)
      Surround WP and Snow were evaluated for their ability to manage citrus thrips populations in lemons on the Yuma Mesa, and their impact on lemon yield, fruit quality, and packout. Both Surround and Snow effectively controlled citrus thrips and prevented fruit scarring, but their ability to manage Yuma spider mite was inconclusive. Preference tests indicated that both Surround and Snow act primarily by repelling the thrips, but also induce some mortality. Surround produced higher yields than Snow at the first harvest (#8 ring), but did not differ from the commercial standard. There were no differences in yield among treatments for the strip harvest, nor were their any differences in total yield. These data suggest that Surround may have some yield or increased fruit earliness enhancement qualities and that Snow may be slightly detrimental. There were no statistical differences among any of the treatments in fruit size frequency or quality for any of the harvests, and there was no apparent benefit from applying an additional application of Surround or Snow post thrips season solely for quality, fruit size, or yield enhancement.
    • Woodrat Control in Citrus Groves with Zinc Phosphide and Diphacinone

      Kerns, David L.; Sullivan, Lawrence M., 1939-; Wright, Glenn; Gibson, Rick (College of Agriculture, University of Arizona (Tucson, AZ), 2002-11)
      Two studies were conducted investigating the efficacy of Prozap (zinc phosphide), Ramik Green, and Ramik Brown (diphacinone) rodenticides on woodrats infesting citrus. Based primarily on using feeding activity as an indication of population density, Zinc phosphide (ZP) provided a rapid knockdown of the rat population, and offered 60 to 75% control. However, this product is known to cause "bait-shyness" following the initial application so additional control with subsequent applications of ZP targeting the same rat population would not likely result in a significant increase in control. Ramik Green and Ramik Brown are slow acting anticoagulant rodenticides, and performed similarly to each other. Anticoagulant rodenticides are not known to cause bait-shyness. In this study, these products only offered 20 to 38% control, but it is possible that these values may be artificially low since the rats may have been preferentially feeding on stored oat groats used to gauge feeding activity rather than consuming the anticoagulant baits.