• Insecticide Rotation and Pre-Petal Fall Applications for Citrus Thrips Management

      Kerns, David L.; Tellez, Tony; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      Under low citrus thrips pressure and cool temperatures, Alert, Baythroid, Carzol, Success and Acetamiprid applied at petal fall were all effective control agents. Mid-season applications of Baythroid and Danitol were also effective but appeared to be slightly inferior to Success and Alert in residual control. Despite the prolonged blooming and petal drop period experienced during this trial, plots receiving pre-petal fall applications of Acetamiprid did not produce higher quality fruit than treatments where applications began following petal fall. The fact that thrips densities were low during this period may be the reason. Before pre-petal fall insecticide applications can be deemed useful and economically justifiable, evaluations must be made at higher thrips infestation levels.
    • Residual Activity of Insecticides to Citrus Thrips on Lemon Foliage

      Kerns, David L.; Tellez, Tony; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      The residual activity of insecticides to second instar citrus thrips was measured on lemon foliage in 1998 and 1999. Dimethoate, Agri-Mek and acetamiprid provided only knockdown control of thrips, dropping to <70% mortality by 3 days after treatment (DAT). Baythroid performed slightly better, providing about 95% mortality 3 DAT during three of the evaluation periods, but by 7 DAT was giving about 75% mortality. Alert, Carzol, and Success provided the longest residual activity, lasting 7 to 14 DAT. Residual activity in general appeared to be greater in the May and June evaluation, relative to the April evaluation. The apparent shorter residual activity under cooler condition in April 1998 is not understood but maybe due to a difference in the physiological nature of the leaves earlier in the season.
    • Tank Mixing Success for Citrus Thrips Control is Not Necessary

      Kerns, David L.; Tellez, Tony; Wright, Glenn; Kilby, Mike (College of Agriculture, University of Arizona (Tucson, AZ), 2000-10)
      A small plot efficacy trial was conducted evaluating thrips control with Dimethoate, Baythroid, and Success at rates of 4, 6, and 9 oz/ac, and tank mixes of the low and medium rates of Success with Dimethoate or Baythroid. Based on a 10% fruit infestation threshold, Dimethoate required three applications while the other treatments required two applications to achieve season long thrips control. However, when evaluating the treatments based on a cost effectiveness index, none of the tank mixes or Success at 9 oz./ac were economically advisable. The most cost effective treatment was Success at 4 oz/ac, followed by Success at 6 oz/ac, Dimethoate, and Baythroid.