• Validity of the Pinhead Square Treatment Program for Pink Bollworm Suppression and Impact of Several Insecticides on Arthropod Fauna in Cotton

      Ellsworth, Peter C.; Meade, Donna L.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      A limited chemical control tactic known as pinhead square treatment has gained recent Favor as a component of pink bollworm population management. The strategy has economic and ecologic goals of using reduced insecticides early in the season (to include lower rates, half the acreage, and less potent chemistry) in order to reduce later season risk of pink bollworm infestations. This strategy also depends in part on the cultural tactic which results in "suicidal emergence" of overwintering pink bollworms through optimal planting date management. The combination of these tactics has been used in the past to overcome boll weevil populations area-wide. This study is focused on the evaluation of this system as a basis for pink bollworm suppression. Though only preliminary is presented here, it is clear that there are numerous insects impacted by this practice which interact in complex ways to influence pest populations of all kinds. Furthermore, the fate of such a practice in any production system is also influenced by the specific chemical agent used. This experiment details the use of four different classes of insecticide chemistry as well as one bioinsecticide. The experiment has been duplicated in 1993; however, only 1992 data are shown here.
    • Varietal and Nitrogent-level Effects on Sweepotato Whitefly Populations in Cotton

      Watson, T. F.; Silvertooth, J. C.; Tellez, A.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      Four cotton varieties, each differing in leaf pubescence, and three nitrogen (N) levels were investigated for effects upon development of SPWF populations. The N treatments appeared to have no effect upon population development. However, there was a direct correlation of increased SPWF numbers with increased hairiness. Both DPL 5415 and SALCOTIO had significantly lower seasonal means of all stages than did the more hairy varieties of CB1135 and STV453.
    • Whole Season Rotational Pesticide System for Integrated Pest Management for Control of Sweetpotato Whitefly in Cotton

      Akey, D. H.; Henneberry, T. J.; Wuertz, D. A.; Silvertooth, Jeff; USDA, ARS, Western Cotton Res. Lab., Phoenix, 85040; Sundance Farms, Coolidge, AZ 85228 (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      A season long pesticide rotational system for cotton management of Bemisia tabaci (Gennadius) (SPWF) was put in place. The system tried to minimize pesticide impact on midseason build -up of beneficials against SPWF. SPWF thresholds were used to begin use of "potent, efficient" insecticides to stop exponential increase of SPWF in late season. Insecticide class rotation was a key element of the system to prevent insecticide resistance. Comparisons between test blocks and best agricultural practices for rest of field showed that SPWF eggs and large immature of September populations, yields (2.68 bales /Ac), and beneficials were about the same among the blocks. The cotton was free of stickiness in the entire field.