• Chemical Control of the Sweetpotato Whitefly in Cotton

      Watson, T. F.; Telles, A.; Peña, M.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1994-03)
      Various registered and experimental insecticides were evaluated for sweetpotato whitefly (Bemisia tabaci Gennadius) control in several field experiments at Yuma, Arizona in 1993. Best controls were obtained with insecticide mixtures, particularly a pyrethroid and an organophosphate, rather than with individual materials. Results of these experiments indicate that severe population densities can be controlled using insecticide combinations, even though sustained use of these insecticides would probably lead quickly to the development of resistance.
    • 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.