• ABA and Auxin Contents of Squared and Flowers in Relation to Water Deficit Stress and Subsequent Young Boll Shedding

      Guinn, G.; Brummett, D. L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Water deficit increases boll shedding. Large squares, however, are much less likely to shed, possibly because they contain high concentrations of free and total auxin (indole-3-acetic acid or IAA). Our previous research indicated that much of this IAA disappears by the time the squares open as flowers and the IAA content remains low for about four days after anthesis. If water deficit decreases the IAA content, or increases the ABA conten4 of squares and flowers, then water deficit before flowering could have a carry-over effect and increase the shedding rate of young bolls that subsequently develop from them. In field plots, water deficit increased the ABA content of flowers as much as 66 %. Water deficit first decreased and later increased the concentrations of free and total IAA in squares that were analyzed about three days before anthesis. Flowers contained much less IAA than squares. Despite pronounced effects of water deficit on the IAA content of squares it is unlikely that it had any carry-over effect on the free IAA content of young bolls that subsequently developed from them. Water deficit slightly increased the total IAA content of flowers, but had no effect on their free IAA. Because water deficit increased the ABA content but did not decrease the IAAA content of flowers, any carry-over effect of water deficit on young boll shedding might have been from changes in ABA but not from changes in IAA before the young-boll stage.
    • Influence of Multiple Applications of PIX on Long and Short Staple Cotton, Safford 1989

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A four-by-four factorial experiment was performed on the Safford Agricultural Center to determine if CaZn, Foliar Triggrr or Soil Triggrr would cause increases in lint yields on short or long staple cotton. Four levels of PIX were used to see if there would be any interaction between PIX and the other materials. The results in 1989 showed that CaZn and the Trier products did not increase yields, the levels of PIX did not increase yields and there was no interaction between them. Very favorable weather conditions and good crop management kept plants from growing vegetative and prevented crop stress, thus reducing the opportunity for the plant growth regulators to increase yields. Yields were excellent with over 1700 and 1600 pounds of lint per acre for short and long staple cotton, respectively.
    • PIX Multiple Application Evaluations in Arizona on Upland and Pima Cotton, 1989

      Silvertooth, J. C.; Malcuit, J. E.; Howell, D. R.; Farr, C. R.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Plant Growth Regulator Research on Upland Cotton at the Maricopa and Marana Agricultural Centers in 1989

      Briggs, R. E.; Nelson, J. M.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Field tests were conducted at the Maricopa and Marana Agricultural Centers to evaluate the effectiveness of growth regulators on Deltapine 90 cotton. With full season management, the check treatment yielded as well as any of the growth regulator treatments at both locations.
    • A Study of PIX Rates across CaZa and Triggrr on Long and Short Staple Cotton, Safford Agricultural Center, 1989

      Clark, L. J.; Carpenter, E. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      An experiment was designed to test seven treatments of PIX on both short and long staple cotton. The treatments included single applications of 1/2- and 1-pint rates and multiple applications of 1/8- and 1/4-pint rates. Because of the exceptionally good growing season with lots of early heat units, both short- and long-staple plants set fruit early, which limited their vegetative growth naturally without the need for FIX. Yields were high with lint production over 1800 and 1400 pounds of lint for short and long staple, respectively. Plant mapping also was performed on each treatment.