• Response of Cotton to a Preplant Zinc Sulfate Application

      Hofmann, W. C.; Else, P. T.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The effect of a single preplant application of zinc sulfate on DPL 77 yield was investigated at the Maricopa Agricultural Center on a field that had tested as marginal with respect to zinc availability. No significant difference in yield was found between the plants receiving zinc sulfate and the control.
    • Response of Cotton to Various Fertilization Histories

      Hofmann, W. C.; Else, P. T.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Effects of various fertilization histories on cotton yield were investigated for the fourth consecutive year in the same field at the Maricopa Agricultural Center. Treatments included: 1) no fertilizers added for the past 4 seasons, 2) aggressive nitrogen fertilization in the 1988 season, no fertilization for the previous 3 seasons, 3) standard nitrogen fertilization in 1988 similar treatment for the previous 3 seasons, 4) aggressive nitrogen fertilization in 1988 same history as treatment #3 for previous 3 seasons, and 5) a commercial alternative fertilization program (BioHumaNetics, Inc.). Yields in 1988 were significantly different with treatment 2 having the highest yield followed by treatments 3 and 4, followed by treatment 5; treatment 1 had the lowest yield.