• Defoliation of Pima Cotton

      Silvertooth, Jeff; Howell, Don R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Afield study was conducted in Yuma County to evaluate the relative effects of a plant growth regulator application and several defoliation treatments on Pima cotton. There were no statistically significant effects recorded with regard to the plant growth regulator application. There was a significant difference among defoliation treatments by analysis of percent leaf drop estimates. Promising results were recorded for DROPP as a defoliant material for Pima cotton under the given test conditions.
    • Effect of Ethphon (PREP™) on Short Staple Cotton in Marana, 1987

      Thacker, Gary; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Ethephon was applied to Deltapine 55 cotton with 35% of the bolls open. Ethephon significantly increased the percent first pick yield of the cotton. There was no significant difference in the total yield.
    • Effect of Spray Dilution and Rate of Pix Application on Long and Short Staple Cotton, Safford Agricultural Center, 1987

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      PIX was applied to long and short staple cotton in 5, 10 and 20 gallons of water in an incomplete factorial design involving 0.5, 1 and 2 pints of the product per acre. Plant heights were significantly shortened and the percent of lint obtained in the first picking was significantly increased when Piz was applied on the short staple cotton. No statistically significant yield differences were observed between the volumes of dilution or the rates of application for either long or short staple cotton. A factor underlying the experiment was that the monsoon rains. They kept the surface of the ground moist and the plants looking good; however, the subsurface moisture had apparently been depleted, and the plants were under some stress. This stressed condition offset what good the FIX might have done for yield.
    • Lint Yield of Several Cotton Varieties Planted on Five Dates at Three Locations in Arizona in 1987

      Kittock, D. L.; Silvertooth, Jeff; Hofmann, C.; Malcuit, J.; Else, P. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Wide variations existed in the performance of cotton varieties over the five planting dates among three locations over three years. However, on the average, DP 77 performed best when planted between 27 March and 22 April at Maricopa and Marana. DP 90 was best for April and early May plantings at Safford. Stoneville 506 and DP 50 were among the best for May plantings. DP 20 Stoneville 112, and DP 50 averaged best for early June plantings, except Germain 510 was superior at Safford.
    • Preplant Zinc Applications to Short Staple Cotton in Marana, 1987

      Thacker, Gary; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      A preplant application of zinc was made to a short staple cotton field where the soil analysis had shown a zinc concentration of 0.64 ppm. No significant yield response was measured.
    • Response of Texas Root Rot to a Soil Sterilant in Marana in 1987

      Thacker, Gary; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Methyl bromidelchloropicrin, a soil sterilant, was deep-injected into cotton beds ten days before planting. Within the kill areas of the Texas Root Rot, the soil sterilant had some significant effects on the mortality and yield of the cotton.
    • Ripping After the Uprooter-Shredder-Mulcher

      Thacker, Gary; Rein, Brad; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      This test was conducted on the LDS Church Farm in Marana to determine whether ripping after the Uprooter-Shredder-Mulcher (USM) benefits yields. The three treatments were rip furrows only, rip -beds only, and no ripping after the USM. Depth of water penetration was measured after the preplant irrigation; no significant differences were observed between the treatments. Differences in lint yields were not statistically significant, although average lint yields for the ripped treatments were higher.
    • Upland Cotton Defoliation Test

      Silvertooth, Jeff; Stedman, Sam (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      A field study was carried out to test the effectiveness of several defoliation treatments on Upland cotton in Pinal County. Three defoliation treatments were utilized. Results showed no significant differences among treatments in terms of percent leaf drop estimates taken seven and 14 days after initial application. Subsequent applications of defoliant materials were made to accomplish satisfactory levels of defoliation prior to harvest.