• Cotton Defoliation Evaluations, 1998

      Silvertooth, Jeffrey C.; Norton, Eric R.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1999)
      A field experiment was conducted near Marana, AZ in 1998 to evaluate the effectiveness of a number of defoliation treatments on Upland (var. Stoneville 474) cotton.. All treatments consisted of materials commercially available in Arizona. Results reinforce general recommendations regarding the use of low rates (relative to the label ranges) under warm weather conditions and increasing rates as temperatures cool. Defoliation treatments of Ginstar alone did a satisfactory job of defoliation and regrowth/topgrowth contol and were very similar to Dropp + Def combination treatments. Adding Prep to Ginstar in this experiment did not improve defoliation or topgrowth control.
    • Date of Planting by Long Staple and Short Staple Variety Trial, Safford Agricultural Center, 1998

      Clark, Lee J.; Carpenter, E. W.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1999)
      Four varieties each of Long Staple and Short Staple cotton were tested over four dates of planting in this study. The first date of planting for the Long Staple cotton was delayed to the 3rd of April because of poor weather earlier. The latest planting was May 13th. Cultivars of differing maturities were tested for both long and short staple cotton to determine their optimal planting time. Many agronomic and hvi values were evaluated to determine the effect of different planting dates.
    • Defoliation of Pima Upland Cotton at the Safford Agricultural Center, 1998

      Clark, Lee J.; Carpenter, E. W.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1999)
      Nine defoliation treatments were applied to Pima and upland cotton to compare the treatment effects on percent leaf drop, trash sent to the gin, lint yields, percent lint turnout and percent first pick. All of the treatments were beneficial to leaf drop compared to the untreated check with the Ginstar treatments generally performing better than the others. The addition of nonionic surfactants and drift retardants seemed to reduce the activity of Ginstar. Yield differences on long staple treatments were notices and discussed in the paper.
    • Defoliation Tests with Ginstar at the Maricopa Agricultural Center in 1998

      Nelson, J. M.; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1999)
      Defoliation tests were conducted on upland and Pima cotton at the Maricopa Agricultural Center to evaluate the use of low rates of Ginstar for preconditioning cotton, several rates of Ginstar and tank mixes of Ginstar and Def. The upland cotton used in this test was generally difficult to defoliate, probably because of cool night temperatures. One application of Ginstar + Def gave acceptable defoliation of upland cotton 14 days after treatment (DAT) and this treatment was as good as using Ginstar as a preconditioner followed by Ginstar (2 applications of defoliant). For Pima cotton, most Ginstar treatments gave acceptable defoliation 7 DAT. Although defoliation treatments caused some leaf desiccation, it was not a serious problem in these tests. All defoliation treatments resulted in excellent control of terminal regrowth for both upland and Pima cotton.
    • Narrow Row Cotton Production in Vicksberg

      Knowles, Tim C.; Cramer, Roc; Silvertooth, Jeff (College of Agriculture, University of Arizona (Tucson, AZ), 1999)
      Deltapine 458B/RR, Deltapine 5415RR, Deltapine 20B, and Deltapine 20 cotton varieties were planted on June 5 into narrow 15 inch wide rows. Populations ranged from 80,000 to 100,000 plants per acre. Seed cotton was stripper harvested on December 17. Although lint yields were somewhat low (1- 2 bale/acre) for this late planted cotton, we learned several important practices for effective narrow row cotton production systems, based on our first years experience in western Arizona.