• 1986 Publications of the Western Cotton Research Laboratory, USDA, ARS

      Unknown author (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Antibiosis in Cotton to Pink Bollworm

      Wilson, F. Douglas; Szaro, Jayne L.; Stapp, Benny R.; Western Cotton Research Laboratory (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Ninety-nine germplasm lines and a resistant check line of cotton, Gossypium hirsutum L., were infested artificially in the field with eggs of pink bollworm (PBW), Pectinophora gossypiella (Saunders), and evaluated for an antibiosis type of resistance to the insect and also for yield potential. All 99 lines came from crosses of well -adapted cultivars, or the nectariless, or nectariless-okra-leaf versions of those cultivars, with previously identified sources of antibiosis (a type of resistance that affects the growth and development of the insect once inside the boll). Twenty-three of the 99 were selected for low PBW damage or for a combination of high lint yield and low damage.
    • Application of Systemic Fungicides Through Subsurface Drip Irrigation for Control of Phymatotrichum Root Rot

      Olsen, Mary W.; George, Steven; Heathman, Stanley (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Application of two systemic fungicides, propiconazole (Tilt) and triadimenol (Summit), through subsurface drip irrigation resulted in a significant reduction in the number of dead plants in a Phymatotrichum-infested cotton field. The percent reductions in Tilt treatments were 72% in 1985 and 66% in 1986 and in Summit treatments were reduced 90% in 1985 and 70% in 1986.
    • Comparison of Increased Irrigation Frequency

      Farr, C. R. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Controlling Purple Nutsedge on Fallowed Ground with EPTC and Butylate

      Chernicky, J. P.; Heathman, E. S.; Stedman, S. W.; Barstow, B.; Department of Plant Science (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Field research was conducted at Yuma and Goodyear, AZ on fallowed ground to measure the response of purple nutsedge to butylate and EPTC (Goodyear only). At Yuma, the greatest reduction in the number of live tubers resulted when two years of fallow were combined with annual summer application of 3.3 lb/A of butylate. At Goodyear, butylate and EPTC were more effective at controlling purple nutsedge when applied in early July vs early September. Also, one timely application of EPTC or butylate made in July was more successful in reducing the number of live tubers than two applications (July, Sept). September herbicide treatments were not as effective with an irrigation compared to without.
    • Cotton Variety Observations, Safford Agricultural Center, 1986

      Clark, Lee J.; Thatcher, L. Max (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Cotton Variety Trians, Greenlee County, 1986

      Clark, Lee J.; DeRosa, Edith (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Cyanazine Combinations Preplant for Broadleaf Weed Control in Cotton

      Chernicky, J. P.; Hamilton, K. C.; Heathman, E. Stan; Barstow, Ben B.; Department of Plant Science (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Development and Fecundity of Aphis gossypii (Homoptera: Aphididae) on Cotton

      Akey, David H.; Butler, George D.; Western Cotton Research Laboratory (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Cotton aphids. Aphis gossypii. from a source near Phoenix. AZ were found to have an optimal developmental temperature of 27.5 °C with a developmental time of 5 days. Fecundity was optimal at 25 °C with 2.85 mean nymphs/day. Both development and fecundity were linear. The optimal temperature for fecundity was higher than those previously reported for cotton aphids in more moderate climates.
    • Development of Pink Bollworm Population in Field Cages Containing Deltapine Nextaried and Nectariless Cottons

      Flint, Hollis M.; Wilson, F. Douglas; Western Cotton Research Laboratory (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The development of populations of pink bollworm, Pectinophora gossypiella (Saunders) in 0.003 ha field cages containing 'Deltapine 61' (DPL-61) or a closely related nectariless cultivar 'Deltapine NSL' (DPL-NSL) was studied at the University of Arizona Maricopa Agricultural Center, Maricopa, AZ. Boll infestations were significantly lower in cages of DPL-NSL and total catches of moths in gossyplure-baited Delta traps at the end of the season were lower in these cages. The overall seasonal increases were 15.3- fold for DPL-NSL and 21.4 fold for DPL-61, a highly significant 29% reduction for DPLNSL.
    • Direct and Indirect Stimulation of Primary Root Growth of Cotton Seed Imbibed at a Low Temperature by Calcium Sulfate

      Lehle, Fredric; Hofmann, W. C.; Guhy, Bonnie (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The effect of calcium sulfate on cotton seed radicle growth at a low temperature was evaluated under laboratory conditions. Direct imbibition of solutions of calcium sulfate was stimulatory to radicle growth at 15 C at concentrations up to 10 mM. Anomalous stimulation of radicle growth at 15 C occurred when seed rolls moistened with water were placed adjacent to dilute open solutions of calcium and magnesium sulfate inside sealed chambers. The stimulation appeared due to an indirect influence of sulfate by an unknown mechanism.
    • Drip Irrigated Cotton Responses to Fertilizer Levels, Varieties and Plant Population

      Stroehlein, J. L.; Hofmann, W. C.; Michaud, C.; Scheuring, E. P.; Knowles, T. C. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Three cotton cultivars (DPL 41, 90 and 775) were planted at 3 seeding rates (5, 10 and 20 lbs/A). These variables were evaluated under 5 fertilizer treatments which included increasing nitrogen levels and one treatment with nitrogen (N), phosphorus (P), potassium (K) and zinc (Zn). Residual soil N was high and variable and no clear response to applied N was found, although generally higher yields were found with the high N rate. The plots receiving P, K and Zn yielded less than plots receiving an equal amount of N. Increased seeding rates significantly increased yields which was probably an effect of early weed competition. Delta Pine 90 produced significantly more than 41 which was greater than 775. Petiole and soil nitrate values reflected the high and variable available soil N.
    • Drip Irrigated Cotton Responses to Water Level, Varieties and Plant Population

      Hofmann, W.; Stroehlein, J.; Michaud, C.; Else, P.; Dahlberg, J. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      Three cotton cultivars (DPL 41, 90 and 775) were planted at 3 seeding rates (5, 10 and 20 lbs/A). These variables were evaluated under 5 drip irrigation treatments, which included 23.3, 25.7, 28.0, 30.7 and 31.4 inches of water applied over the growing season. There were 3" of precipitation over the growing season. Only the lowest irrigation level showed significantly reduced yields. DPL 90 had superior yields as compared to DPL 775, with DPL 41 having an intermediate response. The 10 lb/a seeding rate resulted in higher yields as compared to the other 2 rates.
    • Effect of Calcium Nitrate and Calcium Chloride on the Primary Root Growth of Cotton Seed Imbibed at Low Temperatures

      Lehle, Fredric; Hofmann, W. C.; Guhy, Bonnie (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The effect of various concentrations of calcium nitrate and calcium chloride on the primary root (radicle) growth of cotton seed at a suboptimal temperature was evaluated 14 days after imbibition onset under laboratory conditions. Both forms of calcium at concentrations up to 10 mM enhanced cotton seed radicle growth at 15 C.
    • The Effect of Nitrification Inhibitors on Nitrogen Use Efficiency in Drip and Furrow Irrigated Cotton

      Doerge, Thomas A.; Tucker, T. Curt (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The use of nitrification inhibitors delays the conversion of ammonium fertilizers to the nitrate form and has the potential to increase nitrogen use efficiency in irrigated agriculture. Two field experiments were conducted at the Maricopa Agricultural Center in 1986 to evaluate the effect of two nitrification inhibitors (N-Serve and an experimental compound, ACP) on the growth, yield, nitrogen uptake, and fertilizer use efficiency obtained by growing cotton using buried-drip and furrow irrigation. ¹⁵N labeled ammonium sulfate was applied with and without nitrification inhibitors at the beginning of the season. Whole plant samples were taken at the end of the season to determine N uptake efficiency. No significant differences in growth, lint yield or N uptake efficiency were detected due to the application of either inhibitor. The conditions where nitrification inhibitors might improve nitrogen use efficiency in furrow irrigated cotton production are discussed.
    • Effect of RESPOND and PIX on Short Staple Cotton, 1986

      Briggs, R. E.; Ledbetter, C. A.; Nelson, J. M. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Effect of Spray Dilution on PIX on Cotton, Safford Agricultural Center, 1986

      Clark, Lee J.; Thatcher, L. Max; Department of Plant Science (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
    • Effect of Timing and Herbicide Compatibility in the Application of Burst on Upland Cotton

      Stedman, Sam (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      A field trial was conducted to study the elements of application timing and herbicide compatibility in the use of Burst, a plant growth regulator, and the effects of these two factors on yield of upland cotton. Eight treatments combined the two factors of timing and tank mix. The results showed no significant difference in yield between treatments.
    • The Effects of Burst Yield Booster on DPL 61

      Hofmann, W. C.; Else, P. T. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The third year was completed of a study designed to evaluate the effects of Burst Yield Booster, a cytokinin based plant growth regulator, on upland cotton. Five treatments were included in the 1986 experiment, which varied application timing, rate, and frequency. Consistent with our studies of the past two seasons, no significant differences in yield were observed.
    • The Effects of Cotton Leaf Crumple on Greenhouse-Grown Cotton Incoulated at Five Growth Stages

      Mihail, J. D.; Brown, J. K.; Nelson, M. R. (College of Agriculture, University of Arizona (Tucson, AZ), 1987-03)
      The effects of cotton leaf crumple disease on components of yield and on symptom expression were examined for cotton inoculated at five growth stages. As a result of virus infection, the total leaf area was reduced and significant reductions in yield were observed, regardless of plant age at time of inoculation. Yield reductions resulted from a smaller number of bolls set and/or a decrease in boll weight. Foliar symptoms were associated with plants inoculated at all five growth stages, but were observed sooner and were more severe for plants inoculated at the 2-3, 5-8, and 8-10 leaf stages than those inoculated at the 14-16 or 18-20 leaf stages.