• The 1989 Upland Cotton Program: How Profitable for Arizona Producers?

      Ayer, H. W.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The profitability of full and "50/92" participation in the 1989 upland cotton program was estimated for representative farms in Maricopa, Pinal, LaPaz and Yuma counties. Special attention was given to the effect on profits of the reduction in permitted acreage, and to farm size and multiple-partner ownership. Full participation was more profitable than "50/92" or nonparticipation given the assumptions used here. The expected profitability of the crops used on 'free acres" in the large farm case -- alfalfa or pima cotton --has a major positive effect on program profitability. The possible use of upland base acres to produce pima cotton or durum wheat, given the current high prices of those crops, is also discussed.
    • Aflatoxin Contamination of Cottonseed From Pink Bollworm Damaged Bolls

      Cotty, P. J.; Lee, L. S.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Aflatoxin contamination of cottonseed from bolls damaged by the pink bollworm was compared with contamination of cottonseed from undamaged bolls. Cottonseed produced in pink bollworm damaged bolls was the predominant source of aflatoxin contaminated cottonseed.
    • Application of Zinc Chelate and Ammonium Sulphate Supplements: Increased Damange to Cotton Foliage from Beet Armyworm and Cabbage Looper

      Akey, D. H.; Flint, H. M.; Mauney, J. R.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Foliar applications of zinc as a chelate or sulphate with ammonium sulphate to plots of cotton resulted in beet armyworm infestations with leaf damage that was 2.3 to 3.1 times greater than that in control plots.
    • Can Cotton (Cossypium hirsutum) Seed Vigor Be Assessed in the Absence of Growth?

      Lehle, F. R.; Zegeer, A. M.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Although seed vigor is ultimately expressed in terms of growth, it is not clear if metabolic processes unlinked to growth can also estimate vigor. The objective of this study was to determine if the relationship between seed vigor and ethanol metabolism differed depending on whether seed growth was presence or absence. For individua1 imbibed cotton seed, ethanol assimilation in air and ethanol biosynthesis in N₂ gas was correlated to seed vigor as measured by cool test performance. Seed growth in N₂ gas was prevented by the addition of polyethylene glycol. Results were inconclusive, because seed performance (radicle growth) during cool testing was not significantly correlated to either ethanol biosynthesis or ethanol assimilation. It was concluded that ethanol metabolism both in the absence and presence of seed growth has limited usefulness as a metabolic marker of cotton seed vigor.
    • Comparison of Irrigation Termination Dates on the Yield of Upland and Pima Cotton

      Silvertooth, J. C.; Terry, L. I.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Field experiments were conducted in 1988 to begin an assessment of both the agronomic and entomological implications from differences in irrigation termination dates imposed on both upland and pima cotton. Nine study sites were established with non-replicated treatment arrangements. Two replicated experiments were established at Marana, AZ on both upland and pima comparing early and late irrigation terminations. The upland (DPL 20) field was planted 26 April 1988 and irrigation terminations of 18 August (early) and 5 September (late) were imposed. The pima S-6 field was also planted 26 April and irrigation was terminated on 13 August (early) and 1 September (late). Yield measurements showed no significant differences (P ≤ 0.05) between early or late termination with the DPL 20, but quite substantial and significant differences were observed between treatments in the pima experiment.
    • Comparison of Three Irrigation Scheduling Methods and Evaluation of Irrigation Leaching Characteristics

      Scherer, T.; Slack, D.; Watson, J.; Fox, F.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Three methods were used to schedule irrigations on replicated plots at the Maricopa Ag Center using DPL 90 cotton. The three methods were: a soil water balance model based on historic consumptive use curves, a soil water balance model based on the Modified Penman Equation and daily weather (AZMET), and infrared thermometry using the C.W.S.I. A potassium-bromide conservative tracer was applied at selected sites in the plots to evaluate leaching characteristics. The irrigation scheduling test was duplicated at the Safford Experiment Station and is presented in another report. Results from the 1988 data indicate that there was no significant difference in yield between the 3 methods. There was a significant difference in water applied; the historic consumptive-use curves was the lowest and the Penman equation method was the highest.
    • Cotton Irrigation Scheduling, Safford Agricultural Center, 1988

      Clark, L. J.; Carpenter, E. W.; Scherer, T.; Slack, D.; Fox, F.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Cotton was grown using historical evapotranspiration data in the Erie method a checkbook method using real-time AZMET weather data, an infrared thermometer, and a faint manager to schedule irrigations. Yields of 4 bales per acre were recorded with no significant differences between the scheduling methods. Differences were seen in the plant growth and maturity. More refining will be done in subsequent investigations.
    • Cotton Response to Water and Nitrogen, 1988

      Roth, R. L.; Gardner, B. R.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Water - nitrogen production functions were determined for cotton cultivars, DPL 77 and DPL 90. Cotton yields for the DPL 90 cultivar were reduced more than the DPL 77 cultivar when water applications were reduced. Cotton yields of 3.0 to 3.4 bales/acre were predicted for nitrogen applications of 160 to 210 lbs/acre with appropriate water applications.
    • Cotton Variety Observation, Safford Agricultural Center 1988

      Clark, L. J.; Carpenter, E. W.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Twenty-four short staple cotton varieties were compared in a strip trial on the Safford Agricultural Center, 15 of which were seen for the first time, 7 of which were acala varieties from New Mexico. Three varieties, BR 110, Delta Pine Experimental 7124-293, and Northrup King KNX111 (now KC 311) exceeded the yield of the standard variety DP 90 by 12.6 %, 8.1 %, and 4 %, respectively. Other new cultivars that performed well but didn't exceed the yield of the standard, were HYP 1211, HYP 274, and Acala 2745. The first 2 are hybrids supplied by Dr. Warner Fisher, the latter is an experimental acala from New Mexico State University. Per acre values were affected by lint value as well as lint yield per acre. Using a value of $0.65/lb for New Mexico acala and $0.56/lb for Delta Pine acala, Acala 2745 produced $975/ac compared with DP 90's $916/ac and BR 110's $1031/ac.
    • Cotton Variety Trial, Mohave Valley, 1988

      Grumbles, R.; Silvertooth, J.; Malicut, J.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Seven upland cotton varieties and pima S-6 were demonstrated in Mohave Valley in Mohave County in 1988. The elevation there is 500 feet. Of the 7 upland varieties, 2 were new and had not previously been tried in the area; 1 had been tried for the first time last year. Pima S-6 was a new introduction to the Valley. Trial results indicated that the new introduction Tifcot 56 led the trial, yielding 901 lbs. of lint per acre. It was followed by DPL 90 at 886, DPL 50 at 884, DPL 77 at 819, BR 110 at 76$ DES 119 at 755, and Delcott 344 at 664. The first attempt at pima S-6 yielded 447 pounds of lint per acre. Its plot in 1988 was basically new ground that had not had a crop on it for the past 5 years.
    • Current Use of Module Makers

      Farr, C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Moduling of cotton has increased strongly since its introduction in 1973. The usage is different from gin to gin due to a variety of conditions. However, the addition of moduling has reduced the pressure on ginning capacity so that some growers can continue using trailers without slowing the speed of the harvest.
    • Defoliation of Pima Cotton, 1988

      Silvertooth, J. C.; Howell, D. R.; Stedman, S. W.; Thacker, G.; Winans, S. S.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Four field experiments were carried out in several areas of Arizona to evaluate the effects of a plant growth regulator and an array of conventional cotton defoliant treatments on pima cotton. Variable conditions were encountered across locations at the time of defoliant- treatment applications. However, there was a consistent trend observed in terms of treatment effectiveness, and a few distinct treatments appeared to have considerable promise for 1-time applications for satisfactory defoliation of pima cotton.
    • Defoliation Research on Pima Cotton at the Maricopa Agricultural Center in 1988

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      A field study was conducted at the Maricopa Agricultural Center to evaluate the effectiveness of selected defoliation treatments on pima cotton. Defoliants were applied in October under relatively warm conditions. Treatments containing Dropp generally resulted in the highest leaf drop percentages (over 90 %). Def 6 treatments were ineffective in defoliating pima cotton.
    • Earlier Timing Can Reduce Rainfall Losses

      Farr, C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The analysis of grades of upland cotton picked before and after a 29 October rainfall at Waddell in 1987 reveals significant financial losses for growers. Early harvesters in the area harvested over two thirds of the crop in October; over 98.0% of grades 21 and 31 were harvested before the rainfall. A Buckeye operation also accounted for a difference of $98.60 per acre between an early and a late harvested pima field the same season. The survey indicates that important losses can be reduced by a harvest begun 10 to 15 days earlier than mid- October.
    • Effect of Irrigation Termination Date on Defoliation and Yield of Upland Cotton

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      A field study was conducted at the Maricopa Agricultural Center to determine the influence of plant water stress on the effectiveness of defoliants and yield of cotton. Irrigation termination dates of 12 August, 24 August, and 8 September were used to achieve different levels of plant water stress at the time defoliants were applied (22 September). The defoliants tested performed well on cotton, which had termination irrigations in August. Def 6 was not as effective as other defoliants in defoliating plants with an 8 September termination irrigation, unless used in combination with Prep. Cotton with an 8 September termination irrigation produced lint yields 9% higher than cotton with August irrigation termination dates.
    • Effect of Plant Nitrogen Status and Growth Regulators on Earliness, Effectiveness of Defoliants, and Yield of Upland Cotton

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      A field study was conducted at the Maricopa Agricultural Center to determine the effect of nitrogen fertility level and growth regulators on earliness, yield of cotton, and effectiveness of defoliants. Nitrogen application rates of 80, 120 and 160 lbs N/A did not influence lint yields or the response of cotton to growth regulators. The growth regulator Piz tended to promote earliness but did not affect final yield. The defoliants tested achieved good leaf drop results independent of the plant nitrogen status. Petiole nitrate-N content at the time of defoliation (4 October) did not correlate well with the response of cotton to defoliation treatments.
    • Effects of Banded Phosphorus Fertilizer on Cotton

      Silvertooth, J. C.; Doerge, T. A.; Thacker, G. W.; Stedman, S. W.; Malcuit, J. E.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Four field experiments were established in 1988 in Arizona to evaluate the effects of banded phosphorus (P) fertilizers on cotton. 2 sites involved upland cotton (Gossypium hirsutum L.) and 2 sites with pima (G. barbadense L. var Pima S-6), with 1 of each located near Marana, AZ (Vinton Anthony sandy loam). A site with 1 of each kinds was also located near Coolidge, AZ (Mohall sandy loam). At the Marana studies, P was applied 6 inches directly below the zone of seed placement at the time of listing and at the Coolidge sites, P was applied 6 inches below and 2 inches to the side of the zone of seed placement after listing but before planting. In all cases, the P source was 10-34-0 at rates of 0, 30, and 65 lb. P₂O₅ acre⁻¹. At the Marana location, a treatment of banded 10-34-0 at 30 lb. P₂O₅ acre⁻¹ plus a foliar application of 10 lb. P₂O₅ acre⁻¹ (early bloom) as 10-34-0 was included in both the upland and the pima experiments. Plant measurements for plant height, flower numbers, node numbers, boll numbers, and nodes to first fruiting branch were taken to evaluate plant response throughout the season. Plant tissue samples were also taken for leaf petiole PO₄-P and leaf blade total P analysis. Lint yield measurements were also taken. No statistically significant (P < 0.05) differences were found among any of the treatments for any of the measured parameters, except in the petiole PO₄-P levels from the upland study at Coolidge on the second sampling date.
    • Effects of Date of Planting on the Lint Yield of Several Cotton Varieties Planted at Four Locations in Arizona, 1988

      Silvertooth, J. C.; Malcuit, J. E.; Howell, D. R.; Else, P.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Field experiments were carried out at 4 locations in Arizona to evaluate the effects of planting date on the lint yield of several varieties of cotton. One pima and eleven upland varieties were planted on 5 dates at 2 locations and 1 pima and nine upland varieties were planted on 5 dates at a third location. At a fourth location, 1 pima and 3 upland varieties were planted on 4 dates. General trends in lint yields indicate an advantage in yield potential from full- season type varieties, particularly when they are planted early. Full-season varieties, however, diminish rather quickly with regard to yield potential, when planting is delayed in comparison to varieties that are considered mid-or shorter-season varieties.
    • The Effects of Methyl Bromide Fumigants on Verticillium Wilt on Two Varieties of Short Staple Cotton, Safford Agricultural Center, 1988

      Clark, L. J.; Carpenter, E. W.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Methyl bromid/chloropicrin formulations were applied to strips in the verticillium nursery at the Safford Agricultural Center where two varieties of short staple cotton were subsequently planted. More robust plant growth and reduced incidence of disease were noted with some of the treatments. Yield increases over the check plots were also seen. A study of the residual effects of the treatments will be performed in 1989.
    • Effects of Oxygen Stress and Water Stress on Cotton (Gossypium hirsutum) Seed Growth

      Lehle, F. R.; Zegeer, A. M.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The effects of oxygen stress and water stress on cotton seed radicle growth was studied. High vigor Deltapine 90 seed were imbibed in individual test tubes at 28°C for 28 hours. Seed were then subjected for 2 hours at 28°C to either 1) oxygen stress imposed by N₂ gas, 2) water stress imposed by polyethylene glycol 6000 (0.8 gm mL water⁻¹), or 3) a combination of both 1) and 2). Following imposition of either oxygen stress or water stress, radicle growth stopped temporarily; growth resumed while either stress was still imposed but at a greatly reduced rate relative to the unstressed control. Cotton radicle growth was prevented however, in the presence of both oxygen and water stress. The prevention of growth was reversible, as growth resumed when both stresses were relieved.