• Lint Yield, Earliness and Pink Bollworm Resistance of Cottons Treated with Ethephon and Untreated

      Wilson, F. Douglas; Flint, Hollis M.; Bariola, Louis A. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      An early -maturing, nectariless, okra-leaf germplasm line of cotton, Gossypium hirsutum L., designated WC-12NL, was compared with a full- season, nectaried, regular -leaf cultivar, 'Deltapine 61' (DPL-61) over two locations, Maricopa, Arizona (AZ) and Brawley, California (CA), and two seasons, 1986 and 1987. Half of each plot was treated with ethephon ( =Prep) when the crop was approximately 60% open. Lint yields were higher in WC-12NL than in DPL-61 at AZ, but not at CA. WC-12NL was earlier maturing than DPL-61, but the difference was greater in untreated than in ethephon-treated plots and at AZ than at CA. From 33 to 67% less insecticide was needed to control pink bollworm, Pectinophora gossypiella (Saunders), on WC-12NL than on DPL-61. Pink bollworm infestations were also significantly lower in bolls of WC-12NL.
    • Effect of Bractedness on Early Season Square Shed Due to Thrips, Frankliniella occidentalis, in Cotton in Arizona

      Flint, Hollis M.; Wilson, F. Douglas; Cutice, Nancy J. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Populations of the western flower thrips, Frankliniella occidentalis (Pergande), were observed in field plots of cotton, Gossypium hirsutum L., Deltapine-61 (DPL-61) and WC-12NL, a nectariless, okra -leaf variety in the DES -56 germplasm line, and in fields of Stoneville-825 (ST-825), DPL-61, and DP -77 in Maricopa, AZ, during June - August 1987. The thrips were collected from plant terminals; square shed was observed on the upper five nodes of plants; and the bractedness (three-bract = normal) of matchhead-size squares was determined from samples of squares picked from the plants and from shed squares beneath the plants. Shed squares were microscopically examined to determine the cause of shedding. Populations of Lygus hesperus Knight were determined from sweep-net samples.
    • Field Evaluation of a Presence-Absence, Sequential Sampling Plan for Pink Bollworm Eggs

      Hutchinson, Bill; Stroschein, Debra; Beasley, Bud; Martin, Jeanette; Henneberry, Tom (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      During 1987, a sequential sampling plan for pink bollworm eggs was field-tested in eight 40-acre fields in the Palo Verde Valley, CA. Final analysis of the sequential procedure, including the time necessary to collect and check all bolls, required an average sampling time of 16 minutes/field, approximately a 70% savings over the fixed sample size of 160 bolls/field. Using the sequential plan, the number of bolls examined averaged 46.75/field. The sequential sampling plan error rate for making no-treat recommendations when a field actually required treatment (i.e., actual egg infestation 6%) averaged only 6.4% throughout the season. A final sequential sampling chart, based on the field validation data, is presented.
    • Leakage of Reducing Sugards and Amino Acids During Cotton (Gossypium hirsutum) Seed Imbibation

      Lehle, Fredric R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Leakage of reducing sugars and amino acids during cotton seed imbibition was evaluated as a possible vigor test. Seed samples from a single cotton seed lot were subjected to accelerated aging at 46°C and 100% R.H. for up to 216 hours. Aged seeds were imbibed at optimal and suboptimal temperatures, and the leakage of total reducing sugars and amino acids into the imbibition solution was quantified spectrophotometrically. Leakage of seed reserves was positively correlated with the duration of accelerated aging, in terms of subsequent germination performance at 30°C and of similar quantity at both imbibition temperatures.
    • Fermentation in Cotton (Gossypium hirsutum) Seeds

      Lehle, Fredric R.; Ahmed, Omer K. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Ethanol and acetaldehyde production by cotton seeds subjected to anoxic stress imposed by CO₂ or N₂ gas was quantified during the imbibition phase. Fermentation capacity was low in dry seeds and quickly increased during the first few hours of imbibition. In hydrated seeds, ethanol and acetaldehyde excretion following anoxic stress followed a linear trend in time. Ethanol excretion exceeded that of acetaldehyde by an order of magnitude. Similar rates of production were observed whether anoxic was imposed by either CO₂ or N₂ gas. Excreted ethanol and acetaldehyde were rapidly metabolized following alleviation of anoxic stress.
    • Variety/Date of Planting Test

      Pegelow, E. J. Jr. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Three upland cotton varieties (Stoneville 506, Deltapine 20, and Centennial) were planted on four dates in 1987 at the Maricopa Agricultural Center and observed for flowering, boll opening, and lint yield. Results from 1985-1987 are being used to develop heat unit models for the timing of these events.
    • Preplant and Pre-harrow Cyanazine (Bladex) Trials

      Chernicky, J. P.; Heathman, S.; Hamilton, K. C.; Barstow, B. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Research was conducted at Maricopa, AZ in 1986 and 1987 to measure cotton and weed control response to preplant applications of cyanazine (Bladex) and prometryn (Caparol). Cyanazine was applied in combination with pendimethalin and trifluralin as either preplant incorporated or preharrow treatments. Neither cyanazine or prometryn significantly reduced cotton stands or yields.
    • Development and Validation of a Simulation Model of Pink Bollworm Population Dynamics

      Huntchinson, Bill (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      A process- oriented simulation model of pink bollworm population dynamics in commercial cotton has been developed. The model, written in FORTRAN, is driven primarily by temperature and crop phenology. In addition to key ecological parameters, the model incorporates the impact of multiple insecticide applications. The model is presently being validated and modified for use as an on-line management tool.
    • Profitibility of the 1988 Upland Cotton Program

      Ayer, Harry W. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      The profitability of full and "50/92" participation in the 1988 upland cotton program is estimated for representative farms in Maricopa, Pinal, LaPaz and Yuma counties. Special attention is given to the effect on profitability of farm size, multiple partner ownership and changes in program provisions for harvesting alfalfa hay. In general, full participation is shown to be the most profitable, given the assumptions used here.
    • 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.
    • Fermentation as an Estimator of Cotton (Gossypium hirsutum) Seed Vigor

      Lehle, Fredric R. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Anoxic -induced fermentation was evaluated as a potential cotton seed vigor test. Seed samples from a single seed lot were subjected to accelerated aging for different durations to create five classes of seeds on the basis of vigor. The ethanol and acetaldehyde excreted from seeds from each class during brief periods of anoxia was quantified by gas-liquid-chromatography. Ethanol and acetaldehyde production during anoxia was negatively correlated with standard germination test results of all seed samples receiving accelerated aging. The fermentation capacity of hydrated cotton seeds remained intact at imbibition temperatures, which significantly reduced radicle growth.
    • Effects of XE-1019 and Pix on Upland Cotton in Arizona, 1987

      Briggs, R. E.; Nelson, J. M. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      The plant regulators XE-1019 and PIX were tested at the Maricopa and Marana Agricultural Centers. Few yield responses were found in 1987, apparently due to the short stature of the crop at both locations.
    • Influence of Liquid Sewage Sludge on Commercial Cotton Production

      Day, A. D.; Taylor, B. B.; Pepper, I. L.; Minnich, M. M. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      A field experiment was conducted in 1987 in Avra Valley, Arizona, to compare the plant growth and cotton lint yield from upland cotton fertilized with liquid sewage sludge with the plant growth and cotton lint yield from cotton fertilized with commercial inorganic fertilizer. Plant growth and cotton lint yields were similar when cotton was fertilized with liquid sewage sludge or inorganic fertilizers.
    • Effect of Pix on Three Tall Statured Short Staple Cotton Varieties and One Short Statured Cotton Variety, in Graham County, 1987

      Clark, Lee J.; Cluff, Ronald E. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Four short staple cotton varieties were grown with and without an application of PIX to see its affect on their growth, maturity and yield. PIX is a plant growth regulator thatmodifies plant architecture, Two of the tall -statured varieties, Delta Pine 90 and Acala 1517-75, showed increases in lint yield of 5.8 and 13.7%, respectively, coupled with a hastening of their maturity. Stoneville 506, a short- statured, medium- maturing variety was unaffected by the plant growth regulator. A tall, gangly variety, Germains GC 365, was shortened in height and in maturity, but exhibited a small decrease in yield.
    • Cotton Seed Treatment, Greenlee County, 1986

      Clark, Lee J.; DeRosa, Edith (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Six different seed treatments and one in furrow granular treatment were used in a field with a history of black root rot, caused by Thielaviopsis basicola. The treatment was a follow-up on the study done the previous year (1). Stand counts, root lengths and seed cotton yields were taken to see if any of the treatments increased stand counts or stimulated root growth. Thielaviopsis was not isolated in the plants this year, so the effect of the fungicides on this pathogen were not evaluated. Stand counts were, however, significantly influenced by the seed treatments.
    • Outlook on Cotton Markets and Marketing for 1988

      Firch, Robert S. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
    • The Use of Drip Irrigation in Maricopa County

      Farr, Charles (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Drip irrigation of cotton in Maricopa County decreased from 13,335 acres in 1984 to approximately 600 acres in 1987 at five locations. The most common reason was that drip was not cost effective.
    • Regional Variety Test

      Pegelow, E. J. Jr.; McAlister, A. C. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
    • Weather Conditions Associated with the Development of Southwestern Rust on Cotton

      Young, Deborah; Brown, Paul (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Weather conditions leading to the development of southwestern rust on cotton were evaluated at 3 locations in southeastern Arizona. Rust appeared following an extended period of wet, humid weather. In excess of 16 hours of wet canopy/high humidity conditions were observed on two consecutive days between 5 and 7 days prior to the appearance of rust. Temperatures during the wet canopy/high humidity periods were moderate, ranging from 65 F to 76 F. Afternoon rain showers initiated these extended periods of wet canopy /high humidity conditions.
    • Short Staple Variety Demonstration, Graham County

      Clark, Lee J.; Cluff, Ronald E. (College of Agriculture, University of Arizona (Tucson, AZ), 1988-03)
      Two short staple variety trials were held in Graham county, one toward the west end of the valley (Eden), and one in the center of the valley (Thatcher), both with 15 varieties. Delta Pine 90 was the highest yielding variety at both locations, with yields of 1,386 pounds of lint per acre at Thatcher and 1,123 pounds at Eden. Two new varieties, Northrup King 111 and BR 110, show some promise in the area, with yields close to that of Delta Pine 90. Lint quality and grade are listed for each variety.