• Strategies to Capture Higher Gross Revenues

      Firch, R. S.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Research on futures price behavior indicates that farmers may find it feasible to use selective hedging or forward contracting to increase gross receipts from the sale of their commodities. University economists have been telling farmers for many years that selective hedging-hedging only in some years rather than all years or no years -- should not be considered as an alternative to hedging every year or never hedging. If selective hedging is to be a feasible strategy for farmers, they must have some system for correctly predicting the direction of futures price changes during the production period in most years.
    • Successes and Failures in Foliar Applications to Correct Zinc Deficiency

      Mauney, J. R.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • 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.
    • 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.
    • Irrigation Frequency During Fruiting as a Yield Determinant in Upland Cotton

      Radin, J. W.; Mauney, J. R.; French, O. F.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      When cotton is irrigated at long intervals, the root systems become less effective at absorbing water during heavy fruiting, even when the soil is moist. That ineffectiveness, if not counteracted by frequent watering can exaggerate water stress responses during fruiting and promote early cutout. Deltapine 90 cotton was grown at the Maricopa Agricultural Center in 1988 and watered either by daily drip irrigation or by level -basin flooding. In the flood-irrigated plots, various schedules for applying water during fruiting were compared with minimal differences in total water applied. The check treatment (9 postplant irrigations) yielded approximately 2 bales of lint per acre. Small supplemental irrigations on 13 July and 22 July, splitting the normal irrigation cycles, increased yield 45% for only 6% more applied water. Daily drip irrigation in the trials increased yield 63% above the check on 1% more applied water over the season. The results show that flood- irrigated yields can approach drip-irrigated yields without excessive water use, if the irrigation cycle is shortened during fruiting.
    • 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.
    • Response of Cotton to a Preplant Zinc Sulfate Application

      Hofmann, W. C.; Else, P. T.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The effect of a single preplant application of zinc sulfate on DPL 77 yield was investigated at the Maricopa Agricultural Center on a field that had tested as marginal with respect to zinc availability. No significant difference in yield was found between the plants receiving zinc sulfate and the control.
    • 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.
    • 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.
    • Tierra Prospera Farms CWSI Irrigation Scheduling Demonstration Test

      Garrot, D. J. Jr.; Stedman, S.; Benedict, D. B.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • 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.
    • Evaluation of PIX Multiple Application Treatments on Upland and Pima Cotton in Arizona, 1988

      Silvertooth, J. C.; Howell, D. R.; Farr, C. R.; Malcuit, J. E.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Four field experiments were conducted in Arizona in 1988 to evaluate the effects of various multiple application treatment combinations of PIX on the growth and development, as well as the lint yields of both upland and pima cotton. Plant height was significantly reduced (P ≤ 0.05) in some FIX treatments in comparison to the checks for short periods of time after the treatment applications. Those effects did not persist, nor did they translate into any significant positive differences among treatments in terms of lint yields for either of the upland or pima experiments.
    • Phosphate Sorption of Several Arizona Soils

      Silvertooth, J. C.; Gardner, B. R.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Phosphate (P) adsorption of 6 agriculturally- important Arizona soils was studied by use of adsorption isotherm experiments and with conventional Langmuir and Freundlich adsorption models. Adsorption experiments were conducted at 25°C where each soil was placed in a 10:1 (solution:soil) ratio using 0.01M CaCl₂ as a background solution. Each soil was subjected to 4 levels of inorganic P addition using Ca(H₂PO₄)₂H₂O as the P source. Use of the Langmuir model was significant in all cases (P ≤ 0.05) with r² values ranging from 0.93 to 0.99. Capacity parameter estimates obtained from the models indicated P adsorption potentials of up to 357 lb. acre⁻¹ (818 lb. P₂0₅ acre⁻¹) for the soils studied. Application of the Freundlich model revealed r² values of 0.88 to 0.99 with all models proving to be significant (P ≤ 0.05).
    • Short Staple Variety Demonstration, Graham County, 1988

      Clark, L. J.; Cluff, R. E.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Cotton lint yields in the variety trials in Graham county were higher than the 1987 yields by close to 200 pounds per acre. Two varieties, BR 110 and NK KNX 111 (now KC 311) yielded more than DP 90 at the Thatcher site, the highest yield being 1,569 pounds of lint per acre. In Eden, DP 90 was the highest yielding variety with 1,237 pounds of lint per acre. The New Mexico acalas didn't yield as much lint per acre as the top yielding varieties, but with 1988's premium, produced substantial income per acre. In Thatcher the highest yielding acala produced $861 per acre compared with BR 110's $910, whereas in Eden the highest yielding acala produced $736 per acre against DP 90's $717.
    • 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.
    • 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.
    • 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.
    • Growth Regulator Test on Upland Cotton at the Marana Agricultural Center, 1988

      Briggs, R. E.; Nelson, J. M.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      A field study was conducted at the Marana Agricultural Center to evaluate the effectiveness of growth regulators on Deltapine 90 cotton. The Pix treatment yielded significantly higher than the check and any of the other treatments.
    • 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.
    • Hormonal Changes in Relation to Cutout

      Guinn, G.; Brummett, D. L.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Experiments were conducted in 1987 and 1988 to determine whether hormonal changes may be involved in the decreases in growth and boll retention commonly referred to as cutout. Nitrogen deficiency decreased the auxin content and growth of fruiting branches. The auxin contents of fruiting branches, squares, and bolls decreased during the season as the plants entered cutout. ABA in bolls increased slightly, but the ABA content of squares and fruiting branches showed no consistent changes. The results indicate that decreases in auxin (IAA) may be involved in cutout.