• Pima Cotton Improvement

      Turcotte, E. L.; Percy, R. G.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Five experimental strains, P65, P67, P64 P69, P70, and pima S-6 were grown in 9 regional tests across the pima belt in 1988. Mean yields from the 9 locations showed that P67 averaged highest in yield followed by P69, P70, P65, P68 and pima S-6 respectively. The difference in mean yield between P67, the highest yielding entry, and pima S-6 was 82 pounds of lint per acre. Pima S-6 was the latest maturing and tallest entry in the regional test at Maricopa. The 5 experimental strains had longer, finer, and whiter fiber than pima S-6.
    • The Probability of Temperature Thresholds for Defoliation

      Farr, C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The probability of favorable temperatures for some cotton defoliants decreases importantly in the month of October. More effective and earlier defoliation is crucial to advancing the cotton harvest to reduce rainfall damage and diapausing boll weevil numbers. Probabilities indicate more defoliation should be carried out earlier.
    • Profenofos as an Ovicide for Heliothis spp. In Short Staple Cotton and Comparison of the Ovicidal and Commercial Efficacy of Profenofos and Two Tank Mixes

      Dick, G. L.; Moore, L.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • Progress of Upland Cotton Harvesting

      Farr, C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      In 1984 Maricopa County produced more acres of upland cotton with lower yields than it had in 1987 but also started harvest later. Weather and insects reduced yield and early maturity of the crop; rainfall delayed harvest in the October-November period less than it had in 1987.
    • Regional Variety Test

      Pegelow, E. J. Jr.; McAlister, A. C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • 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.
    • Response of Cotton to Various Fertilization Histories

      Hofmann, W. C.; Else, P. T.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Effects of various fertilization histories on cotton yield were investigated for the fourth consecutive year in the same field at the Maricopa Agricultural Center. Treatments included: 1) no fertilizers added for the past 4 seasons, 2) aggressive nitrogen fertilization in the 1988 season, no fertilization for the previous 3 seasons, 3) standard nitrogen fertilization in 1988 similar treatment for the previous 3 seasons, 4) aggressive nitrogen fertilization in 1988 same history as treatment #3 for previous 3 seasons, and 5) a commercial alternative fertilization program (BioHumaNetics, Inc.). Yields in 1988 were significantly different with treatment 2 having the highest yield followed by treatments 3 and 4, followed by treatment 5; treatment 1 had the lowest yield.
    • Response of Pima Cotton to Zinc Fertilization in Pima County, 1988

      Silvertooth, J. C.; Thacker, G.; Doerge, T. A.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      A single field experiment was conducted near Marana, AZ, in 1988 to evaluate the effects of both soil - and foliar- applied zinc (Zn) fertilizers on the yield of pima cotton. The soil had a preseason level of 0.6 ppm Zn (DTPA extractable). Treatments included 10 lbs. Zn acre⁻¹ (as ZnSO₄) broadcast incorporated preplant, 0.5 lbs. Zn acre⁻¹ applied as a foliar treatment at early bloom, and a treatment consisting of both the soil and foliar Zn applications. Yield results revealed no differences among any of the treatments in comparison to one another, or the check treatment.
    • Response of Texas Root Rot to a Soil Sterilant the Second Year After Application in Marana, 1988

      Thacker, G.; Silvertooth, J.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Methyl bromid/chloropicrin, a soil sterilant, was deep injected into cotton beds 10 days before planting in 1987. The 1987 cotton lint yields were significantly increased by injecting the sterilant into the Texas root rot kill areas. Cotton yield and mortality data were taken in the same plots in 1988 to measure the carry-over of the treatments. Lint yields trended higher and plant mortality trended lower in the sterilant- treated plots, but no significant differences were detected.
    • Response of Texas Root Rot to an Application of a Soil Sterilant in Marana, 1988

      Thacker, Gary; Silvertooth, Jeff; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Methyl bromide/chloropicrin (MB/C), a soil sterilant, was deep injected into cotton beds 6 days before planting in 1988. Application rates were zero, 300, 400, and 500 pounds of MB/C per acre, injected 18-inches deep into the sandy loam soil. Short staple lint yields in all of the MB/C treatments were significantly higher than the untreated check. MB/C at all application rates was 100% effective in preventing the plants from dying from the disease, while 86% of the plants in the untreated check plots died.
    • Scheduling Pima Cotton Irrigations Using Infrared Thermometers

      Garrot, D. J. Jr.; Fangmeier, D. D.; Husman, S. H.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Plots of pima S-6 cotton were scheduled for irrigation using the Crop Water Stress Index (CWSI). Irrigations were applied when CWSI levels reached 0.08 (wet), 0.34 (medium), and 0.68 (dry) units. The medium treatment had significantly higher lint yield. Preliminary test results indicate the CWSI can be useful in irrigation-management decisions regarding pima cotton production.
    • Short and Long Staple Variety Trials, Greenlee County, 1988

      DeRosa, E.; Clark, L. J.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Two short staple variety trials and 1 long staple variety trial were harvested in Greenlee county in 1988. In the short staple trial comparing the new and experimental New Mexico acalas with 2 other lower quality varieties, Genhains new GC 260 was the top yielding variety with 1,087 pounds of lint per acre, but it came in fifth when comparing dollar value per acre because of the premium structure for the New Mexico acalas. Two new experimental acalas, 2745 and B510, produced the highest income per acre. The short staple trial, which tested longer - season varieties, had problems with low micronaire values. The newly released 1517-88 variety produced the top yield and produced the most income per acre. Two of the experimental long staple varieties topped the yield of S-6 and 3 of the 7 varieties tested yielded over 650 pounds of lint per acre.
    • 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.
    • Short Staple Variety Demonstrations, Pinal County

      Malcuit, J.; Stedman, S.; Silvertooth, J.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • Short Staple Variety Trial, Cochise County, 1988

      Clark, L. J.; Schwennesen, E.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Nine acala varieties were grown in the Cochise area of Cochise county. An experimental New Mexico variety B510 was the top yielder in the test, producing 1,287 pounds of lint per acre. The top variety in 1987, 1517-77BR, was next to the bottom in the 1988 test, probably due to low plant population. Variety characteristics such as plant height, wilt susceptibility, relative maturity and lint turnout are quantified in the study along with final plant populations and lint quality. Information on cotton variety strip trials implemented in the county is also given.
    • Soil Amendments on 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)
      Cotton was grown in the fourth year of a soil amendment trial that evaluated 4 different soil amendments in 12 treatments on the Safford Agricultural Center. Yields varied from 1,659 to 1,392 pounds of lint per acre but none of the treatments yielded statistically different from the check. The higher yields were seen in the treatments with high and medium rates of soil sulfur, Boligrow, or gypsum, the lower yields were seen in the treatments with low rates of those amendments or with a biological amendment, but the conclusion of the study is that soil amendments did not significantly increase yields on that soil with its EC value of 2.3 dS/m. Crop and fiber quality measurements are reported here.
    • 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)
    • 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)
    • Variety and Date-of-Planting Test

      Pegelow, E. J. Jr.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Three upland cotton varielies--Stoneville 506, Deltapine 20, and Deltapine 77--were planted on 4 dates in 1988 at the Maricopa Agricultural Center and observed for flowering boll opening and lint yield. Results from the 1988 studies and those from similar tests in 1985-1987 are being used to determine the relationship of accumulated heat units to the timing of key stages in crop development.