• Late Season Boll Weevil Infestations and Survival in a Cotton Bolls in Arizona

      Henneberry, T. J.; Meng T. Jr.; Bariola, L. A.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Studies were conducted in Phoenix AZ, to determine the development of boll weevil, Anthonomus grandis Boheman, infestations in late - season cotton bolls, the pattern of boll weevil emergence, and survival /mortality in the bolls. Boll weevils emerged from bolls buried in moist vermiculite over a period of 232 to 239 days, from 29 January to 2 August. Higher percentages of emergence and lowest mortality in bolls occurred in bolls collected in November as compared to bolls collected in December. Few boll weevils emerged from bolls held under dry conditions in an outdoor insectary for 174 days. However, an average of 16% of the weevils were found alive in the dry bolls in late May.
    • Management of Rootknot Nematode in Arizona Cotton

      Nigh, E. L. Jr.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • Nematocide Treatment of Upland and Pima Cotton

      Farr, C.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      The loss of dying pima cotton after a rainfall in August 1987 made apparent the different responses pima and upland cottons have to stress. A trial compairing pima S-5 and DP 77 found more response of pima to treatment of rootknot nematodes with 1,3-Dichloropropene than the upland variety. A second trial found more response of DP 77 to 1,3-Dichloropropene treatment than from fenamiphos injection on sandy loam.
    • On Farm Cotton Irrigation Scheduling Management Using Infrared Thermometers in Arizona

      Garrot, D. J. Jr.; Fangmeier, D. D.; Husman, S. H.; Stedman, S.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • Outlook on Cotton Markets and Marketing for 1989

      Firch, R. S.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
    • 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).
    • Pima Cotton Genetics

      Percy, R. G.; Turcotte, E. L.; Silvertooth, Jeff; Isbell, Joan (College of Agriculture, University of Arizona (Tucson, AZ), 1989-03)
      Seed increase of 104 accessions and data collection on 65 accessions were obtained in 1988 to further the maintenance and evaluation of the Gossypium barbadense L. germplasm collection. In a program of conversion of tropical non flowering cottons to a day-neutral flowering habit, 63 accessions were advanced 1 generation by backcross. A systematic screening of the G. barbadense collection for bacterial blight resistance involving 200 accessions from 21 countries yielded 8 accessions resistant to races 1, 2, 7, and 18 of the pathogen. Genetic inheritance and linkage investigations of a male sterile and a foliar mutant progressed. An investigation of the geographic and taxonomic distribution of the ovate leaf trait was concluded with negative results. The frequency of the 2 mutant genes ov₁ and ov₂ proved to be too rare to yield meaningful taxonomic or geographic information about the species. Preliminary results from a performance evaluation of interspecific hybrid cottons conducted at Maricopa and Safford AZ, indicated strong environmental influences on hybrids, but generally favorable yield earliness and plant height data were obtained from the higher -elevation Safford location.
    • 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.