• Defolation of Pima Cotton, 1989

      Silvertooth, J. C.; Howell, D. R.; Thacker, G.; Stedman, S. W.; Winans, S. S.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Four field experiments were carried out in several representative cotton producing areas of Arizona to evaluate the effectiveness of a number of defoliation treatments on Pima cotton. Variable conditions were encountered among the experimental locations in 1989 for treatment comparisons. However, it appears that consistencies in the effectiveness of several treatments for Pima defoliation offer a better basis for recommendations across the state.
    • Short Staple Variety Demonstration, Yuma County, 1989

      Howell, D. R.; Silvertooth, J.; Malcuit, J.; Sharp, D.; Sharp, C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The standard variety DPL 61 yielded higher in this trial. M-5, a California acala type was tested for the first time.
    • Effects of Date of Planting on the Yield of Four Cotton Varieties at Yuma, Arizona

      Malcuit, J. E.; Howell, D. R.; Silvertooth, J. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A field experiment was conducted in Yuma, Arizona, to evaluate the effects of planting date on cotton yields. One Pima and the Upland cotton varieties were planted on four dates from 23 February to 5 April. DPL-90 produced the highest yield (1760 lbs lint acre⁻¹) at the second planting date (9 March). The lowest yields, for all varieties, resulted from the latest planting date (5 April). The greatest reductions in yield when comparing an early planting date to the latest planting date, were observed for DPL-90 and Pima S-6. However, in spite of the reduction in yield, DPL-90 was the highest yielding variety at the latest planting date.
    • Exogenous L- and D-Proline Does Not Reduce NaCl Inhibition of Radidle Growth of Germinating Cotton (Gossypium hirsutum L.) Seeds

      Lehle, F. R.; Zegeer, A. M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The adaptive significance of proline (Pm) accumulation in cotton seeds can be assessed by determining if NaCl tolerance is influenced by changes in the Pm level of the seed. The objective of this study was to determine if exogenous L-Pro and D-Pro reduce NaCl inhibition of radicle growth of germinating cotton seeds. Seeds were imbibed for 24 h at 32°C before transfer to agar medium containing either Pro, NaCl or mixtures of both. Results indicate that exogenous Pro increases the Pro contents of cotton seed radicles and cotyledons to a similar extent. Such increases are independent of whether L- or D-Pro is fed exogenously. Results also show that exogenous Pro does not significantly reduce NaCl inhibition of radicle growth in germinating cotton seeds. .
    • Effect of Harvest Date on Aflatoxin Contamination in the Yuma Valley

      Cotty, P. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Experiments were performed at the Yuma Valley Agricultural Center to determine how timely harvest of cotton may affect aflatoxin contamination of cottonseed As the cotton was held in the field between the final irrigation and harvest, the quantity of aflataxin in the crop increased. Significant reductions in aflatoxin contents of seed were realized by harvesting in early September.
    • Early-season Cotton Square Removal with Ethephon and Initiation of Pink Bollworm Infestations

      Henneberry, T. J.; Bariola, L. A.; Chu, C. C.; Meng, T. Jr.; Deeter, B.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Ethephon applied at rates of 0.50 or 0.75 lb AI/acre removed early-season squares and delayed initiation of pink bollworm, Pectinophora gossvpiella (Saunders) infestations and reduced the number of infested bolls on early-season fruiting branches, without affecting yield except for ethephon at 0.751b AI /acre at one location. Higher rates of application reduced yields. In most cases, ethephon treatments delayed flowering but plants compensated for removal of early- season squares and equalled or surpassed accumulated flowering of untreated control plants later in the season.
    • Influence of Multiple Applications of PIX on Long and Short Staple Cotton, Safford 1989

      Clark, Lee J.; Carpenter, Eddie W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      A four-by-four factorial experiment was performed on the Safford Agricultural Center to determine if CaZn, Foliar Triggrr or Soil Triggrr would cause increases in lint yields on short or long staple cotton. Four levels of PIX were used to see if there would be any interaction between PIX and the other materials. The results in 1989 showed that CaZn and the Trier products did not increase yields, the levels of PIX did not increase yields and there was no interaction between them. Very favorable weather conditions and good crop management kept plants from growing vegetative and prevented crop stress, thus reducing the opportunity for the plant growth regulators to increase yields. Yields were excellent with over 1700 and 1600 pounds of lint per acre for short and long staple cotton, respectively.
    • A Study of PIX Rates across CaZa and Triggrr on Long and Short Staple Cotton, Safford Agricultural Center, 1989

      Clark, L. J.; Carpenter, E. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      An experiment was designed to test seven treatments of PIX on both short and long staple cotton. The treatments included single applications of 1/2- and 1-pint rates and multiple applications of 1/8- and 1/4-pint rates. Because of the exceptionally good growing season with lots of early heat units, both short- and long-staple plants set fruit early, which limited their vegetative growth naturally without the need for FIX. Yields were high with lint production over 1800 and 1400 pounds of lint for short and long staple, respectively. Plant mapping also was performed on each treatment.
    • Upland and Pima Cotton Response to Banded Phophate Fertilization

      Silvertooth, J. C.; Malcuit, J. E.; Doerge, T. A.; Thacker, G. W.; Stedman, S. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Four field experiments were established in Arizona in 1988 and six in 1989 to evaluate the effects of banded phosphorus (P) fertilizer on cotton. Experiments each year involved both Upland (Gossvpium hirsutum L.) and American Pima (Q. barbadense L.). Banded applications of P fertilizer were made with placement of the concentrated band of fertilizer 6 in. below and 3 in. to the side of the zone of seed placement. Fertilizer sources of P₂O₅ were with 10-34-0 or 16-20-0. At all locations, a series of rates of applied P₂O₅ were established as the treatment variables, including a check (0 lb P₂O₅/acre). Rates of applied P ranged from 0 to 90 lb P₂O₅/acre, at increments of approximately 30 lb. P₂O₅/acre. In all cases, treatments in the field were arranged in a randomized complete block design with four replications. Plant measurements for plant height, flower numbers per unit area, number of mainstem nodes, and nodes to the first fndting branch were initiated by the fifth true leaf stage to evaluate plant response in terms of growth and development. Plant tissue samples were also taken at several stages of growth from each experiment throughout the growing season. Tissue samples consisted of petioles and leaf blades from the uppermost fully developed leaves. Petioles were analyzed for extractable PO₄-P and leaf blades for total P. Lint yield measurements also were taken. With the exception of one of the experimental locations in each year, no statistically significant differences (P≤0.05) were found among any treatments for any of the plant growth parameters. The same was true with regard to petiole PO₄-P and leaf blade total P levels measured. No significant differences among treatments were found for either Upland or Pima cotton with regard to lint yield in 1988 or 1989.
    • Response of Texas Root Rot to a Soil Sterilant the Second Year After Application in Marana, 1989

      Thacker, G. W.; Silvertooth, J. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two years after sterilizing a sandy loam soil in Marana, we measured significant yield responses of short staple cotton. The yield response was significant in the first year as well, but was not enough to pay the cost of sterilization. This second year of yield response made the treatment economically feasible.
    • Potential Injury to Rotational Crops Following Single or Multiple Applications of Bladex to Cotton 3

      Chernicky, J. P.; Rodgers, C. A.; Heathman, E. S.; Hamilton, K. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Pima Cotton Irrigation Scheduling Using Infrared Thermometers and the Crop Water Stress Index

      Garrot, D. J. Jr.; Stedman, S.; Fangmeier, D. D.; Husman, S. H.; Benedict, B.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      The Crop Water Stress Index (CWSI) was used to schedule irrigations on Pima S-6 cotton on 12 four-acre furrow-irrigated test plots in Coolidge and 20 drip- irrigated test plots at the Campus Agricultural Center in Tucson. Scheduling irrigations between 0.30 and 0.50 CWSI units resulted in highest lint production and plant water use efficiency at both locations.
    • Gossyplure-baited Pink Bollworm Male Moth Trap Studies

      Chu, C. C.; Henneberry, T. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Gossyplure, the pink bollworm, Pectinophora gossvpiella (Saunders), sex pheromone is an excellent tool as a bait in traps for detection, survey, research and monitoring male moth populations. We studied the within - and between-seasonal changes of pink bollworm male moth catches in gossyplure-baited live traps installed in cotton fields each year from 1981 to 1988. Seasonal average number of male moths caught varied from 14/trap/night in 1982 to 148 /trap /night in 1981. Male moths caught/trap/night were highly correlated with the minimum air temperatures. The number of male moths caught from March to June were significantly correlated with those caught from July to August, indicating that early spring trapping can be used to identify potential problem fields.
    • A Sensor System for Monitoring Cotton Water Status

      Fangmeier, D. D.; Husman, S. H.; Garrot, D. J. Jr.; Yitajew, M.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Pima Cotton Improvement

      Turcotte, E. L.; Percy, R. G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Five experimental strains, P67, P69, P71, P72, P73, and Pima S -6 were grown in Regional tests at eight locations in 1989. P69 averaged highest in mean yield across locations followed by P73, Pima S-6, P71, P67 and P72. The difference in mean yield between P69, the highest yielding entry, and Pima S-6 was 35 pounds of lint per acre. Pima S-6 was the latest maturing and tallest entry in the Regional test at Maricopa. Pima S-6 also showed less tolerance to heat stress than the experimental strains. The experimental strains had longer, stronger, finer, and more whitish fiber than Pima S-6.
    • Effect of Irrigation Termination Date on Defolation and Yield of Upland Cotton for Short-Season Production

      Nelson, J. M.; Briggs, R. E.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      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 short season cotton. Irrigation termination dates of 11, 18 and 24 August were used to achieve different levels of water stress at the time defoliants were applied (1 September). Irrigation termination dates had little effect on the response of cotton to defoliants. Def-6 at the lowest rate tested, 0.75 lbs a.i./A, was less effective in defoliating cotton with a 24 August irrigation termination date than cotton terminated earlier. Dropp resulted in higher defoliation percentages and 30% fewer unopened bolls at harvest than Def-6. Although the irrigation termination dates provided a range of CWSI values at the time of chemical termination, no clear relationship was found between CWSI values and defoliation percentages. Short season cotton (149 days) produced 3.2 bales of lint/A compared to 4.4 bales for a full-season crop (208 days).
    • Evaluation of Date of Planting and Irrigation Termination on the Yield of Upland and Pima Cotton

      Silvertooth, J. C.; Watson, T. F.; Terry, L. I.; Malcuit, J. E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Three field experiments were conducted in 1989 in Arizona to evaluate the response of Upland and Pima cotton to two dates of planting and two dates of irrigation termination. Planting dates ranged from as early as 22 February in the Yuma Valley (150 ft. elevation) to 4 May at Marana (2,000 ft. elevation). Dates of irrigation termination ranged from 27 July in the Yuma Valley to 8 September at Maricopa and Marana. Based upon the final lint yield, planting date provided a significant main effect within two of the three experimental locations (Yuma Valley and Marana). At the Maricopa location, there was a significant effect on yield due to date of irrigation termination with both 30-inch- and 40-inch-row Upland cotton experiments, resulting in differences of 167 and 157 lbs. lint /acre, respectively, by extending two irrigations (approximately 12 acre inches) past 10 August to 8 September. The Pima experiment at Maricopa was similar with a significant (P <0.05) response to two additional irrigations (approximately 12 acre-inches) of 184 lbs. lint /acre. Return from additional lint yield must be considered against additional costs (water, insect control, etc.), as well as possible quality losses from insect infestations.
    • Regional Variety Tests

      Pegelow, E. J. Jr.; McAlister, A. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Regional variety tests were conducted at Maricopa, and Marana Agricultural Centers in continuing cooperation with the beltwide testing program. The national standards included in this test were Coker 139, Deltapine 50, and Paymaster 145. Lint yields for each variety, at both locations, are given in Table 1.
    • Cottonseed Treatment Evaluations in Arizona, 1989

      Silvertooth, J. C.; Malcuit, J. E.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • Short and Long Staple Variety Trials, Greenlee County, 1989

      Clark, Lee. J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two short staple and one long staple variety trials were implemented in Greenlee County in 1989, with new varieties topping each trial. The most exciting new discovery was HS 46, which topped the competition in the short-staple trial by nearly 200 pounds of lint per acre. In the acala trial, the top four entries were composed of three New Mexico experimentals and Prema from the San Joaquin Valley. Any one of these acalas could become the new standard for the valley. P-69 in the long staple cotton trial yielded over 850 pounds of lint per acre and topped the S-6 yield by 25%. The testing program in Greenlee County is not only of benefit to the cotton producers and related agri-businesses in southeastern Arizona, but also to southwestern New Mexico.