• 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)
    • Controlling Purple and Yellow Nutsedge with Postemergence Applications of EPTC

      Chernicky, J. P.; Heathman, E. S.; Rodgers, C.; Hamilton, K. C.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • PIX Multiple Application Evaluations in Arizona on Upland and Pima Cotton, 1989

      Silvertooth, J. C.; Malcuit, J. E.; Howell, D. R.; Farr, C. R.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
    • 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)
    • 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)
    • 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.
    • Cotton Variety Trial, Mohave Valley, 1989

      Grumbles, R.; Malcuit, J.; Green, L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Seven cotton varieties including Pima S -6 were demonstrated in Mohave Valley, Mohave County in 1989. Of the six upland varieties two were new varieties not previously demonstrated in this area. Trial results indicated DP77 at 1697 lbs. led other varieties by 109 lbs. of lint over DP90, 1590 lbs. and 287 lbs. over bottom variety STV115 at 1412 lbs. STV110 yielded 1482 lbs., DES 119 at 1429 lbs., DP50 at 1414 lbs. Pima S-6 yielded 950 lbs. The two new varieties STV110 and STV115 placed last and third on yield but when economic values were calculated based on grade and price they ranked third and fourth. The second attempt on Pima saw an increase in yield from 447 lbs., the previous year to 950 lbs. in current trial.
    • Pima Gotton Genetics

      Percy, R. G.; Turcotte, E. L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      In an investigation of the genetic diversity and structure of Gossvpium barbadense L. it was determined that northwestern South America was the species' center of variability and probably the species' center of origin. Cultivars of the species were found to possess as much genetic variability as the center of variability. Cultivar variability was due in large part to introgression with G. hirsutum. Studies of interspecific hybrid performance revealed that development of G. barbadense parents could significantly affect the plant height, earliness, and yield of the resulting hybrids. Environment significantly affected hybrid performance and could enhance or obscure any beneficial effects of hybrid parent selection. A conversion program to convert photoperiodic short-day flowering tropical accessions to day neutrality continues. Preliminary results from inheritance and linkage studies of a male sterility factor and a foliar mutant indicate that both are single gene, recessive traits. No linkages between the male sterility factor and 21 marker traits were found.
    • 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.
    • 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.
    • Sweetpotato Whitefly Populations in Cotton Genotypes at Poston, Arizona in 1988

      Butler, G. D. Jr.; Henneberry, T. J.; Perkins, H. H. Jr.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Studies were conducted to identify potential sources of cotton germ plasm resistant to sweetpotato whitefly (SPW), Bemisia tabaci (Gennadius). Numbers of adult SPW sampled using black pan and vacuum methods showed reduced numbers of SPW on GC-EXP-7007 experimental variety vs. all other entries. However, numbers of SPW pupae on leaf samples in most cases were not different. Pima P-62 had the high numbers of SPW adults per blackpan sample, and highest number of pupae/leaf sample.
    • ABA and Auxin Contents of Squared and Flowers in Relation to Water Deficit Stress and Subsequent Young Boll Shedding

      Guinn, G.; Brummett, D. L.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Water deficit increases boll shedding. Large squares, however, are much less likely to shed, possibly because they contain high concentrations of free and total auxin (indole-3-acetic acid or IAA). Our previous research indicated that much of this IAA disappears by the time the squares open as flowers and the IAA content remains low for about four days after anthesis. If water deficit decreases the IAA content, or increases the ABA conten4 of squares and flowers, then water deficit before flowering could have a carry-over effect and increase the shedding rate of young bolls that subsequently develop from them. In field plots, water deficit increased the ABA content of flowers as much as 66 %. Water deficit first decreased and later increased the concentrations of free and total IAA in squares that were analyzed about three days before anthesis. Flowers contained much less IAA than squares. Despite pronounced effects of water deficit on the IAA content of squares it is unlikely that it had any carry-over effect on the free IAA content of young bolls that subsequently developed from them. Water deficit slightly increased the total IAA content of flowers, but had no effect on their free IAA. Because water deficit increased the ABA content but did not decrease the IAAA content of flowers, any carry-over effect of water deficit on young boll shedding might have been from changes in ABA but not from changes in IAA before the young-boll stage.
    • Plant Growth Regulator Research on Upland Cotton at the Maricopa and Marana Agricultural Centers in 1989

      Briggs, R. E.; Nelson, J. M.; Hart, G.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Field tests were conducted at the Maricopa and Marana Agricultural Centers to evaluate the effectiveness of growth regulators on Deltapine 90 cotton. With full season management, the check treatment yielded as well as any of the growth regulator treatments at both locations.
    • Short Staple Variety Demonstrations, Pinal County, 1989

      Malcuit, J.; Stedman, S.; Silvertooth, J.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Short staple variety demonstrations were conducted in Pinal County in 1989 at the Prechel and Benedict Farms near Coolidge Az. Twelve varieties were included in the demonstration at Prechel Farms. Results from the analysis showed significant differences among varieties. Seedcotton yields in this test ranged from 4826 to 2844 lbs. acre⁻¹ for STV BR-110 and S-55 respectively. Seven varieties were included in the demonstration at Benedict Farms. Results from the analysis showed significant differences among varieties. Seedcotton yields in this test ranged from 4127 to 3530 lbs. acre⁻¹ for STV BR-110 and DP-50 respectively.
    • 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.
    • 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.
    • 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.
    • Nitrogen Management in Irrigated Cotton

      Silvertooth, J. C.; Clark, L. J.; Carpenter, E. W.; Malcuit, J. E.; Else, P. T.; Doerge, T. A.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two field experiments were conducted in 1989 in Arizona to compare several methods of nitrogen (N) management in Upland and Pima cotton. Standard preplant, preplant plus sidedress, and use of soil and petiole analysis for NO₃⁻-N were the basic methods of N fertilization management compared. A nonfertilized check treatment also was included with the N management treatments, which were arranged in a randomized complete block design in each experiment. Preseason soil samples and a series of in- season petiole samples were taken for all treatments and analyzed for NO₃⁻-N. The concentrations of NO₃⁻-N in the petioles reflected the boll load obtained and the crop fruiting patterns as well as the N fertilization patterns in the respective treatments. Final lint yield analysis revealed distinct differences among the treatments imposed at the Maricopa location but no statistically significant differences at the Safford location.
    • A Comparison of Three Cotton Tillage Systems

      Coates, W. E.; Thacker, G. W.; Silvertooth, Jeff; Bantlin, Marguerite (College of Agriculture, University of Arizona (Tucson, AZ), 1990)
      Two alternative tillage systems used significantly less energy than conventional tillage. The Sundance system used the least energy, averaging 35 horsepower-hours per acre (Hp-hr /ac), the Uprooter Shredder-Mulcher (USM) was intermediate at 50 Hp-hr /ac, and the conventional system used the most energy at 69 Hp-hr /ac. These energy savings translated directly into cost savings of about the same proportions. The USM and Sundance systems can plow down and prepare the next seedbed in about one-half the time that conventional tillage requires. In the two years of testing we could not measure any significant differences in cotton yield. So far, we have not found any significant differences in soil compaction.
    • 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. .